[Show abstract][Hide abstract] ABSTRACT: Objective:
To design a bidimensional facial movement measuring tool and study its reliability.
We utilized the free video-analysis software Kinovea that can track preselected points during movements and measure two-point distances off-line. Three raters positioned facial markers on 10 healthy individuals and video-taped them during maximal bilateral contractions of frontalis, corrugator, orbicularis oculi, zygomaticus, orbicularis oris, and buccinator, on two occasions. Each rater also analyzed the first video twice, one week apart. For each muscle, intrarater reliability was measured by percent agreements (PA) and intraclass correlation coefficients (ICC) between two assessments of the same video one week apart and between assessments of two videos collected one week apart. Interrater reliability was measured by PA, ICC, and coefficients of variation (CV) between assessments of the first video-recording by the three raters.
Intrarater and interrater reliabilities were good to excellent for frontalis (PA and ICC > 70%; CV < 15%), moderate for orbicularis oculi, zygomaticus, and orbicularis oris, and poor for corrugator and buccinators.
Without formal prior training, the proposed method was reliable for frontalis in healthy subjects. Improved marker selection, training sessions, and testing reliability in patients with facial paresis may enhance reliability for orbicularis oculi, zygomaticus, and orbicularis oris.
[Show abstract][Hide abstract] ABSTRACT: In spastic paresis, stretch applied to the antagonist increases its inappropriate recruitment during agonist command (spastic co-contraction). It is unknown whether antagonist stretch: (1) also affects agonist recruitment; (2) alters effort perception. We quantified voluntary activation of ankle dorsiflexors, effort perception, and plantar flexor co-contraction during graded dorsiflexion efforts at two gastrocnemius lengths. Eighteen healthy (age 41 ± 13) and 18 hemiparetic (age 54 ± 12) subjects performed light, medium and maximal isometric dorsiflexion efforts with the knee flexed or extended. We determined dorsiflexor torque, Root Mean Square EMG and Agonist Recruitment/Co-contraction Indices (ARI/CCI) from the 500 ms peak voluntary agonist recruitment in a 5-s maximal isometric effort in tibialis anterior, soleus and medial gastrocnemius. Subjects retrospectively reported effort perception on a 10-point visual analog scale. During gastrocnemius stretch in hemiparetic subjects, we observed: (1) a 25 ± 7 % reduction of tibialis anterior voluntary activation (maximum reduction 98 %; knee extended vs knee flexed; p = 0.007, ANOVA); (2) an increase in dorsiflexion effort perception (p = 0.03, ANCOVA). Such changes did not occur in healthy subjects. Effort perception depended on tibialis anterior recruitment only (βARITA = 0.61, p < 0.01) in healthy subjects (not on gastrocnemius medialis co-contraction) while it depended on both tibialis anterior agonist recruitment (βARITA = 0.41, p < 0.001) and gastrocnemius medialis co-contraction (βCCIMG = 0.43, p < 0.001) in hemiparetic subjects. In hemiparesis, voluntary ability to recruit agonist motoneurones is impaired-sometimes abolished-by antagonist stretch, a phenomenon defined here as stretch-sensitive paresis. In addition, spastic co-contraction increases effort perception, an additional incentive to evaluate and treat this phenomenon.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Upper limb robot-assisted rehabilitation is a highly intensive therapy, mainly recommended after stroke. Whether robotic therapy is suitable for subacute patients with severe impairments including cognitive disorders is unknown. This retrospective study explored factors impacting on motor performance achieved in a 16-session robotic training combined with standard rehabilitation.
Seventeen subacute inpatients (age 53 ± 18; 49 ± 26 days post-stroke) were assessed at baseline using upper extremity motor impairments scales, Functional Independence Measure, aphasia and neglect scores. Number of movements and robotic assistance were compared between Session 2 (S2), 8 (8) and 16 (S16), Motricity Index between pre and post-treatment. Correlation analyses explored predictors of motor performance.
Overall, number of movements and Motricity Index increased significantly while robot-assistance decreased. The mean number of movements per session correlated positively with baseline motor capacities but not with age, aphasia and neglect. However, the increase in Motricity index correlated negatively with baseline Motricity index and the increase in the number of movements correlated negatively with the number of movements at S2.
High intensity robot-assisted training may be associated with motor improvement in subacute hemiparesis. More severely impaired patients may derive greater benefit from robot-assisted training; age, aphasia and neglect do not represent exclusion criteria.
[Show abstract][Hide abstract] ABSTRACT: To determine the efficacy and safety of 2 doses of botulinum toxin type B (rimabotulinumtoxinB, BoNT/B) in spastic upper limb muscles.
Randomized, double-blind, placebo-controlled trial with a 3-month follow-up SETTING: Tertiary care center PARTICIPANTS: Referred sample of 24 adult hemiparetic patients with disabling elbow flexor overactivity after stroke or traumatic brain injury.
Injection of 10,000U of rimabotulinumtoxinB (fixed 2500U dose into elbow flexors; n=8), 15,000U (5000U into elbow flexors; n =8), or placebo (n=8), into overactive upper limb muscles selected as per investigator's discretion.
At 1 month post-injection, active range of elbow extension (goniometry; primary outcome); active upper limb function (Modified Frenchay Scale, MFS); subjective global self-assessment (GSA) of arm pain, stiffness, and function; rapid alternating elbow flexion-extension movement frequency over the maximal range; elbow flexor spasticity grade and angle (Tardieu), and tone (Ashworth).
No adverse effects were associated with either BoNT/B dose. Both doses improved active elbow extension vs placebo (+8.3°, 95%CI [1.1-15.5°], p=0.028, ANCOVA). The high dose of BoNT/B also improved subject-perceived stiffness (p=0.005) and the composite pain, stiffness and function GSA (p=0.017), effects that persisted 3 months from injection. No MFS change was demonstrated although subjects with baseline MFS <70/100 seemed more likely to benefit from BoNT/B.
In this short-term study, BoNT/B up to 15,000U into spastic upper limb muscles including elbow flexors, was well tolerated and improved active elbow extension and subject-perceived stiffness.
Archives of physical medicine and rehabilitation 04/2014; 95(7). DOI:10.1016/j.apmr.2014.03.016 · 2.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction:
In this study of spastic hemiparesis we evaluated cocontraction during sustained agonist/antagonist efforts, before and after botulinum toxin (BoNT) injection in 1 agonist.
Nineteen hemiparetic subjects performed maximal isometric elbow flexion/extension efforts with the elbow at 100° (extensors stretched). Using flexor and extensor surface electromyography we calculated agonist recruitment/cocontraction indices from 500-ms peak voluntary agonist recruitment, before and 1 month after onabotulinumtoxinA injection (160 U) into biceps brachii.
Before injection, agonist recruitment and cocontraction indices were higher in extensors than flexors [0.74 ± 0.15 vs. 0.59 ± 0.10 (P < 0.01) and 0.43 ± 0.25 vs. 0.25 ± 0.13 (P < 0.05), respectively]. Biceps injection decreased extensor cocontraction index (-35%, P < 0.05) while increasing flexor agonist recruitment and cocontraction indices.
In spastic hemiparesis, stretch may facilitate agonist recruitment and spastic cocontraction. In the non-injected antagonist, cocontraction may be reduced by enhanced reciprocal inhibition from a more relaxed, and therefore stretched, agonist, or through decreased recurrent inhibition from the injected muscle.
[Show abstract][Hide abstract] ABSTRACT: Objective:
Spastic co-contraction is a misdirected supraspinal command in spastic paresis. We quantified the influence of effort and gastrocnemius stretch on plantar flexor co-contraction and torque during dorsiflexion efforts in hemiparetic and healthy subjects.
Eighteen healthy and 18 hemiparetic subjects produced "light", "medium" and "maximal" isometric dorsi- and plantar flexion efforts in two gastrocnemius positions, stretched (knee extended) and slack (knee flexed), ankle at 90°. Measuring ankle torque and soleus and medial gastrocnemius surface EMG, we calculated the co-contraction index (CCI) as the ratio of the EMG root mean square (RMS) from the muscle acting as antagonist over its RMS when acting as agonist in a maximal effort, in each knee position.
Co-contraction was abnormally high in hemiparetic subjects at all effort levels, e.g. for soleus in the knee extended position (CCI(SO) 0.37±0.08 in hemiparesis vs 0.18±0.02 in healthy subjects, p<0.05). In hemiparetic subjects knee extended, dorsiflexion torque, (i) was reversed or canceled in 26% trials; and (ii) correlated negatively with plantar flexor CCI.
Major dynamometric impact of co-contraction with stretched position of the cocontracting muscle may justify muscle length modifications (e.g. through aggressive stretch programs) to improve function in spastic paresis.
Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 10/2012; 124(3). DOI:10.1016/j.clinph.2012.08.010 · 3.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gait training at fast speed has been suggested as an efficient rehabilitation method in hemiparesis. We investigated whether maximal speed walking might positively impact inter-segmental coordination in hemiparetic subjects.
We measured thigh-shank and shank-foot coordination in the sagittal plane during gait at preferred (P) and maximal (M) speed using the continuous relative phase (CRP), in 20 healthy and 27 hemiparetic subjects. We calculated the root-mean square (CRP(RMS)) and its variability (CRP(SD)) over each phase of the gait cycle. A small CRP(RMS) indicates in-phasing, i.e. high level of synchronization between two segments along the gait cycle. A small CRP(SD) indicates high stability of the inter-segmental coordination across gait cycles.
Increase from preferred to maximal speed was 57% in healthy and 49% in hemiparetic subjects (difference NS). In healthy subjects, the main change was shank-foot in-phasing at stance (CRP(Shank-Foot/RMS), P, 98±10; M, 67±12, p<0.001). In hemiparetic subjects, we also found shank-foot in-phasing at late stance bilaterally (non-paretic CRP(Shank-Foot/RMS), P, 37±9; M, 29±8, p<0.001; paretic CRP(Shank-Foot/RMS), P, 38±13; M, 32±12, p<0.001), and thigh-shank in-phasing at mid-stance in the non-paretic limb (CRP(Thigh-Shank/RMS), P, 57±9; M, 49±9, p<0.001). CRP(Thigh-Shank) variability diminished in the paretic limb (CRP(Thigh-Shank/SD), P, 18.3±6.3; M, 16.1±5.2, p<0.001).
During gait velocity increase in hemiparesis, there is improvement of thigh-shank coordination stability in the paretic limb and of shank-foot synchronization at late stance bilaterally, which optimizes the propulsive phase similarly to healthy subjects. These findings may add incentive for rehabilitation clinicians to explore maximal velocity gait training in hemiparesis.
[Show abstract][Hide abstract] ABSTRACT: To examine the safety and efficacy of onabotulinumtoxinA (Botox) for plantarflexor overactivity following stroke.
Double-blind randomized controlled trial, open-label extension phase.
Neurology rehabilitation facilities.
Eighty-five subjects with lower limb hypertonia received 200 U (n = 28) or 300 U (n = 28) of onabotulinumtoxinA or saline (n = 29) injection.
Plantarflexor Ashworth scores at 12 weeks post injection and adverse events. Secondary measures: self-reported spasm frequency and pain, physician rating of hypertonia severity, gait quality and active dorsiflexion.
Differences were not seen between onabotulinumtoxinA groups; hence data were pooled. Incidence of adverse events was not different between groups (P = 0.61). Reduction in hypertonia was not different between groups at 12 weeks (P = 0.53); however for subjects with Ashworth scores of >3 at baseline, 14/31 in the onabotulinumtoxinA group demonstrated a reduction of >1 grade versus 1/17 receiving placebo injection (P = 0.01). Overall, onabotulinumtoxinA-injected subjects demonstrated significantly greater improvement in spasm frequency (22/54 versus 4/29, P = 0.01), pain reduction (8/54 versus 1/29, P = 0.02), active dorsiflexion (8/54 versus 1/29 P = 0.03) and gait quality (17/54 versus 6/29, P = 0.02) than controls. In the open-label phase, a second onabotulinumtoxinA injection was associated with greater hypertonia reduction (P = 0.005) and gait quality (P = 0.002) compared with single injection.
OnabotulinumtoxinA injection for ankle flexor overactivity after stroke was safe and well tolerated but did not alter local spasticity at 12 weeks; it did reduce spasms and improve gait quality. There were no detectable differences between higher and lower doses. A second injection may be associated with greater change.
[Show abstract][Hide abstract] ABSTRACT: Consistent with the hypothesis that dopamine is implicated in the processing of salient stimuli relevant to the modification of various behavioral responses, Parkinson's disease is associated with emotional blunting. To address the hypothesis that emotional attention and memory are modulated by dopaminergic neurotransmission in Parkinson's disease, we assessed 15 nondemented patients with Parkinson's disease while on and off dopaminergic medication and 15 age-matched healthy controls. Visual stimuli were presented, and recognition was used to assess emotional memory. Response latency was used as a measure of emotional attention modulation. Stimuli were varied based on valence (pleasant, neutral, and unpleasant) and arousal (high and low) dimensions. Controls had significantly better memory for positive than negative stimuli, whereas patients with Parkinson's disease tested off medication had significantly better memory for negative than positive items. This negativity bias was lost when they were tested while on dopaminergic medication. Reaction times in patients with Parkinson's disease off medication were longer than in healthy controls and, paradoxically, were even longer when on medication. Further, although both healthy controls and patients with Parkinson's disease in the "off" state had arousal-induced prolongation of reaction time, this effect was not seen in patients with Parkinson's disease on medication. These data indicate that dopaminergic neurotransmission is implicated in emotional memory and attention and suggest that dopamine mediates emotional memory via the valence dimension and emotional attention via arousal. Furthermore, our findings suggest that emotional changes in Parkinson's disease result from the effects of both the disease process and dopaminergic treatment.
Movement Disorders 08/2011; 26(9):1677-83. DOI:10.1002/mds.23728 · 5.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Whereas aging affects cognitive and psychomotor processes negatively, the impact of aging on emotional processing is less clear. Using an "old-new" binary decision task, we ascertained the modulation of response latencies after presentation of neutral and emotional pictures in "young" (M = 27.1 years) and "young-old" adults with a mean age below 60 (M = 57.7 years). Stimuli varied on valence (pleasant, neutral, and unpleasant) and arousal (high and low) dimensions. Young-old adults had significantly longer reaction times. However, young and young-old adults showed the exact same pattern of response time modulation by emotional stimuli: Response latencies were longer for high-arousal than for low-arousal pictures and longer for negative than for positive or neutral stimuli. This result suggests that the specific effects of implicitly processed emotional valence and arousal information on behavioral response time are preserved in young-old adults despite significant age-related psychomotor decline.
The International journal of neuroscience 05/2011; 121(8):430-6. DOI:10.3109/00207454.2011.568656 · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Emotions can affect various aspects of human behavior. The impact of emotions on behavior is traditionally thought to occur at central, cognitive and motor preparation stages. Using EMG to measure the effects of emotion on movement, we found that emotional stimuli differing in valence and arousal elicited highly specific effects on peripheral movement time. This result has conceptual implications for the emotion-motion link and potentially practical implications for neurorehabilitation and professional environments where fast motor reactions are critical.
[Show abstract][Hide abstract] ABSTRACT: The mechanisms altering knee flexion in hemiparetic gait may be neurological (muscle overactivity) or orthopedic (soft tissue contracture) in nature, a distinction which is difficult to ascertain clinically during gait. This study aimed to distinguish the 2 mechanisms in evaluating thigh-shank coordination, which may show instability across the gait cycle in the case of bursting rectus femoris overactivity.
We measured thigh-shank coordination in the sagittal plane using the continuous relative phase during gait in 15 healthy subjects without and with an orthotic knee constraint (control and constrained) and 14 subjects with hemiparesis and rectus femoris overactivity before (pre) and after botulinum toxin injection.
Compared with the control group, both orthopedic and neurological knee flexion limitations were associated with decreased root-mean square of continuous relative phase over swing (control, 72.9; constrained, 26.0, P<0.001; pre, 31.3, P<0.001). However, only the neurological limitation was characterized by a higher number of continuous relative phase reversals over swing (control, 2.3; pre, 4.0; P=0.001) and late stance (control, 0.6; pre, 1.7; P<0.001). Botulinum toxin injection was associated with a 40% increase in root-mean square of continuous relative phase during swing and a 41% decrease in number of continuous relative phase reversals during late stance, while peak knee flexion was increased by 31%.
In hemiparesis, rectus femoris overactivity at swing phase is associated with alternating thigh-shank coordination in swing and late stance, which improves after botulinum toxin injection. Coordination analysis may help to distinguish neurological from orthopedic factors in knee flexion impairment.
[Show abstract][Hide abstract] ABSTRACT: Among the three main factors of motor impairment that emerge in chronological order following a lesion to central motor pathways, the last two antagonize movement: 1) stretch-sensitive paresis, a reduction of agonist motor unit recruitment upon voluntary command, worsened by antagonist stretch; 2) soft tissue contracture, and 3) muscle overactivity. Types of muscle overactivity include 1) spasticity, an increase in the velocity-dependent response to muscle stretch, measured at rest; 2) spastic dystonia, i.e., chronic tonic muscle activity at rest, sensitive to stretch of the dystonic muscle and 3) spastic co-contraction, an inappropriate degree of antagonistic contraction during voluntary agonist command, sensitive to stretch of the co-contracting muscle. A five-step clinical assessment may closely parallel this phenomenology, in which the first four steps aim at quantifying the antagonistic potential of each muscle group. Step-1 measures passive range of motion, i.e., the angle of arrest upon slow stretch of the muscle group assessed (minimizing spastic dystonia), which provides insight on soft tissue length and extensibility. Step-2 measures the angle of catch or clonus upon fast passive stretch of the muscle group assessed, which provides insight on stretch reflex excitability. Step-3 measures the range of active motion against the muscle group assessed, a net result of agonist recruitment minus the combined resistance from passive soft tissue stiffness and spastic co-contraction in the muscle group assessed. Step-4 measures the maximal frequency of rapid alternating movements along the maximal active range of motion, evaluating Step-3 performance repeatability. Step-5 evaluates active function, using for example a walking test (10 m or 2 min) for lower limb and the Modified Frenchay Scale for upper limb assessment, and perceived function through patient global subjective assessment.
European journal of physical and rehabilitation medicine 09/2010; 46(3):411-21. · 1.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Botulinum toxin (BTX) injection into rectus femoris (RF) is a therapeutic modality used to improve knee flexion during the swing phase of gait in hemiparesis. The impact of this treatment on lower limb coordination is unknown. The authors evaluated whether BTX injection into RF is associated with modifications of intersegmental coordination in hemiparesis.
The authors evaluated gait in 10 control and 14 hemiparetic subjects with low peak knee flexion associated with inappropriate RF activity in mid-swing, using 3-dimensional analysis before and 1 month after BTX injection into RF (Botox, 200 units). Thigh-shank coordination was measured in the sagittal plane by averaging the continuous relative phase (CRP(Thigh-Shank)) during each phase of the gait cycle in both lower limbs. The CRP is a validated metric that integrates angle positions and velocities of 2 limb segments to quantify their temporal-spatial coordination.
Before treatment, the low peak knee flexion in hemiparetic subjects (paretic limb 29 +/- 9 degrees) was associated with a decreased CRP(Thigh-Shank) in the paretic limb in swing (paretic limb 26.0 +/- 16.6 degrees vs controls 73.5 +/- 7.4 degrees, P < .001) and with a trend of an increased CRP(Thigh-Shank) in the nonparetic limb over the full gait cycle (nonparetic limb 77.9 +/- 14.1 degrees vs controls 66.2 +/- 19.8 degrees, P = .083). After treatment, the CRP(Thigh-Shank) increased by 11.9 degrees in the swing phase of the paretic limb (P = .002) and decreased by 8.0 degrees over the full gait cycle ( P = .002) in the nonparetic limb.
BTX injection into RF was associated with improved thigh-shank coordination in parts of the gait cycle, in both injected paretic and noninjected nonparetic limbs.