Tetsuo Ota

Effects of neurofeedback training with an electroencephalogram-based brain-computer interface for hand paralysis in patients with chronic stroke: a preliminary case series study.

OBJECTIVE To explore the effectiveness of neurorehabilitative training using an electroencephalogram-based brain- computer interface for hand paralysis following stroke. DESIGN A case series study. SUBJECTS Eight outpatients with chronic stroke demonstrating moderate to severe hemiparesis. METHODS Based on analysis of volitionally decreased amplitudes of sensory motor rhythm during motor imagery involving extending the affected fingers, real-time visual feedback was provided. After successful motor imagery, a mechanical orthosis partially extended the fingers. Brain-computer interface interventions were carried out once or twice a week for a period of 4-7 months, and clinical and neurophysiological examinations pre- and post-intervention were compared. RESULTS New voluntary electromyographic activity was measured in the affected finger extensors in 4 cases who had little or no muscle activity before the training, and the other participants exhibited improvement in finger function. Significantly greater suppression of the sensory motor rhythm over both hemispheres was observed during motor imagery. Transcranial magnetic stimulation showed increased cortical excitability in the damaged hemisphere. Success rates of brain-computer interface training tended to increase as the session progressed in 4 cases. CONCLUSION Brain-computer interface training appears to have yielded some improvement in motor function and brain plasticity. Further controlled research is needed to clarify the role of the brain-computer interface system.

Functional assessment of patients with spinal cord injury: measured by the motor score and the Functional Independence Measure

There is some information about the Functional Independence Measure (FIM) score of patients with spinal cord injury (SCI), but there are a few publications dealing with the relationship between the FIM score and the motor score of the American Spinal Injury Association (ASIA). We have studied the relationship of all FIM items with the motor score, and reviewed the disability of patients with spinal cord injury in greater detail. The purpose of this study was to describe the characteristics of impairment and disability in patients with SCI, using the FIM and motor score of the ASIA. The subjects were 100 inpatients with SCI (Frankel A, B). Neurological level, days from the onset, and the FIM were examined. In addition to these items, the ASIA motor scores were calculated for 22 tétraplégie patients. We investigated the relationships among these various respects. We also examined the changes of the physical items of the FIM score (physical FIM) over time for 18 patients. The mean FIM scores of those with tetraplegia with C4, C5, C6, C7, C8 lesions, and those with paraplegia with above T5 levels, and those below T6 were 35, 61, 82, 90, 116, 114 and 114 respectively. The FIM score reached the plateau in approximately 10 months, 6 months and 3 months post-injury, in tetraplegia, paraplegia above T5 and that below T6 respectively. The FIM scores in C6 patients were widely distributed from 56 to 104. On the other hand, the ASIA motor score could subdivide C6 patients and related well to the FIM score. The mean FIM scores for each neurological level were similar to those previously reported, thus they appeared to be plateau scores. With regard to the motor score, we feel that it could reflect the disability of the patients better than considering the neurological levels alone. Also considering the changes in the physical FIM score over time within a year from the onset of the injury, there were differences in the ADL improvement patterns among patients with different neurological levels. It appears that timing of the highest physical FIM improvement for each neurological level can exist. Thus it is important not to delay the start of the rehabilitation of patients with spinal cord injury in proper time.

Efficacy of brain-computer interface-driven neuromuscular electrical stimulation for chronic paresis after stroke.

OBJECTIVE Brain computer interface technology is of great interest to researchers as a potential therapeutic measure for people with severe neurological disorders. The aim of this study was to examine the efficacy of brain computer interface, by comparing conventional neuromuscular electrical stimulation and brain computer interface-driven neuromuscular electrical stimulation, using an A-B-A-B withdrawal single-subject design. METHODS A 38-year-old male with severe hemiplegia due to a putaminal haemorrhage participated in this study. The design involved 2 epochs. In epoch A, the patient attempted to open his fingers during the application of neuromuscular electrical stimulation, irrespective of his actual brain activity. In epoch B, neuromuscular electrical stimulation was applied only when a significant motor-related cortical potential was observed in the electroencephalogram. RESULTS The subject initially showed diffuse functional magnetic resonance imaging activation and small electro-encephalogram responses while attempting finger movement. Epoch A was associated with few neurological or clinical signs of improvement. Epoch B, with a brain computer interface, was associated with marked lateralization of electroencephalogram (EEG) and blood oxygenation level dependent responses. Voluntary electromyogram (EMG) activity, with significant EEG-EMG coherence, was also prompted. Clinical improvement in upper-extremity function and muscle tone was observed. CONCLUSION These results indicate that self-directed training with a brain computer interface may induce activity- dependent cortical plasticity and promote functional recovery. This preliminary clinical investigation encourages further research using a controlled design.

Associated reaction and spasticity among patients with stroke.

Honaga K, Masakado Y, Oki T, Hirabara Y, Fujiwara T, Ota T, Kimura A, Liu M: Associated reaction and spasticity among patients with stroke. Am J Phys Med Rehabil 2007;86:656–661. Objectives:The objectives were to investigate the relationship between associated reaction (AR) and clinical spasticity in the paretic arm. Design:The participants were ten patients with hemiparetic stroke, mean age of 65.2 yrs, and duration of stroke of 13.3 mos. The AR of the hemiparetic arm was analyzed with surface EMG, and AR ratio was calculated on the basis of comparison of the surface amplitude of the affected side to that of the nonaffected side. Simultaneously, we measured M-, H-, and T-wave amplitudes and calculated H/M and T/M in the paretic arm. The AR ratio, H/M, and T/M were compared with spasticity as assessed with the modified Ashworth scale (MAS). We repeated the same measurements after median nerve block to examine its effects on the parameters. Results:The AR ratio correlated significantly with MAS (P < 0.01), whereas H/M and T/M did not. Median nerve block did not alter these relationships. Conclusion:AR, which could be elicited easily in patients with spastic hemiparesis, correlated strongly with spasticity, both before and after the median nerve block. However, the so-called monosynaptic reflex (H- and T reflexes) did not correlate significantly with spasticity. These results indicate that AR and spasticity partially share common pathways.

Development of EMG-controlled electrical stimulation system

Some of the hemiplegic patients cannot fully dorsiflex their ankle joints in the swing phase during gait. The EMG-controlled electrical stimulation system was developed to improve their gait, and it gave the stimulation whose intensity was corresponding to the EMG activity. The same pair of electrode was used for recording EMG and output the electrical stimulation.

Evaluation of biofouling for implantable micro dialysis system

Implantable artificial kidney can drastically improve the quality of life of the renal disease patients. In previous study, our group has developed a multi-layered micro dialysis device which is composed of micro stainless steel channels and nano-porous polyethersulfone (PES) membranes. The device conducts hemofiltration without dialysis fluids, which is advantageous in miniaturization. We investigated the water-permeability of the PES membrane through in vivo experiments using rat model of renal disease for 5 hours and verified the effectiveness of the device. We investigated the permeability of PES membrane via in vitro experiments for 24 days. Biofouling on the PES membrane was found and caused deterioration of dialysis performance of the membrane. In this research, we investigated the biofouling such as thrombus, coagulation and protein adhesion on the sidewall of the micro fluidic channels. We investigated the micro fluidic channel geometry and surface condition associated with the processing methods. Conducting in vitro experiment for 7 days, biofouling was found to be mainly caused by the surface conditions. The mirror surface formed by electrolytic etching could substantially prevent biofouling.

Relief of neuropathic pain after spinal cord injury by brain-computer interface training.

Objectives:The aim of this study was to report the effects of brain–computer interface (BCI) training, a neurofeedback rehabilitation technique, on persistent neuropathic pain (NP) after cervical spinal cord injury (SCI).Subjects and methods:We present the case of a 71-year-old woman with NP in her left upper extremity after SCI (C8). She underwent BCI training as outpatient rehabilitation for 4 months to enhance event-related desynchronization (ERD), which is triggered by the patient’s motor intuition. Scalp electroencephalography was recorded to observe the ERD during every BCI training session. The patient’s pain was evaluated with the McGill Pain Questionnaire (MPQ) and a visual analog scale (VAS). The MPQ was performed after every BCI training session, and the patient assessed the VAS score on her own, once every few days during the BCI training period.Results:After the BCI training started, the patient’s ERD during the BCI training period increased significantly, from 15.6–30.3%. Moreover, her VAS score decreased gradually, from 8 to 5, after the BCI training started, although the MPQ did not change significantly.Conclusion:BCI training has the potential to provide relief for patients with persistent NP via brain plasticity, and to improve their activities of daily living and quality of life.

Treatment effectiveness of brain-computer interface training for patients with focal hand dystonia: A double-case study

Neuronal mechanism underlying dystonia is poorly understood. Dystonia can be treated with botulinum toxin injections or deep brain stimulation but these methods are not available for every patient therefore we need to consider other methods Our study aimed to develop a novel rehabilitation training using brain-computer interface system that decreases neural overexcitation in the sensorimotor cortex by bypassing brain and external world without the normal neuromuscular pathway. To achieve this purpose, we recorded electroencephalograms (10 channels) and forearm electromyograms (3 channels) from 2 patients with the diagnosis of writers cramp and healthy control participants as a preliminary experiment. The patients were trained to control amplitude of their electroencephalographic signal using feedback from the brain-computer interface for 1 hour a day and then continued the training twice a month. After the 5-month training, a patient clearly showed reduction of dystonic movement during writing.

41. SNAP in the lower limbs – interside difference

Association between migraine and epilepsy is well known. However, few previous studies characterized migraine and EEG findings. The purpose of this study was to evaluate the correlation of migraine with EEG findings in the patients with/without epilepsy, and to discuss the pathophysiology of migraine with EEG abnormality. The subjects were 21 patients with migraine, divided into 16 patients without other neurological involvement (migraine group) and the other 5 patients complicated with epilepsy (epilepsy group). We compared clinical manifestations, EEG findings and locations of headache. Six (37.5%) of the 16 patients with migraine and all (100%) with epilepsy group showed EEG abnormalities. EEG demonstrated centrotemporal paroxysms in 4 (66.7%) with migraine and 4 (80%) with epilepsy group. In 11 (68.8%) of the 16 patients with migraine and 4 (80%) of the 5 patients with epilepsy group, headache was located at frontotemporal area. These results revealed clinical features in migraine were similar to those in epilepsy group. Furthermore, EEG demonstrated centrotemporal paroxysms in many patients of both groups. These results suggest that the presence of EEG abnormalities with migraine is not related to the underlying epileptogenic pathology. The pathophysiology of migraine with EEG abnormalities cannot be explained by the epileptic syndrome.