Kimitaka Hase

Identification of a simple screening tool for dysphagia in patients with stroke using factor analysis of multiple dysphagia variables

OBJECTIVE To identify a most useful and simple clinical screening tool to predict videofluoroscopic aspiration in patients with stroke. DESIGN Factor analysis of multiple dysphagia variables and sensitivity and specificity testing with chi-square test. PATIENTS Sixty-one consecutive stroke patients with symptoms suggestive of dysphagia admitted to a university hospital and its 4 affiliated hospitals in Japan. METHODS Factors were extracted from 6 oromotor examinations (lip closure, tongue movement, palatal elevation, gag reflex, voice quality and motor speech function), 2 swallow screen tests (saliva swallowing test and our modified water swallowing test using 30 ml of water) and 4 parameters evaluated with a videofluoroscopic swallow study. Sensitivity and specificity of each dysphagia-related variable was determined against aspiration in a videofluoroscopic swallow study. RESULTS Factor analysis revealed that cough/voice change in the water swallowing test and aspiration on videofluoroscopic swallow study belonged to the same factor. Chi-square analysis showed that cough/voice change in the water swallowing test was the only variable that was significantly associated with aspiration on videofluoroscopic swallow study, with a sensitivity of 72% (95% CI: 61-83%) and a specificity of 67% (CI: 55-79%) as a predictor of aspiration (p<0.05). CONCLUSION We recommend our modified 30 ml water-swallowing test as a useful single task-screening tool to detect aspiration.

Prism adaptation therapy enhances rehabilitation of stroke patients with unilateral spatial neglect: a randomized, controlled trial.

Background and objective. Unilateral spatial neglect (USN) can interfere with rehabilitation processes and lead to poor functional outcome. The purpose of this study was to determine whether prism adaptation (PA) therapy improves USN and functional outcomes in stroke patients in the subacute stage. Methods. A multicenter, double-masked, randomized, controlled trial was conducted to evaluate the effects of a 2-week PA therapy on USN assessed with the Behavioral Inattention Test (BIT), the Catherine Bergego Scale (CBS), and activities of daily living (ADL) as evaluated with the Functional Independence Measure (FIM). A total of 38 USN patients with right-brain damage were divided into prism (n = 20) and control (n = 18) groups. Patients were divided into mild and severe USN groups according to BIT behavioral test (mild ≥ 55 and severe<55). The prism group performed repetitive pointing with prism glasses that induce rightward optical shift twice daily, 5 days per week, for 2 weeks, whereas the control group performed similar pointing training with neutral glasses. Results. The FIM improved significantly more in the prism group. In mild USN patients, there was significantly greater improvement of BIT and FIM in the prism group. Conclusions. PA therapy can significantly improve ADL in patients with subacute stroke.

Motor Improvement and Corticospinal Modulation Induced by Hybrid Assistive Neuromuscular Dynamic Stimulation (HANDS) Therapy in Patients With Chronic Stroke

Background and objective . We devised a therapeutic approach to facilitate the use of the hemiparetic upper extremity (UE) in daily life by combining integrated volitional control electrical stimulation with a wrist splint, called hybrid assistive neuromuscular dynamic stimulation (HANDS). Methods. Twenty patients with chronic hemiparetic stroke (median 17.5 months) had moderate to severe UE weakness. Before and immediately after completing 3 weeks of training in 40-minute sessions, 5 days per week over 3 weeks and wearing the system for 8 hours each day, clinical measures of motor impairment, spasticity, and UE functional scores, as well as neurophysiological measures including electromyography activity, reciprocal inhibition, and intracortical inhibition were assessed. A follow-up clinical assessment was performed 3 months later. Results. UE motor function, spasticity, and functional scores improved after the intervention. Neurophysiologically, the intervention induced restoration of presynaptic and long loop inhibitory connections as well as disynaptic reciprocal inhibition. Paired pulse transcranial magnetic stimulation study indicated disinhibition of the short intracortical inhibition in the affected hemisphere. The follow-up assessment showed that improved UE functions were maintained at 3 months. Conclusion. The combination of hand splint and volitional and electrically induced muscle contraction can induce corticospinal plasticity and may offer a promising option for the management of the paretic UE in patients with stroke. A larger sample size with randomized controls is needed to demonstrate effectiveness.

Comparison of the After-Effects of Transcranial Direct Current Stimulation Over the Motor Cortex in Patients With Stroke and Healthy Volunteers

ABSTRACT It is known that weak transcranial direct current stimulation (tDCS) induces persistent excitability changes in the cerebral cortex. There are, however, few studies that compare the after-effects of anodal versus cathodal tDCS in patients with stroke. This study assessed the after-effects of tDCS over the motor cortex in patients with hemiparetic stroke and healthy volunteers. Seven stroke patients and nine healthy volunteers were recruited. Ten minutes of anodal and cathodal tDCS (1 mA) and sham stimulation were applied to the affected primary motor cortex (M1) on different days. In healthy subjects, tDCS was applied to the right M1. Before and after tDCS, motor-evoked potentials (MEPs) in the first dorsal interosseous (FDI) muscle and silent period were measured. Anodal tDCS increased the MEPs of the affected FDI in patients with stroke as well as in healthy subjects. Cathodal tDCS increased the MEPs of the affected FDI in patients with stroke. In healthy subjects, however, cathodal tDCS decreased the MEPs. We found no significant change in the duration of the silent period after anodal or cathodal tDCS. We found that both anodal and cathodal tDCS increased the affected M1 excitability in patients with stroke. It is thought that the after-effects of tDCS are different in patients with stroke compared with healthy subjects.

Between-subject variance in the magnitude of corticomuscular coherence during tonic isometric contraction of the tibialis anterior muscle in healthy young adults.

Oscillatory activity of the sensorimotor cortex has been reported to show coherence with muscle activity in the 15- to 35-Hz frequency band (β-band) during weak to moderate intensity of isometric contraction. The present study examined the variance of the magnitude of the corticomuscular coherence across a large number of subjects. We quantified the coherence between EEG over the sensorimotor cortex and rectified electromyogram (EMG) from the tibialis anterior muscle during tonic isometric contraction at 30% of maximal effort in 100 healthy young individuals. We estimated the maximal peak of EEG-EMG coherence (Cohmax) and the ratio of the sum of the autopower spectral density function within the β-band to that of all frequency ranges for both EEG (EEGβ-PSD) and EMG (EMGβ-PSD) signals. The frequency histogram of Cohmax across all subjects showed a broad bell-shaped continuous distribution (range, 0.048-0.816). When the coherence was thresholded at the estimated significance level of P < 0.05 (0.114), 46 out of 100 subjects showed significant EEG-EMG coherence. Cohmax occurred within the β-band in the majority of subjects who showed significant EEG-EMG coherence (n = 43). Furthermore, Cohmax showed significant positive correlations with both EEGβ-PSD (r = 0.575, P < 0.001) and EMGβ-PSD (r = 0.606, P < 0.001). These data suggest that even during simple tonic isometric contraction, the strength of oscillatory coupling between the sensorimotor cortex and spinal motoneurons varies among individuals and is a contributory factor determining muscle activation patterns such as the degree of grouped discharge in muscle activity within the β-band for each subject.

Development of a new measure to assess trunk impairment after stroke (trunk impairment scale): its psychometric properties.

Fujiwara T, Liu M, Tsuji T, Sonoda S, Mizuno K, Akaboshi K, Hase K, Masakado Y, Chino N: Development of a new measure to assess trunk impairment after stroke (Trunk Impairment Scale): Its psychometric properties. Am J Phys Med Rehabil 2004;83:681–688. Objective:The purpose of this study was to investigate reliability, validity, internal structure, and responsiveness of our newly developed Trunk Impairment Scale (TIS) for patients with stroke. Design:A total of 73 patients with stroke participated in this prospective study. Interrater reliability (weighted kappa statistics), content validity (principal component analysis), concurrent validity (Spearmans rank correlation with the Trunk Control Test), predictive validity (prediction of discharge FIM™ scores), and responsiveness (standardized response mean values) were examined. Internal consistency and item difficulties were analyzed with Rasch analysis. Results:The weighted kappa of each TIS item ranged from 0.66 to 1.0. Principal component analysis revealed that the TIS measured a domain similar to the Stroke Impairment Assessment Set trunk items but different from the Stroke Impairment Assessment Set motor and visuospatial items. The TIS correlated with the Trunk Control Test (r = 0.91). To predict discharge FIM motor scores, addition of the TIS as one of the predictors to age, time from onset, and admission FIM score increased the adjusted R2 from 0.66 to 0.75. With Rasch analysis, the misfit was acceptable, except for the abdominal muscle strength item. The difficulty patterns were similar at admission and discharge, except for the abdominal muscle strength item. The responsiveness of the TIS was satisfactory and comparable with that of the Trunk Control Test (standardized response mean values, 0.94 and 1.06). Conclusions:Our newly developed TIS is reliable, valid, and responsive for use in stroke outcome research.

Psychometric properties of the Stroke Impairment Assessment Set (SIAS).

Objective: To review the psychometric properties of the Stroke Impairment Assessment Set (SIAS), which was developed in 1990 as a comprehensive instrument to assess stroke impairment. Method: Articles related to the SIAS were retrieved from the MEDLINE and the Folia Centro Japonica. Results: Thirty-five articles were retrieved and analyzed. 1) Scale quality: Rasch analysis demonstrated the unidimensionality of the SIAS. Factor analysis produced 6 factors corresponding to the 6 SIAS subscales. 2) Interrater reliability: The weighted kappas were high except for the unaffected side quadriceps item for which the score distribution was skewed. 3) Concurrent validity: Significant correlations were found between a) SIAS motor items and the Motricity Index or the Brunnstrom stage, b) SIAS lower extremity scores and the Functional Independence Measure (FIMSM) locomotion scores, c) trunk scores and abdominal manual muscle testing, d) visuospatial scores and line bisection and copying task scores, and e) speech scores and the FIMSM communication scores. 4) Predictive validity: Three studies attempting to predict discharge functional status demonstrated that adding the SIAS as one of the predictors enhanced the predictive power. 5) Responsiveness: The SIAS was more responsive to changes than the Motricity Index, the Brunnstrom stage, or the National Institutes of Health Stroke Scale. Conclusion: The SIAS is a useful measure of stroke impairment with well-established psychometric properties.

TRUNK MUSCLES IN PERSONS WITH HEMIPARETIC STROKE EVALUATED WITH COMPUTED TOMOGRAPHY

OBJECTIVES To analyse side difference in bilateral trunk muscles in patients with hemiparetic stroke, to relate it with impairment and disability variables and to evaluate longitudinal changes. METHODS In a sample of 83 inpatients with hemiparetic stroke undergoing rehabilitation, we measured the cross-sectional area of the paravertebral muscle and thigh muscles using computed tomography at admission and discharge. Classifying them by paravertebral muscle side difference (group I: contralateral > ipsilateral; II: contralateral = ipsilateral; III: contralateral < ipsilateral) we analysed group difference in the Stroke Impairment Assessment Set, the Functional Independence Measure and walk velocity. RESULTS In contrast to thigh muscles, the paravertebral muscle cross-sectional area was significantly greater on the side contralateral to the brain lesion. Discharge paravertebral muscle cross-sectional area increased significantly from admission values. The Stroke Impairment Assessment Set, Functional Independence Measure and walk velocity were significantly lower in group I. CONCLUSION The contralateral paravertebral muscle cross-sectional area was larger than the ipsilateral ones, and this was related to the degree of impairment and functional limitations.

Dysphagia in patients with duchenne muscular dystrophy evaluated with a questionnaire and videofluorography

Purpose. To investigate swallowing problems in patients with Duchenne muscular dystrophy (DMD) using a questionnaire and videofluorography (VF). Method. A questionnaire survey was performed of swallowing-related symptoms and VF in 31 male patients with DMD (mean age 19.9 years, range 9 – 26 years). The relationships among age, frequency of symptoms and VF abnormalities were analysed using Spearmans rank correlation. The differences in VF abnormalities among different food textures were analysed with the Kruskal – Wallis test. Results. Symptoms related to pharyngeal phase dysfunction were more frequent than those related to oral and oesophageal phases. Coughing while eating was seen in 71% of the patients, choking while eating in 32% and the need to clear the throat in 26%. VF abnormalities were observed in 30 patients (96.8%). Common VF abnormalities included pooling in the valleculae (90.3%) and in the pyriform sinus (90.3%). Pharyngo-oral regurgitation was seen in 35.5% of the patients. Pooling in the pyriform sinus after repeated swallowing seen in VF correlated significantly with symptoms related to the pharyngeal phase (Spearmans rho 0.356 – 0.544). Conclusion. Because oropharyngeal dysphagia in DMD was evident in teenage patients as well as those without clinical symptoms, VF is recommended in patients with DMD.

Effectiveness of hybrid assistive neuromuscular dynamic stimulation therapy in patients with subacute stroke: a randomized controlled pilot trial.

Background and objective. Hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy was devised to facilitate the use of the hemiparetic upper extremity in daily life by combining assistive neuromuscular electrical stimulation, referred to as the integrated volitional electrical stimulator (IVES), with a splint. The aim of this study is to assess the effectiveness of HANDS therapy for patients with subacute stroke. Methods. The participants were 24 inpatients receiving rehabilitation for hemiparetic stroke within 60 days of onset. Entry criteria included inability to individuate finger extension. Patients were randomly assigned to 2 groups. The HANDS group (n = 12) used the IVES combined with a wrist splint for 8 hours a day for 3 weeks, and the control group (n = 12) wore a wrist splint alone. All patients received the same daily dose and length of standard poststroke multidisciplinary rehabilitation. Outcome measures were the upper extremity portion of the Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Motor Activity Log-14 (MAL). Results. In all, 10 patients in each group completed the interventions. Compared with the control group, the HANDS group showed significantly greater gains in distal (wrist/hand) portion of the FMA (P < .01) and improvement of the ARAT (P < .05). The gains in the MAL did not differ. No adverse effects occurred and the HANDS therapy was well accepted. Conclusion. HANDS therapy in addition to conventional therapy may improve hand function in patients with moderate to severe hand impairment during early rehabilitation.