Changes in Corticospinal Excitability and Motor Control During Cerebellar Transcranial Direct Current Stimulation in Healthy Individuals.

Cerebellar transcranial direct current stimulation (ctDCS) modulates the primary motor cortex (M1) via cerebellar brain inhibition (CBI), which affects motor control in humans. However, the effects of ctDCS on motor control are inconsistent because of an incomplete understanding of the real-time changes in the M1 excitability that occur during ctDCS, which determines motor output under regulation by the cerebellum. This study investigated changes in corticospinal excitability and motor control during ctDCS in healthy individuals. In total, 37 healthy individuals participated in three separate experiments. ctDCS (2 mA) was applied to the cerebellar hemisphere during the rest condition or a pinch force-tracking task. Motor-evoked potential (MEP) amplitude and the F-wave were assessed before, during, and after ctDCS, and pinch force control was assessed before and during ctDCS. The MEP amplitudes were significantly decreased during anodal ctDCS from 13 min after the onset of stimulation, whereas the F-wave was not changed. No significant changes in MEP amplitudes were observed during cathodal and sham ctDCS conditions. The MEP amplitudes were decreased during anodal ctDCS when combined with the pinch force-tracking task, and pinch force control was impaired during anodal ctDCS relative to sham ctDCS. The MEP amplitudes were not significantly changed before and after all ctDCS conditions. Motor cortical excitability was suppressed during anodal ctDCS, and motor control was unskilled during anodal ctDCS when combined with a motor task in healthy individuals. Our findings provided a basic understanding of the clinical application of ctDCS to neurorehabilitation.

Impacts of increases and decreases of drugs on rehabilitation outcomes of subacute stroke patients.

OBJECTIVE: To examine changes in drugs for subacute stroke patients and elucidate the impact of medications on rehabilitation outcomes. MATERIALS AND METHODS: A total of 295 subacute stroke patients who were admitted to the convalescent rehabilitation ward between June 2018 and May 2019 were included. Polypharmacy was defined as five or more drugs at admission. The primary outcome was the Functional Independence Measure Total score (FIM-T) at discharge. Multiple regression analysis was performed to examine the relationships between the FIM-T at discharge and drug changes or other factors. This study was conducted in two stages. The first analysis included all stroke patients, and the second analysis included only stroke patients with polypharmacy. RESULTS: On multiple regression analysis, the number of drugs at admission (ß=-0.628) was associated with FIM-T at discharge of all stroke patients. Furthermore, the number of additional drugs during hospitalization (ß=-1.964) was associated with FIM-T at discharge in the 176 stroke patients with polypharmacy. CONCLUSION: This study suggested that the number of drugs at admission and the addition of drugs during hospitalization might have a negative impact on the rehabilitation outcomes of subacute stroke patients.

Cognitive function is associated with home discharge in subacute stroke patients: a retrospective cohort study.

AIM: To investigate the cognitive function and its relation to the home discharge of patients following subacute stroke. METHODS: This retrospective cohort study included 1,229 convalescent patients experiencing their first subacute stroke. We determined discharge destination and demographic and clinical information. We recorded the following measurement scores: Mini-Mental State Examination (MMSE) score, Stroke Impairment Assessment Set score, grip strength, and Functional Independence Measure (FIM). We performed a multivariable logistic regression analysis with the forced-entry method to identify factors related to home discharge. RESULTS: Of the 1,229 participants (mean age: 68.7 ± 13.5 years), 501 (40.8%), 735 (59.8%), and 1,011 (82.3%) were female, had cerebral infarction, and were home discharged, respectively. Multivariable logistic regression analysis revealed that age (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.91 - 0.96; P < 0.001), duration from stroke onset to admission (OR, 0.98; 95% CI, 0.96 - 0.99; P = 0.003), living situation (OR, 4.40; 95% CI, 2.69 - 7.20; P < 0.001), MMSE score at admission (OR, 1.05; 95% CI, 1.00 - 1.09; P = 0.035), FIM motor score at admission (OR, 1.04; 95% CI, 1.01 - 1.06; P = 0.001), and FIM cognitive score at admission (OR, 1.08; 95% CI, 1.04 - 1.13; P < 0.001) were significantly associated with home discharge. CONCLUSIONS: MMSE at admission is significantly associated with home discharge in patients with subacute stroke.

Relationship between initial nutritional status and functional independence measures at discharge in subacute stroke.

OBJECTIVE: This retrospective study examined the association between nutritional status at admission and functional independence measure (FIM™) at discharge. MATERIALS AND METHODS: This study included 205 patients, aged ≥ 65, discharged from a convalescent ward between April 2017 and March 2018. The primary outcome was discharge FIMTM, and the secondary outcomes were the length of stay (LOS) and FIM efficiency. The explanatory variables included demographic data, stroke type, admission FIMTM, body mass index (BMI), controlling nutritional status (CONUT), and Geriatric Nutritional Risk Index (GNRI). Patients were divided into three groups based on BMI and GNRI scores and four groups based on the CONUT score. Univariate and multiple regression analyses were performed to predict discharge FIMTM. Kruskal-Wallis and Dunn's tests were also performed for intergroup comparisons. RESULTS: In the univariate analyses, age, sex, onset-to-admission interval, admission FIMTM, GNRI, and BMI (all factors were p<0.001) were significant explanatory variables for discharge FIMTM. In the multiple linear regression analysis, admission FIMTM, LOS, age, and onset-to-admission interval were significant explanatory variables (adjusted R2 = 0.791; p<0.001). Although those with poor nutritional status required a longer hospital stay, they achieved the same FIM gain as those without poor nutritional status. CONCLUSIONS: Nutritional status on admission did not affect the FIMTM at discharge in the convalescent ward. Patients with subacute stroke require adequate rehabilitation regardless of their nutritional status.

Blind Spots in Hospital Fall Prevention: Falls in Stroke Patients Occurred Not Only in Those at a High Risk of Falling.

OBJECTIVES: Although the standard falls prevention strategy is to identify and respond to patients with high-risk conditions, it remains unclear whether falls in patients with high fall risk account for most observed falls. In this study, fall risk and number of falls were calculated based on patients' motor and cognitive abilities, and the relationship between the two was examined. DESIGN: We conducted a retrospective cohort study. SETTING AND PARTICIPANTS: We included 2518 consecutive patients with stroke who were admitted to a rehabilitation hospital. METHODS: Data on falls during hospitalization and biweekly assessed Functional Independence Measure scores were retrieved from the medical records. The average Functional Independence Measure scores for the motor and cognitive items were obtained and categorized as complete dependence, modified dependence, and independence. The fall rate (falls/1000 person-days) and number of observed falls in each combined condition were investigated. RESULTS: Modified dependence on motor ability and complete dependence on cognitive ability had the highest risk of falls, with a fall rate of 10.8/1000 person-days and 51 fall observations, which accounted for 4.3% of all falls. Independent motor and cognitive ability had the lowest risk of falls, a fall rate of 2.6/1000 person-days and 146 observed falls, accounting for 12.4% of all falls, which was 2.8 times higher than the number of falls observed in the highest risk of falls condition. CONCLUSIONS AND IMPLICATIONS: The combined motor-cognitive ability with the highest risk of falls in stroke inpatients did not have the highest number of observed falls. Rather, the combined motor-cognitive ability with the lowest risk of falls tended to have a high number of observed falls. A different strategy is needed to reduce the total number of falls.

Comparing the contribution of each clinical indicator in predictive models trained on 980 subacute stroke patients: a retrospective study.

Post-stroke disability affects patients' lifestyles after discharge, and it is essential to predict functional recovery early in hospitalization to allow time for appropriate decisions. Previous studies reported important clinical indicators, but only a few clinical indicators were analyzed due to insufficient numbers of cases. Although review articles can exhaustively identify many prognostic factors, it remains impossible to compare the contribution of each predictor. This study aimed to determine which clinical indicators contribute more to predicting the functional independence measure (FIM) at discharge by comparing standardized coefficients. In this study, 980 participants were enrolled to build predictive models with 32 clinical indicators, including the stroke impairment assessment set (SIAS). Trunk function had the most significant standardized coefficient of 0.221. The predictive models also identified easy FIM sub-items, SIAS, and grip strength on the unaffected side as having positive standardized coefficients. As for the predictive accuracy of this model, R2 was 0.741. This is the first report that included FIM sub-items separately in post-stroke predictive models with other clinical indicators. Trunk function and easy FIM sub-items were included in the predictive model with larger positive standardized coefficients. This predictive model may predict prognosis with high accuracy, fewer clinical indicators, and less effort to predict.

Improvement of predictive accuracies of functional outcomes after subacute stroke inpatient rehabilitation by machine learning models.

OBJECTIVES: Stepwise linear regression (SLR) is the most common approach to predicting activities of daily living at discharge with the Functional Independence Measure (FIM) in stroke patients, but noisy nonlinear clinical data decrease the predictive accuracies of SLR. Machine learning is gaining attention in the medical field for such nonlinear data. Previous studies reported that machine learning models, regression tree (RT), ensemble learning (EL), artificial neural networks (ANNs), support vector regression (SVR), and Gaussian process regression (GPR), are robust to such data and increase predictive accuracies. This study aimed to compare the predictive accuracies of SLR and these machine learning models for FIM scores in stroke patients. METHODS: Subacute stroke patients (N = 1,046) who underwent inpatient rehabilitation participated in this study. Only patients' background characteristics and FIM scores at admission were used to build each predictive model of SLR, RT, EL, ANN, SVR, and GPR with 10-fold cross-validation. The coefficient of determination (R2) and root mean square error (RMSE) values were compared between the actual and predicted discharge FIM scores and FIM gain. RESULTS: Machine learning models (R2 of RT = 0.75, EL = 0.78, ANN = 0.81, SVR = 0.80, GPR = 0.81) outperformed SLR (0.70) to predict discharge FIM motor scores. The predictive accuracies of machine learning methods for FIM total gain (R2 of RT = 0.48, EL = 0.51, ANN = 0.50, SVR = 0.51, GPR = 0.54) were also better than of SLR (0.22). CONCLUSIONS: This study suggested that the machine learning models outperformed SLR for predicting FIM prognosis. The machine learning models used only patients' background characteristics and FIM scores at admission and more accurately predicted FIM gain than previous studies. ANN, SVR, and GPR outperformed RT and EL. GPR could have the best predictive accuracy for FIM prognosis.

Risk Factors for Post-Stroke Pneumonia in a Patient Population with Subacute Stroke: A Retrospective Cohort Study.

The risk of pneumonia and death is higher in acute stroke patients with signs of pulmonary infection on chest computed tomography (CT) at admission. However, few reports have examined the incidence of pneumonia and its predictors in subacute stroke patients. The aim of this study was to examine factors related to post-stroke pneumonia in subacute stroke patients. A total of 340 subacute stroke patients were included. Univariable logistic regression analysis was performed using variables that may contribute to pneumonia, with the development of pneumonia as the dependent variable. Multivariable logistic regression analysis using the three independent variables with the lowest p-values on the univariable logistic regression analysis was also performed to calculate adjusted odds ratios. Twenty-two patients developed pneumonia during hospitalization. The univariable logistic regression analysis showed that the top three items were serum albumin (Alb), functional Oral Intake Scale (FOIS) score, and signs of pulmonary infection on chest CT at admission. Multivariable logistic regression analysis adjusted for these three items showed that the presence of signs of pulmonary infection on chest CT at admission was the independent variable (OR: 4.45; 95% CI: 1.54-12.9). When signs of pulmonary infection are seen on admission chest CT, careful follow-up is necessary because pneumonia is significantly more likely to occur during hospitalization.

Determinants of Step-through Gait Pattern Acquisition in Subacute Stroke Patients.

Objectives: Stroke patients may have a step-to gait pattern during the early stages of gait reacquisition. This gait provides stability, but it is slow and inefficient. Therefore, acquiring step-through gait is desirable for better efficiency as ability improves. This study aimed to examine the relevant factors affecting the acquisition of step-through gait pattern in subacute stroke patients based on assessments of physical function at admission. Methods: This was a retrospective cohort study. A total of 91 patients with hemiplegic stroke, Functional Independence Measure (FIM) gait item of 4 or less on admission, and FIM gait item of 5 or greater on discharge were included. Factors necessary for the acquisition of step-through gait pattern were examined based on the motor function assessed by Stroke Impairment Assessment Set (SIAS) at the time of admission. Gait pattern was defined by the gait step length of the Tinetti Performance-Oriented Mobility Assessment at discharge. Results: Knee-joint extension function on the paralyzed side was determined as a factor associated with the acquisition of step-through gait pattern at discharge [odds ratio 2.24, 95% confidence interval (CI) 1.44‒3.50, P<0.001]. The area under the receiver operating characteristic curve for predicting the step-through gait pattern at discharge was 0.786 (95% CI 0.676-0.896, P<0.001) for the SIAS knee joint score at admission; the optimal cut-off score being 2 or greater (sensitivity 81%, specificity 61%). Conclusions: Knee function on the paralyzed side in subacute stroke patients is an independent predictor for the acquisition of step-through gait pattern.

Investigation of the Effect of Nutritional Supplementation with Whey Protein and Vitamin D on Muscle Mass and Muscle Quality in Subacute Post-Stroke Rehabilitation Patients: A Randomized, Single-Blinded, Placebo-Controlled Trial.

In post-stroke hemiparesis patients, the skeletal muscle mass decrease rapidly with the histological degradation. We investigated the effect of nutritional supplementation with whey protein and vitamin D on the muscle mass and muscle quality, in post-stroke convalescent rehabilitation patients in a randomized, single-blinded, placebo-controlled trial. Fifty patients were randomly assigned to two groups; HP group received supplemental jelly (100 kcal; whey protein 10 g; vitamin D 20 µg) twice a day throughout up to 16-week period, the control group received placebo jelly. Cross-sectional area (CSA) of thigh muscle, skeletal muscle index (SMI), muscle strength, activity of daily living (ADL), and some nutritional indicators in blood were measured. Although no significant difference was observed in CSA and SMI between the groups, fat infiltration into the thighs muscle was singnificantly lower in the HP group. There were no significant difference in muscle strength and ADL between the groups. Blood urea nitrogen and serum 25(OH)D at endpoint were significantly higher in the HP group but physiological normal ranges. Supplementation with whey protein and vitamin D in post-stroke patients led to suppression of fat infiltration into the muscle. Long-term follow-up studies are needed to verify whether this nutritional intervention provides substantial benefits for the prognosis of stroke survivors.

Comparison of the sit-up test and head-up tilt test for assessing blood pressure and hemodynamic responses in healthy young individuals.

OBJECTIVE: The sit-up test is used to assess orthostatic hypotension, without the use of a tilt table, in populations who are unable to stand. The primary objective of this study was to determine the differences in blood pressure and hemodynamic responses between the sit-up and head-up tilt tests. The secondary objective was to determine the hemodynamic responses related to changes in blood pressure during each test. METHODS: Nineteen healthy volunteers (nine males, aged 24.3 ± 2.4 years) underwent the sit-up and head-up tilt tests. Systolic and diastolic blood pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance were measured. RESULTS: The increase in systolic blood pressure (15 ± 9 vs. 8 ± 8 mmHg) was greater, while the increase in heart rate (8 ± 5 vs. 12 ± 8 bpm) and reduction in stroke volume (-17 ± 10 vs. -21 ± 10 ml) were smaller during the sit-up test than during the head-up tilt test (P < 0.05). Additionally, the increases in blood pressure variables were significantly associated with the increase in total peripheral resistance (P < 0.05), but not with changes in other hemodynamic variables in both tests. CONCLUSION: Although the magnitudes of changes in systolic blood pressure, heart rate, and stroke volume differed between the tests, the hemodynamic variable related to changes in blood pressure was the same for both tests. These results may contribute to the clinical application of the sit-up test for identifying the presence and hemodynamic mechanisms of orthostatic hypotension.

Effects of the COVID-19 Pandemic on Physical Function of Community-Dwelling People with Disabilities in Japan.

In 2020, COVID-19 spread throughout the world, and international measures such as travel bans, quarantines, and increased social distancing were implemented. In Japan, the number of infected people increased, and a state of emergency was declared from 16 April to 25 May 2020. Such a change in physical activity could lead to a decline in physical function in people with disabilities. A retrospective study was conducted to determine the impact of the pandemic on the physical function of disabled persons living in the community. Data were collected at four points in time: two points before the declaration of the state of emergency was issued and two points after the declaration period had ended. Time series data of physical function at four points in time were compared for 241 people with disabilities. The mean age was 72.39 years; 157 had stroke, 59 musculoskeletal disease, and 26 other diseases. Overall, there was a long-term decrease in walking speed (p < 0.001) and a worsening of the Timed Up-and-Go (TUG) score (p < 0.001) after the period of the state of emergency. The TUG score worsened only in the group with a walking speed of 1.0 m/s or less before the state of emergency (p = 0.064), suggesting that this group was more susceptible.

Rehabilitation outcomes of stroke patients with low left ventricular ejection fraction in the subacute rehabilitation phase.

OBJECTIVE: To examine the left ventricular ejection fraction in patients with subacute stroke and compare rehabilitation outcomes between those with decreased left ventricular ejection fraction and those without. DESIGN: Retrospective chart review. SUBJECTS: A total of 482 consecutive patients with stroke admitted to a convalescent rehabilitation hospital. METHODS: Patients were assessed using transthoracic echocardiography within 7 days of admission. The patients were divided into a group with low left ventricular ejection fraction and a group with preserved left ventricular ejection fraction. Functional Independence Measure (FIM) scores at admission and discharge, FIM gain, FIM efficiency, and discharge disposition were compared between groups. RESULTS: The low left ventricular ejection fraction group had significantly lower cognitive and total FIM scores on admission than the preserved left ventricular ejection fraction group. The patients in the low left ventricular ejection fraction group tended to be transferred to acute hospitals more frequently. How-ever, the total score of discharge FIM, FIM gain, and FIM efficiency did not differ significantly between the groups when rehabilitation was continued until discharge. CONCLUSION: Stroke patients with low left ventricular ejection fraction in the subacute phase could achieve almost the same functional outcomes as those of patients with preserved left ventricular ejection fraction. Although the general medical condition should be considered, the finding of low left ventricular ejection fraction did not pose a barrier to successful rehabilitation after stroke.

Echocardiographic abnormalities in patients with stroke during the subacute rehabilitation phase.

OBJECTIVE: To evaluate cardiac function using echocardiography in patients with stroke admitted to subacute rehabilitation units. DESIGN: Retrospective, cross-sectional study. PARTICIPANTS: A total of 750 consecutive patients with stroke who were admitted to a suburban rehabilitation hospital. Mean age 67.5 years (standard deviation (SD) 12.3 years). Mean time since stroke 36.7 days (SD 13.2 days). METHODS: Patients were assessed using transthoracic echocardiography within 7 days of admission. The prevalence of echocardiographic abnormalities was analysed and compared between cerebral infarction and haemorrhage using the Mantel-Haenszel method controlled for age. RESULTS: Arrhythmias were found in 13.7% of the patients, 94.2% of whom had atrial fibrillation. Left atrial enlargement and left ventricular hypertrophy were found in 20.4% and 19.5% of all patients, respectively. Left ventricular asynergy was detected in 6.1% of all patients, but 47.8% of them had no history of myocardial infarction. Left ventricular ejection fraction was low in 12.2% of all patients. Abnormal rhythms and left atrial enlargement were significantly more frequent in patients with cerebral infarction than in those with cerebral haemorrhage (p < 0.01). CONCLUSION: The prevalence of cardiac problems is high among patients with subacute stroke regardless of a history of heart disease, and this should be taken into account when planning rehabilitation programmes.