Kazu Amimoto

Generalization of Prism Adaptation for Wheelchair Driving Task in Patients With Unilateral Spatial Neglect

OBJECTIVES To verify the efficacy of prism adaptation as a practical means of rehabilitation for subjects with unilateral spatial neglect by conducting goal-directed tasks in the presence of similar visual flankers in the right hemispace using an activity of daily living, namely, wheelchair operation. DESIGN Prospective cohort study. SETTING Rehabilitation center located in Japan. PARTICIPANTS Patients with unilateral spatial neglect (N=10). INTERVENTION Prism adaptation. MAIN OUTCOME MEASURES A midpoint-directed task in which the subject faces the center of 2 symbols placed in front and moves the wheelchair toward it, and a goal-directed task in which the subject must differentiate a single target from multiple symbols and move the wheelchair toward it. RESULTS In the midpoint-directed task, there was a significant shift in the reach position bias from +27.7 cm prior to prism adaptation to +3.1cm after prism adaptation (P<.01). In the goal-directed task, the time taken to reach the outer left target decreased from 21.2 seconds prior to prism adaptation to 11.8 seconds after prism adaptation, and the difference between placement of the targets was eliminated. CONCLUSIONS Prism adaptation exhibited the potential to generalize the effects on activities of daily living such as driving a wheelchair and to ameliorate unilateral spatial neglect even in the presence of right-hemispace flankers. Prism adaptation is an effective therapeutic modality in rehabilitation because it prevents the appearance of neglect symptoms despite situational or contextual changes.

Analysis of dynamic sitting balance on the independence of gait in hemiparetic patients

The purpose of this study was to investigate the relationship between dynamic sitting balance and walking ability in stroke patients. Patients were evaluated using functional independence measure (FIM), and those with a locomotion score of 5 or below were categorized into the dependent walking and below group (dependent group) and those with a score of 6 or above were categorized into the independent walking group (independent group). They were asked to take a sitting position at the center of an unstable platform (seesaw). The experimenter passively tilted the unstable platform to the paretic side or non-paretic side by 10 degrees in the frontal plane. The unstable platform was released suddenly, with the experimenter supporting the platform with both hands, and the subjects were asked to control their posture so that their body axis came to the vertical position and the platform came to the horizontal position in the frontal plane. As a result, the body axis of left hemiplegic patients significantly tilted to the non-paretic side. On the other hand, in the dependent group in the right as well as left hemiplegic patients, the patients heads were tilted to the side from which tilting was started, though not significantly in both conditions. This study demonstrated that patients with poor walking function have a deviated verticality of the head and the body axis. We surmise that patients whose body axis tilts towards the non-paretic side during a dynamic balance maintenance task like this test would have lower walking independence.

Influence of peripheral magnetic stimulation of soleus muscle on H and M waves

[Purpose] This study evaluated the effects of repetitive peripheral magnetic stimulation of the soleus muscle on spinal cord and peripheral motor nerve excitability. [Subjects and Methods] Twelve healthy adults (mean age 22 years) who provided written informed consent were administered repetitive peripheral magnetic stimulation for 10 min. Pre-and post-stimulation latencies and amplitudes of H- and M-waves of the soleus muscle were measured using electromyography and compared using paired t-tests. [Results] Pre- and post-stimulation latencies (28.3 ± 3.3 vs. 29.1 ± 1.3 ms, respectively) and amplitudes (35.8 ± 1.3 vs. 35.8 ± 1.1 mV, respectively) of H-waves were similar. Pre-stimulation latencies of M-waves were significantly higher than post-stimulation latencies (6.1 ± 2.2 vs. 5.0 ± 0.9 ms, respectively), although pre- and post-stimulation amplitudes were similar (12.2 ± 1.4 vs. 12.2 ± 1.3 mV, respectively). Motor neuron excitability, based on the excitability of motor nerves and peripheral nerve action, was increased by M-waves following magnetic stimulation. [Conclusion] The lack of effect of magnetic stimulation on the amplitude and latency of the H-reflex suggests that magnetic stimulation did not activate sensory nerve synapses of α motor neurons in the spinal cord. However, because motor nerves were stimulated together with sensory nerves, the increased H-wave amplitude may have reflected changes in peripheral rather than in α motor nerves.

The effects of aging on the subjective vertical in the frontal plane in healthy adults

[Purpose] To determine age-related differences in the subjective vertical in the frontal plane in healthy adults. [Subjects and Methods] The subjects were 26 healthy adults. For the subjective visual vertical (SVV), subjects were presented with a visual indicator in front of them that was rotated. For the subjective postural vertical-eyes open (SPV-EO) and subjective postural vertical (SPV), subjects sat in a seating device that was tilted right or left. The subjects gave a signal when they perceived true verticality. Each task was performed eight times. The items examined were the mean (tilt direction) and standard deviation (variability) of the eight trials, then the mean of four trials that started from the right or left side position. These items were compared between the young (age: 22–30 years [range]) and elderly (age: 60–74 years) groups. [Results] As for variability, the elderly group demonstrated significantly higher values of SPV-EO and SPV. As for the starting point effect, the elderly group demonstrated greater bias toward the starting direction than did the young group in SPV-EO and SPV in frontal plane. [Conclusion] The postural vertical was shown to change with age. Consideration of age-related changes and the starting point effect was indicated to be important.

Effects of transcranial direct current stimulation over the supplementary motor area body weight-supported treadmill gait training in hemiparetic patients after stroke

Transcranial direct current stimulation (tDCS) is used in a variety of disorders after stroke including upper limb motor dysfunctions, hemispatial neglect, aphasia, and apraxia, and its effectiveness has been demonstrated. Although gait ability is important for daily living, there were few reports of the use of tDCS to improve balance and gait ability. The supplementary motor area (SMA) was reported to play a potentially important role in balance recovery after stroke. We aimed to investigate the effect of combined therapy body weight-supported treadmill training (BWSTT) and tDCS on gait function recovery of stroke patients. Thirty stroke inpatients participated in this study. The two BWSTT periods of 1weeks each, with real tDCS (anode: front of Cz, cathode: inion, 1mA, 20min) on SMA and sham stimulation, were randomized in a double-blind crossover design. We measured the time required for the 10m Walk Test (10MWT) and Timed Up and Go (TUG) test before and after each period. We found that the real tDCS with BWSTT significantly improved gait speed (10MWT) and applicative walking ability (TUG), compared with BWSTT+sham stimulation periods (p<0.05). Our findings demonstrated the feasibility and efficacy of tDCS in gait training after stroke. The facilitative effects of tDCS on SMA possibly improved postural control during BWSTT. The results indicated the implications for the use of tDCS in balance and gait training rehabilitation after stroke.

Non-Invasive Brain Stimulation (TMS/tDCS) and Rehabilitation for Stroke and Parkinson’s

The aim of this study was to clarify and compare the efficacies of rehabilitation using transcranial direct current stimulation (tDCS) and continuous theta burst stimulation (cTBS), a form of repetitive transcranial magnetic stimulation (rTMS), in convalescing stroke and Parkinson’s disease patients. For both types of stimuli, kinetic analysis and performance analysis of upper limb motor paralysis and gait analysis showed an increase in speed of movement, and an improvement in performance was observed. Both stimuli resulted in significant improvement compared with a sham stimulus. Change in speed of movement and performance was observed with both tDCS and cTBS, but there was not a significantly large difference between the stimuli. Improved movement due to reduction of excessive tension caused by spasticity was observed. In patients with Parkinson’s disease, gait speed and step length were increased. It is suggested that performance was improved because movement became smoother. The efficacy of tDCS and cTBS in patients with motor disorders caused by stroke or Parkinson’s disease will probably be further improved when combined with physical therapy.

Relationship of white matter lesions and severity of pushing behavior after stroke

[Purpose] The relationship between white matter lesions (WMLs) and pushing behavior (PB) is still poorly understood. The purpose of this study was to investigate whether damage from WMLs affects the functional outcome of PB after acute stroke. [Subjects and Methods] In total, 37 patients were included. PB was assessed using the standardized Scale for Contraversive Pushing (SCP). Stroke types were classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), or lacunar syndrome using the Bamford classification. WML severity was categorized into four groups using the Fazekas visual scale. Thereafter, patients were divided into 4 groups according to the stroke type and/or presence of WMLs. The SCP, Trunk Control Test (TCT), Stroke Impairment Assessment Set (SIAS), and Barthel Index were the outcome measures. [Results] The SCP and TCT in patients with PACI without WMLs were better than those in patients with TACI with or without WMLs. Regarding SCP, TCT, and SIAS, patients with TACI had poorer values compared with PACI, regardless of WML severity. Barthel Index efficiency was not significantly different between the groups. [Conclusion] Our results suggest that moderate to severe WMLs and PACI had a relationship with PB severity and truncal balance.

Does training sitting balance on a platform tilted 10° to the weak side improve trunk control in the acute phase after stroke? A randomized, controlled trial.

Background: Trunk performance and sitting balance, especially lateral sitting control, are important predictors of functional outcome after stroke. However, no studies have focused only on trunk function in the frontal plane for persons with acute-phase stroke. Objective: To investigate the effects of lateral sitting training on a tilting platform in persons with stroke. Methods: An assessor-blinded, randomized, controlled trial was carried out involving inpatients at a stroke rehabilitation center. Patients were allocated to either an experimental group (n = 15) or a control group (n = 15). The experimental group sat without leg support on a platform tilted 10° to the paretic side in the frontal plane, while the controls sat on a horizontal platform. Both groups were asked to move their trunk laterally from the paretic side to the nonparetic side. In addition to conventional therapy, this training was performed 60 times/session, with 6 sessions/week. Trunk function was assessed using the Trunk Control Test (TCT), and the ability to move the trunk laterally was evaluated kinematically. Measurements were performed at baseline and after training. Two-way repeated measures analysis of variance was used to test the significance between and within treatments for each dependent variable. Results: None of the demographic data differed between the groups. After training, a significant improvement was noted in the experimental group compared to the controls in the TCT and the ability for lateral trunk transference (P < 0.05, 1 − β = 0.98, effect size = 0.4). Conclusion: Lateral sitting training on the tilting platform improved the impaired trunk function of persons with stroke.

Prone positioning reduces severe pushing behavior: three case studies

[Purpose] Pushing behavior is classically described as a disorder of body orientation in the coronal plane. Most interventions for pushing behavior have focused on correcting the deviation in vertical perception. However, pushing behavior seems to involve erroneous movements associated with excessive motor output by the non-paretic limbs and trunk. The present study aimed to inhibit muscular hyper-activity by placing the non-paretic limbs and trunk in the prone position. [Subjects and Methods] The subjects of the present study were 3 acute stroke patients with severe pushing behavior. The study consisted of the following 3 phases: baseline, intervention, and follow-up. In addition to conventional therapy, patients received relaxation therapy in the prone position for 10 minutes a day over 2 days. The severity of pushing behavior was assessed using the scale for contraversive pushing, and truncal balance was evaluated using the trunk control test. These assessments were performed before and after the baseline phase, and after the intervention and follow-up phases. [Results] At the baseline phase, both scores were poor. Both scores improved after the intervention and follow-up phases, and all the patients could sit independently. [Conclusion] Relaxation therapy in the prone position might ameliorate pushing behavior and impaired truncal balance.