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Respiratory muscle training in stroke patients with respiratory muscle weakness, dysphagia, and dysarthria – a prospective randomized trial

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Objective: To examine the efficacy of combined inspiratory and expiratory respiratory muscle training (RMT) with respect to the swallowing function, pulmonary function, functional performance, and dysarthria in patients with stroke. Design: Prospective, randomized controlled trial. Setting: Tertiary hospital. Participants: The trial included 21 subjects (12 men, 9 women) aged 35 to 80 years presenting with 6 months history of unilateral stroke, respiratory muscle weakness (≥70% predicted maximal inspiratory pressure (MIP) and/or ≤70% maximal expiratory pressure (MEP)), dysphagia, or dysarthria. These subjects were randomly assigned to the control (n = 10, rehabilitation) and experimental (n = 11, rehabilitation with RMT) groups. Intervention: Inspiratory RMT starting from 30% to 60% of MIP and expiratory RMT starting from 15% to 75% of MEP for 5 days/week for 6 weeks. Main outcome measures: MIP, MEP, pulmonary function, peak cough flow, perception of dyspnea, Fatigue Assessment Scale, Modified Rankin Scale, Brunnstrom stage, Barthel index, Functional Oral Intake Scale (FOIS), and parameters of voice analysis. Results: Significant differences were observed between both groups in terms of MIP, forced vital capacity (FVC), and forced expiratory volume per second (FEV1) of the percentage predicted. Significant difference was found with respect to the change in fatigue, shimmer percent, amplitude perturbation quotient, and voice turbulence index (VTI) according to the acoustic analysis in the RMT group. The FEV1/FVC ratio was negatively correlated with jitter percent, relative average perturbation, pitch perturbation quotient, and VTI; the maximum mid-expiratory flow (MMEF) and MMEF% were also negatively correlated with VTI. Significant differences among participants of the same group were observed while comparing the Brunnstrom stage before and after training of the affected limbs and the Barthel scale and FOIS scores in both the groups. Conclusions: Altogether, 6-week combined inspiratory and expiratory RMT is feasible as adjuvant therapy for stroke patients to improve fatigue level, respiratory muscle strength, lung volume, respiratory flow, and dysarthria.Clinical trial registration number (Clinical Trial Identifier): NCT03491111.
Respiratory muscle training in stroke patients
with respiratory muscle weakness, dysphagia, and
dysarthria a prospective randomized trial
Mei-Yun Liaw, MD
a
, Chia-Hao Hsu, MD
a
, Chau-Peng Leong, MD
a
, Ching-Yi Liao, ST
a
, Lin-Yi Wang, MD
a
,
Cheng-Hsien Lu, MD
b
, Meng-Chih Lin, MD
c,
Abstract
Objective: To examine the efcacy of combined inspiratory and expiratory respiratory muscle training (RMT) with respect to the
swallowing function, pulmonary function, functional performance, and dysarthria in patients with stroke.
Design: Prospective, randomized controlled trial.
Setting: Tertiary hospital.
Participants: The trial included 21 subjects (12 men, 9 women) aged 35 to 80 years presenting with 6 months history of unilateral
stroke, respiratory muscle weakness (70% predicted maximal inspiratory pressure (MIP) and/or 70% maximal expiratory pressure
(MEP)), dysphagia, or dysarthria. These subjects were randomly assigned to the control (n =10, rehabilitation) and experimental (n =
11, rehabilitation with RMT) groups.
Intervention: Inspiratory RMT starting from 30% to 60% of MIP and expiratory RMT starting from 15% to 75% of MEP for 5days/
week for 6 weeks.
Main outcome measures: MIP, MEP, pulmonary function, peak cough ow, perception of dyspnea, Fatigue Assessment Scale,
Modied Rankin Scale, Brunnstrom stage, Barthel index, Functional Oral Intake Scale (FOIS), and parameters of voice analysis.
Results: Signicant differences were observed between both groups in terms of MIP, forced vital capacity (FVC), and forced
expiratory volume per second (FEV1) of the percentage predicted. Signicant difference was found with respect to the change in
fatigue, shimmer percent, amplitude perturbation quotient, and voice turbulence index (VTI) according to the acoustic analysis in the
RMT group. The FEV1/FVC ratio was negatively correlated with jitter percent, relative average perturbation, pitch perturbation
quotient, and VTI; the maximum mid-expiratory ow (MMEF) and MMEF% were also negatively correlated with VTI. Signicant
differences among participants of the same group were observed while comparing the Brunnstrom stage before and after training of
the affected limbs and the Barthel scale and FOIS scores in both the groups.
Conclusions: Altogether, 6-week combined inspiratory and expiratory RMT is feasible as adjuvant therapy for stroke patients to
improve fatigue level, respiratory muscle strength, lung volume, respiratory ow, and dysarthria.
Clinical trial registration number (Clinical Trial Identier): NCT03491111.
Abbreviations: APQ =amplitude perturbation quotient, ERMT =expiratory respiratory muscle training, FAS =fatigue
assessment scale, FEV1 =forced expiratory volume in rst second, FOIS =functional oral intake scale, FVC =forced vital capacity,
IRMT =inspiratory respiratory muscle training, Jitt =jitter percent, MEP =maximal expiratory pressure, MIP =maximal inspiratory
pressure, MMEF =maximum mid-expiratory ow, MRS =Modied Rankin scale, PPQ =pitch perturbation quotient, RAP =relative
Editor: Qinhong Zhang.
The study was approved by the Institutional Review Board of the Chang Gung Memorial Hospital, Kaohsiung Medical Board (IRB number: 105-1989C).
This research was funded by Chang Gung Memorial Hospital, Taiwan (grant number: CMRPG8E0911; 2016-5-1 to 2018-4-30).
The authors report no conicts of interest.
The devices used are as follows: Model 4500 (MultiDimensional Voice) for Dimensional Voice Program, Model 5105 (KayPENTAX), Computerized Speech Lab (CSL).
Don Breathing Trainer (a threshold trainer), (DT 11 GaleMed Corporation), (DT 14 GaleMed Corporation). Product number: PO09000038.
Pulmonary function tests: spirometer (Vitalograph, Serial Spirotrac, Buckingham, USA).
a
Department of Physical Medicine and Rehabilitation,
b
Department of Neurology,
c
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine,
Department of Respiratory Therapy, Chang Gung Memorial Hospital Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Correspondence: Meng-Chih Lin, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital Kaohsiung
Medical Center, Chang Gung University College of Medicine, No. 123, Ta-Pei Road, Niao-Sung District, Kaohsiung 83305, Taiwan
(e-mail: mengchih@adm.cgmh.org.tw).
Copyright ©2020 the Author(s). Published by Wolters Kluwer Health, Inc.
This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to
download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal.
How to cite this article: Liaw MY, Hsu CH, Leong CP, Liao CY, Wang LY, Lu CH, Lin MC. Respiratory muscle training in stroke patients with respiratory muscle
weakness, dysphagia, and dysarthria - a prospective randomized trial. Medicine 2020;99:10(e19337).
Received: 26 June 2019 / Received in nal form: 3 January 2020 / Accepted: 27 January 2020
http://dx.doi.org/10.1097/MD.0000000000019337
Clinical Trial/Experimental Study Medicine®
OPEN
1
average perturbation, RMT =respiratory muscle training, ShdB =shimmer in dB, Shim =shimmer percent, VTI =voice turbulence
index.
Keywords: stroke, dysphagia, respiratory muscular training, acoustic analysis, functional performance
1. Introduction
Stroke patients often experience respiratory muscle weakness,
swallowing disturbances,
[13]
decreased peak expiratory ow,
blunted reexive cough, impaired voluntary cough,
[4]
im-
pairment of the cardiorespiratory tness,
[5]
and voice dysfunction
in dysarthria.
[6]
An 8-week inspiratory muscle training (IMT) can increase the
inspiratory muscle strength and endurance in chronic stroke
patients with >90% of predicted maximal inspiratory pressure
(MIP),
[7]
while a 6-week IMT can increase the forced expiratory
volume in the rst second (FEV1), forced vital capacity (FVC),
vital capacity, force expiratory ow rate 25% to 75%, and
maximal voluntary ventilation in patients with unilateral stroke
during the previous 12 months; this nding was also correlated
with the exercise capacity, sensation of dyspnea, and quality of
life.
[8]
Expiratory muscle training (EMT) can improve the MIP
and peak expiratory ow rate in stroke patients
[2]
and improve
the voice aerodynamics,
[9]
MEP, and swallowing ability, in acute
stroke patients along with reducing vallecular residue and
penetration-aspiration.
[3]
Messaggi-Sartor et al reported that 3-week IMT of patients
with 30% MIP and EMT of patients with 30% MEP could
improve the inspiratory and expiratory muscle strength and
potentially reduce the occurrence of respiratory complications at
6 months after the onset of acute stroke.
[10]
Furthermore,
Guillen-Sola et al reported that 3-week inspiratory/expiratory
muscle training could improve inspiratory and expiratory muscle
strength and swallowing function.
[11]
However, the efcacy of
combined IMT and EMT in subacute stroke patients (within 6
months) with respiratory muscle weakness, swallowing distur-
bance, and dysarthria has not been reported.
Respiration and swallowing require the activation of common
anatomical structures. EMT can facilitate the contraction of
submental muscles, elevate the hyolaryngeal complex,
[12,13]
pull
the hyoid bone in the anterior-superior direction, and invert
the epiglottis towards the pharynx during swallowing.
[1416]
Dysarthria (including wet voice) and dysphagia have similar
pathogeneses in stroke patients, especially those related to the
laryngopharyngeal functions.
[17]
The acoustic change in phona-
tion following a swallow is a high-risk indicator of uid
aspiration.
[18]
Moreover, the subglottal pressure initiates and
maintains the vocal fold vibration that facilitates voice produc-
tion.
Five-week EMT followed by 6 sessions of traditional voice
therapy increased the subglottal pressure leading to a higher vocal
intensity and increased voice dynamic range in professional voice
users.
[9]
Meanwhile, a multi-dimensional voice program (MDVP)
is suitable for voice analysis in dysarthria associated with various
neurologic diseases of different severity,
[6]
and the MDVP Model
5105 (KayPENTAX) is reliable and advanced for speech analysis
and acquisition.
[19]
We hypothesized that the repetitive resistance, pressure, and
force generated by threshold RMT could improve the respiratory
muscle strength, swallowing function, and voice quality via
sensory stimulation and motor activation of the oropharynx and
respiratory muscles. RMT can also assist in the upregulation of
reex cough.
[2]
To our knowledge, this is the rst follow-up study
that investigated the feasibility and efcacy of a combined IMT
and EMT with respect to pulmonary dysfunction, swallowing
dysfunction, voice dysfunction due to dysarthria, and activities of
daily living of subacute stroke patients.
2. Methods
2.1. Participants and setting
This prospective, single-blinded, randomized controlled study
was conducted in a tertiary hospital from April 2016 to October
2018 with 47 unilateral stroke patients aged 35 to 80 years with
respiratory muscle weakness, swallowing disturbance, or dysar-
thria for 6 months. The patients were screened by attending
physicians and randomly divided into the control (conventional
rehabilitation) and experimental (rehabilitation with RMT)
groups by a research assistant using a random number generator
algorithm. Signed informed consent from the patients or a
family member was obtained, and the Institutional Review Board
approved the study.
Sixteen subjects declined to participate, not meeting the
inclusion criteria regarding inspiratory and expiratory muscle
weakness (70% predicted MIP and/or predicted MEP).
[20,21]
In addition, patients with increased intracranial pressure,
uncontrolled hypertension, decompensated heart failure, unsta-
ble angina, recent myocardial infarction, complicated arrhyth-
mias, pneumothorax, bullae/blebs in the preceding 3 months,
severe cognitive function or infection, recurrent stroke, brain
stem stroke, and aphasia were excluded.
Each patient underwent physical and neurological examina-
tion, and assessment of clinical characteristics, height, weight,
body mass index, duration of stroke, Modied Rankin scale
(MRS), Brunnstrom stage, hand grip of unaffected upper limb,
Barthel activity of daily living index, spirometry, peak cough
ow, MIP, MEP, resting heart rate, perception of dyspnea using
modied Borg scale,
[22]
resting oxyhemoglobin saturation,
fatigue assessment scale (FAS),
[23]
functional oral intake scale
(FOIS),
[24]
and voice quality.
[18]
These parameters were recorded
before and after the 6-week RMT. The technician was blinded to
the group allocation.
2.2. Intervention
Patients were trained using the Don Breathing Trainer (DT 11 or
DT 14 GaleMed Corporation), a hand-held threshold trainer
with a spring-loaded valve and a colored ball that indicates
whether breathing strength exceeds the set target pressure. Ten
training levels were set for IMT and EMT. The DT11 has a
pressure range of 5 to 39cmH
2
O during inspiration and 4 to 33
cmH
2
O during expiration, while DT14 has a pressure range of 5
to 79cmH
2
O during inspiration and 4 to 82 cmH
2
O during
expiration.
Liaw et al. Medicine (2020) 99:10 Medicine
2
For IMT, the subjects were instructed to tightly seal their lips
around the breathing trainer with a nose clip in a sitting position,
and inhale deep and forceful breathes that were sufcient for
opening the valve with a whistling sound (due to the movement of
the colored ball inside the trainer). Then, they were instructed to
exhale slowly and gently through the mouthpiece. The
inspiratory training pressure ranged from 30% to 60% of each
individuals MIP for 6 sets of 5 repetitions. For EMT, the subjects
were instructed to blow fast and forcefully which could open the
valve following maximal inhalation. Expiration training pressure
commenced from 15% to 75% of threshold load of an
individuals MEP for 5 sets of 5 repetitions, 1 to 2 times per
day, 5 days a week for 6 weeks
[2,25,26]
; 1 to 2 minutes of rest was
allowed between each set.
The training resistance was adjusted according to tolerance.
We requested the patients to stop if they experienced discomfort
and, in case of desaturation, the threshold load was decreased.
The patients were called once a week for checking their
compliance with the program and were encouraged to continue
with it. A training diary was provided for them to keep a record.
In addition to RMT, both the groups underwent the regular
rehabilitation, which included postural training, breathing
control, improving cough technique, checking chest wall
mobility, fatigue management, orofacial exercises, thermal-
tactile stimulation, Mendelsohn maneuvering, effort swallowing,
or supra-glottic maneuver among others.
2.3. Main outcome measurement
The primary outcome variables were: change in MIP (cmH
2
O)
and MEP (cmH
2
O). For MIP, negative pressure is favorable and
for MEP, positive pressure is favorable. The secondary outcome
variables were the pulmonary functional parameters including
FVC (liter), FVC (% prediction), FEV1 (liter), FEV1 (% of
prediction), FEV1/FVC (%), maximum mid-expiratory ow
(MMEF) (liter/s), MMEF%, peak cough ow (liter/s), resting
heart rate, resting respiratory rate, FOIS [7-point scale, from 1
(nothing by mouth) to 7 (total oral diet with no restrictions)],
[24]
Modied Borg scale (0.5 to 10),
[22]
FAS (10-item, 5 levels (1:
never to 5: always), score: 10 to 50),
[23]
non-affected hand grip
strength, Barthel index (0 to 100),
[27]
MRS (5: severe disability to
0: no symptoms),
[28]
and the variables of acoustic analysis.
Pulmonary function test: Pulmonary function was assessed
using a spirometer (Vitalograph, Serial Spirotrac, Buckingham,
VA) as per the American Thoracic Society standards.
[29]
MIP and
MEP: MIP was measured after maximal expiration near residual
volume. MEP was measured after maximal inspiration near total
lung capacity while patients were sitting and wearing a nose-clip
in an upright position. All pressure measurements were
maintained for at least 1 second. The highest recorded value
was used for calculations only when two technically satisfactory
measurements were obtained.
[30,31]
Voice quality analysis: Voice quality was assessed with the
Computerized Speech Lab (CSL), Model 4500 (Multi-Dimen-
sional Voice). The participant was asked to phonate the vowel a
at their most comfortable speaking pitch and loudness for at least
3 seconds while sitting at a 30 cm distance from the microphone.
The lowest pitch and highest pitch with increasing and decreasing
loudness were measured.
[6]
The parameters of voice analysis
included jitter percent (Jitt), relative average perturbation (RAP),
and pitch perturbation quotient (PPQ) for frequency perturba-
tion. Amplitude was determined based on the shimmer in decibels
(ShdB), shimmer percent (Shim), amplitude perturbation quotient
(APQ), and peak-to-peak amplitude variation, while the noise-
related parameters included noise-to-harmonic ratio and voice
turbulence index (VTI).
[6]
2.4. Sample size calculation
Based on the study by Sutbeyaz et al,
[8]
the mean differences of
MIP between experimental group and control group before and
after IMT training were xed at 7.87 cmH
2
O and 2.90 cmH
2
O,
respectively, with standard deviation of 6.6 cmH
2
O and 1.9
cmH
2
O. After calculation, we realized that the study required at
least 17 subjects in each group. While setting these conditions at a
two-sided signicance level at 0.05 with a statistical power of
0.80, the number of subjects in each group should be 24 under the
estimation that the dropout rate was about 30%. Number of
participants in the RMT group to that in the control group was
set at 1:1 ratio.
2.5. Data analysis
Values were expressed as the mean ±standard deviation for
continuous variables and number (%) for categorical variables.
Linear regression analysis was used to adjust for sex, BMI, and
the Brunnstrom stage of the distal part of the affected upper limb.
Clinical characteristics were compared using the MannWhitney
Utest for continuous variables and the Fisher exact test for
categorical variables. The Wilcoxon signed-rank test was used to
examine the change in clinical data from baseline in both the
groups, and the Mann-Whitney Utest was applied for
comparisons between the groups. The Spearman rank correlation
coefcient was calculated to analyze the correlations between
cardiopulmonary function parameters and clinical character-
istics. All collected data were analyzed using the SPSS Statistics
version 22.0 software (IBM, Armonk, NY). Pvalue <.05 was
considered statistically signicant.
3. Results
A total of 47 patients were determined to be eligible initially.
After exclusion of 16 patients, 31 were randomly allocated to the
RMT (15 patients) and control (16 patients) groups. During
training, 10 patients (32.2%) dropped out of the study, 5 from
the RMT group (reasons being: they lived far away from the
study venue, insisted to stay at home or in the nursing home, and
had impaired vision in one eye and upper gastrointestinal
bleeding) and 5 from the control group (reasons being: 4 patients
did not undergo follow-up at the outpatient department and 1
patient had another disease). Finally, 21 patients completed the
study (RMT group, n =10; control group, n =11) (Fig. 1). The
Intention-To-Treat and Per Protocol analysis for all the data is
shown in Tables 1 and 2.
No statistically signicant difference between the groups was
noted in the clinical characteristics, cardiopulmonary function,
and acoustic analysis parameters (Tables 13), except sex
(P=.036), height (training vs control group: 1.58 ±0.08 vs
1.68±0.08cm, P=.011), body mass index (BMI) (26.0 ±3.7 vs
21.82±2.29, P=.011kg/m
2
) (Table 1), and Brunnstrom stage of
the distal part of affected upper extremity (3.10 ±0.99 vs 2.18 ±
0.75, P=.021) (Table 2).
Signicant correlations were found between MIP and MEP (r =
0.632, P<.01); peak cough and MEP (r =0.504, P<.05), FVC
Liaw et al. Medicine (2020) 99:10 www.md-journal.com
3
(r =0.781, P<.01), and FEV1 (r=0.739, P<.01); Borg scale and
MEP (r =0.505, P<.05); age and FVC (r =0.536, P<.05),
FEV1 (r=0.590, P<.01), and MMEF (r =0.584, P<.01);
post-stroke duration and FVC (% predicted) (r =0.594, P<.01),
FEV1 (% predicted) (r =0.458, P<.05), and FEV1/FVC (%
predicted) (r =0.456, P<.05) (Table 4).
Signicant differences within each group were noted for the
change from baseline of the Brunnstrom stage of the affected
upper and lower limbs, Barthel scale, and FOIS. However, no
signicant difference between the groups was observed (Table 5).
Signicant change from the baseline was seen in fatigue (P=.007)
(Table 5), MIP (P=.008) only in the RMT group, and signicant
between-group differences were seen for MIP (P=.001), FVC
(P=.017), and FEV1 (% predicted) (P=.047) according to the
linear regression analysis adjusted for the differences already
present between the groups in terms of sex, BMI, and Brunnstrom
stage of the distal part of affected limb (Table 6).
Regarding voice analysis, there were signicant changes among
participants of the RMT group in the Shim (P=.043), APQ
(P=.036), and VTI (P=.025) values (Table 7). Signicant
negative correlations were found between FEV1/FVC and Jitt
(r =0.574, P<.05), RAP (r =0.574, P<.05), PPQ (r =
0.538, P<.05), and VTI (r =0.835, P<.01). MMEF (r=
0.659, P<.05) and MMEF% (r =0.692, P<.05) were
negatively correlated with VTI (Table 8).
4. Discussion
Both RMT and control groups showed signicant changes from
the baseline in Brunnstrom stage of the affected limb, Barthel
index, and FOIS; the stroke duration positively correlated with
FVC and FEV1 (% prediction) and negatively correlated with
FEV1/FVC%. These ndings can be partially explained by
neurologic recovery with time and the effectiveness of regular
rehabilitation after stroke onset.
Assessed for eligibility (n= 47)
Excluded (n=16)
Declined to participate (n=9)
Not met inclusion criteria (n=7): maximal
inspiratory pressure stronger than 70%,
maximal expiratory pressure stronger than
70% of predicted value
Completed the study (n=10)
Lost to follow-up (n=5)
Discontinued intervention (n=3)
Other disease affected (n=2)
Experimental group (n=15)
Respiratory muscle training (inspiratory and
expiratory muscle training)
Usual rehabilitaon program
Lost to follow-up (n=5)
Could not contact (n=4)
Other disease affected (n=1)
Control group (n=16)
Usual rehabilitaon program
Completed the study (n=11)
Analysis
Follow -Up
Randomized (n=31)
Enrollment
Follow-up, re-assessment after 6-week program (n=21)
Figure 1. Design and ow of participants through the study.
Liaw et al. Medicine (2020) 99:10 Medicine
4
Signicant changes in MIP, MEP, and fatigue level from
baseline were observed only in the RMT group. However, the
linear regression analysis, adjusted for between-group differences
in sex, BMI, and Brunnstrom stage of the affected limb,
demonstrated signicant between-group differences in the change
from baseline in mean MIP, FVC, and FEV1 (% predicted).
Table 1
Characteristics of patients in the training and control groups.
Intention to treat analysis
Pvalue
Per protocol analysis
Pvalue
Total Training Control Total Training Control
n=31 n =15 n =16 between groups n =21 n =10 n =11 between groups
Sex .019.036
Male 12 (38.71%) 6 (40.00%) 13 (81.25%) 12 (59.09%) 3 (30.00%) 9 (81.82%)
Female 19 (61.29%) 9 (60.00%) 3 (18.75%) 9 (40.91%) 7 (70.00%) 2 (18.18%)
Age (years) 62.84 (11.19) 65.40 (11.54) 60.44 (10.65) .223 63.86 (11.16) 66.80 (11.47) 61.18 (10.69) .230
Body Height (meter) 1.63 (0.08) 1.59 (0.07) 1.67 (0.06) .002∗∗ 1.63 (0.09) 1.58 (0.08) 1.68 (0.08) .011
Body Weight (kilogram) 63.72 (9.78) 65.00 (9.45) 62.51 (10.23) .488 63.53 (9.82) 65.20 (10.17) 62.02 (9.72) .621
BMI (kg/m
2
) 24.05 (3.44) 25.84 (3.35) 22.36 (2.63) .003∗∗ 23.81 (3.66) 26.00 (3.70) 21.82 (2.29) .011
Respiratory weakness 31 (100%) 15 (100%) 16 (100%) 21 (100%) 10 (100%) 11 (100%)
Swallowing disturbance 21 (67.74%) 11 (73.33%) 10 (62.50%) .535 14 (66.67%) 6 (60.00%) 8 (66.67%) .872
Stroke Duration (months) 2.45 (1.36) 2.67 (1.76) 2.25 (0.86) .404 2.67 (1.46) 3.00 (2.00) 2.42 (0.67) .797
(median) 2.50 (1.005.25) 2.50 (1.005.25) 2.00 (2.003.00) 2.50 (1.005.25) 2.50 (1.005.25) 2.00 (2.003.00)
Stroke Type .382 .414
Hemorrhage 15 (48.39%) 6 (40.00%) 9 (56.25%) 12 (54.55%) 4 (40.00%) 8 (66.66%)
Ischemic 16 (51.61%) 9 (60.00%) 7 (43.75%) 10 (45.45%) 6 (60.00%) 4 (33.33%)
Affected side .624 1.000
Right 9 (29.03%) 5 (33.33%) 4 (25.00%) 8 (36.36%) 4 (40.00%) 4 (33.33%)
Left 22 (70.97%) 10 (66.67%) 12 (75.00%) 14 (63.64%) 6 (60.00%) 8 (66.66%)
Values were expressed as mean (SD) for continuous variables and number (%) for categorical variables. MannWhitney Utest for continuous variables and Fisher exact test for categorical variables. (P<.05,
∗∗P<.01). BMI =body mass index.
Table 2
Functional and pulmonary baselines of patients in the training and control groups.
Intention to treat analysis Per protocol analysis
Total
(n =31)
Training groups
(n =15)
Control groups
(n =16)
Total
(n =21)
Training groups
(n =10)
Control groups
(n =11)
Mean (SD) Mean (SD) Mean (SD) Pvalue Mean (SD) Mean (SD) Mean (SD) Pvalue
Brunnstrom stage
Upper extremity
Proximal part 2.77 (1.06) 3.13 (1.30) 2.44 (0.63) .066 2.81 (0.98) 3.10 (1.20) 2.55 (0.68) .304
Distal part 2.65 (1.05) 3.13 (1.19) 2.19 (0.65) .0102.62 (0.97) 3.10 (0.99) 2.18 (0.75) .021
Lower extremity 3.29 (0.90) 3.60 (0.99) 3.00 (0.73) .063 3.14 (0.85) 3.40 (0.97) 2.91 (0.70) .204
Barthel index 27.26 (18.97) 27.33 (18.98) 27.19 (19.58) .983 26.43 (16.29) 25.00 (15.09) 27.73 (17.94) .859
FOIS 4.00 (2.48) 4.40 (2.50) 3.63 (2.47) .393 4.29 (2.43) 4.30 (2.45) 4.27 (2.53) .884
MRS 4.26 (0.78) 4.33 (0.90) 4.19 (0.65) .608 4.33 (0.66) 4.50 (0.71) 4.18 (0.60) .212
Hand grip of unaffected
side (kg)
24.70 (10.03) 22.51 (10.16) 26.75 (9.77) .246 22.56 (9.47) 19.90 (10.09) 24.97 (8.61) .217
FAS 23.90 (6.40) 24.87 (6.08) 23.00 (6.76) .427 24.19 (6.37) 24.30 (5.70) 24.09 (8.61) .915
Resting heart rate 84.70 (14.56) 79.93 (14.13) 88.88 (14.02) .093 84.15 (13.35) 80.00 (10.79) 87.55 (14.75) .287
Peak cough 257.24 (108.89) 246.15 (102.99) 266.25 (115.98) .630 271.05 (103.92) 268.75 (112.31) 272.73 (102.97) .901
SpO
2
at rest (%) 97.45 (1.26) 97.80 (1.32) 97.13 (1.15) .139 97.38 (1.16) 97.50 (1.18) 97.27 (1.19) .715
Borg scale 0.50 (0.43) 0.63 (0.52) 0.38 (0.29) .094 0.55 (0.44) 0.65 (0.58) 0.45 (0.27) .466
MIP (cm H
2
O) 47.29 (26.67) 38.40 (16.16) 55.63 (32.04) .069 44.57 (22.20) 35.60 (17.33) 52.73 (23.70) .081
MEP (cm H
2
O) 50.45 (18.28) 45.60 (16.36) 55.00 (19.32) .154 49.71 (18.21) 44.40 (17.07) 54.55 (18.64) .157
Pulmonary function test
FVC (liter) 2.23 (0.84) 2.01 (0.76) 2.47 (0.89) .142 2.03 (0.69) 1.83 (0.64) 2.26 (0.71) .327
FVC (% pred) 67.42 (21.12) 70.85 (24.53) 63.75 (16.88) .375 68.11 (20.31) 74.22 (24.99) 61.31 (11.23) .270
FEV1 (liter) 1.90 (0.73) 1.69 (0.59) 2.13 (0.83) .108 1.76 (0.61) 1.58 (0.54) 1.96 (0.66) .288
FEV1 (% pred) 71.88 (21.34) 74.77 (24.47) 68.79 (17.79) .461 73.05 (20.68) 79.08 (25.90) 66.36 (10.57) .391
FEV1/FVC (%) 86.60 (9.58) 86.83 (9.95) 86.67 (9.55) .968 86.82 (9.90) 87.11 (9.78) 86.49 (10.63) .775
MMEF (liter/s) 2.50 (1.29) 2.31 (1.10) 2.69 (1.49) .436 2.23 (1.00) 1.98 (0.71) 2.51 (1.23) .165
MMEF (%) 74.60 (29.88) 70.11 (21.87) 79.10 (36.51) .438 72.93 (28.88) 71.10 (26.81) 74.77 (32.35) .691
Mann-Whitney UTest (P<.05, ∗∗P<.01).
FAS =fatigue assessment scale, FEV1 =forced expiratory volume in rst second, FOIS =Functional oral intake scale, FVC =forced vital capacity (expressed in liters and in % of theoretical value), MEP =maximal
expiratory pressure, MIP =maximal inspiratory pressure, MMEF =maximum mid-expiratory ow, MRS =modied Rankin scale, SpO
2
=oxyhemoglobin saturation by pulse oximetry.
Liaw et al. Medicine (2020) 99:10 www.md-journal.com
5
Table 3
Data of MultiDimensional Voice report in the training and control groups.
Unit Training Non-training
T-Test
Pvalue between training
and non-+training
Jitter Percent (Jitt) % 2.59 (1.56) 2.40 (2.81) .973
Shimmer in dB (ShdB) dB 0.92 (0.62) 0.61 (0.55) .435
Shimmer Percent (Shim) % 10.06 (7.18) 6.41 (5.45) .378
Relative Average Perturbation (RAP) % 1.52 (0.93) 1.39 (1.64) .934
Pitch Perturbation Quotient (PPQ) % 1.54 (1.05) 1.50 (1.84) .967
Amplitude Perturbation Quotient (APQ) % 7.62 (5.80) 5.19 (4.07) .499
Peak-to-peak Amplitude Variation (vAm) % 23.32 (6.18) 23.21 (9.94) .763
Noise to Harmonic Ratio (NHR) 0.27 (0.70) 0.23 (0.16) .695
Voice Turbulence Index (VTI) 0.09 (0.31) 0.11 (0.09) .682
MannWhitney UTest. (P<.05,∗∗P<.01).
Table 4
Relationships between cardiopulmonary function and clinical characteristics.
Predictors MIP (cmH2O) MEP (cmH2O) FVC (liter) FVC (%predicte d) FEV1 (liter) FEV1 (%predicted) FEV1/FVC (%) MMEF MMEF (%)
Age .270 .052 .536.301 .590∗∗ .384 .208 .584∗∗ .292
Stroke Duration (months) .044 .104 .438 .594∗∗ .256 .458.456.219 .162
Barthel index .250 .165 .001 .030 .176 .152 .179 .233 .353
FOIS .158 .077 .084 .142 .019 .140 .082 .067 .000
MRS .245 .088 .229 .360 .173 .374 .107 .200 .286
FAS .314 .422 .115 .158 .276 .118 .272 .362 .348
Borg Scale .216 .505.437 .128 .274 .023 .245 .142 .024
Resting heart rate .336 .060 .047 .038 .328 .251 .411 .457 .528
Peak cough ow .358 .504.781∗∗ .196 .739∗∗ .214 .043 .466 .213
MIP 1.000 .632∗∗ .348 .091 .407 .255 .200 .386 .277
MEP .632∗∗ 1.000 .419 .000 .346 .030 .043 .246 .130
Spearman correlation (P<.05,∗∗P<.01).
FAS =fatigue assessment scale, FOIS =functional oral intake scale, MEP =maximal expiratory pressure, MIP =maximal inspiratory pressure, MRS =modied Rankin scale, SpO
2
=oxyhemoglobin saturation by
pulse oximetry.
Table 5
Clinical data before and after the 6-week study in the training and control groups.
Baseline Post 6-week Change from baseline Pvalue for change Pfor change Pfor change between
Mean (SD) Mean (SD) Mean (SD) from Baseline between groups groups (linear regression)
Brunnstrom stage Upper extremity Proximal part
Training 3.10 (1.20) 3.80 (1.23) 0.70 (0.82) .038.878 .252
Control 2.55 (0.69) 3.09 (0.70) 0.55 (0.68) .034
Brunnstrom stage Upper extremity Distal part
Training 3.10 (0.99) 3.90 (1.20) 0.80 (0.79) .023.878 .118
Control 2.18 (0.75) 2.91 (0.70) 0.73 (0.65) .011
Brunnstrom stage Lower extremity
Training 3.40 (0.97) 4.30 (0.82) 0.90 (0.99) .024.537 .198
Control 2.91 (0.70) 3.91 (0.30) 1.00 (0.63) .005
Barthel index
Training 25.00 (15.09) 41.00 (14.87) 16.00 (19.41) .049.831 .628
Control 27.73 (17.94) 43.18 (19.01) 15.45 (18.90) .026
FOIS
Training 4.30 (2.45) 6.50 (0.85) 2.20 (2.20) .027.971 .586
Control 4.27 (2.53) 6.45 (0.93) 2.18 (2.44) .020
MRS
Training 4.50 (0.71) 4.20 (0.42) 0.30 (0.95) .317 .612 .145
Control 4.18 (0.60) 4.00 (0.78) 0.18 (0.87) .480
Hand grip of unaffected side (kg)
Training 19.90 (10.09) 20.30 (8.78) 0.40 (4.20) .514 .359 .347
Control 24.97 (8.61) 26.30 (6.74) 1.33 (4.94) .050
FAS
Training 24.30 (5.70) 18.20 (3.46) 6.10 (3.96) .007∗∗ .215 .495
Control 24.09 (7.20) 20.64 (4.92) 3.45 (6.31) .093
Wilcoxon Signed-Ranks Test, Mann-Whitney U Test. (P<.05, ∗∗P<.01).
FAS =fatigue assessment scale, FOIS =functional oral intake scale, MRS =modied Rankin scale.
Liaw et al. Medicine (2020) 99:10 Medicine
6
Furthermore, a signicant mean change from baseline of MEP
was found only in the RMT group. The mean MEP positively
correlated with MIP and peak cough ow, which in turn
positively correlated with FVC and FEV1; MEP also negatively
correlated with the Borg scale. These ndings indicate that the 6-
week combined RMT could improve the respiratory muscle
strength patients. The effect of RMT on MIP was apparently
greater than that observed on MEP.
Clinically, the discoordination between inhaling and exhaling
should be resolved at the beginning of RMT and the active
inspiratory volume needs to be enough for forceful expiration or
cough ow. This explains why a signicant between-group
difference was seen only in MIP and not in MEP or peak cough as
a 6-week program may be too short to achieve a signicant effect
on expiratory muscle force. This nding was consistent with
results of a systemic review, which showed that RMT shows
greater improvement in MIP, but has no effect on MEP in patients
with various neurologic diseases.
[32]
Further, 5-week EMT for
ischemic stroke patients increases the average expiratory muscle
strength by approximately 30 cmH
2
O and improves the urge and
strength of reex cough, but is not effective for voluntary cough
or swallow function. Therefore, the efcacy of EMT was
attributed to the upregulation of reex cough.
[2]
Moreover, a 4-
week RMT by using threshold resistance device in acute stroke
patients signicantly improved the mean MIP by 14 cmH
2
O,
MEP by 15 cmH
2
O, and the peak expiratory ow rate (74 L/min)
of all three groups, regardless of the allocation of expiratory,
inspiratory, or sham training; but no between-group differences
was noted.
[33]
Similarly, our study showed no signicant
between-group difference in MEP and peak cough ow.
Furthermore, our study also revealed no difference between
both groups in terms of MRS, hand grip strength, and FOIS,
Table 6
Data changes in cardiopulmonary function before and after the 6-week study in the training and control groups.
Baseline Post 6-week
Change from baseline
Mean (SD)
Pvalue for change
from Baseline
Pfor change
between groups
Pfor change between
groups (linear regression)
Resting heart rate
Training 83.00 (9.89) 82.43 (13.70) 0.57 (10.49) 1.000 .171 .676
Control 88.90 (14.81) 79.70 (15.41) 9.20 (19.67) .074
Peak cough
Training 278.57 (117.53) 305.71 (102.45) 27.14 (54.69) .236 .845 .570
Control 290.00 (90.19) 337.00 (83.14) 47.00 (85.38) .123
SpO
2
_Rest (%)
Training 97.50 (1.18) 97.50 (1.65) 0.00 (1.94) 1.000 .500 .838
Control 97.27 (1.19) 97.82 (0.87) 0.55 (0.93) .084
Borg scale
Training 0.65 (0.58) 0.70 (0.75) 0.05 (0.55) .783 .114 .317
Control 0.46 (0.27) 0.23 (0.26) 0.23 (0.26) .025
MIP (cm H
2
O)
Training 35.60 (17.33) 81.50 (41.64) 45.90 (29.31) .005∗∗ .008∗∗ .001∗∗
Control 52.73 (23.70) 58.18 (24.42) 5.45 (20.18) .366
MEP (cm H
2
O)
Training 44.40 (17.07) 71.00 (26.44) 26.60 (26.92) .017.227 .256
Control 54.55 (18.64) 68.18 (16.01) 13.64 (24.61) .093
FVC (liter)
Training 1.98 (0.58) 2.21 (091) 0.24 (0.47) .575 .793 .017
Control 2.33 (0.73) 2.50 (0.77) 0.18 (0.25) .093
FVC (% pred)
Training 79.93 (24.61) 81.55 (21.36) 1.63 (17.61) .889 .529 .105
Control 63.26 (10.24) 68.40 (9.77) 5.14 (.50) .069
FEV1 (liter)
Training 1.66 (0.85) 1.73 (0.47) 0.07 (0.79) .944 .753 .569
Control 2.00 (0.69) 1.97 (0.74) 0.03 (0.25) .889
FEV1 (% pred)
Training 85.49 (25.06) 87.20 (20.25) 1.71 (16.79) 1.000 1.000 .047
Control 67.86 (10.21) 67.55 (15.37) 0.31 (10.59) .889
FEV1/FVC (%)
Training 88.46 (7.37) 88.40 (7.74) 0.06 (4.45) .889 .345 .995
Control 85.42 (10.82) 80.94 (16.73) 4.48 (8.55) .161
MMEF (liter/s)
Training 2.14 (0.59) 2.25 (0.64) 0.11 (0.43) .327 .270 .076
Control 2.48 (1.31) 2.35 (1.86) 0.13 (0.96) .674
MMEF (%)
Training 77.00 (21.53) 81.54 (16.33) 4.54 (18.01) .263 .294 .082
Control 74.09 (34.51) 71.71 (54.39) 2.38 (31.69) .674
Wilcoxon Signed-Ranks Test, Mann-Whitney U Test. Adjusted for sex, BMI and Brunntrom stage of distal part of affected upper limb by using linear regression analysis. (P<.05, ∗∗P<.01).
FEV1 =forced expiratory volume in rst second, FVC =forced vital capacity (expressed in liters and in % of theoretical value), MEP =maximal expiratory pressure, MIP =maximal inspiratory pressure, MMEF =
maximum mid-expiratory ow, SpO
2
=oxyhemoglobin saturation by pulse oximetry.
Liaw et al. Medicine (2020) 99:10 www.md-journal.com
7
Table 7
Data of MultiDimensional Voice report before and after the 6-week study in the training and non-training groups.
Baseline Post 6-week Change from baseline P value for change P for change
Mean (SD) Mean (SD) Mean (SD) from Baseline between groups
Jitter Percent (Jitt)
Training 2.59 (1.56) 2.30 (1.63) 0.29 (0.61) 0.298 0.101
Non-training 2.40 (2.81) 1.65 (2.22) 0.75 (1.04) 0.104
Shimmer in dB (Shdb)
Training 0.92 (0.62) 0.79 (0.65) 0.13 (0.14) 0.075 0.101
Non-training 0.61 (0.55) 0.48 (0.32) 0.14 (0.42) 0.427
Shimmer Percent (Shim)
Training 10.06 (7.18) 8.46 (6.65) 1.60 (1.45) 0.0430.116
Non-training 6.41 (5.45) 5.10 (3.23) 1.31 (4.37) 0.458
Relative Average Perturbation (RAP)
Training 1.52 (0.93) 1.38 (0.97) 0.14 (0.32) 0.332 0.087
Non-training 1.39 (1.64) 0.93 (1.28) 0.46 (0.60) 0.091
Pitch Perturbation Quotient (PPQ)
Training 1.54 (1.05) 1.53 (1.17) 0.01 (0.27) 0.974 0.272
Non-training 1.50 (1.84) 0.99 (1.45) 0.51 (0.72) 0.109
Amplitude Perturbation Quotient (APQ)
Training 7.62 (5.80) 6.55 (5.50) 1.07 (0.92) 0.0360.087
Non-training 5.19 (4.07) 3.96 (2.11) 1.23 (3.35) 0.368
Peak-to-peak Amplitude Variation (vAm)
Training 23.32 (6.18) 21.74 (7.51) 1.58 (7.68) 0.636 0.133
Non-training 23.21 (9.94) 19.97 (7.67) 3.24 (5.11) 0.145
Noise to Harmonic Ratio (NHR)
Training 0.27 (0.70) 0.22 (0.11) 0.05 (0.06) 0.126 0.116
Non-training 0.23 (0.16) 0.17 (0.58) 0.06 (0.12) 0.238
Voice Turbulence Index (VTI)
Training 0.09 (0.31) 0.07 (0.16) 0.02 (0.88) 0.0250.100
Non-training 0.11 (0.09) 0.07 (0.04) 0.04 (0.06) 0.274
Wilcoxon Signed-Ranks Test, MannWhitney UTest. (P<.05).
Table 8
Data of MultiDimensional Voice report before and after the 6-week study in the training and non-training groups.
Baseline Post 6-week Change from baseline Pvalue for change Pfor change
Mean (SD) Mean (SD) Mean (SD) from Baseline Pfor change
Jitter Percent (Jitt)
Training 2.59 (1.56) 2.30 (1.63) 0.29 (0.61) .298 .101
Non-training 2.40 (2.81) 1.65 (2.22) 0.75 (1.04) .104
Shimmer in dB (Shdb)
Training 0.92 (0.62) 0.79 (0.65) 0.13 (0.14) .075 .101
Non-training 0.61 (0.55) 0.48 (0.32) 0.14 (0.42) .427
Shimmer Percent (Shim)
Training 10.06 (7.18) 8.46 (6.65) 1.60 (1.45) .043.116
Non-training 6.41 (5.45) 5.10 (3.23) 1.31 (4.37) .458
Relative Average Perturbation (RAP)
Training 1.52 (0.93) 1.38 (0.97) 0.14 (0.32) .332 .087
Non-training 1.39 (1.64) 0.93 (1.28) 0.46 (0.60) .091
Pitch Perturbation Quotient (PPQ)
Training 1.54 (1.05) 1.53 (1.17) 0.01 (0.27) .974 .272
Non-training 1.50 (1.84) 0.99 (1.45) 0.51 (0.72) .109
Amplitude Perturbation Quotient (APQ)
Training 7.62 (5.80) 6.55 (5.50) 1.07 (0.92) .036.087
Non-training 5.19 (4.07) 3.96 (2.11) 1.23 (3.35) .368
Peak-to-peak Amplitude Variation (vAm)
Training 23.32 (6.18) 21.74 (7.51) 1.58 (7.68) .636 .133
Non-training 23.21 (9.94) 19.97 (7.67) 3.24 (5.11) .145
Noise to Harmonic Ratio (NHR)
Training 0.27 (0.70) 0.22 (0.11) 0.05 (0.06) .126 .116
Non-training 0.23 (0.16) 0.17 (0.58) 0.06 (0.12) .238
Voice Turbulence Index (VTI)
Training 0.09 (0.31) 0.07 (0.16) 0.02 (0.88) .025.100
Non-training 0.11 (0.09) 0.07 (0.04) 0.04 (0.06) .274
Wilcoxon Signed-Ranks Test, MannWhitney U Test. (P<.05).
Liaw et al. Medicine (2020) 99:10 Medicine
8
which may be attributed to the heterogeneity in neurological
lesion characteristics and existence of multiple comorbidities
including congestive heart failure, atrial brillation, hyperten-
sion, and diabetes mellitus. Most of our participantsbrain
lesions were located in the middle cerebral artery territory.
Moreover, quite a few participants had borderline cardiomegaly
or congestive heart.
The physical activity level in stroke patients is usually limited
by fatigue and dyspnea. Some patients were too fatigued to attend
the program at the time of eligibility screening. However, our
RMT group patients showed a signicant change from baseline
of FAS in contrast to that in the control group.
For stroke patients, the perception of dyspnea is low and
blunted, which is due to their dissociation between respiratory
effort and dyspnea.
[34]
This can explain the similar Borg scale
scores of both groups.
Regarding voice signals, Shim and ShdB are associated with
hoarse and breathy voices; APQ and PPQ indicate the inability of
the cords to support a periodic vibration. Hoarse and breathy
voices usually have increased APQ, PPQ, or RAP.
[19]
Moreover,
the subglottal pressure initiates and maintains the vocal fold
vibration and voice production. Wingate et al reported that 5-
week EMT followed by 6 sessions of traditional voice therapy
could increase subglottal pressure, which increased the vocal
intensity and voice dynamic range.
[9]
After the 6-week RMT, our
stroke patients showed signicant changes in Shim, APQ, and
VTI from baseline in the voice analysis thus indicating that RMT
is benecial for the improvement of voice quality in stroke
patients showing dysarthria. Further, considering that FEV1/
FVC% was negatively correlated with Jitt, RAP, PPQ, and VTI,
FEV1/FVC% may be correlated to voice quality, although no
signicant between-group difference after RMT was obtained for
this parameter.
No adverse event was reported throughout the program,
except in one subject with transient facial muscle soreness, which
subsided within 2 to 3 days. Similar to previous studies,
[10,11,33]
the results proved that RMT could be feasible as adjunct therapy
in stroke patients with respiratory muscle weakness, dysphagia,
and dysarthria. However, the 6-week combined RMT was
considered not long enough to demonstrate efcacy for
expiratory muscle strength, swallowing, functional activity,
and dysarthria and designing an intervention strategy based
on the intensity, frequency, and duration of training program
remains a challenge.
Study limitations: This study is limited by the small number of
patients recruited. It took us two to three years to recruit the
participants and those with apraxia, aphasia, and loose teeth, and
those who could not hold a breath or perform a spirometry test
were excluded. This study is also limited by the marked degree of
drop-out rate (33.3% in RMT and 31.3% in control group).
Moreover, the long-term effects and maintenance of RMT were
not evaluated.
5. Conclusions:
Altogether, RMT signicantly improved the respiratory muscle
strength, FVC, FEV1, and fatigue in stroke patients with
respiratory muscle weakness. In addition, the improvement in
post-stroke dysphagia and dysarthria was also enhanced through
RMT. The 6-week combined inspiratory and expiratory RMT is
thus feasible as adjuvant therapy in stroke patients.
Acknowledgments
The authors would like to thank Andrew Wei-Hsiang Tiong for
his assistance with this research.
Author contributions
Conceptualization: Mei-Yun Liaw, Chau-Peng Leong, Ching-Yi
Liao, Cheng-Hsien Lu, Meng-Chih Lin.
Data curation: Mei-Yun Liaw, Chia-Hao Hsu, Chau-Peng
Leong, Ching-Yi Liao, Lin-Yi Wang, Cheng-Hsien Lu, Meng-
Chih Lin.
Formal analysis: Mei-Yun Liaw, Chia-Hao Hsu, Meng-Chih Lin.
Funding acquisition: Mei-Yun Liaw.
Investigation: Mei-Yun Liaw.
Methodology: Mei-Yun Liaw, Chau-Peng Leong, Ching-Yi Liao,
Cheng-Hsien Lu, Meng-Chih Lin.
Resources: Chia-Hao Hsu, Lin-Yi Wang.
Supervision: Lin-Yi Wang.
Writing original draft: Mei-Yun Liaw, Meng-Chih Lin.
Writing review & editing: Mei-Yun Liaw.
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Liaw et al. Medicine (2020) 99:10 Medicine
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... The diaphragm is elevated with less movement on the affected side. [27][28][29][30] EMG activities of diaphragm and intercostal muscles have been reported as reduced and diaphragm muscle thickness measurement with ultrasound has shown diaphragm dysfunction. Ventilatory dysfunction is associated with reduced VC, inspiratory capacity (IC), TLC, maximum inspiratory capacity and especially expiratory residual volume (ERV) in these patients. ...
... [31] Nearly half of patients with stroke report dyspnea. [28,30] Significant correlations have been found between measures of inspiratory strength and dyspnea and quality of life in this population. [27][28][29][30] Respiratory muscle training (expiratory and inspiratory muscles), controlled breathing techniques (DB, air-shifting techniques, pursed lip breathing, segmental breathing/lateral costal breathing), airway clearance techniques (incentive spirometry), posture exercises, and aerobic, strength and combined training are the modalities applied for PR in these patients. ...
... [28,30] Significant correlations have been found between measures of inspiratory strength and dyspnea and quality of life in this population. [27][28][29][30] Respiratory muscle training (expiratory and inspiratory muscles), controlled breathing techniques (DB, air-shifting techniques, pursed lip breathing, segmental breathing/lateral costal breathing), airway clearance techniques (incentive spirometry), posture exercises, and aerobic, strength and combined training are the modalities applied for PR in these patients. It has been reported that pulmonary function test results (FVC, FV1, IC, TV, MIP, MEP and maximum voluntary ventilation [MVV] as a measure of the endurance of respiratory muscle), exercise capacity (peak oxygen consumption [VO 2peak ]), inspiratory muscle endurance, fatigue level, respiratory muscle strength, lung volume, respiratory f low, and trunk control ability have been reported to be improved after the training program. ...
... Daraufhin wurden die Volltexte der verbliebenen fünf Studien gelesen. Insgesamt erfüllten nur die drei in Tabelle 3 aufgeführten Studien die Einschlusskriterien: Levy et al.[9], Liaw et al.[10] und Mendoza Ramos et al.[11] (Tab. 3).Für Patient*innen mit einem Schlaganfall ist in den ersten 12 Monaten nach dem Ereignis ein sechswöchiges kombiniertes inspiratorisches und exspiratorisches Muskeltraining als unterstützende Therapie wirksam. ...
... Dies ergab die Studie von Levy et al.[9], in der sowohl das inspiratorische Muskeltraining (IMT) als auch das exspiratorische Muskeltraining (EMT) zu signifikanten Veränderungen im Outcome führten. Die Patient*innen sollten dafür fünf bis sechs Sets mit je fünf Wiederholungen IMT und EMT ein bis zwei Mal täglich für mindestens fünf Tage pro Woche durchführen[9].Die Studie von Liaw et al.[10] zeigte, dass signifikant stärkere Veränderungen in der Stimmgruppe (Lee Silverman Voice Treatment [LSVT] LOUD) zu beobachten waren, wohingegen es keine signifikanten Unterschiede im Outcome zwischen der Artikulationsgruppe (LSVT ARTIC) und der No-Treatment Gruppe gab. Somit ist für eine mittel-bis schwergradige chronische hypokinetische Dysarthrie bei M. Parkinson das LSVT LOUD Programm als Trainingsprogramm zur Verbesserung der Aussprache und Lautstärke zu empfehlen[10].Tab. ...
... Die Patient*innen sollten dafür fünf bis sechs Sets mit je fünf Wiederholungen IMT und EMT ein bis zwei Mal täglich für mindestens fünf Tage pro Woche durchführen[9].Die Studie von Liaw et al.[10] zeigte, dass signifikant stärkere Veränderungen in der Stimmgruppe (Lee Silverman Voice Treatment [LSVT] LOUD) zu beobachten waren, wohingegen es keine signifikanten Unterschiede im Outcome zwischen der Artikulationsgruppe (LSVT ARTIC) und der No-Treatment Gruppe gab. Somit ist für eine mittel-bis schwergradige chronische hypokinetische Dysarthrie bei M. Parkinson das LSVT LOUD Programm als Trainingsprogramm zur Verbesserung der Aussprache und Lautstärke zu empfehlen[10].Tab. 1: Ein-und Ausschlusskriterien RCTs ...
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Hintergrund: Sprechen ist ein essenzieller Teil der Kommunikation und hat damit eine hohe Relevanz für die Partizipation, Teilhabe und die Lebensqualität. Dysarthrien, als häufigste Form einer neurologisch bedingten Sprechstörung, führen dazu, dass Betroffene entweder gar nicht oder nur erschwert zu verstehen sind. Eine qualitativ hochwertige Dysarthriediagnostik und -therapie erhalten daher in der Logopädie eine besondere Bedeutung. Methode: Es wurde eine systematische Literaturrecherche zu RCTs und Leitlinien mit dem Ziel durchgeführt, evidenzbasierte und aktuelle Empfehlungen für die Dysarthriediagnostik und -therapie zu identifizieren. Die Recherche schloss daher nur Evidenzen ein, die nicht älter als fünf Jahre sind. Die Qualität der gefundenen RCTs wurde mit Hilfe der CASPCheckliste bewertet. Ergebnisse: Es wurden drei RCTs und acht Leitlinien in die Auswertung eingeschlossen. Allgemein wird eine sprachtherapeutische Behandlung bei Dysarthrie empfohlen. Dabei ist eine therapeutische Anpassung an den individuellen Bedarf der Betroffenen notwendig. Der Einsatz nicht-sprachlicher oralmotorischer Bewegungen wird nicht empfohlen. Hingegen sollen Kommunikationshilfen wie die technisch unterstützte Kommunikation bei geringer Verständlichkeit in Betracht gezogen werden. Diskussion: Es liegen nur wenige Wirksamkeitsnachweise von angemessener Qualität für die Behandlung von Dysarthrien vor. Daher beinhalten die Leitlinien nur allgemein gehaltene Empfehlungen, aus denen kaum konkrete Handlungshilfen für die Praxis abgeleitet werden können. In den Empfehlungen der Leitlinien werden darüber hinaus die Störungsbilder Dysarthrie und Aphasie nicht immer konsequent und klar voneinander getrennt betrachtet. Schlussfolgerung: Um evidenzbasierte Empfehlungen für die Dysarthriediagnostik und -therapie geben zu können, bedarf es weiterer Forschung. Wünschenswert wäre auch mehr Diversität bei der Untersuchung der Behandlungsmethoden. Abstract Background: Speaking is an essential part of communication and therefore highly relevant for participation and quality of life. Dysarthrias are the most common form of neurologically induced speech disorders which means that those affected either cannot be understood at all or only with difficulty. Highquality dysarthria diagnosis and therapy therefore have a high priority in speech therapy. Methods: A systematic literature search for RCTs and guidelines was conducted with the aims of identifying evidence-based and current recommendations for dysarthria diagnosis and therapy. Thus, the search included only evidence that was not older than five years. The quality of the RCTs found was assessed using the CASP checklist. Results: Three RCTs and eight guidelines were included in the analysis. In general, speech therapy treatment is recommended for dysarthria. Therapeutic adaptation to the individual needs of the affected person is necessary. The use of non-linguistic oral-motor movements is not recommended. On the other hand, communication aids such as technology-assisted communication should be considered when intelligibility is low. Discussion: Although dysarthria often occurs as a result of stroke and neurodegenerative diseases, there is little evidence of efficacy of adequate quality for the treatment of dysarthria. As a result, guidelines only contain generalized recommendations that are unlikely to provide concrete guidance for practice. In the guidelines’ recommendations, the disorders dysarthria and aphasia are not consistently and clearly separated from each other. Conclusion: Further research is needed to make evidence-based recommendations for dysarthria diagnosis and treatment. Also, more diversity in the study of treatment methods would be desirable.
... Of the 26 included studies and trials, 18 are randomised controlled trials (n=10 to n=306), [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] one is a nonrandomised controlled trial (n=24), 48 three are cohort studies (n=24 to n=208), 8 49 50 two are case series 51 52 and two are case reports. 53 54 The studies are published between 1998 and 2020. ...
... 45 The final study was categorised as respiratory muscle training (RMT) with a hand-held threshold trainer and investigated the feasibility and efficacy of a combined inspiratory and expiratory muscle training on pulmonary dysfunction and swallowing function. 46 The outcome measures of the studies are categorised and presented in table 2. ...
... 45 Liaw et al found no significant difference between the groups over time on FOIS in an RCT comparing regular rehabilitation with and without RMT. 46 ...
Article
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Introduction Dysphagia is a common and critical consequence of acquired brain injury (ABI) and can cause severe complications. Dysphagia rehabilitation is transforming from mainly compensatory strategies to the retraining of swallowing function using principles from neuroscience. However, there are no studies that map interventions available to retrain swallowing function in patients with moderate-to-severe ABI. Objective To systematically map the accessible research literature to answer the research question: Which non-surgical, non-pharmacological interventions are used in the treatment of dysphagia in patients with moderate and severe ABI in the acute and subacute phase? Design Scoping review based on the methodology of Arksey and O’Malley and methodological advancement by Levac et al. Data sources MEDLINE, Embase, Cochrane Library, CINAHL, PsycINFO, Web of Science, OTseeker, speechBITE and PEDro were searched up until 14 March 2021. Eligibility criteria All studies reporting rehabilitative interventions within 6 months of injury for patients with moderate-to-severe ABI and dysphagia were included. Data extraction and synthesis Data was extracted by two independent reviewers and studies were categorised based on treatment modality. Results A total of 21 396 records were retrieved, and a final of 26 studies were included. Interventions were categorised into cortical or non-cortical stimulation of the swallowing network. Cortical stimulation interventions were repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation. Non-cortical were complex swallowing interventions, neuromuscular electrical stimulation, pharyngeal electrical stimulation (PES), sensory stimulation, strengthening exercises and respiratory muscle training. Conclusion This scoping review provides an overview of rehabilitative dysphagia interventions for patients with moderate and severe ABI, predominantly due to stroke, in the acute and subacute phase. Positive tendencies towards beneficial effects were found for rTMS, complex swallowing interventions, PES and cervical strengthening. Future studies could benefit from clear reporting of patient diagnosis and disease severity, the use of more standardised treatment protocols or algorithms and fewer but standardised outcome measures to enable comparison of effects across studies and interventions.
... Remarkably, the deep core muscles are also the main respiratory muscles, such as the diaphragm, multifidus and pelvic floor muscles. We generally found that the decline of the deep core muscle group in stroke patients lead to the decline of maximum inspiratory and maximum expiratory pressures (6,7). A cross-sectional study found that maximum expiratory and maximum inspiration pressures were positively associated with static and dynamic balance (8,9). ...
... The study recruited 160 eligible stroke patients from March 2018 to August 2019 in the rehabilitation department of Shanghai Xuhui Central Hospital. All subjects met the following inclusion criteria: (1) Diagnosis of cerebral hemorrhage or cerebral infarction (18); (2) Meet traditional Chinese medicine (TCM) diagnostic criteria of stroke (19); (3) Sitting balances > 2 levels; (4)Age range between 40 and 80 years; (5) The course of the disease was 2 weeks to 6 months; (6) People who were physically active and could tolerate 45 mins of exercise; (7) The patient was left with hemiplegia or quadriplegia, If the patient is quadriplegic after stroke, he or she should qualify for a Brunnstrum grade 4 or higher on at least one upper limb; (8) The patient's vital signs were stable; (9) Agreed to sign an informed consent form; (10) All subjects in the study were able to independently complete the static balance ability test. ...
Article
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Aims Liuzijue Qigong (LQG) exercise is a traditional Chinese exercise method in which breathing and pronunciation are combined with movement guidance. Breathing is closely related to balance, and LQG, as a special breathing exercise, can be applied to balance dysfunction after stroke. The purpose of this study was to observe the clinical effects of short-term LQG exercise on balance function in patients recovering from stroke. Methods Stroke patients were randomly divided into an Intervention Group (IG) ( n = 80) and a Control Group (CG) ( n = 80). The IG received conventional rehabilitation training plus LQG and the CG received conventional rehabilitation training plus Core Stability Training (CST). All patients received treatment once a day, 5 times a week for 2 weeks. The primary outcome was Berg Balance Scale (BBS). Secondary outcome measures were static standing and sitting balance with eyes open and closed, Fugl-Meyer Assessment (FMA), Maximum Phonation Time (MPT), Modified Barthel Index (MBI) and diaphragm thickness and mobility during quiet breath (QB) and deep breath (DB). Results Compared with the CG, the IG showed significant improvement in the BBS (10.55 ± 3.78 vs. 9.06 ± 4.50, P = 0.039), MPT (5.41 ± 4.70 vs. 5.89 ± 5.24, P = 0.001), MBI (12.88 ± 6.45 vs. 10.00 ± 4.84, P = 0.003), diaphragmatic mobility during QB (0.54 ± 0.73 vs. 0.33 ± 0.40, P = 0.01) and diaphragmatic mobility during DB (0.99 ± 1.32 vs. 0.52 ± 0.77, P = 0.003), Cop trajectory in the standing position with eyes open (−108.34 ± 108.60 vs. −89.00 ± 140.11, P = 0.034) and Cop area in the standing positions with eyes open (−143.79 ± 431.55 vs. −93.29 ± 223.15, P = 0.015), Cop trajectory in the seating position with eyes open (−19.95 ± 23.35 vs. −12.83 ± 26.64, P = 0.001) and Cop area in the seating position with eyes open (−15.83 ± 9.61 vs. −11.29 ± 9.17, P = 0.002). Conclusions The short-term LQG combined with conventional rehabilitation training significantly improved the balance functions of stroke patients. It also improved static standing and sitting balance with the eyes open, diaphragm functions, maximum phonation time and the quality of daily life for stroke patients. Clinical Trial Registration http://www.chictr.org.cn/edit.aspx?pid=25313&htm=4 , Identifier: ChiCTR1800014864.
... [3] Our recent study revealed that 6week combined inspiratory and expiratory RMT could improve fatigue level, respiratory muscle strength, lung volume, respiratory flow, and dysarthria in stroke patients with respiratory muscle weakness. [13] However, the effect of RMT on the swallowing function of poststroke patients with respiratory muscle weakness remains unclear. ...
... The inspiratory RMT started from 30% to 60% of MIP, and expiratory RMT started from 15% to 75% of MEP for 5 days per week for 6 weeks. [13] ...
Article
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Background: Dysphagia has been reported to be associated with the descent of the hyolaryngeal complex. Further, suprahyoid muscles play a greater role than infrahyoid muscles in elevation of the hyolarngeal complex. Respiratory muscle training (RMT) can improve lung function, and expiratory muscle strength training can facilitate elevation of the hyoid bone and increase the motor unit recruitment of submental muscles during normal swallowing. This study aimed to investigate the surface electromyography (sEMG) of the swallowing muscles, bilaterally, and the effect of RMT on swallowing muscles in stroke patients with respiratory muscle weakness. Methods: Forty patients with first episode of unilateral stroke were included in this retrospective controlled trial. After exclusion of 11 patients with respiratory muscle strength stronger than 70% of the predicted value, 15 were allocated to the RMT group and 14 to the control group. However, eventually, 11 patients in RMT group and 11 patients in control group completed the study. The sEMG of the orbicularis oris, masseter, submental, and infrahyoid muscles were recorded during dry swallowing, water swallowing (2 mL), and forced exhalation against a threshold breathing trainer set at different intensities, at baseline and after 6-week RMT. Results: Regarding the sEMG of submental muscles, there were significant between-group differences on the latency of the unaffected side (P = .048), significant change from baseline force on the unaffected side (P = .035), and significant between-side difference (P = .011) in the RMT group during dry swallowing. Significant change in the duration from baseline was observed on the affected side of the RMT group when blowing was set at 50% maximal expiratory pressure (MEP; P = .015), and on the unaffected side of the control group when blowing set at 15% MEP (P = .005). Significant difference was observed in the duration between 50% MEP and 15% MEP after 6-week program in the control group (P = .049). Conclusions: A 6-week RMT can improve the electric signal of the affected swallowing muscles with more effect on the unaffected side than on the affected side during dry swallowing. Furthermore, RMT with 50% MEP rather than 15% MEP can facilitate greater submental muscle activity on the affected side in stroke patients with respiratory muscle weakness.
... The routine treatment measures for swallowing disorders include the following: dietary modification (Reyes-Torres et al., 2019), postural substitution (Terré and Mearin, 2012), physical therapy (Kilinç et al., 2020;Liaw et al., 2020;Lin et al., 2021), acupuncture (Chen and Guo, 2018;Yuan et al., 2019), and sensorimotor stimulation (Simonelli et al., 2019;Wang et al., 2019;Oh et al., 2020). These treatments aim at improving the swallowing function and increasing the speed of eating, but their therapeutic effect is limited to some extent. ...
Article
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Background Repetitive transcranial magnetic stimulation (rTMS) applied to the mylohyoid cortical region has positive clinical effects on post-stroke. Therefore, we conducted a meta-analysis to investigate the efficacy of rTMS for patients with post-stroke dysphagia. Methods According to PRISMA guidelines, we searched the databases of MEDLINE (PubMed), Cochrane Library, Embase, Web of Science, CNKI, Wangfang. We searched for studies of randomized controlled trials (RCTs) of rTMS to treat dysphagia after stroke and screened by inclusion and exclusion criteria. Features of RCTs were extracted. The heterogeneity of the trials was measured by I ² statistic. Results In total, 11 RCTs with 463 dysphagia patients fulfilled our inclusion criteria. In our analysis, rTMS demonstrated a great beneficial effect for post-stroke dysphagia when combined with traditional swallowing exercises. Moreover, a greatly significant difference ( P = 0.008) was noted based on stimulation frequency (high frequency vs. low frequency). Additionally, no significant difference ( P = 0.53) was observed based on stimulation site (affected vs. unaffected hemisphere). Conclusions Overall, rTMS can effectively accelerate the improvement of swallowing function in patients with post-stroke swallowing disorders.
... Visto que o relaxamento sistémico é um componente nuclear no retorno à calma, aconselha-se a realização de exercícios respiratórios (Pelka et al., 2017). Além disso, promovem o trabalho da musculatura respiratória, com consequente melhoria da perfusão pulmonar (Liaw et al., 2020). Existem muitas técnicas respiratórias diferentes. ...
... The non-invasive tDCS is a cortical stimulation technique aimed to project the pharyngeal representation to the unaffected hemisphere, hypothetically ensuring increased input to the brainstem swallowing centres. The integrity of brainstem is fundamental [79,80]. However, only one study showed an improvement in DOSS in the tDCS group compared with sham and a recent review underlined the low-quality evidence of the studies that could show the effectiveness of non-invasive brain stimulation in improving dysphagia after acquired brain injury [81]. ...
Article
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Neurogenic dysphagia is a difficulty in swallowing food caused by disease or impairment of the nervous system, including stroke and traumatic brain injury. The most clinically apparent complication of neurogenic dysphagia is pulmonary aspiration, which may manifest itself acutely as choking or coughing, respiratory distress, wheezing, gasping or gurgling, and tachycardia. However, chronic symptoms, including weight loss, production of excessive oral secretions and aspiration pneumonia, may be also present, especially in patients with a disorder of consciousness (DOC). Usually, patients with dysphagia after the acute phase need to be treated with enteral nutrition using a feeding tube. This avoids patient malnutrition and supports the rehabilitation program. This narrative review aims to investigate dysphagia and its complications and management in patients with DOC. Clinical indications and practical advice on how to assess and treat this complex problem are also provided.
Article
Introdução: As alterações multiorgânicas presentes no processo de envelhecimento associadas a uma situação de doença podem intensificar o declínio funcional e provocar uma maior fragilidade cardiorrespiratória. Objetivo: Identificar as intervenções suscetíveis de melhorarem o desempenho respiratório e a capacidade funcional nas pessoas idosas em contexto de agudização. Metodologia: Revisão sistemática da literatura segundo o protocolo Joanna Briggs Institute através de pesquisa nas bases de dados de artigos científicos pela plataforma EBSCOhost, sendo incluídos artigos publicados de 2015 a 2021, através da utilização dos Medical Subject Heading. Resultados: Após a pesquisa realizada foram identificados 144 artigos, dos quais sete respondiam aos critérios de inclusão definidos: quatro estudos clínicos randomizados, dois estudos prospetivos quase experimentais e um estudo de corte transversal. Conclusão: De acordo com os autores dos estudos incluídos nesta revisão da literatura, as intervenções de reabilitação respiratória, como a técnica de controlo da respiração e o uso de dispositivos para treino dos músculos respiratórios permitiram a redução da fadiga, o aumento da tolerância ao esforço e a melhoria dos volumes e das capacidades pulmonares, com resultados favoráveis no desempenho funcional.
Article
Background: Previous reviews relating to the effects of respiratory muscle training (RMT) after stroke tend to focus on only one type of training (inspiratory or expiratory muscles) and most based the results on poor-quality studies (PEDro score ≤4). Objectives: With this systematic review and meta-analysis, we aimed to determine the effects of RMT (inspiratory or expiratory muscle training, or mixed) on exercise tolerance, respiratory muscle function and pulmonary function and also the effects depending on the type of training performed at short- and medium-term in post-stroke. Methods: Databases searched were MEDLINE, PEDro, CINAHL, EMBASE and Web of Science up to the end of April 2020. The quality and risk of bias for each included study was examined by the PEDro scale (including only high-quality studies) and Cochrane Risk of Bias tool. Results: Nine studies (463 patients) were included. The meta-analysis showed a significant increase in exercise tolerance [4 studies; n = 111; standardized mean difference [SMD] = 0.65 (95% confidence interval 0.27-1.04)]; inspiratory muscle strength [9 studies; n = 344; SMD = 0.65 (0.17-1.13)]; inspiratory muscle endurance [3 studies; n = 81; SMD = 1.19 (0.71-1.66)]; diaphragm thickness [3 studies; n = 79; SMD = 0.9 (0.43-1.37)]; and peak expiratory flow [3 studies; n = 84; SMD = 0.55 (0.03-1.08)] in the short-term. There were no benefits on expiratory muscle strength and pulmonary function variables (forced expiratory volume in 1 sec) in the short-term. Conclusions: The meta-analysis provided moderate-quality evidence that RMT improves exercise tolerance, diaphragm thickness and pulmonary function (i.e., peak expiratory flow) and low-quality evidence for the effects on inspiratory muscle strength and endurance in stroke survivors in the short-term. None of these effects are retained in the medium-term. Combined inspiratory and expiratory muscle training seems to promote greater respiratory changes than inspiratory muscle training alone.
Article
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[Purpose] This study was conducted to identify the effects of expiratory muscle strength training on swallowing function in acute stroke patients with dysphagia. [Subjects and Methods] A total of 18 stroke patients with dysphagia were enrolled in the study. All participants were randomly assigned to either an experimental group (n=9) or a control group (n=9). All participants performed traditional-swallowing rehabilitation therapy in 30-minute sessions five times a week for four weeks; however, only the experimental group received expiratory muscle strength training. [Results] Both groups showed significant improvements after mediation. When compared with the control group, the functional dysphagia scale, vallecular residue, and penetration-aspiration scale were significantly improved in the experimental group. [Conclusion] Expiratory muscle strength training is an effective intervention for impaired swallowing function in acute strike patients with dysphagia.
Article
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Objective To investigate the effect of laryngopharyngeal neuromuscular electrical stimulation (NMES) on dysphonia in patients with dysphagia caused by stroke or traumatic brain injury (TBI). Methods Eighteen patients participated in this study. The subjects were divided into NMES (n=12) and conventional swallowing training only (CST, n=6) groups. The NMES group received NMES combined with CST for 2 weeks, followed by CST without NMES for the next 2 weeks. The CST group received only CST for 4 weeks. All of the patients were evaluated before and at 2 and 4 weeks into the study. The outcome measurements included perceptual, acoustic and aerodynamic analyses. The correlation between dysphonia and swallowing function was also investigated. Results There were significant differences in the GRBAS (grade, roughness, breathiness, asthenia and strain scale) total score and sound pressure level (SPL) between the two groups over time. The NMES relative to the CST group showed significant improvements in total GRBAS score and SPL at 2 weeks, though no inter-group differences were evident at 4 weeks. The improvement of the total GRBAS scores at 2 weeks was positively correlated with the improved pharyngeal phase scores on the functional dysphagia scale at 2 weeks. Conclusion The results demonstrate that laryngopharyngeal NMES in post-stroke or TBI patients with dysphonia can have promising effects on phonation. Therefore, laryngopharyngeal NMES may be considered as an additional treatment option for dysphonia accompanied by dysphagia after stroke or TBI.
Article
Objective: To evaluate the effectiveness of inspiratory/expiratory muscle training (IEMT) and neuromuscular electrical stimulation (NMES) to improve dysphagia in stroke. Design: Prospective, single-blind, randomized-controlled trial. Setting: Tertiary public hospital. Subjects: Sixty-two patients with dysphagia were randomly assigned to standard swallow therapy (SST) (Group I, controls, n=21), SST+ IEMT (Group II, n=21) or SST+ sham IEMT+ NMES (Group III, n=20). Interventions: All patients followed a 3-week standard multidisciplinary rehabilitation program of SST and speech therapy. The SST+IEMT group's muscle training consisted of 5 sets/10 repetitions, twice-daily, 5 days/week. Group III's sham IEMT required no effort; NMES consisted of 40-minute sessions, 5 days/week, at 80Hz. Main outcomes: Dysphagia severity, assessed by Penetration-Aspiration Scale, and respiratory muscle strength (maximal inspiratory and expiratory pressures) at the end of intervention and 3-month follow-up. Results: Maximal respiratory pressures were most improved in Group II: treatment effect was 12.9 (95% confidence interval 4.5-21.2) and 19.3 (95% confidence interval 8.5-30.3) for maximal inspiratory and expiratory pressures, respectively. Swallowing security signs were improved in Groups II and III at the end of intervention. No differences in Penetration-Aspiration Scale or respiratory complications were detected between the 3 groups at 3-month follow-up. Conclusion: Adding IEMT to SST was an effective, feasible, and safe approach that improved respiratory muscle strength. Both IEMT and NMES were associated with improvement in pharyngeal swallowing security signs at the end of the intervention, but the effect did not persist at 3-month follow-up and no differences in respiratory complications were detected between treatment groups and controls.
Article
Objective: To determine the effect of expiratory muscle strength training on both cough and swallow function in stroke patients. Design: Prospective pre-post intervention trial with one participant group. Setting: Two outpatient rehabilitation clinics PARTICIPANTS: Fourteen adults with a history of ischemic stroke in the preceding 3 - 24 months participated in this study. Intervention: Expiratory muscle strength training (EMST). The training program was completed at home and consisted of 25 repetitions per day, 5 days per week, for 5 weeks. Main outcome measures: Baseline and post-training measures were: maximum expiratory pressure, voluntary cough airflows, reflex cough challenge to 200μM capsaicin, sensory perception of urge-to-cough, and fluoroscopic swallow evaluation. Repeated measures and one-way analyses of variance were used to determine significant differences pre/post training. Results: Maximum expiratory pressure increased in all participants by an average of 30cmH2O post training. At baseline, all participants demonstrated a blunted reflex cough response to 200 μM capsaicin. Following 5 weeks of training, measures of urge to cough and cough effectiveness increased for reflex cough, however voluntary cough effectiveness did not increase. Swallow function was minimally impaired at baseline, and there were no significant changes in the measures of swallow function post training. Conclusions: Expiratory muscle strength training improves both expiratory muscle strength, reflex cough strength and urge-to-cough. Voluntary cough and swallow measures were not significantly different post training. It may be that stroke patients benefit from the training for up-regulation of reflex cough and thus improved airway protection.
Article
Expiratory muscle strength training (EMST) involves forcible blowing as a means of generating high expiratory pressure, against adjustable resistance. EMST has recently been introduced as a potential treatment for dysphagia. This study was performed to investigate the effects of EMST on the activity of suprahyoid muscles, aspiration and dietary stages in stroke patients with dysphagia. Twenty-seven stroke patients with dysphagia were randomly divided into two groups. The experimental group performed EMST with a 70% threshold value of maximal expiratory pressure, using an EMST device, 5 days a week for 4 weeks. The placebo group trained with a sham device. The EMST regime involved 5 sets of 5 breaths through the EMST device for a total of 25 breaths per day. Activity in the suprahyoid muscle group was measured using surface electromyography (sEMG). Further, the penetration-aspiration scale (PAS) was used to assess the results of the videofluoroscopic swallowing study (VFSS). In addition, dietary stages were evaluated using the Functional Oral Intake Scale (FOIS). The experimental group exhibited improved suprahyoid muscle group activity and PAS results, when compared to the placebo group. Following intervention, statistical analysis indicated significant differences in measured suprahyoid muscle activity (P = 0·01), liquid PAS outcomes (P = 0·03) and FOIS results (P = 0·06), but not semisolid type PAS outcomes (P = 0·32), between the groups. This study confirms EMST as an effective treatment for the development of suprahyoid muscle activity in stroke patients with dysphagia. Additionally, improvements in aspiration and penetration outcomes were observed.
Article
o assess the effectiveness, feasibility, and safety of short-term inspiratory and expiratory muscle training (IEMT) in subacute stroke patients. METHODS: Within 2 weeks of stroke onset, 109 patients with a first ischemic stroke event were randomly assigned to the IEMT (n = 56) or sham IEMT (n = 53) study group. The IEMT consisted of 5 sets of 10 repetitions, twice a day, 5 days per week for 3 weeks, at a training workload equivalent to 30% of maximal respiratory pressures. Patients and researchers assessing outcome variables were blinded to the assigned study group. The main outcome was respiratory muscle strength assessed by maximal inspiratory and expiratory pressures (PImax, PEmax). Respiratory complications at 6 months were also recorded. RESULTS: Both groups improved respiratory muscle strength during the study. IEMT was associated with significantly improved %PImax and %PEmax: effect size d = 0.74 (95% confidence interval [CI] 0.28-1.20) and d = 0.56 (95% CI 0.11-1.02), respectively. No significant training effect was observed for peripheral muscle strength. Respiratory complications at 6 months occurred more frequently in the sham group (8 vs 2, p = 0.042), with an absolute risk reduction of 14%. The number needed to treat to prevent one lung infection event over a follow-up of 6 months was 7. No major adverse events or side effects were observed. CONCLUSION: IEMT induces significant improvement in inspiratory and expiratory muscle strength and could potentially offer an additional therapeutic tool aimed to reduce respiratory complications at 6 months in stroke patients. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that short-term training may have the potential to improve respiratory muscle strength in patients with subacute stroke.
Article
Background and Purpose—Cough protects the lungs from aspiration. We investigated whether respiratory muscle training may improve respiratory muscle and cough function, and potentially reduce pneumonia risk in acute stroke. Methods—We conducted a single-blind randomized placebo-controlled trial in 82 patients with stroke (mean age, 64±14 years; 49 men) within 2 weeks of stroke onset. Participants were masked to treatment allocation and randomized to 4 weeks of daily expiratory (n=27), inspiratory (n=26), or sham training (n=25), using threshold resistance devices. Primary outcome was the change in peak expiratory cough flow of maximal voluntary cough. Intention-to-treat analyses were conducted using ANCOVA, adjusting for baseline prognostic covariates. Results—There were significant improvements in the mean maximal inspiratory (14 cmH2O; P<0.0001) and expiratory (15 cmH2O; P<0.0001) mouth pressure and peak expiratory cough flow of voluntary cough (74 L/min; P=0.0002) between baseline and 28 days in all groups. Peak expiratory cough flow of capsaicin-induced reflex cough was unchanged. There were no between-group differences that could be attributed to respiratory muscle training. There were also no differences in the 90-day incidence of pneumonia between the groups (P=0.65). Conclusions—Respiratory muscle function and cough flow improve with time after acute stroke. Additional inspiratory or expiratory respiratory muscle training does not augment or expedite this improvement. Clinical Trial Registration—URL: http://www.controlled-trials.com. Unique identifier: ISRCTN40298220.
Article
We undertook two systematic reviews to determine the levels of respiratory muscle weakness and effects of respiratory muscle training in stroke patients. Two systematic reviews were conducted in June 2011 using a number of electronic databases. Review 1 compared respiratory muscle strength in stroke and healthy controls. Review 2 was expanded to include randomized controlled trials assessing the effects of respiratory muscle training on stroke and other neurological conditions. The primary outcomes of interest were maximum inspiratory and expiratory mouth pressure (maximum inspiratory pressure and maximum expiratory pressure, respectively). Meta-analysis of four studies revealed that the maximum inspiratory pressure and maximum expiratory pressure were significantly lower (P < 0·00001) in stroke patients compared with healthy individuals (weighted mean difference -41·39 and -54·62 cmH(2) O, respectively). Nine randomized controlled trials indicate a significantly (P = 0·0009) greater effect of respiratory muscle training on maximum inspiratory pressure in neurological patients compared with control subjects (weighted mean difference 6·94 cmH(2) O) while no effect on maximum expiratory pressure. Respiratory muscle strength appears to be impaired after stroke, possibly contributing to increased incidence of chest infection. Respiratory muscle training can improve inspiratory but not expiratory muscle strength in neurological conditions, although the paucity of studies in the area and considerable variability between them is a limiting factor. Respiratory muscle training may improve respiratory muscle function in neurological conditions, but its clinical benefit remains unknown.