Group Of Post-stroke Patients Research Articles

Novel evaluation of upper-limb motor performance after stroke based on normal reaching movement model

BackgroundUpper-limb rehabilitation robots provide repetitive reaching movement training to post-stroke patients. Beyond a pre-determined set of movements, a robot-aided training protocol requires optimization to account for the individuals’ unique motor characteristics. Therefore, an objective evaluation method should consider the pre-stroke motor performance of the affected arm to compare one’s performance relative to normalcy. However, no study has attempted to evaluate performance based on an individual’s normal performance. Herein, we present a novel method for evaluating upper limb motor performance after a stroke based on a normal reaching movement model.MethodsTo represent the normal reaching performance of individuals, we opted for three candidate models: (1) Fitts’ law for the speed-accuracy relationship, (2) the Almanji model for the mouse-pointing task of cerebral palsy, and (3) our proposed model. We first obtained the kinematic data of healthy (n = 12) and post-stroke (n = 7) subjects with a robot to validate the model and evaluation method and conducted a pilot study with a group of post-stroke patients (n = 12) in a clinical setting. Using the models obtained from the reaching performance of the less-affected arm, we predicted the patients’ normal reaching performance to set the standard for evaluating the affected arm.ResultsWe verified that the proposed normal reaching model identifies the reaching of all healthy (n = 12) and less-affected arm (n = 19; 16 of them showed an R2 > 0.7) but did not identify erroneous reaching of the affected arm. Furthermore, our evaluation method intuitively and visually demonstrated the unique motor characteristics of the affected arms.ConclusionsThe proposed method can be used to evaluate an individual’s reaching characteristics based on an individuals normal reaching model. It has the potential to provide individualized training by prioritizing a set of reaching movements.

EEG Signal Complexity Measurements to Enhance BCI-Based Stroke Patients' Rehabilitation.

The second leading cause of death and one of the most common causes of disability in the world is stroke. Researchers have found that brain-computer interface (BCI) techniques can result in better stroke patient rehabilitation. This study used the proposed motor imagery (MI) framework to analyze the electroencephalogram (EEG) dataset from eight subjects in order to enhance the MI-based BCI systems for stroke patients. The preprocessing portion of the framework comprises the use of conventional filters and the independent component analysis (ICA) denoising approach. Fractal dimension (FD) and Hurst exponent (Hur) were then calculated as complexity features, and Tsallis entropy (TsEn) and dispersion entropy (DispEn) were assessed as irregularity parameters. The MI-based BCI features were then statistically retrieved from each participant using two-way analysis of variance (ANOVA) to demonstrate the individuals' performances from four classes (left hand, right hand, foot, and tongue). The dimensionality reduction algorithm, Laplacian Eigenmap (LE), was used to enhance the MI-based BCI classification performance. Utilizing k-nearest neighbors (KNN), support vector machine (SVM), and random forest (RF) classifiers, the groups of post-stroke patients were ultimately determined. The findings show that LE with RF and KNN obtained 74.48% and 73.20% accuracy, respectively; therefore, the integrated set of the proposed features along with ICA denoising technique can exactly describe the proposed MI framework, which may be used to explore the four classes of MI-based BCI rehabilitation. This study will help clinicians, doctors, and technicians make a good rehabilitation program for people who have had a stroke.

A Comparative Analysis of Functional Status and Mobility in Stroke Patients with and without Aphasia.

All researchers agree that aphasia is a serious consequence of a stroke, but they also report contradictory data regarding the functional outcome. The aim of this study was, therefore, to assess the functional outcomes of stroke patients with and without aphasia, who were undertaking a regular rehabilitation programme. Materials and Methods: The study group consisted of 116 post-stroke patients, including 54 patients without aphasia (G1) and 62 patients with aphasia (G2). The following tests were used before (T1) and after (T2) rehabilitation measurement points: Barthel Index (BI), Sitting Assessment Scale (SAS), Berg Balance Scale (BBS), Trunk Control Test (TCT), Test Up & Go (TUG) and the Timed Walk Test (TWT). Results: The group of post-stroke patients with aphasia had a significantly longer time since a stroke on admission, a significantly longer length of stay in the ward and significantly worse SAS and TCT scores at T2, compared to patients without aphasia. Both groups achieved significant improvement in all studied parameters (SAS, TCT, BI, BBS, TUG and TWT). Aphasia was a predictor of functional status in the stroke patients group, but only at the time of admission to the ward. Conclusions: Patients with and without aphasia have an equal likelihood of improving their functional status and returning to independence. Aphasia should not be an absolute factor that excludes stroke patients from research studies on their functional status.

Comparison of Objective Indicators of Proprioception of Single–joint Arm Movements in Healthy Subjects and Post–Stroke Patients in Sitting and Lying Positions

Testing of sensory-motor performance and motor rehabilitation training in post-stroke patients are often executed in lying position. At the same time, influence of the body position on proprioceptive perception is poorly studied. In this study, we have investigated proprioceptive perception of single-joint arm movements in 10 healthy subjects and 17 post-stroke patients with unilateral arm paresis in the sitting and lying positions using the method we developed. Movements of flexion–extension in shoulder, elbow and wrist joints and abduction–adduction in shoulder and wrist joints were tested. The subjects were made to perform a series of the passive single-joint movements with the eyes closed and had to copy these movements simultaneously by active movements of another arm. We recorded the angles at the tested joint and the homonymous joint of the other arm, and the status of proprioceptive sensitivity was evaluated basing on the degree of similarity of these “passive” and “active” movements. Qualitative and quantitative indicators were used to assess the similarity. It was found that healthy subjects reproduce the passive movements without rough qualitative errors in both the sitting and lying positions. The movement reproduction was less accurate in the lying position by values of some quantitative indicators, however only 3% of trails did not match the conventional criterion for proprioceptive sensitivity intactness. On the contrary, the movement reproduction in almost half of tests in the group of post-stroke patients was performed with qualitative and quantitative errors and did not match the requirements of the conventional criterion. A deficit of proprioception was observed in 1 to 5 different test-movements in 88% of patients in the sitting position and 71% of patients in the lying position. Most frequent and rough errors in the movement reproduction were observed in distal segments of the paretic arm. It was found that the body position could have different effects on the proprioceptive perception of the same test-movement in patients: the proprioceptive perception was evaluated as intact in the sitting position and as distorted in the lying position in 14% of all test trials and vice versa it was evaluated as distorted in sitting position and as intact in lying positions in 17% of trials. Such individual differences must be considered when choosing conditions for motor rehabilitation procedures in patients with paresis of the arm.

EPA-0277 – Post-stroke depression and suicidality correlated with personality features among elderly patients

Depression may occur as a result of cerebrovascular disease in a significant subpopulation of elderly persons. Recent studies indicate a high frequency of depression in older patients with cardiovascular and cerebrovascular diseases, and the possibility of a bidirectional relationship between depression and vascular disease. Our research included 62 post-stroke patients above age 60 undergoing post-stroke treatment in department of Neurology and 30 elderly patients who had suffered stroke one year ago and underwent psychiatric treatment. Each patient were given scales for assessment of depressive symptomes (Hamilton depression rating scale HAM-D), suicidality (Columbia suicide severity rating scale CSSR-S) and the list for assessment of borderline personality symptoms (Borderline Symptom List BSL) with examination of mental state (MMSE). These scales were given prior to antidepressant treatment and two weeks following the treatment. The obtained results shown positive correlation of depressive symptoms, suidical ideation and cognitive impairment in the group of post-stroke patients in psychiatric (with higher positive correlation in women). While in the group of elderly patients in psychiatric treatment (> than 1 year) the depressive symptoms were highly correlated with positive bordeline personality features and these specific personality features were highly correlated with suicidal ideation. Our research showed how depressive symptoms are variable and highly correlated with personality features along with cognitive functioning. However, suicidal ideation was more correlated with specific personality features than depression itself. We have also concluded that concept of suicidality in the elderly seems unjustifiable neglected and should be more vigorously identified.

Assessing Mechanisms of Recovery During Robot-Aided Neurorehabilitation of the Upper Limb

Objective. The present study aimed to qualify and quantify the different components of motor recovery in a group of stroke patients treated by robot-aided techniques. In addition, the learning model of each motor recovery component was analyzed. Methods . Two groups of poststroke patients were treated with the use of an elbow-shoulder manipulator, respectively, within (recent) and after (chronic) the first 6 months of their cerebrovascular accident. Both groups were evaluated by means of standard clinical assessment scales and a robot-measured evaluation method. Results. These findings confirm that motor training consisting of voluntary movements assisted by the robot device led to significant improvements in motor performance in terms of the kinematic and dynamic components of the arm movements. This corresponded to improvement of impairment as confirmed by the clinical scale results. Conclusions. Knowledge of the recovery components and of the associated performance acquisition model may be useful in assessing and training stroke patients and should make it possible to precisely plan and, if necessary, modify the rehabilitation strategies.

Relation between incidence of pneumonia and protective reflexes in post‐stroke patients with oral or tube feeding

Although attenuated protective reflexes have been implicated in the development of aspiration pneumonia, the relation between the incidence of pneumonia and the state of these reflexes has not been investigated. Furthermore, the role of feeding tube placement in preventing pneumonia in patients with attenuated protective reflexes is unknown. We studied the relationship between the incidence of pneumonia and the state of cough and swallowing reflexes in post-stroke patients with oral or tube feeding. The incidence of pneumonia was prospectively analysed for 1 year in three groups of post-stroke patients on the basis of the following clinical conditions: oral feeding without dysphagia (n = 43); oral feeding with dysphagia (n = 48); and nasogastric tube feeding with dysphagia (n = 52). We also studied the incidence of pneumonia in bedridden patients with nasogastric tube feeding (n = 14). Before the start of the study, the swallowing and cough reflexes of each patient were measured. The swallowing reflex was evaluated according to latency of response, which was timed from the injection of 1 mL of distilled water into the pharynx through a nasal catheter to the onset of swallowing. The cough threshold of citric acid aerosols was defined as the concentration at which the patient coughed five times. RESULTS.;: The incidence of pneumonia was observed in patients having both a latency of response longer than 5 s and a cough threshold for citric acid higher than a concentration of 1.35 (log mg mL-1). The incidence of pneumonia was significantly higher in patients with oral feeding than in those with tube feeding (54.3 vs. 13.2%, P < 0.001). In bedridden patients with tube feeding, the latency of response was longer than 20 s and no patient coughed at the highest concentration of citric acid. The incidence of pneumonia was 64.3% in such patients. The state of protective reflexes had a significant relation to the incidence of pneumonia. Feeding tube placement may have a beneficial role in preventing aspiration pneumonia in mildly or moderately disabled post-stroke patients with attenuated protective reflexes. Bedridden patients who were tube-fed had the highest incidence of pneumonia.