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Influence of lip force on swallowing capacity in stroke patients and in healthy subjects

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In spite of no clinical signs of facial paresis, a pathological lip force (LF) will strongly influence swallowing capacity (SC). Stroke patients with impaired SC suffer a subclinical facial paresis. The results support earlier findings that LF training can be used to treat dysphagia. Lip muscle training with an oral screen can improve both LF and SC in stroke patients, irrespective of the presence or absence of facial palsy. The aim was therefore to study the influence of LF on SC. This prospective study included 22 stroke patients, aged 38–90 years, with dysphagia, 12 with initial unilateral facial paresis and 45 healthy subjects, aged 25–87 years. All were investigated with a Lip Force Meter (LF100), and with an SC test. A significant correlation was found between LF/SC (p = 0.012) in stroke patients but not in healthy subjects. LF/SC was not age-related in stroke patients. LF was not age-dependent in healthy subjects, but SC decreased with increasing age (p < 0.0001). However, SC did not reach a pathological value and a regression analysis showed that 73% of the variation in SC is attributable to LF and age.
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Acta Oto-Laryngologica, 2010; Early Online, 15
REVIEW ARTICLE
Inuence of lip force on swallowing capacity in stroke patients
and in healthy subjects
MARY HÄGG
1,2
& MATTI ANNIKO
3
1
Speech & Swallowing Centre, Department of Otorhinolaryngology, Hudiksvall Hospital,
2
Research & Development
Centre, Uppsala University/Gävleborg County Council and
3
Department of Otorhinolaryngology, Head & Neck Surgery,
University Hospital, Uppsala, Sweden
Abstract
Conclusion: In spite of no clinical signs of facial paresis, a pathological lip force (LF) will strongly inuence swallowing capacity
(SC). Stroke patients with impaired SC suffer a subclinical facial paresis. The results support earlier ndings that LF training
can be used to treat dysphagia. Objectives: Lip muscle training with an oral screen can improve both LF and SC in stroke
patients, irrespective of the presence or absence of facial palsy. The aim was therefore to study the inuence of LF on SC.
Methods: This prospective study included 22 stroke patients, aged 3890 years, with dysphagia, 12 with initial unilateral facial
paresis and 45 healthy subjects, aged 2587 years. All were investigated with a Lip Force Meter (LF100), and with an SC test.
Results: A signicant correlation was found between LF/SC (p=0.012) in stroke patients but not in healthy subjects. LF/SC was
not age-related in stroke patients. LF was not age-dependent in healthy subjects, but SC decreased with increasing age
(p<0.0001). However, SC did not reach a pathological value and a regression analysis showed that 73% of the variation in SC
is attributable to LF and age.
Keywords: Dysphagia, facial palsy, healthy subjects, lip force, swallowing capacity, stroke
Introduction
More than half of stroke patients present a unilateral
central facial palsy at admission [1,2]. Oropharyngeal
dysphagia is also a common feature in the initial phase
[35]. Impaired lip muscle closure [68] is well known
to debilitate swallowing by leaking through the corner
of the mouth. Even when visual detectable signs of
facial palsy are lacking in stroke patients, both
impaired lip force (LF) [9] and dysphagia have been
observed [10]. Furthermore it has been shown that lip
muscle training with an oral screen can improve LF
and swallowing capacity (SC) in stroke patients [10].
In light of the involvement of the facial nerve in lip
closure, LF, and even in swallowing (the buccinator
muscles, the stylohyoid muscles, and the rear portion
of the digastric muscles) it was of interest to study if a
weak LF could have impact on SC. To this end stroke
patients with dysphagia and healthy subjects were
included in the study.
Material and methods
Study population
Twenty-two stroke patients with oropharyngeal dys-
phagia, 13 women, 9 men (median age 78 years, range
3890 years; Table I) were recruited from a stroke
unit. According to an earlier study on reliability of LF
measurement [9], the stroke patients were separated
into two groups: 12 with initial unilateral central facial
paresis, 6 on the left side and 6 on the right, and 10
without initial facial paresis. At the time of investiga-
tion, 13 weeks after the acute attack, no patient had
any residual clinical signs of facial palsy. Inclusion
Correspondence: Mary Hägg PhD DDS, Speech & Swallowing Centre, ENT Department, Hudiksvall Hospital, SE 824 81 Hudiksvall, Sweden.
Tel: +46 (0)650 92754. Fax: +46 (0)650 92412. E-mail: mary.hagg@lg.se
(Received 9 January 2010; accepted 22 February 2010)
ISSN 0001-6489 print/ISSN 1651-2251 online 2010 Informa UK Ltd. (Informa Healthcare, Taylor & Francis AS)
DOI: 10.3109/00016481003745550
criteria were that they were able to cooperate, could
be fed orally, and had no other diseases/injuries that
might affect their ability to swallow. Forty-ve healthy
subjects without dysphagia, 30 women, 15 men
(median age 57 years, range 2587 years; Table I)
were recruited from a hospital staff (n=30) and from a
clinic with orthopedic patients (n=15). None had any
swallowing or eating problems, or any neurological
disease.
All participants in this study received verbal
and written information and gave verbal consent to
participate. The study was approved by the Ethics
Committee for Human Research at the Medical
Faculty of Uppsala University (Dnr 2004: M-435).
Lip Force Meter LF100 (LF100)
LF, measured in newtons (N) was recorded with an
LF100 (MHC1 AB Detector, Gothenburg, Sweden)
[9]. LF100 is a modied strain gauge for recording
the ability of lips to withstand pressure from a
CPS
CPM
CPI
CR
CR
A. B.
Figure 1. (a) The buccinator mechanism (marked with a line) involves m. orbicularis oris, m. buccinator, m. constrictor pharyngeus superior
(CPS). CPM, m. constrictor pharyngeus middle; CPI, m. constrictor pharyngeus inferior; CR, m. cricopharyngeus =upper esophageal
sphincter. (b) The buccinator mechanism during activity. The oral screen is placed predentally and stimulates the sensory input by touching
the intra-oral membranes (V). When pulling the oral screen and pressing the lips (VII) the entire buccinator mechanism will be activated
(VII, IX, X), tonus and contraction of the bottom of the mouth increase (V, XII) and act as a valve mechanism, thereby enhancing the intra-oral
negative pressure. That in turn activates tongue retraction (XII), which in turn stimulates the sensory part of the anterior faucial arcs (IX), the
soft palate (V, VII, X), and the intra-oral mucous membranes (V). Finally the stylohyoid and the digastric posterior muscles (VII) are activated.
This complex sensorimotor activity supports earlier ndings that physical lip muscle training can be used to improve both the lip force (LF) and
the swallowing capacity (SC) [10].
Table I. Lip force (LF) and swallowing capacity (SC) in stroke patients with and without initial facial palsy and in healthy subjects.
Characteristics
Stroke patients
(n=22)
Stroke with initial facial
palsy (n=12)
Stroke without facial
palsy (n=10)
Healthy subjects
(n=45)
Age (years),
median (range)
78 (3890) 77 (4990) 81 (5985) 57 (2587)
Female/male 13/9 7/5 6/4 30/15
LF (N),
mean ±SD (range)
9.5 ±5.5 (025) 8.3 ±4.0 (214) 11.0 ±6.9 (025) 24.4 ±6.2 (1340)
SC (ml/s),
mean ±SD (range)
2.7 ±2.2 (06.4) 2.7 ±2.0 (05.0) 2.7 ±2.5 (06.4) 22.5 ±8.4 (5.037.5)
N, Newton.
2M. Hägg & M. Anniko
predentally placed preformed acrylic oral screen [9]
(Figure 1). The detector is connected to an electronic
unit for measuring maximum LF. The subject was
instructed to hold the screen for as long as possible
while trying to resist the force maximally by tightening
the lips and pressing the head backwards. Traction
was applied at right angles to the patients mouth, with
increasing force for 10 s, or until the subject lost grip
of the oral screen. The maximum LF values were
recorded by an independent person, and data were
blinded to the investigator. The lower limit for normal
LF is 15 N [9].
Swallowing capacity test (SCT)
The participants were asked to swallow 150 ml of
water as quickly as possible without pauses. They
were instructed to sit upright with the glass close to
the lower lip, to start drinking when the gosignal was
given, and to stop drinking in case of difculty. The
time was measured from the start of drinking until the
last swallow was completed. Any water remaining in
the glass was measured. An SC index of 10 ml/s is
regarded as the lower normal limit [11].
Both the LF100 test [9] and the SCT [11,12] have
been demonstrated to have high intra- and inter-rater,
and test-retest reliability, and to be valid for assessing
LF and SC [10].
Study design
This was a prospective and comparative study
describing the inuence of LF on SC in stroke
patients and in healthy subjects.
Statistics
Professional statisticians and a data manager from
Uppsala Clinical Research Centre (UCR) were
involved from the outset in planning the study design.
The Good Clinical Practice (GCP) database consol-
idated all study data and all analyses, which were
performed according to the initial protocol. Students
ttest was used to assess the difference in LF and SC
between stroke patients and healthy subjects. Multiple
linear regression analysis and Pearsons correlation
coefcient were used to assess the relationship
between LF and SC and a possible age-dependent
factor on these parameters. A plevel <0.05 was
deemed signicant. All statistical analyses were per-
formed using SAS version 9.1 software (SAS Institute
Inc., Carey, NC, USA).
Results
In stroke patients there was a signicant correlation
between LF and SC (p=0.012; Table II). No
signicant correlation between LF and SC was found
in healthy subjects (Table II). LF and SC did not
differ signicantly between 12 patients with initial
facial palsy and 10 stroke patients without facial palsy
(Table I). LF and SC values were signicantly lower
in the stroke group than in the healthy subjects
(Table I, Figure 2).
A regression analysis in stroke patients showed that
LF and SC were not age-related (Table II). Further-
more, LF was not age-dependent in healthy subjects,
but SC decreased signicantly with increasing age
(p<0.0001; Table II, Figure 3). However, the mean
SC did not reach a pathological value and a regression
analysis in the healthy subjects showed that 73% of the
variation in SC was attributable to LF and age.
LF values in the stroke group were on average
9.5 ±5.5 N, range 025 N, and in the healthy
subjects they were 24.4 ±6.2 N, range 1340 N
(Table I, Figure 2). The mean SC in stroke patients
was 2.7 ±2.2 ml/s, range 06.4 and in healthy subjects it
was 22.5 ±8.4 ml/s, range 5.037.5 (Table I, Figure 2).
Discussion
LF was found to signicantly inuence SC in stroke
patients with oropharyngeal dysphagia but did not
differ between stroke patients with or without initial
clinical facial palsy. LF did not signicantly inuence
SC in the healthy subjects. However, it was shown
that 73% of the variation in SC was attributable to LF
and age in the healthy group. Furthermore, the SC
was signicantly reduced within normal ranges in
healthy subjects by increasing age. Since the stroke
patients were much older and had a narrower age
distribution than the normal subjects, no age corre-
lation could be found. SC in the stroke group was
pathological low or almost zero. And as Fucile et al.
[13] have shown, a stroke disease in itself is much
more important for impaired SC than age.
The main question is: why do stroke patients with-
out clinical facial palsy have such a weak LF? Yildiz
et al. [2] claimed that facial paresis in stroke patients
generally is incomplete and mild because of ipsilateral
cortical and multiple innervation outside the infarc-
tion area, the reason why the facial nerve recovers
quickly through cortical reorganization. Apparently,
there is a subclinical facial paresis in stroke patients
that gives a weak LF without ordinarily signs of
unilateral facial paresis [7,10]. This subclinical paresis
seems therefore to be part of an impaired swallowing
Inuence of lip force on swallowing 3
mechanism. Meyer et al. [14] showed that EMG
responses recorded from lower facial muscles on
the right/left side (depressor labii inferioris or depres-
sor anguli oris) usually were bilateral and had the
same latency (1112 ms) on both sides of the face.
The present study did not investigate whether this
subclinical central facial paresis was bilateral or
unilateral.
What about the present nding in healthy subjects
that SC decreased signicantly with increasing age
without affecting LF? Indeed, sensory signals via the
trigeminal, glossopharyngeal, and vagal nerves are
involved in proper swallowing. Perhaps this sensory
function deteriorates in the same way as can be found
regarding vision, hearing, taste, and balance.
The next question then is what are the common
denominators between LF and dysphagia in stroke
patients? The lower branch of the facial nerve supplies
perioral facial muscles, the buccinator muscles, and
platysma (involved in lip closure and in creating a
negative intraoral pressure), the digastric posterior
and stylohyoid muscles (involved in preparing the
swallowing act), and partly the levator veli palatine
(involved in closure of the nasopharyngeal area). The
lip muscles and the buccinator muscles are further-
more part of the buccinator mechanism. This bucci-
nator mechanism [1518] (Figure 1) also includes the
superior muscles of the pharyngeal constrictor, which
means that when LF is measured with an LF test a
chain of neuromuscular activity will start in the mouth
and pharynx (Figure 1), an activity that is the same as
that initiating a swallow. The LF test is therefore not
only a test of the facial nerves ability to activate
lip muscles, but also a test to investigate if the neu-
romuscular chain in oropharyngeal swallowing is
functioning properly.
The fact that LF testing and SC are dependent on
the same complex sensorimotor system, whereas the
facial nerve is the only cranial nerve responsible for a
clinical facial paresis may be the reason why there are
no signicant differences in LF and SC between
patients with and without initial central facial palsy.
The dependence on the same complex neuromuscu-
lar activity when testing LF and when swallowing
may explain the functional correlation between LF
and SC.
Conclusion
Pathological LF will strongly inuence SC in stroke
patients with oropharyngeal dysphagia, despite the
absence of clinical signs of facial paresis. Stroke
Table II. Pearsons correlation coefcient (r) between lip force
(LF) and swallowing capacity (SC), LF and age, and SC and
age in stroke patients and in healthy subjects.
Correlation
between
Stroke patients,
n=22
Healthy subjects,
n=45
LF and SC r=0.53 p=0.012 r=0.16 p=0.290
LF and age r=0.18 p=0.430 r=0.06 p=0.708
SC and age r=0.00 p=0.983 r=0.67 p<0.001
40
30
20
SC (ml/s)
10
0
01020
LF (N)
30 40
Figure 2. Swallowing capacity (SC) vs lip force (LF) in stroke
patients, O (n=22, D=2 stroke patients) and in healthy
subjects, X (n=45, &=2 healthy subjects).
40
35
30
25
20
SC (ml/s)
15
10
5
0
20 30 40 50 60 70
A
g
e (yrs)
80 90 100
Figure 3. Swallowing capacity (SC) vs age in healthy subjects,
X(n=45, &=2 healthy subjects).
4M. Hägg & M. Anniko
patients with impaired SC suffer a subclinical facial
paresis. In healthy subjects the SC is diminished by
age, probably due to a certain loss of the sensory
function involved in normal swallowing. The results
support earlier ndings that physical lip muscle
training can be used to treat dysphagia.
Acknowledgments
This work was supported by grants from the Centre
for Research & Development, Uppsala University;
Gävleborg County Council, Sweden; and the Capios
Research Foundation, Sweden. Many thanks to Lita
Tibbling Grahn MD PhD, for invaluable help with
the manuscript and interpretation of data. Biostatis-
tician Lisa Wernroth, and clinical data manager Patrik
Holmqvist, Uppsala Clinical Research Center (UCR),
were involved from the outset in planning the study
design and were responsible for statistical evaluation.
Figure 1 was created by Mary Hägg.
Declaration of interest: The authors report no
conicts of interest. The authors alone are responsible
for the content and writing of the paper.
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Inuence of lip force on swallowing 5
... The normal mechanism of swallowing begins with the closure of the mouth/lips. In the first phase of preparing to swallow, the oral phase, a majority of abnormalities are caused by a reduction of lip closure force that proceeds with muscular dysfunction of the orofacial complex lip muscles [4]. The oral phase involves a chewing process in which food is crushed and ground using the teeth. ...
... It is well known that an inability to close the lip muscles results in food being expelled from the corners of the mouth, which impairs swallowing [4,11]. Both impaired lip strength and dysphagia have been observed even when stroke patients lack visual detectable signs of facial paralysis [11]. ...
... Both impaired lip strength and dysphagia have been observed even when stroke patients lack visual detectable signs of facial paralysis [11]. A study [4] reported that patients with stroke (9.5 N), patients with stroke and initial facial palsy (8.3 N), and patients with stroke without facial palsy (11.0 N) had weak lip strength, which was approximately 30-40% of that of healthy participants (24.2 N). These results suggest that a reason for the observed difference of lip strength and function between healthy individuals and stroke patients without facial palsy is because there is a subclinical facial paresis in stroke patients which results in weak lip function without ordinary signs of unilateral facial paresis [26]. ...
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Lip muscle strength has been shown to influence daily functional activities such as facial expression, speech production, and eating. In this review, recent literature regarding lip strength and exercise training responses are summarized, highlighting the influence of sex, age, and disease (e.g., stroke). A search using five electronic databases was conducted. Twelve studies were identified from the search, which included five studies using healthy adults and seven studies using patients with diseases or chronic ailments. Regardless of the population, lip strength training multiple times a day for a relatively short term (<24 weeks) has resulted in improvements of lip muscle strength. This change in lip strength has been observed in both young and old participants. Although changes in strength have been observed in both men and women, we are unaware of any studies that have tested whether there are sex differences in this response. The same directional change can be expected for patients with stroke and patients with lip incompetence, but the magnitude of the training effect seems to be higher in healthy people.
... Through screening of bibliographies of the included articles, three additional articles seemed relevant at a first glance. Following full-text reading, one of these articles was added, totaling 16 articles in the final review (8)(9)(10)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). The included articles were published in scientific journals from year 1992-2019 (Table 1). ...
... Volk (2018, 29) also applied patient-reported questionnaires, the Facial Disability Index (33) and the Facial Clinimetric Evaluation scale (34). Park (2018, 28), Choi (2016, 25), Schimmel (2013, 23), and Hägg (2008Hägg ( , 2010, applied strain gauges such as the Iowa Oral Performance Instrument (35) for assessing lip-, cheek-, and bite strength. Yildiz (2005, 8), Urban (2001, 30), and Ishikawa (2000, 18) assessed central facial palsy on a neurophysiological level by investigating motor neuron pathways; Ishikawa (2000, 18) assessed this by measuring motor neuron excitability in the mentalis muscles with F-waves, and Yildiz (2005, 8) and Urban (2001, 30) through corticofacial motor evoked potentials applied with transcranial magnetic stimulation ( Table 1). ...
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... Lip force and swallowing function are shown to depend on the same complex neuromuscular activity [7]. The same activity that initiates a swallow is activated when lip-force is measured [8]. This suggested that patients with dysphagia could use an oral device to self-train their weak oral and pharyngeal muscles; that is, for neuromuscular training. ...
... A significant between-group difference was observed only at the 12-month follow-up. These findings, combined with the improvements in swallowing rate, seem to support the finding of previous studies [8,13] in which oral neuromuscular training improved both swallowing rate and lip force. ...
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Background Oral and pharyngeal swallowing dysfunction are common complications in acute stroke patients. This primary aim of this study was to determine whether oral neuromuscular training improves swallowing function in participants with swallowing dysfunction after stroke. A secondary aim was to assess how well results of the timed water-swallow test (TWST) correspond with swallowing dysfunction diagnosed by videofluoroscopy (VFS). Methods This was an intention-to-treat two-centre prospective randomized open-label study with blinded-evaluators (PROBE) design. At 4 weeks after stroke onset, participants with swallowing dysfunction were randomized to 5 weeks of continued orofacial sensory-vibration stimulation with an electric toothbrush or additional oral neuromuscular training with an oral device (Muppy®). Participants were examined with TWST, a lip-force test, and VFS before (baseline), after 5 weeks’ treatment (the end-of-treatment), and 12 months after treatment (follow-up). The baseline VFS results were compared with the TWST results. The primary endpoint was changes in swallowing rate assessed using TWST, from baseline to the end of training and from baseline to follow-up based on intention-to-treat analyses. The secondary endpoint was the corresponding changes in lip-force between baseline, the end of treatment, and follow-up. Results The participants were randomly assigned as controls (n = 20) or for intervention with oral neuromuscular training (n = 20). After treatment, both groups had improved significantly (intervention, P < 0.001; controls, P = 0.001) in TWST but there was no significant between-group difference in swallowing rate. At the 12-month follow-up, the intervention group had improved further whereas the controls had deteriorated, and there were significant between-group differences in swallowing rate (P = 0.032) and lip force (P = 0.001). A TWST < 10 mL/sec at baseline corresponded to VFS-verified swallowing dysfunction in all assessed participants. Conclusion The 5-week oral neuromuscular training improved swallowing function in participants with post-stroke dysphagia compared with the controls 12 months after intervention, but there was no between-group difference in improvement immediately after treatment. TWST results corresponded with VFS results, making TWST a feasible method for identifying persons with swallowing dysfunction after stroke. Larger randomized controlled trials are required to confirm our preliminary positive long-term results. Trial registration Retrospectively registered at ClinicalTrials.gov: NCT04164420. Registered on 15 November 2019.
... Lip force and swallowing function are shown to depend on the same complex neuromuscular activity [7]. The same activity that initiates a swallow is activated when lip-force is measured [8]. This suggested that patients with dysphagia could use an oral device to selftrain their weak oral and pharyngeal muscles; that is, for neuromuscular training. ...
... A signi cant between-group difference was observed only at the 12-month follow-up. These ndings, combined with the improvements in swallowing rate, seem to support the nding of previous studies [8,13] in which oral neuromuscular training improved both swallowing rate and lip force. ...
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Background: Oral and pharyngeal swallowing dysfunction are common complications in acute stroke patients. This primary aim of this study was to determine whether oral neuromuscular training improves swallowing function in participants with swallowing dysfunction after stroke. A secondary aim was to assess how well results of the timed water-swallow test (TWST) correspond with swallowing dysfunction diagnosed by videofluoroscopy (VFS). Methods: This was an intention-to-treat two-centre prospective randomized open-label study with blinded-evaluators (PROBE) design. At 4 weeks after stroke onset, participants with swallowing dysfunction were randomized to 5 weeks of continued orofacial sensory-vibration stimulation with an electric toothbrush or additional oral neuromuscular training with an oral device (Muppy®). Participants were examined with TWST, a lip-force test, and VFS before (baseline), after 5 weeks’ treatment (the end-of-treatment), and 12 months after treatment (follow-up). The baseline VFS results were compared with the TWST results. The primary endpoint was changes in swallowing rate assessed using TWST, from baseline to the end of training and from baseline to follow-up based on intention-to-treat analyses. The secondary endpoint was the corresponding changes in lip-force between baseline, the end of treatment, and follow-up. Results: The participants were randomly assigned as controls (n = 20) or for intervention with oral neuromuscular training (n = 20). After treatment, both groups had improved significantly (intervention, P < 0.001; controls, P = 0.001) in TWST but there was no significant between-group difference in swallowing rate. At the 12-month follow-up, the intervention group had improved further whereas the controls had deteriorated, and there were significant between-group differences in swallowing rate (P = 0.032) and lip force (P = 0.001). A TWST <10 mL/sec at baseline corresponded to VFS-verified swallowing dysfunction in all assessed participants. Conclusion: The 5-week oral neuromuscular training improved swallowing function in participants with post-stroke dysphagia compared with the controls 12 months after intervention, but there was no between-group difference in improvement immediately after treatment. TWST results corresponded with VFS results, making TWST a feasible method for identifying persons with swallowing dysfunction after stroke. Larger randomized controlled trials are required to confirm our preliminary positive long-term results. Trial registration: Retrospectively registered at ClinicalTrials.gov: NCT04164420. Registered on 15 November 2019.
... Many older people adapt slowly to dysphagia by eating slower and changing food consistency; thus, many hold the opinion that developing dysphagia is a natural consequence of aging [7]. In recent years, more attention has been directed toward swallowing rehabilitation, and different treatment designs have been developed to improve swallowing function [8,9]. One promising method of swallowing rehabilitation is training with an oral screen, which has been shown to improve dysphagia significantly [10]. ...
... The SCT [18] is a simple, easy-to use screening test for determining the risk of dysphagia in a non-hospital context. The SCT is a feasible tool for evaluating training paradigms for treating dysphagia [8]. The SCT requires an evaluation of age as a covariate, when performing data analysis. ...
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Background: Extensive studies have shown that older people are negatively impacted by impaired eating and nutrition. The abilities to eat, enjoy food, and participate in social activities associated with meals are important aspects of health-related quality of life (HRQoL) and recovery after illness. This project aims to (i) describe and analyze relationships between oral health and oral HRQoL, swallowing ability, eating ability, and nutritional risk among older individuals admitted to short-term care; (ii) compare the perceptions that older individuals and staff report on care quality related to oral hygiene and eating; and (iii) study the feasibility and effects of a training program for people with impaired swallowing (i.e., dysphagia). Methods/Design: This project consists of two parts, which will be performed in five Swedish counties. It will include approximately 400 older individuals and 200 healthcare professionals. Part 1 is a cross-sectional, descriptive study of older people admitted to short-term care. Subjects will be assessed by trained professionals regarding oral health status, oral HRQoL, eating and nutritional risk, and swallowing ability. Swallowing ability will be measured with a teaspoon test and a swallowing capacity test (SCT). Furthermore, subjects and staff will complete a questionnaire regarding their perceptions of care quality. Part 2 is a cluster randomized intervention trial with controls. Older participants with dysphagia (i.e., SCT <10 ml/s, measured in part 1) will be recruited consecutively to either the intervention or control group, depending on where they were admitted for short-term care. At baseline, all subjects will be assessed for oral health status, oral HRQoL, eating and nutritional risk, swallowing ability, and swallowing-related QoL. Then, the intervention group will receive 5 weeks of training with an oral screen for neuromuscular training focused on orofacial and pharyngeal muscles. After completing the intervention, and at six months post-intervention, all assessments will be repeated in both study groups.
... Usually, the exercise is recommended to be executed during a few minutes one to three times daily (Hägglund et al., 2019;Sjögreen et al., 2010). Subsequent research has suggested that oral screen exercises not only improve the strength of the lip musculature (Sjögreen et al., 2010) but also improve oropharyngeal swallowing (Hägg & Anniko, 2010;Hägg & Tibbling, 2015;Hägglund et al., 2019), affect the position of the incisors (Owman-Moll & Ingervall, 1984;Thüer & Ingervall, 1990) and soft palate closure (Hägg & Tibbling, 2016;Hägg et al., 2015a), reduce gastroesophageal reflux (Hägg et al., 2015b), and improve postural control (Hägg & Tibbling, 2016). Sjögreen et al. noted that the maximal lip force and lip force endurance improved in school aged children with myotonic dystrophia type 1 after oral screen training (Sjögreen et al., 2010). ...
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Objective: The oral screen is a device commonly used for treatment of orofacial disorders. The objective of this exploratory study was to examine the effect of oral screen exercise on the muscle activity in the lips, submental complex, masseter muscle, and kinematic activity of the tongue base, soft palate, pharynx, and larynx in healthy adults. This was compared with the kinematic activity during a dry swallow. It was hypothesized that not only the lip musculature but also other structures in the oral and pharyngeal cavities are activated while using an oral screen device. Method: Ten healthy subjects used an oral screen during examination with videofluoroscopy and surface electromyography (EMG). Three different instructions for oral screen application and a dry swallow were examined. Results: The lip muscles showed the highest activity during oral screen exercise. The other muscle groups were activated to a lesser degree. The pattern of activation differed between individuals. Compared with a dry swallow, the range of motion of the tongue base, posterior pharyngeal wall, and the larynx was significantly smaller during oral screen activation. No major differences were found between three different instructions. Conclusion: This study indicates that the lips and submental complex and, to a lesser degree, oral, pharyngeal, and laryngeal structures are activated with the oral screen, but the pattern of activation varied between individuals. In comparison to the activity during a dry swallow, range of motion during oral screen exercise is small.
... A significant between-group difference was observed only at the 12-month follow-up. These findings, combined with the improvements in swallowing rate, seem to support the finding of previous studies [11,22] in which oral neuromuscular training improved both swallowing rate and lip force. ...
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Background: Oral and pharyngeal swallowing dysfunction are common complications in acute stroke patients. This primary aim of this study was to determine whether oral neuromuscular training improves swallowing function in participants with swallowing dysfunction after stroke. A secondary aim was to assess how well results of the timed water-swallow test (TWST) correspond with swallowing dysfunction diagnosed by videofluoroscopy (VFS). Methods: This was an intention-to-treat two-centre prospective randomized open-label study with blinded-evaluators (PROBE) design. At 4 weeks after stroke onset, participants with swallowing dysfunction were randomized to 5 weeks of continued orofacial sensory-vibration stimulation with an electric toothbrush or additional oral neuromuscular training with an oral device (Muppy®). Participants were examined with TWST, a lip-force test, and VFS before (baseline), after 5 weeks’ training (the end-of-treatment), and 12 months after treatment (follow-up). The primary endpoint was changes in swallowing rate assessed using TWST, from baseline to the end of training and from baseline to follow-up based on intention-to-treat analyses. The secondary endpoint was the corresponding changes in lip-force between baseline, the end-of-treatment, and follow-up. Results: The participants were randomly assigned as controls ( n = 20) or for intervention with oral neuromuscular training ( n = 20). After treatment, both groups had improved significantly (intervention, P < 0.001; controls, P = 0.001) in TWST but there was no significant between-group difference in swallowing rate. At the 12-month follow-up, the intervention group had improved further whereas the controls had deteriorated, and there were significant between-group differences in swallowing rate ( P = 0.032) and lip force ( P = 0.001). A TWST <10 mL/sec at baseline corresponded to VFS-verified swallowing dysfunction in all assessed participants. Conclusion: The 5-week oral neuromuscular training improved swallowing function in participants with post-stroke dysphagia compared with the controls 12 months after intervention, but there was no between-group difference in improvement immediately after treatment. TWST results corresponded with VFS results, making TWST a feasible method for identifying persons with swallowing dysfunction after stroke. Larger randomized controlled trials are required to confirm our preliminary positive long-term results. Trial registration: Retrospectively registered at ClinicalTrials.gov: NCT04164420. Registered on 15 November 2019.
... [20][21][22] Studies concerned on this topic are mostly focused on the assessment of mastication quality and lip and bite force measurement which are indirectly related to TMJD assessment in patients with stroke. 23,24 To the best of our knowledge no study was found which assesses directly the relationship between TMJD and stroke. From this point of view aim of our study was to assess TMJD in patients with stroke. ...
Goal: The aim of this study was to assess temporomandibular joint dysfunction in patients with stroke. Materials and methods: Total of 100 participants, 50 healthy and 50 who had stroke, were recruited into this study. Digital caliper and algometer were used to assess temporomandibular joint range of motion and masticatory muscle pressure pain threshold. Labial commissure angle measurement was used for the assessment of facial paralysis severity. Fonseca questionnaire was used for temporomandibular joint dysfunction assessment and categorization. In addition, dominant mastication shift was measured by the question that asks the pre and poststroke dominant mastication side. Findings: In intergroup comparison, significant decrease was found in all temporomandibular range of motion parameters in favor of stroke group (P < .05). Despite the fact that no significant difference was found between groups for the pain threshold in masticatory muscles except for middle part of the left temporalis muscle, values were higher in healthy group (P > .05). As a result of intergroup examination of labial commissure angle degree, Fonseca questionnaire score, it was found that labial commissure angle and Fonseca questionnaire scores were higher in stroke group (P < .05). Intragroup examination of patients with stroke showed that dominant mastication side shift was seen in patients with stroke (P < .05). Conclusion: It was concluded that, temporomandibular joint dysfunction prevalence was higher in stroke group compared with healthy group and use of modalities specific to temporomandibular joint dysfunction treatment would be beneficial.
Chapter
There is a clear need for new advances in treating dysphagia; healthcare professionals currently have a restricted range of options to treat swallowing problems and related conditions. Usual treatments for dysphagia are based on compensatory measures which allow patients to live within the limitations of their condition. These measures do not address the underlying cause of dysphagia: neurological and physiological dysfunction. A senior speech and language therapist working with young people with Cerebral Palsy bemoans the fact that official care pathway guidelines list only medication and surgical intervention as alternatives to treat drooling. Neither of which, she contends, is effective or desirable. Esophageal dysphagia causes reflux-based diseases, which are also poorly served by current treatment alternatives and are currently managed by medication, or remedied by surgical intervention. Medication reduces the symptoms of reflux but does nothing to address the underlying pathophysiology, muscular dysfunction, at the root of the problem. That now changes with IQoro: a simple, innovative treatment that is available to patients and healthcare professionals to address all of the above conditions. The chapter explains the physiological and neurological process of the functional swallow in detail, with illustrations and explanations. The efficacy of IQoro treatment is proven with evidence from internationally published scientific studies, case studies, an NHS service evaluation, and NICE briefings.
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Objectives: Lip-seal strength, which represents the muscle strength of the lips, appears to chiefly contribute to mastication and pronunciation. However, the functional characteristics of lip-seal strength in adults are still undefined. The present study aimed to understand not only the distribution of lip-seal strength in adult men and women but also the effect of age on this strength and identify oral motor functions correlated with lip-seal strength. Materials and methods: The subjects included 339 participants (men: 170, age 39.2 ± 18.2 years; women: 169, age 43.1 ± 19.7 years). Oral motor function was evaluated for lip-seal strength, oral diadochokinesis (ODK), tongue pressure, occlusal force, and masticatory performance. Statistical analyses included the Shapiro-Wilk, Mann-Whitney U, and Jonckheere-Terpstra tests, in addition to the Spearman's correlation analysis and curvilinear regression analysis. Results: Lip-seal strength did not have a normal distribution (p < 0.001). The mean ± standard deviation and median (first quartile, third quartile) of lip-seal strength were 11.2 ± 3.4 and 10.9 (8.7, 13.2)N for the whole sample, 12.3 ± 3.4 and 11.9 (9.4, 14.4)N for men, and 10.2 ± 3.0 and 9.9 (8.0, 12.0)N for women. A significant difference was observed in lip-seal strength between men and women (p < 0.001). Oral motor functions showed a marked correlation with lip-seal strength, including tongue pressure, occlusal force, and masticatory performance and ODK (/pa/ and /ta/), tongue pressure, and masticatory ability in men and women, respectively. In women, lip-seal strength declined with increase in age. Conclusions: Lip-seal strength was non-normally distributed in both men and women, and lip-seal strength was affected by age only in women. Lip-seal strength and multiple oral motor functions were significantly correlated. Because the indicators of perioral muscle strength and performance were correlated with lip-seal strength, lip-seal strength may also partially reflect the condition of the perioral muscles.
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Training with an oral screen can improve lip force (LF) and swallowing capacity (SC) in stroke patients with oropharyngeal dysphagia, irrespective of the duration of pretreatment of dysphagia, and irrespective of the presence or absence of central facial paresis. It is more plausible that treatment results are attributable to sensory motor stimulation and the plasticity of the central nervous system than to the training of the lip muscles per se. A close relationship has been demonstrated between LF and SC in stroke patients whether or not they are affected by facial paresis. It is not known how training of lip function can improve swallowing capacity. The present study was therefore designed to ascertain: (i) if training with an oral screen can improve the LF and SC of stroke patients with oropharyngeal dysphagia; to establish (ii) if improvement in LF and SC is connected with the presence or absence of central facial palsy, (iii) on the interval between stroke onset and initiation of treatment, (iv) on age, or (v) on sex. This was a retrospective study of 30 stroke patients, 49-88 years old, who were investigated with a Lip Force Meter, LF100 (LF100) and a swallowing capacity test (SCT) before and after a period of self-training lasting at least 5-8 weeks, using an oral screen. Initial central facial paresis was present in 24 patients. The median LF was 7 Newtons (N) (range 0-27) before treatment and 18.5 N (range 7-44) after treatment (p < 0.001). The median SC was 0 ml/s (range 0-9.1) before treatment and 12.1 ml/s (range 0-36.7) at follow-up (p < 0.001). There was no significant difference in swallowing improvement between patients with versus those without facial paresis. The interval between stroke attack and start of treatment, ranging from a few days up to 10 years, had no significant influence on the treatment results, nor did age or sex. The facial paresis was improved or at least ameliorated in all patients after the lip training period.
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A timed test of swallowing capacity has been designed for use in patients with neurogenic dysphagia. Swallowing speed (ml/s) has been demonstrated to have high intra- and inter- rater and test- retest reliability, and to be essentially independent of flavour or temperature. "Guideline" normal values were established in individuals without a swallowing disorder: swallowing speed was less in females than males and declined in both groups with age. The validity of a swallowing speed less than 10 ml/s as an index of abnormal swallowing was tested by comparison with the complaint of abnormal swallowing in a group of 81 neurological patients. Swallowing speed had a sensitivity of 96% and specificity of 69%: some apparent false positive responses were found in patients with disordered swallowing, mainly due to multiple sclerosis. Using a standard questionnaire and examination a similar pattern of symptoms and signs were statistically associated with both the clinical complaint of abnormal swallowing and swallowing speed. It is concluded that swallowing speed is a reliable and valid index for assessing disordered swallowing in neurological patients and may be of value in monitoring response to therapy.
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EMG responses were recorded from lower facial muscles (depressor labii inferioris or depressor anguli oris) of 12 normal subjects after magnetic stimulation of the motor cortex. Using a figure-of-eight stimulating coil, the largest responses were obtained from points around 8-10 cm lateral to the vertex. Usually they were bilateral and had the same latency (11-12 ms) on both sides of the face. Patients with complete Bell's palsy had no response in muscles on the same side as the lesion, indicating that the ipsilateral component to cortical stimulation was not the result of recrossing in the periphery of nerve fibres from the contralateral side. Single-unit studies showed that cortical stimulation produced two phases of motoneuronal facilitation: a short-latency (central motor delay from contralateral cortex to the intracranial portion of the facial nerve, 7.6 ms), short-duration (1- to 2-ms duration peak in the post-stimulus time histogram) input, which was more commonly evoked by contralateral than ipsilateral stimulation; and a longer latency (central delay > 15 ms), long-duration input evoked equally well from either hemisphere. The former may represent activity in a predominantly contralateral oligosynaptic corticobulbar pathway; the latter, a polysynaptic indirect (e.g. cortico-tegmento-nuclear) bilateral pathway to lower facial muscles.
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Swallowing was studied prospectively in a consecutive group of 90 neurology outpatients under 70 years of age. No patient had been referred primarily because of dysphagia. Patients were classified into four groups: those with (1) neurological or (2) non-neurological diagnoses possibly relevant to disordered swallowing, (3) functional disorders, and (4) definite diagnoses not likely to be relevant. They were defined as having abnormal or probably abnormal swallowing if two or more of the following were present: a complaint of swallowing problem, abnormal symptoms or signs, a slow swallowing speed (< 10 ml.s-1). Nineteen patients among the four groups (21%) were found to have abnormal/probably abnormal swallowing. Swallowing speed was significantly slower in patients who perceived a swallowing problem or who had abnormal symptoms or signs compared with those who did not, providing further evidence for the validity of a timed test of swallowing capacity. The study also provides evidence of a significant incidence of disordered swallowing in outpatients who may not have complained spontaneously but who have diagnoses potentially relevant to swallowing.
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Dysphagia, a difficulty eating or drinking, appears to increase with age and is a concern for our growing elderly population. Mastication, tongue mobility, and lip closure are skills of the oral phase of ingestion, and have been shown to deteriorate with age. However, it is not clear whether these changes affect functional feeding. It is also unclear whether dysphagia is the result of the aging process itself, or whether it is secondary to disease. Therefore, the purpose of this study was to identify changes during the oral phase of ingestion in a group of healthy seniors. Functional feeding skills and oral praxis abilities were measured in 79 healthy adults aged 60-97 years. The Modified Functional Feeding Assessment (FFAm) subscale of the Multidisciplinary Feeding Profile (MFP) and the Oral Praxis Subtest (OPS) of the Southern California Sensory Integration Test were administered respectively. An interview followed to obtain information on denture wear, use of hearing aids and glasses, and types of foods avoided. Seniors maintained functional feeding skills throughout the four decades studied. These skills were not age-dependent, but depended on whether or not subjects wore full dentures. Even though all of the seniors maintained functional feeding skills, more seniors in the younger group (7th decade 60%, 8th decade 67%) had difficulty with a variety of food textures such as soft, hard, fibrous, and some with tough skins, than the older group (9th decade 40%, 10th decade 44%). Oral praxis abilities were correlated significantly with age, but not with hearing aid use. Overall, healthy seniors maintained their functional feeding and oral praxis skills. Good health and natural dentition appear to be excellent indicators for functional feeding ability.
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Unlabelled: Swallowing is a complex motor event that is difficult to investigate in man by neurophysiological experiments. For this reason, the characteristics of the brain stem pathways have been studied in experimental animals. However, the sequential and orderly activation of the swallowing muscles with the monitoring of the laryngeal excursion can be recorded during deglutition. Although influenced by the sensory and cortical inputs, the sequential muscle activation does not alter from the perioral muscles caudally to the cricopharyngeal sphincter muscle. This is one evidence for the existence of the central pattern generator for human swallowing. The brain stem swallowing network includes the nucleus tractus solitarius and nucleus ambiguus with the reticular formation linking synaptically to cranial motoneuron pools bilaterally. Under normal function, the brain stem swallowing network receives descending inputs from the cerebral cortex. The cortex may trigger deglutition and modulate the brain stem sequential activity. The voluntarily initiated pharyngeal swallow involves several cortical and subcortical pathways. The interactions of regions above the brain stem and the brain stem swallowing network is, at present, not fully understood, particularly in humans. Functional neuroimaging methods were recently introduced into the human swallowing research. It has been shown that volitional swallowing is represented in the multiple cortical regions bilaterally but asymmetrically. Cortical organisation of swallowing can be continuously changed by the continual modulatory ascending sensory input with descending motor output. Significance: Dysphagia is a severe symptom complex that can be life threatening in a considerable number of patients. Three-fourths of oropharyngeal dysphagia is caused by neurological diseases. Thus, the responsibility of the clinical neurologist and neurophysiologist in the care for the dysphagic patients is twofold. First, we should be more acquainted with the physiology of swallowing and its disorders, in order to care for the dysphagic patients successfully. Second, we need to evaluate the dysphagic problems objectively using practical electromyography methods for the patients' management. Cortical and subcortical functional imaging studies are also important to accumulate more data in order to get more information and in turn to develop new and effective treatment strategies for dysphagic patients.
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To describe the clinical features of patients with posterior circulation ischemic stroke. 216 patients with posterior circulation ischemic stroke admitted in our department during 2004-2006 were analyzed retrospectively. All patients were undertaken MRI on admission and responsible lesions were identified at the posterior circulation territories. The patients' clinical symptoms and signs were evaluated and the relationships between lesion locations and clinical characteristics were analyzed. The common symptoms of posterior circulation ischemic stroke were unilateral limb weakness (81.9%), speech difficulty (46.3%), dizziness (33.8%), and unilateral limb numbness (31.0%). The common signs of posterior circulation ischemic stroke were unilateral limb weakness (81.9%), central facial or lingual palsy (61.1%), dysarthria (46.3%), unilateral limb sensory loss (31.0%), and ataxia (30.1%). The incidence of crossed paralysis was low (2.8%). Isolated vertigo was rare (1.4%). Predominant clinical features such as bulbar paralysis, unconsciousness, visual disorder and amnesia can help to localize the lesions. Typical brainstem syndromes had topographic meanings. The clinical features of patients with posterior circulation ischemic stroke were complex. Predominant symptoms can help to diagnose the posterior circulation ischemic stroke.
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Electromyography of the muscles of the "buccinator mechanism" was undertaken, utilizing indwelling fine-wire electrodes. Electromyograms were made of 14 subjects with normal occlusion during various oral activities. Several activities elicited simultaneous contraction of all muscles. Simultaneous activity represents a potential restraining force of this muscular band on the dentition.
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Patients with dysphagia as a result of neurologic disease can be effectively evaluated and managed, particularly if the dysphagia is recognized before any medical complications such as aspiration pneumonia appear. Management can be cost-effective and efficient when assessment not only defines symptoms but their underlying anatomic or physiologic cause and treatment is designed to eradicate the abnormalities in structure or function. The specific nature of the oropharyngeal dysphagia may also point to the nature of the underlying neurologic damage or disease process. Involvement of a speech-language pathologist early in the neurogenic patient's dysphagia care can speed recovery and reduce cost.