Eun Kyoung Kang

Effect of transcranial direct current stimulation on motor recovery in patients with subacute stroke.

Kim DY, Lim JY, Kang EK, You DS, Oh MK, Oh BM, Paik NJ: Effect of transcranial direct current stimulation on motor recovery in patients with subacute stroke. Objective: To test the hypothesis that 10 sessions of transcranial direct current stimulation combined with occupational therapy elicit more improvement in motor function of the paretic upper limb than sham stimulation in patients with subacute stroke. Design: Eighteen patients with subacute stroke with hand motor impairment were randomly assigned to one of the three 10-day sessions of (a) anodal transcranial direct current stimulation over the affected motor cortex, (b) cathodal transcranial direct current stimulation over the unaffected motor cortex, or (c) sham stimulation. Blinded evaluators assessed upper limb motor impairment and global functional state with the Fugl-Meyer Assessment score and the Modified Barthel Index at baseline, 1 day after stimulation, and 6 mos after stimulation. Results: Baseline scores for Fugl-Meyer Assessment and Modified Barthel Index were comparable in all groups (P > 0.05). At 6-mo follow-up, cathodal transcranial direct current stimulation led to a greater improvement in Fugl-Meyer Assessment than the sham procedure (P < 0.05). There was a significant inverse correlation between baseline Fugl-Meyer Assessment and Fugl-Meyer Assessment increase at 6 mos (r = −0.846; P < 0.01). Conclusions: Our results suggest a potentially beneficial effect of noninvasive cortical stimulation during rehabilitative motor training of patients who have suffered from subacute strokes.

Improved picture naming in aphasia patients treated with cathodal tDCS to inhibit the right Broca's homologue area.

PURPOSE Previous reports have suggested that noninvasive cortical stimulation could influence speech production in patients with chronic stroke. Here, we evaluated the hypothesis that cathodal transcranial DC stimulation (ctDCS), a technique that decreases excitability of stimulated cortical sites, applied over a healthy right Brocas homologue area could improve picture naming in patients with post-stroke aphasia. METHODS Ten right-handed patients with post-stroke aphasia were enrolled in this double blind, counterbalanced sham-controlled, crossover study. Each patient received an intervention of ctDCS (2 mA for 20 min) and of sham tDCS (2 mA for 1 min) daily for 5 consecutive days in a randomized crossover manner with a minimum interval of one week between interventions, over a healthy right Brocas homologue area using a left supraorbital anode and simultaneous daily sessions of conventional word-retrieval training. The primary endpoint measure of this study was a standardized, validated Korean version of the Boston Naming Test, which is a measure of picture naming skills. RESULTS ctDCS was not found to have any adverse effects. Furthermore, significantly improved picture naming (p = 0.02) was observed at 1 hour following the last (5th) ctDCS treatment session, but no changes were observed after sham tDCS. CONCLUSION These results demonstrate that cathodal tDCS over the right healthy Brocas homologue area with a left supraorbital anodal location can improve picture naming task performance in post-stroke aphasia.

Non-invasive cortical stimulation improves post-stroke attention decline

PURPOSE Attention decline after stroke is common and hampers the rehabilitation process, and non-invasive transcranial direct current stimulation (tDCS) has the potential to elicit behavioral changes by modulating cortical excitability. The authors tested the hypothesis that a single session of non-invasive cortical stimulation with excitatory anodal tDCS applied to the left dorsolateral prefrontal cortex (DLPFC) can improve attention in stroke patients. METHODS Ten patients with post-stroke cognitive decline (MMSE 25) and 10 age-matched healthy controls participated in this double blind, sham-controlled, crossover study involving the administration of real (2 mA for 20 min) or sham stimulation (2 mA for 1 min) to the left DLPFC. Attention was measured using a computerized Go/No-Go test before and after intervention. Improvements in accuracy and speed after stimulation relative to baseline were compared for real and sham stimulations. RESULTS In healthy controls, no significant improvement in Go/No-Go test was observed after either real or sham stimulation. However, in stroke patients, tDCS led to a significant improvement in response accuracy at 1 hour post-stimulation relative to baseline, and this improvement was maintained until 3 hours post-stimulation (P< 0.05), whereas sham stimulation did not lead to a significant improvement in response accuracy (P> 0.05). Changes in reaction times were comparable for the two stimulations (P> 0.05). CONCLUSION Non invasive anodal tDCS applied to the left DLPFC was found to improve attention versus sham stimulation in stroke patients, which suggests that non-invasive cortical intervention could potentially be used during rehabilitative training to improve attention.

Factors Related to Gait Function in Post-stroke Patients

[Purpose] Gait function after a stroke is an important factor for determining a patient’s ability to independently perform activities of daily living (ADL). The objective of this study was to elucidate the factors associated with gait function in post-stroke patients. [Subjects] Thirty-nine stroke patients (16 females and 23 males; average age 67.82 ± 10.96 years; post-onset duration: 200.18 ± 27.14 days) participated in this study. [Methods] Their gait function, motor function (Manual Muscle Test [MMT] and Brünnstrom stage), level of cognition (Mini-Mental State Examination score [MMSE], and the Loewenstein Occupational Therapy Cognitive Assessment for the Geriatric Population [LOTCA-G]), and ADL (Korean modified Barthel index [K-MBI]) were assessed. [Results] The degree of gait function showed significant positive correlations with the following variables: MMT of the elbow, knee, ankle and wrist; Brünnstrom stage; MMSE; LOTCA-G subscores except motor praxis; K-MBI. Stepwise linear regression analysis revealed the Brünnstrom stage was the only explanatory variable closely associated with gait level. [Conclusion] Gait function of post-stroke patients was related to motor function, cognition, and ADL. In particular, there is a significant association between gait level and the Brünnstrom stages, reflecting the importance of monitoring the motor recovery of gait function in post-stroke patients.

Farmers’ Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study: Study Design, Methods, and Baseline Characteristics of Enrolled Subjects

Background The ongoing Farmers’ Cohort for Agricultural Work-related Musculoskeletal Disorders (FARM) study was developed to evaluate health status and related factors in farmers. Methods Farmers in Kangwon Province, South Korea, were recruited. Baseline characteristics were determined using questionnaires about sociodemographic and health characteristics and agricultural work-related factors. In addition, laboratory examinations (lumbar spinal radiography and serologic testing) were conducted. Results The FARM study covers eight rural areas and recruited 1013 subjects (534 women; mean [standard deviation {SD}] age, 57.2 [7.5] years). Musculoskeletal pain in multiple areas was reported by 925 subjects (91.3%), and low back pain (63.8%) was the most frequent site of pain. Farmer’s Stress Inventory (mean [SD], 77.7 [10.2]; range, 28–112] and subjective stress index (mean [SD], 5.3 [2.4]; range, 0–10) were above median scale values, reflecting a stressful condition, while the EuroQol-5D-3L index and the EuroQol-Visual Analog Scale scores were high (mean [SD], 0.9 [0.1]; range −0.171–1 and mean [SD], 67.7 [18.7]; range 0–100, respectively), reflecting good life quality. In total, 53% of participants had worked in farming for more than 30 years, and workers involved in dry-field farming comprised the largest subgroup (41.5%). Most participants (94.3%) had no more than a high school education, and families with annual income below 20 million won constituted the largest subgroup (36.3%). Conclusions The FARM study may provide data on the current health status and related sociodemographic and agricultural work-related risk factors in Korean farmers, with the goal of providing a scientific basis for developing coping interventions and preventive strategies.

Cognitive and Language Function in Aphasic Patients Assessed With the Korean Version of Mini-Mental Status Examination.

Objective To assess the clinical usefulness of the relatively short instrument, the Korean version of the Mini-Mental State Examination (MMSE-K), for testing the association between cognition and language function in subacute post-stroke aphasia patients. Methods Medical charts of 111 post-stroke patients (65 men; age 69.6±10.0 years; 124.6±80.6 days post-onset) were reviewed retrospectively. All patients were assessed longitudinally for aphasia using the validated Korean version of the Western Aphasia Battery (K-WAB) and for cognition using the MMSE-K. Patients were categorized and analyzed according to 3 aphasia-severity clusters. Results All subscales of the K-WAB showed significant improvement in follow-up assessments in all groups (p<0.05 or p<0.01). Only the scores of orientation, language function, and total score of MMSE-K showed significant improvement in all groups (p<0.01). The more severely impaired group showed stronger Pearson correlation coefficients between cognition and language function. Additionally, comparisons between correlation coefficients showed that the association of improvement in orientation with that of fluency and AQ% (aphasia quotient %) was significant in the more severely impaired group. Conclusion Among subacute post-stroke aphasic patients, patients with more severe aphasia showed greater impairments to cognitive function; in addition, recovery of orientation may be related to recovery of language function.

Reliability and Validity of a New Method for Isometric Back Extensor Strength Evaluation Using A Hand-Held Dynamometer

Objective To investigate the reliability and validity of a new method for isometric back extensor strength measurement using a portable dynamometer. Methods A chair equipped with a small portable dynamometer was designed (Power Track II Commander Muscle Tester). A total of 15 men (mean age, 34.8±7.5 years) and 15 women (mean age, 33.1±5.5 years) with no current back problems or previous history of back surgery were recruited. Subjects were asked to push the back of the chair while seated, and their isometric back extensor strength was measured by the portable dynamometer. Test-retest reliability was assessed with intraclass correlation coefficient (ICC). For the validity assessment, isometric back extensor strength of all subjects was measured by a widely used physical performance evaluation instrument, BTE PrimusRS system. The limit of agreement (LoA) from the Bland-Altman plot was evaluated between two methods. Results The test-retest reliability was excellent (ICC=0.82; 95% confidence interval, 0.65–0.91). The Bland-Altman plots demonstrated acceptable agreement between the two methods: the lower 95% LoA was −63.1 N and the upper 95% LoA was 61.1 N. Conclusion This study shows that isometric back extensor strength measurement using a portable dynamometer has good reliability and validity.

Subcortical Aphasia After Stroke

Objective To evaluate the types and severity of subcortical aphasia after stroke and to determine the predictors of the degree of aphasic impairment. Methods Medical records of 38 patients with post-stroke subcortical aphasia (19 males; mean age, 61.7±13.8 years) were reviewed retrospectively with respect to the following tests: the Korean version of the Western Aphasia Battery (K-WAB), the Korean version of the Modified Barthel Index (K-MBI), and the Fugl-Meyer Index (FMI). The severity of aphasia was evaluated by the aphasia quotient (AQ) and the language quotient (LQ). Results Anomic aphasia was the most frequent type of aphasia (n=15, 39.5%), and the lesion most frequently observed in subcortical aphasia was located in the basal ganglia (n=19, 50.0%). Patients with lesions in the basal ganglia exhibited the lowest scores on the FMI for the upper extremities (p=0.04). Severity of aphasia was significantly correlated with the K-MBI (Pearson correlation coefficient: γ=0.45, p=0.01 for AQ and γ=0.53, p=0.01 for LQ) and FMI scores for the lower extremities (γ=0.43, p=0.03 for AQ and γ=0.49, p=0.05 for LQ). In a multivariate logistic regression analysis, K-MBI remained the only explanatory variable closely associated with aphasia severity. Conclusion This study showed the general characteristics of post-stroke subcortical aphasia, and it revealed that K-MBI was an associated and explanatory factor for aphasia severity.

The Association between Trunk Body Composition and Spinal Bone Mineral Density in Korean Males versus Females: a Farmers' Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study

The purpose of this study was proposed to identify the association of trunk body composition with spinal bone mineral density (BMD) in Korean male and female farmers. A total of 523 Korean farmers (259 males, 44 premenopausal females, and 220 postmenopausal females) were recruited. Computed tomography scans were acquired at the mid-L4 vertebral level, and total trunk muscle mass (TMM, cm3), back muscle mass (BMM), and abdominal wall muscle mass (AMM), total trunk fat mass (TFM), visceral fat mass (VFM), and subcutaneous fat mass (SFM) were assessed. Spinal BMD (g/cm2) was estimated from dual-energy X-ray absorptiometry at the L4 level. In terms of muscle mass, spinal BMD was significantly correlated with all the components of the trunk muscle mass (r = 0.171-0.360; P < 0.05, P < 0.001) in female farmers, while only with AMM (r = 0.181; P < 0.01) in male farmers. In terms of fat mass, spinal BMD was significantly correlated with all components of the trunk fat mass (r = 0.142-0.424; P < 0.05, P < 0.001) in male and premenopausal female farmers, while only with VFM (r = 0.132; P < 0.05) in postmenopausal females. Adjusted multivariate regression analysis showed that AMM in male and post-menopausal female farmers was closely associated with spinal BMD. There may be positive associations between trunk muscle and fat mass and spinal BMD with sexual dimorphism, and abdominal wall muscle mass was an explanatory variable closely related to spinal BMD in Korean farmers. Registered at the Clinical Research Information Service (CRIS, http://cris.nih.go.kr), number KCT0000829.

Impact of Co-occurring Dysarthria and Aphasia on Functional Recovery in Post-stroke Patients

Objective To elucidate the impact of co-occurring dysarthria and aphasia on functional recovery in post-stroke patients. Methods The medical records, including results of primary screening tests and secondary definite examinations for language problems, of 130 patients admitted to our institutes Department of Rehabilitation Medicine were retrospectively reviewed. Functional outcomes were assessed longitudinally using the Functional Ambulation Category (FAC), Mini-Mental State Examination-Korean version (MMSE-K), European Quality of Life-5 Dimensions 3-Level version (EQ-5D-3L), the Korean version of the Modified Barthel index (K-MBI), and Motricity Index (MI) of the hemiplegic side. Results Patients were classified into four groups regarding language function: aphasia only (group A, n=9), dysarthria only (group D, n=12), aphasia and dysarthria (group AD, n=46), and none (group N, n=55). The initial functional outcome scores in the group AD were significantly poor compared to those of the groups N and A. Within groups, there were significant improvements in all outcome measurements in the groups AD and N. A between-group analysis revealed significant improvements in K-MBI for the group AD after adjusting for the initial severity and patients age compared to other groups. Conclusion Post-stroke patients suffering from aphasia with dysarthria showed significantly lower initial functional level and relatively wide range of recovery potential in activities of daily living compared to patients without language problems.