Fatigue Versus Activity-Dependent Fatigability in Patients With Central or Peripheral Motor Impairments Comments Off
In the rehabilitation literature, fatigue is a common symptom of patients with any neurological impairment when defined as a subjective lack of physical and mental energy that interferes with usual activities. Some complaints may, however, arise from fatigability , an objective decline in strength as routine use of muscle groups proceeds. By this refined definition of fatigue, exercise or sustained use reduces the ability of muscles to produce force or power, regardless of whether the task can be sustained. Fatigability may be masked clinically because (1) the degree of weakening is not profound, (2) activity-induced weakness rapidly lessens with cessation of exertion, and (3) clinicians rarely test for changes in strength after repetitive movements to objectively entertain the diagnosis. The repetitive movements that induce fatigability during daily activities are an iterative physiological process that depends on changing states induced by activation of spared central and peripheral neurons and axons and compromised muscle. Fatigability may be especially difficult to localize in patients undergoing neurorehabilitation, in part because no finite boundary exists between the central and peripheral components of motor reserve and endurance. At the bedside, however, manual muscle testing before and after repetitive movements could at least put some focus on the presence of fatigability in any patient with motor impairments and related disabilities. Reliable measures of fatigability beyond a careful clinical examination, such as physiological changes monitored by cerebral functional neuroimaging techniques and more standardized central and peripheral electrical and magnetic stimulation paradigms, may help determine the mechanisms of activity-dependent weakening and lead to specific therapies. Testable interventions to increase motor reserve include muscle strengthening and endurance exercises, varying the biomechanical requirements of repetitive muscle contractions, and training-induced neural plasticity or pharmacologic manipulations to enhance synaptic efficacy.
Effects of Robot-Assisted Therapy on Upper Limb Recovery After Stroke: A Systematic Review Comments Off
Objective. The aim of the study was to present a systematic review of studies that investigate the effects of robot-assisted therapy on motor and functional recovery in patients with stroke. Methods. A database of articles published up to October 2006 was compiled using the following Medline key words: cerebral vascular accident, cerebral vascular disorders, stroke, paresis, hemiplegia, upper extremity, arm, and robot. References listed in relevant publications were also screened. Studies that satisfied the following selection criteria were included: (1) patients were diagnosed with cerebral vascular accident; (2) effects of robot-assisted therapy for the upper limb were investigated; (3) the outcome was measured in terms of motor and/or functional recovery of the upper paretic limb; and (4) the study was a randomized clinical trial (RCT). For each outcome measure, the estimated effect size (ES) and the summary effect size (SES) expressed in standard deviation units (SDU) were calculated for motor recovery and functional ability (activities of daily living [ADLs]) using fixed and random effect models. Ten studies, involving 218 patients, were included in the synthesis. Their methodological quality ranged from 4 to 8 on a (maximum) 10-point scale. Results. Meta-analysis showed a nonsignificant heterogeneous SES in terms of upper limb motor recovery. Sensitivity analysis of studies involving only shoulder-elbow robotics subsequently demonstrated a significant homogeneous SES for motor recovery of the upper paretic limb. No significant SES was observed for functional ability (ADL). Conclusion. As a result of marked heterogeneity in studies between distal and proximal arm robotics, no overall significant effect in favor of robot-assisted therapy was found in the present meta-analysis. However, subsequent sensitivity analysis showed a significant improvement in upper limb motor function after stroke for upper arm robotics. No significant improvement was found in ADL function. However, the administered ADL scales in the reviewed studies fail to adequately reflect recovery of the paretic upper limb, whereas valid instruments that measure outcome of dexterity of the paretic arm and hand are mostly absent in selected studies. Future research into the effects of robot-assisted therapy should therefore distinguish between upper and lower robotics arm training and concentrate on kinematical analysis to differentiate between genuine upper limb motor recovery and functional recovery due to compensation strategies by proximal control of the trunk and upper limb.
Conceptualizing Functional Cognition in Stroke Comments Off
Background. Up to 65% of individuals demonstrate poststroke cognitive impairments, which may increase hospital stay and caregiver burden. Randomized stroke clinical trials have emphasized physical recovery over cognition. Neuropsychological assessments have had limited utility in randomized clinical trials. These issues accentuate the need for a measure of functional cognition (the ability to accomplish everyday activities that rely on cognitive abilities, such as locating keys, conveying information, or planning activities). Objective. The aim of the study was to present the process used to establish domains of functional cognition for development of computer adaptive measure of functional cognition for stroke. Methods. Functional cognitive domains involved in identifying relevant neuropsychological constructs from the literature were conceptualized and finalized after advisory panel feedback from experts in neurology, neuropsychology, aphasiology, clinical trials, and epidemiology. Results. The following 17 domains were proposed: receptive aphasia, expressive aphasia, agraphia, alexia, calculation, visuospatial, visuoperceptual, visuoconstruction, attention, language usage, executive functions, orientation, processing speed, memory, working memory, mood, awareness and abstract reasoning. The advisory panel recommended retaining the first 12 domains. Recommended changes included: to address only encoding and retrieval of recent information in the memory domain; to add domains for limb apraxia and poststroke depression; and to keep orientation as a separate domain or reclassify it under memory or attention. The final 10 domains included: language, reading and writing, numeric/calculation, limb praxis, visuospatial function, social use of language, emotional function, attention, executive function, and memory. Conclusion. Conceptualizing domains of functional cognition is the first step in developing a computer adaptive measure of functional cognition for stroke. Additional steps include developing, refining, and field-testing items, psychometric analysis, and computer adaptive test programming.
Brain Activity Associated With Stimulation Therapy of the Visual Borderzone in Hemianopic Stroke Patients Comments Off
Background and objective. Visual restoration therapy is a home-based treatment program intended to expand visual fields of hemianopic patients through repetitive stimulation of the borderzone adjacent to the blind field. We hypothesized that the training itself would induce visual field location-specific changes in the brain's response to stimuli, a phenomenon demonstrated in animal experiments but never in humans with brain injury. Methods. Six chronic right hemianopic patients underwent functional magnetic resonance imaging (fMRI)—responding to stimuli in the trained visual borderzone versus the nontrained seeing field before and after 1 month of visual restoration therapy. Spatially normalized fMRI time-series data were analyzed in a fixed-effects group analysis comparing blood oxygen level dependent (BOLD) activity in the borderzone versus seeing location at baseline and at 1 month. Percent BOLD change was measured to determine each condition's contribution to the time-by-condition interaction. Results. There was a significant time by condition interaction manifested as increased BOLD activity for borderzone detection relative to seeing detection after the first month of therapy, which correlated with a relative improvement in response times in the borderzone location out-of-scanner. The right inferior and lateral temporal, right dorsolateral frontal, bilateral anterior cingulate, and bilateral basal ganglia showed the greatest response. Conclusion. Visual restoration therapy appears to induce an alteration in brain activity associated with a shift of attention from the nontrained seeing field to the trained borderzone. The effect appears to be mediated by the anterior cingulate and dorsolateral frontal cortex in conjunction with other higher order visual areas in the occipitotemporal and middle temporal regions. Demonstration of a visual field—specific training effect on brain activity provides an important starting point for understanding the potential for visual therapy in hemianopia.
Changes in Activity After a Complete Spinal Cord Injury as Measured by the Spinal Cord Independence Measure II (SCIM II) Comments Off
Background. The assessment of rehabilitation efficacy in spinal cord injury (SCI) should be based on a combination of neurological and functional outcome measures. The Spinal Cord Independence Measure II (SCIM II) is an independence scale that was specifically developed for subjects with SCI. However, little is known about the changes in SCIM II scores during and after rehabilitation. Objective. The aims of this study were to evaluate changes in functional recovery during the first year after a complete SCI as measured by the SCIM II compared with neurological recovery (motor scores according to the American Spinal Injury Association [ASIA]). Methods. SCIM II data and ASIA motor scores at 1, 3, 6, and 12 months after injury (derived from the database of the European Multicenter Study of Human Spinal Cord Injury) of 64 patients with complete paraplegia and 36 patients with complete quadriplegia were analyzed. Results. In patients with complete paraplegia, the SCIM II total score improved significantly during the 1-year follow-up, even after discharge from rehabilitation. In contrast, the ASIA motor scores showed little recovery. In patients with quadriplegia, functional and motor recovery developed in parallel during rehabilitation and after discharge. Conclusions. The SCIM II is responsive to functional changes in patients with a persistent motor complete SCI. It is clinically useful for monitoring functional improvement during rehabilitation and after discharge. The SCIM II and the clinical examination based on the ASIA protocol are of complementary value and separately describe changes in independence and sensorimotor deficits in SCI patients.
Neural Correlates of Proprioceptive Integration in the Contralesional Hemisphere of Very Impaired Patients Shortly After a Subcortical Stroke: An fMRI Study Comments Off
Background. The effects of physiotherapy are difficult to assess in very impaired early stroke patients. Objective. The aim of the study was to characterize the impact of 4 weeks of passive proprioceptive training of the wrist on brain sensorimotor activation after stroke. Methods. Patients with a subcortical ischemic lesion of the pyramidal tract were randomly assigned to a control or a wrist-training group. All patients had a single pure motor hemiplegia with severe motor deficit. The control group (6 patients) underwent standard Bobath rehabilitation. The second, "trained," group (7 patients) received Bobath rehabilitation plus 4 weeks of proprioceptive training with daily passive calibrated wrist extension. Before and after the training period, patients were examined with validated clinical scales and functional MRI (fMRI) while executing a passive movement versus rest. The effect of standard rehabilitation on sensorimotor activation was assessed in the control group on the wrist, and the effect of standard rehabilitation plus proprioceptive training was assessed in the trained group. The effect of 4-week proprioceptive training alone was statistically evaluated by difference between groups. Results. Standard rehabilitation along with natural recovery mainly led to increases in ipsilesional activation and decreases in contralesional activation. On the contrary, standard rehabilitation and paretic wrist proprioceptive training increased contralesional activation. Proprioceptive training produced change in the supplementary motor area (SMA), prefrontal cortex, and a contralesional network including inferior parietal cortex (lower part of BA 40), secondary sensory cortex, and ventral premotor cortex (PMv). Conclusion. We have demonstrated that purely passive proprioceptive training applied for 4 weeks is able to modify brain sensorimotor activity after a stroke. This training revealed fMRI change in the ventral premotor and parietal cortices of the contralesional hemisphere, which are secondary sensorimotor areas. Recent studies have demonstrated the crucial role of these areas in severely impaired patients. We propose that increased contralesional activity in secondary sensorimotor areas likely facilitates control of recovered motor function by simple proprioceptive integration in those patients with poor recovery.
Sensory Loss in Hospital-Admitted People With Stroke: Characteristics, Associated Factors, and Relationship With Function Comments Off
Objective: To characterize the nature of sensory impairments after stroke, identify associated factors, and assess the relationships between sensory impairment, disability, and recovery. Methods: Prospective cross-sectional survey of 102 people with hemiparesis following their first stroke. Tactile and proprioceptive sensation in the affected arm and leg were measured using the Rivermead Assessment of Somatosensory Perception 2-4 weeks post-stroke. Demographics, stroke pathology, weakness, neglect, disability, and recovery were documented. Results: Tactile impairment was more common than proprioceptive (P < .000), impairment of discrimination was more common than detection (P < .000), and tactile sensation was more severely impaired in the leg than the arm ( P < .000). No difference in proprioception between the arm and leg (P = .703) or between proximal and distal joints (P = .589, P = .705) was found. The degree of weakness and the degree of stroke severity were significantly associated with sensory impairment; demographics, stroke side and type, and neglect were not associated. All the sensory modalities were significantly related to independence, mobility, and recovery (r = 0.287 [P < .011] to r = 0.533 [P < .000]). Conclusion: Sensory impairments of all modalities are common after stroke, although tactile impairment is more frequent than proprioceptive loss, especially in the leg. They are associated with the degree of weakness and the degree of stroke severity but not demographics, stroke pathology, or neglect, and they are related to mobility, independence in activities of daily living, and recovery.
Time Course of Trunk, Arm, Leg, and Functional Recovery After Ischemic Stroke Comments Off
Background. Patterns of recovery provide useful information concerning the potential of physical recovery over time and therefore the setting of realistic goals for rehabilitation programs. Objective. To compare the time course of trunk recovery with the patterns of recovery of arm, leg, and functional ability. Methods . Consecutive stroke patients were recruited in 2 acute neurology wards. Participants were evaluated at 1 week, 1 month, and 3 and 6 months after stroke. Patients were assessed with the Trunk Impairment Scale, Fugl-Meyer arm and leg test, and Barthel Index. Results. Thirty-two patients were included in the study. There were no dropouts. Repeated measures analysis of the recovery patterns of motor and functional performance revealed the most striking improvement for all measures from 1 week to 1 month (P value between .0021 and <.0001) and a significant improvement from 1 month to 3 months after stroke (P value ranges from .0008 to <.0001). No significant improvement was found between 3 and 6 months after stroke for any of the measures. Statistical analysis revealed no significant difference between time course of trunk, arm, leg, and functional recovery (P = .2565). No significant differences in level of motor and functional recovery were found at the different time points. Conclusions. Separate analyses of motor and functional recovery patterns after stroke confirm the importance of the first month for recovery. Contrary to common belief, the time course of recovery of the trunk is similar to the recovery of arm, leg, and functional ability.
Bilateral Arm Training With Rhythmic Auditory Cueing in Chronic Stroke: Not Always Efficacious Comments Off
Objective. Bilateral arm training with rhythmic auditory cueing (BATRAC) has been reported to be efficacious in promoting upper-extremity (UE) recovery in chronic stroke. We tested a modified form of BATRAC (modBATRAC) in a new group of participants with a condensed treatment regime to determine whether we could replicate these reported results. Methods. Fourteen subjects with chronic stroke completed 2 weeks of 2.25 hours per session, 4 sessions per week of modBATRAC. Results. No significant changes were observed in UE Fugl-Meyer or Wolf Motor Function Test scores. Subjects did report increased paretic UE use on the Motor Activity Log (mean change, 0.50; SD = 0.70). Conclusions. The results of this study offer only partial support for the efficacy of modBATRAC. As in previous trials, modBATRAC facilitated increased use of the paretic arm, but unlike previous trials, it did not increase motor performance. These differences may reflect a more temporally condensed training schedule and less impaired patients.