Effectiveness of Repetitive Transcranial Magnetic Stimulation Combined with Visual Feedback Training in Improving Neuroplasticity and Lower Limb Function after Chronic Stroke: A Pilot Study.

After a stroke, sustained gait impairment can restrict participation in the activities listed in the International Classification of Functioning, Disability, and Health model and cause poor quality of life. The present study investigated the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and visual feedback training (VF) training in improving lower limb motor performance, gait, and corticospinal excitability in patients with chronic stroke. Thirty patients were randomized into three groups that received either rTMS or sham stimulation over the contralesional leg region accompanied by VF training groups in addition to the conventional rehabilitation group. All participants underwent intervention sessions three times per week for four weeks. Outcome measures included the motor-evoked potential (MEP) of the anterior tibialis muscle, Berg Balance Scale (BBS) scores, Timed Up and Go (TUG) test scores, and Fugl-Meyer Assessment of Lower Extremity scores. After the intervention, the rTMS and VF group had significantly improved in MEP latency (p = 0.011), TUG scores (p = 0.008), and BBS scores (p = 0.011). The sham rTMS and VF group had improved MEP latency (p = 0.027). The rTMS and VF training may enhance the cortical excitability and walking ability of individuals with chronic stroke. The potential benefits encourage a larger trial to determine the efficacy in stroke patients.

Impairments in cognitive function and brain connectivity in severe asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE: Severe asymptomatic carotid stenosis has been associated with cognitive impairment, but it is unknown whether this association is attributable to effects on brain connectivity. We present cognitive network abnormalities in a group of patients at a presymptomatic stage. METHODS: Seventeen patients with ≥ 70% asymptomatic stenosis of unilateral internal carotid artery were compared with 26 healthy controls utilizing a comprehensive neuropsychological battery, the dizziness handicap inventory, and multimodality neuroimaging including diffusion tensor imaging and resting-state functional connectivity magnetic resonance imaging. Longitudinally, assessments were completed in a subgroup of 10 patients at 3 months after carotid artery stenting. RESULTS: Compared with the healthy controls, the patients had worse dizziness scores, poorer memory, complex visuo-spatial performances, and lower whole-brain mean fractional anisotropy. The Scheltens scores of leukoaraiosis/infarction were not different between groups. Their seed-based functional connectivity magnetic resonance imaging showed marked decrements of interhemispheric and intrahemispheric, ipsilaterally to carotid stenosis, functional connectivity in the frontoparietal network. In the default mode network, the intrahemispheric functional connectivity was bilaterally impaired. Importantly, the disrupted mean fractional anisotropy in the patients significantly correlated with the attention and verbal memory functions. After successful carotid artery stenting, small but measurable increments of the mean fractional anisotropy and little functional connectivity in the default mode network ipsilateral-to-carotid artery stenting were noted. CONCLUSIONS: We identified for the first time distinct patterns of network disruption that correlate with cognitive fragility in patients with asymptomatic carotid stenosis. Brain connectivity may provide early and useful biomarkers for brain ischemia and reperfusion.

Age and sex differences in the biomechanical and viscoelastic properties of upper limb muscles in middle-aged and older adults: A pilot study.

Whether muscle properties gradually change with age and how muscle properties are affected by sex remain unclear. In this study, we investigated the influence of age and sex on the biomechanical and viscoelastic properties of arm muscles in middle-aged and older adults. In this cross-sectional study, 80 healthy participants were divided by sex (male and female), and each sex group, by 10-year age ranges (40-49, 50-59, 60-69, and 70-79 years). Muscle properties, including tone, stiffness, elasticity, and mechanical stress relaxation time, were measured with the MyotonPRO. Our results showed that the muscle tone and elasticity of the deltoid and flexor carpi radialis, and the muscle tone of the flexor carpi ulnaris, were significantly greater in men than in women, whereas the stress relaxation time of the triceps was significantly greater in women than in men. Significantly greater muscle stiffness in the biceps brachii was found in the participants over 50 years old. Less muscle elasticity was found in the deltoid, triceps, and flexor carpi ulnaris in those over 70 years old. In conclusion, age and sex have considerable impacts on upper-limb muscle properties in middle-aged and older adults, which should be taken into consideration when planning health promotion projects.

Predicting admission to post-acute inpatient rehabilitation in patients with acute stroke.

OBJECTIVE: To identify predictors of admission to post-acute inpatient rehabilitation settings follow-ing acute care for stroke survivors in Taiwan. DESIGN: Prospective observation study. PARTICIPANTS: Stroke survivors (n = 558) admitted to acute care wards for inpatient rehabilitation (62% male; mean age 60.0 ± 12.2 years). METHODS: The primary outcome was whether survivors were admitted to post-acute inpatient rehabilitation settings after discharge from acute care wards. Logistic regression model was adopted to examine the predictors of admission to post-acute inpatient rehabilitation. A receiver operating characteristic curve was drawn to compute the ability of the predictors to discriminate the outcome. RESULTS: Multivariate analysis results indicated Activity Measure Post-Acute Care "6-Clicks" Basic Mobility score to be the only significant predictor of admission to post-acute inpatient rehabilitation (odds ratio = 0.44, 95% confidence interval: 0.34-0.56). Receiver operating characteristic curve analysis results indicated that the cut-off point for Basic Mobility was 13 (standardized score: 33.99). This yielded a sensitivity value of 0.98 and a specificity value of 0.96 for determining the admission to post-acute inpatient rehabilitation. CONCLUSION: Activity Measure Post-Acute Care "6-Clicks" Basic Mobility subscale scores at admission for acute care can predict admission to post-acute inpatient rehabilitation for stroke survivors in Taiwan. This tool can aid clinicians in formulating adequate discharge plans at an early stage, and thus improve the quality of care.

Connectivity features for identifying cognitive impairment in presymptomatic carotid stenosis.

Severe asymptomatic stenosis of the internal carotid artery (ICA) leads to increased incidence of mild cognitive impairment (MCI) likely through silent embolic infarcts and/or chronic hypoperfusion, but the brain dysfunction is poorly understood and difficult to diagnose. Thirty cognitively intact subjects with asymptomatic, severe (≥ 70%), unilateral stenosis of the ICA were compared with 30 healthy controls, matched for age, sex, cardiovascular risk factors and education level, on a battery of neuropsychiatric tests, voxel-based morphometry of magnetic resonance imaging (MRI), diffusion tensor imaging and brain-wise, seed-based analysis of resting-state functional MRI. Multivariate regression models and multivariate pattern classification (support vector machines) were computed to assess the relationship between connectivity measures and neurocognitive performance. The patients had worse dizziness scores and poorer verbal memory, executive function and complex visuo-spatial performance than controls. Twelve out of the 30 patients (40%) were considered to have MCI. Nonetheless, the leukoaraiosis Sheltens scores, hippocampal and brain volumes were not different between groups. Their whole-brain mean fractional anisotropy (FA) was significantly reduced and regional functional connectivity (Fc) was significantly impaired in the dorsal attention network (DAN), frontoparietal network, sensorimotor network and default mode network. In particular, the Fc strength at the insula of the DAN and the mean FA were linearly related with attention performance and dizziness severity, respectively. The multivariate pattern classification gave over 90% predictive accuracy of individuals with MCI or severe dizziness. Cognitive decline in stroke-free individuals with severe carotid stenosis may arise from nonselective widespread disconnections of long-range, predominantly interhemispheric non-hippocampal pathways. Connectivity measures may serve as both predictors for cases at risk and therapeutic targets for mitigating vascular cognitive impairment.

Intermittent theta burst stimulation over ipsilesional primary motor cortex of subacute ischemic stroke patients: a pilot study.

BACKGROUND: We demonstrated that prolonged transcranial magnetic intermittent theta burst stimulation (iTBS, 1200 pulses/session=iTBS1200) produces longer-lasting facilitation in corticospinal excitability than ordinary form of iTBS in healthy subjects. OBJECTIVE: Here we show the safety and small-scale efficacy of iTBS1200 over ipsilesional primary motor cortex (M1) in subacute stroke patients. METHODS: Twelve patients with first-time, subacute ischemic stroke of the middle cerebral artery were randomized into two groups that received 10 daily-sessions of either iTBS1200 or sham stimulation (n=6/group) over ipsilesional M1 hand region in addition to medical and rehabilitation treatments. The primary outcome measures were safety and tolerability. The secondary outcome measures included the National Institute of Health Stroke Scale (NIHSS), Upper Extremity Fugl-Meyer Test (UE-FMT), Action Research Arm Test (ARAT), active motor thresholds (aMTs)/motor-evoked potentials (MEPs) from the extensor carpi radialis (ECR), and magnetoencephalography on post-intervention day 1 and post-stroke day 60. RESULTS: iTBS or sham stimulation was well tolerated by all patients without seizures or significant adverse effects. Compared with the matched controls, the iTBS group showed measurable improvements in the NIHSS and the proximal UE-FMT scores on post-intervention day 1 and post-stroke day 60. Nevertheless, the hand ARAT scores, aMT and MEPs from the paretic ECR were not different between groups. Post-movement beta synchronization increased over iTBS-conditioned M1 on post-intervention day 1 in testable patients. CONCLUSIONS: Repetitive sessions of iTBS1200 over ipsilesional M1 of subacute stroke patients are safe and the potential benefits encourage a larger trial to determine the efficacy in stroke patients. (ClinicalTrials.gov: NCT-01323881).