Ross A. Bogey

Gait Training Strategies Utilized in Poststroke Rehabilitation: Are We Really Making a Difference?

Abstract Stroke is the leading cause of disability in the United States. Restoration of walking continues to be a major goal of rehabilitation for persons with stroke. The concept of a minimal change in performance to be considered important or significant has recently been addressed in the field of stroke rehabilitation. We examine some of the changes in locomotor function in poststroke individuals. None of the neurofacilitation approaches have shown significant improvement in walking performance after stroke. Functional electrical stimulation (FES) can be performed by stimulating over the muscle, intra-muscularly, or over the peripheral nerve that innervates a muscle providing insufficient force for gait. To date, no form of artificial stimulation can match natural activation for precision or fatigue resistance. Body weight—supported treadmill training (BWSTT) is thought to contribute substantially to the reorganization of neural circuitry and has been shown to restore gait of nonambulatory individuals. Despite the promising recovery suggested by BWSTT, the time and physical demands on therapists have prevented it from wide clinical acceptance. Thus various robotic devices have been developed to provide such “mechanical” stepping assistance. The magnitude of changes induced with robotic devices does not appear to be any greater than that achieved with more traditional approaches or as compared to task-specific BWSTT.

Use of visual force feedback to improve digit force direction during pinch grip in persons with stroke: A pilot study

OBJECTIVE To investigate whether visual feedback of digit force directions for the index fingertip and thumb tip during repeated practice of grip force production can correct the digit force directions for persons with stroke during grip assessments. Following stroke, the paretic fingers generate digit forces with a higher than normal proportion of shear force to compression force during grip. This misdirected digit force may lead to finger-object slip and failure to stably grasp an object. DESIGN A case series. SETTING Laboratory. PARTICIPANTS Persons (N=11) with severe chronic hand impairment after stroke. INTERVENTIONS Four training sessions during which participants practiced directing the index finger and thumb forces in various target directions during pinch using visual feedback. MAIN OUTCOME MEASURE Digit force direction during pinch and clinical hand function scores were measured before and immediately after the training. RESULTS Study participants were able to redirect the digit force closer to the direction perpendicular to the object surface and increase their hand function scores after training. The mean ratio of the shear force to the normal force decreased from 58% to 41% (SD, 17%), the mean Box and Block Test score increased from 1.4 to 3.4 (SD, 2.0), and the mean Action Research Arm Test score increased from 10.8 to 12.1 (SD, 1.3) (P<.05 for all 3 measures). CONCLUSIONS Repeated practice of pinch with visual feedback of force direction improved grip force control in persons with stroke. Visual feedback of pinch forces may prove valuable as a rehabilitation paradigm for improving hand function.

Mapping the Neglected Space: Gradients of Detection Revealed by Virtual Reality

Background. Spatial neglect affects perception along different dimensions. However, there is limited availability of 3-dimensional (3D) methods that fully map out a patient’s volume of deficit, although this could guide clinical management. Objective. To test whether patients with neglect exhibit simple contralesional versus complex perceptual deficits and whether deficits are best described using Cartesian (rectangular) or polar coordinates. Methods. Seventeen right-hemisphere persons with stroke (8 with a history of neglect) and 9 healthy controls were exposed to a 3D virtual environment. Targets placed in a dense array appeared one at a time in various locations. Results. When tested using rectangular array of targets, subjects in the neglect group exhibited complex asymmetries across several dimensions in both reaction time and target detection rates. Paper-and-pencil tests only detected neglect in 4 of 8 of these patients. When tested using polar array of targets, 2 patients who initially appeared to perform poorly in both left and near space only showed a simple left-side asymmetry that depended almost entirely on the angle from the sagittal plane. A third patient exhibited left neglect irrespective of the arrangements of targets used. An idealized model with pure dependence on the polar angle demonstrated how such deficits could be misconstrued as near neglect if one uses a rectangular array. Conclusions. Such deficits may be poorly detected by paper-and-pencil tests and even by computerized tests that use regular screens. Assessments that incorporate 3D arrangements of targets enable precise mapping of deficient areas and detect subtle forms of neglect whose identification may be relevant to treatment strategies.

Stroke and neurodegenerative disorders. 4. neurodegenerative disorders

Bryant PR, Geis CC, Moroz A, O’Neill BJ, Bogey RA. Stroke and neurodegenerative disorders. 4. Neurodegenerative disorders. 2004;85(3 Suppl 1):S21–33. This self-directed learning module highlights diagnosis, treatment, and rehabilitation issues in patients with neurodegenerative disorders, including multiple sclerosis (MS), Parkinson’s disease, and amyotrophic lateral sclerosis (ALS). It is part of the study guide on stroke and neurodegenerative disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on the differential diagnosis, diagnostic evaluation, medical management, and rehabilitation issues in MS. Similarly, the differential diagnosis treatment and rehabilitation in Parkinson’s disease is discussed. Electrodiagnosis, pharmacologic treatment, and rehabilitation options for ALS are also discussed.

Effect of a serotonin antagonist on delay in grip muscle relaxation for persons with chronic hemiparetic stroke

OBJECTIVE To investigate if, following stroke, sustained involuntary activity after voluntary contraction (e.g., grip) of the long finger flexor muscles of the paretic hand is attributable to augmented serotonin release from brainstem pathways, affecting excitability of spastic motoneurons. METHODS This single-dose placebo-controlled study examined whether a serotonin receptor (5-HT2) antagonist, cyproheptadine hydrochloride, could reduce delay in muscle relaxation of a key paretic long finger flexor muscle immediately after grip for persons with stroke. Time to initiate the long finger flexor muscle contraction, grip and pinch strengths, and clinical hand function scores (the Action Research Arm Test and the Box and Block Test) were also assessed. RESULTS Cyproheptadine hydrochloride reduced mean delays in finger relaxation (n=13; from 7.2 to 4.1 s; SEM=1.2 s; p=.026) in comparison to placebo, while leaving grip and pinch strengths and time to initiate the muscle contraction largely unaffected. Reduction in the relaxation time alone did not lead to increased clinical hand function scores. CONCLUSIONS The findings support the supposition that monoaminergic brainstem pathways may be disinhibited following stroke, thereby resulting in increased delays in muscle relaxation. SIGNIFICANCE Treatments to reduce delay in muscle relaxation may facilitate hand rehabilitation in persons with stroke.

Assessment and monitoring of recovery of spatial neglect within a Virtual Environment

Spatial neglect has proven to be a significant factor limiting the success of the rehabilitation process following stroke. Current tests for neglect however have several substantial drawbacks, which often lead to a misdiagnosis of less severe cases. Further, while asymmetries of performance have been reported in the past along independent spatial dimensions, current tests are mostly limited to the horizontal dimension and do not reflect the reality of a three-dimensional world. We have previously demonstrated the feasibility of virtual reality tools for detailed assessments of attentional deficits [1]. We now provide further evidence for the sensitivity of our Virtual Environment for Spatial Neglect Assessment (VESNA) application for assessment of neglect as well as for monitoring recovery of patients. Seven stroke patients with neglect, nine stroke patients without neglect and nine age-matched healthy controls were tested on a target-detection task. Subjects were exposed to a three-dimensional virtual scene and were instructed to press a response button when they detected a target appearing within the scene. Percent of correct detection and reaction time to initiate a button press were calculated. Our results indicated significant differences between neglect patients and control subjects. All neglect patients exhibited asymmetries of performance, where their mean reaction time and detection accuracy systematically varied across space. This asymmetry was not a harsh transition but instead showed a gradual reduction of attention across the space. Importantly, while these results indicated an obvious spatial neglect for all seven neglect patients, their performance on the standard paper-and-pencil tests, administered at the day of testing, was less conclusive. A follow-up study with two of the neglect patients (10 months following the initial testing) revealed an obvious recovery pattern, showing a reduction of the spatial bias over time. By contrast, the paper-and-pencil tests showed no obvious change. Thus, we demonstrated that our paradigm provided a quantitative and more sensitive assessment and monitoring of recovery of neglect. This might provide clinicians with a more precise description of a patientpsilas deficit which will help direct training.

Stroke and neurodegenerative disorders. 4. neurodegenerative disorders11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated.

Bryant PR, Geis CC, Moroz A, O’Neill BJ, Bogey RA. Stroke and neurodegenerative disorders. 4. Neurodegenerative disorders. 2004;85(3 Suppl 1):S21–33. This self-directed learning module highlights diagnosis, treatment, and rehabilitation issues in patients with neurodegenerative disorders, including multiple sclerosis (MS), Parkinson’s disease, and amyotrophic lateral sclerosis (ALS). It is part of the study guide on stroke and neurodegenerative disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on the differential diagnosis, diagnostic evaluation, medical management, and rehabilitation issues in MS. Similarly, the differential diagnosis treatment and rehabilitation in Parkinson’s disease is discussed. Electrodiagnosis, pharmacologic treatment, and rehabilitation options for ALS are also discussed.

Stroke and neurodegenerative disorderStroke and neurodegenerative disorders. 4. neurodegenerative disorders1

Bryant PR, Geis CC, Moroz A, O’Neill BJ, Bogey RA. Stroke and neurodegenerative disorders. 4. Neurodegenerative disorders. 2004;85(3 Suppl 1):S21–33. This self-directed learning module highlights diagnosis, treatment, and rehabilitation issues in patients with neurodegenerative disorders, including multiple sclerosis (MS), Parkinson’s disease, and amyotrophic lateral sclerosis (ALS). It is part of the study guide on stroke and neurodegenerative disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on the differential diagnosis, diagnostic evaluation, medical management, and rehabilitation issues in MS. Similarly, the differential diagnosis treatment and rehabilitation in Parkinson’s disease is discussed. Electrodiagnosis, pharmacologic treatment, and rehabilitation options for ALS are also discussed.