Publications (54)93.69 Total impact
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Article: Comparison Between Pharmacologic Evaluation and Repetitive Transcranial Magnetic Stimulation-Induced Analgesia in Poststroke Pain Patients.
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ABSTRACT: BACKGROUND: It has been reported that poststroke pain has a complex pharmacologic background and that only about one-half of poststroke pain patients are sensitive to motor cortex stimulation induced by repetitive transcranial magnetic stimulation (rTMS). OBJECTIVES: The relationship between pharmacologic background and effects of rTMS of the primary motor cortex was investigated to clarify the pharmacologic basis of rTMS-induced analgesia in poststroke pain patients. METHODS: Changes in visual analog scale (VAS) score for pain following drug challenge tests using ketamine, morphine, and thiopental were compared with the changes in VAS score following rTMS of the primary motor cortex (frequency 5 Hz, at 100% resting motor threshold, 500 pulses per session) in 20 poststroke pain patients. RESULTS: In our drug challenge test, 10 of 20 (50%) patients in ketamine test, 7 of 20 (35%) in thiopental test, and 3 of 20 (15%) in morphine test showed more than 40% reduction of VAS score. VAS score decreased immediately after rTMS of motor cortex and persisted for 300 min (p < 0.05, Bonferroni's multiple comparisons). Comparison of the magnitude of VAS score reduction between drug challenge test and rTMS showed significant correlations with ketamine test (r = 0.503, p = 0.012), morphine test (r = 0.526, p = 0.009), and thiopental test (r = 0.609, p = 0.002) by regression analysis. CONCLUSIONS: rTMS-induced VAS score reduction correlated well with morphine, ketamine, and thiopental tests. However, ketamine sensitivity was observed in more cases compared with morphine and thiopental in poststroke pain patients. We speculate that additional pharmacologic therapy using ketamine as determined on the basis of the ketamine test may be useful for enhancing the efficacy of rTMS in poststroke pain patients.Neuromodulation 01/2013; · 1.19 Impact Factor -
Article: F-Wave Suppression Induced by Suprathreshold High-Frequency Repetitive Trascranial Magnetic Stimulation in Poststroke Patients with Increased Spasticity.
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ABSTRACT: OBJECTIVE: High-intensity and high-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex was carried out in poststroke patients with increased spasticity, and the changes in F-wave parameters in comparison with M-wave parameters induced by rTMS were examined. METHODS: Ten-hertz rTMS pulses were delivered to the primary motor cortex of the lesion side at 110% intensity of the resting motor threshold, and F-waves were obtained from the first dorsal interosseous muscle. F-waves were recorded before (pre-stim) and immediately after the end of rTMS (post-stim) in poststroke patients. RESULTS: F-wave persistence and F/M Amp.Ratio increased significantly in patients with lesions in upper motor tract as compared with healthy subjects (Wilcoxon rank sum test, p = 0.00023 and p = 0.0073, respectively). After the rTMS application, both F-wave persistence and F/M Amp.Ratio decreased significantly (paired t-test, p = 0.0095 and p = 0.037, respectively). However, the F-wave amplitude did not show a statistically significant variance in poststroke patients. CONCLUSIONS: High-frequency suprathreshold rTMS may suppress the F-waves by enhancing the inhibitory effect on spinal excitability through the corticospinal tract, and F-wave persistence and F/M Amp.Ratio can be used to determine the effect of rTMS on patients with increased spasticity.Neuromodulation 10/2012; · 1.19 Impact Factor -
Article: On-Demand Control System for Deep Brain Stimulation for Treatment of Intention Tremor.
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ABSTRACT: OBJECTIVES: Intention tremor becomes evident only when patients intend to move their body and is characterized by dysmetria. We have developed an on-demand control system that triggers the switching on/off of deep brain stimulation (DBS) instantly for the control of intention tremor. MATERIAL AND METHODS: We used surface electrodes for the recording of electromyographic (EMG) activity, and the power of EMG activity was analyzed instantly employing the fast Fourier transform. The on-demand control system switched on DBS when only the power of tremor frequency exceeded the on-trigger threshold, and the system switched off DBS when the total power of EMG activity decreased below the off-trigger threshold. RESULTS: The on-demand control system triggered the switching on/off of DBS accurately, and controlled intention tremor completely. Our on-demand control system is small and portable, and suitable for clinical use. CONCLUSIONS: The on-demand control system for DBS is useful for controlling intention tremor and may decrease the incidence of tolerance to DBS and may be a powerful tool for various applications of neuromodulation therapy.Neuromodulation 10/2012; · 1.19 Impact Factor -
Article: Fatal Hemorrhage From AVM After DBS Surgery: Case Report.
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ABSTRACT: OBJECTIVES: Intracranial hemorrhage is a crucial complication of deep brain stimulation (DBS) surgery. The bleeding caused by mechanical tissue injury due to microelectrode and/or DBS electrode lead insertion has been well studied. However, hemorrhage caused by a congenital underlying disease such as vascular malformation has not been examined carefully. MATERIALS AND METHODS: We encountered a case of intracerebral hemorrhage from arteriovenous malformation (AVM) after DBS surgery. Preoperative magnetic resonance (MR) imaging did not show any abnormality in the patient. Computed tomography (CT) images taken immediately after the surgery did not show any intracranial hematoma and other abnormal findings. However, the patient did not recover from the general anesthesia, and hemorrhage in the left occipital lobe was detected by CT performed a day after the surgery. The location of the hematoma was markedly distant from the trajectory of DBS leads. Evacuation of the hematoma under general anesthesia was immediately performed. RESULTS: As an intraoperative finding, we noted the presence of abnormal vessels inside the hematoma in the occipital lobe. Tissue specimens including the abnormal vessels were obtained for histopathological analysis, results of which led to the diagnosis was AVM. CONCLUSION: Despite its low incidence, we would like to advise that such a type of hemorrhage could occur and measures should be taken to prevent its occurrence as much as possible. Preoperative detection of abnormal vessels by MR angiography and/or CT angiography might be helpful. Moreover, paying close attention to the possible leakage of cerebrospinal fluid during surgery might be important.Neuromodulation 10/2012; · 1.19 Impact Factor -
Article: Effect of subthalamic nucleus deep brain stimulation on the autonomic nervous system in Parkinson's disease patients assessed by spectral analyses of R-R interval variability and blood pressure variability.
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ABSTRACT: Autonomic nervous system impairment is an untoward symptom that is typically observed in advanced Parkinson's disease (PD) patients. However, details of the effects of subthalamic nucleus deep brain stimulation (STN-DBS) on the autonomic nervous system remain unclear. Twenty-eight patients with advanced PD (12 males and 16 females) who underwent bilateral STN-DBS and 13 age-matched healthy controls were included in this study. We analyzed the dynamic cardiovascular autonomic function regulating the R-R interval and blood pressure by spectral and transfer function analyses of cardiovascular variability before and after STN-DBS. Vagally mediated arterial-cardiac baroreflex function improved after STN-DBS compared to that before STN-DBS (p < 0.05). However, there were no statistically significant differences in the results of the comparison of vagally mediated arterial-cardiac baroreflex function between on-stimulation and off-stimulation. The vagal component in cardiac autonomic dysfunction associated with PD is expected to improve after STN-DBS. We considered that the patients improved their lifestyle; in particular, increasing the amount of exercise by STN-DBS and the best pharmachological treatment may have positive effects on parasympathetic activities.Stereotactic and Functional Neurosurgery 06/2012; 90(4):248-54. · 1.85 Impact Factor -
Article: Simulation to Locate Burr Hole Sites in a Patient for Deep Brain Stimulation Surgery and Clipping of Intracranial Aneurysm.
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ABSTRACT: Background and Objective: Deep brain stimulation (DBS) candidates with neurologic diseases such as unruptured aneurysm present additional challenges to neurosurgeons when craniotomy must precede DBS surgery. Such craniotomy may potentially overlap with intended burr hole sites for the later insertion of DBS electrodes, and the skin incision for craniotomy may lie very close to or intersect with that for the burr holes. We report here a case of forehead craniotomy prior to DBS surgery in which we employed a neuronavigation system to simulate locations for the craniotomy and burr holes. Method: A 62-year-old male patient with Parkinson's disease was a candidate for DBS. He also had an aneurysm and was planned first to undergo frontal craniotomy for clipping before the DBS surgery. The locations of the craniotomy, burr holes, and skin incisions were therefore simulated using a neuronavigation system during craniotomy. Results: Two weeks after the craniotomy, the patient underwent DBS surgery. Planning software confirmed the absence of cortical veins beneath the entry points of tentative burr holes and aided trajectory planning. The DBS surgery was performed without the interference of the burr holes and head pins and the craniotomy. Conclusion: Simulation of the locations of craniotomy and burr holes using a neuronavigation system proved valuable in the present case of frontal craniotomy before DBS surgery.Neuromodulation 06/2012; · 1.19 Impact Factor -
Article: Deep Brain Stimulation and Spinal Cord Stimulation for Vegetative State and Minimally Conscious State.
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ABSTRACT: OBJECTIVE: On the basis of the findings of the electrophysiological evaluation of vegetative state (VS) and minimally conscious state (MCS), the effect of deep brain stimulation (DBS) was examined according to long-term follow-up results. The results of spinal cord stimulation (SCS) on MCS was also examined and compared with that of DBS. METHODS: One hundred seven patients in VS and 21 patients in MCS were evaluated neurologically and electrophysiologically over 3 months after the onset of brain injury. Among the 107 VS patients, 21 were treated by DBS. Among the 21 MCS patients, 5 were treated by DBS and 10 by SCS. RESULTS: Eight of the 21 patients recovered from VS and were able to follow verbal instructions. These eight patients showed desynchronization on continuous electroencephalographic frequency analysis. The Vth wave of the auditory brainstem response and N20 of somatosensory evoked potential were recorded even with a prolonged latency, and pain-related P250 was recorded with an amplitude of more than 7 μV. In addition, DBS and SCS induced a marked functional recovery in MCS patients who satisfied the electrophysiological inclusion criteria. CONCLUSION: DBS for VS and MCS patients and SCS for MCS patients may be useful, when the candidates are selected on the basis of the electrophysiological inclusion criteria. Only 16 (14.9%) of the 107 VS patients and 15 (71.4%) of the 21 MCS patients satisfied the electrophysiological inclusion criteria.World Neurosurgery 04/2012; · 0.68 Impact Factor -
Article: Somatostatin-immunoreactive senile plaque-like structures in the frontal cortex and nucleus accumbens of aged tree shrews and Japanese macaques.
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ABSTRACT: BACKGROUND: Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. Methods: Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. Results: We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. CONCLUSIONS: Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging.Journal of Medical Primatology 04/2012; 41(3):147-57. · 1.30 Impact Factor -
Article: Spinal cord stimulation for treatment of patients in the minimally conscious state.
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ABSTRACT: Minimally conscious state (MCS) is characterized by inconsistent but clearly discernible behavioral evidence of consciousness, and can be distinguished from coma and the vegetative state (VS). Ten MCS patients were evaluated neurologically and electrophysiologically over 3 months after the onset of brain injury, and were treated by spinal cord stimulation (SCS). A flexible four-contact, cylinder electrode was inserted into the epidural space of the cervical vertebrae, and placed at the C2-C4 levels. Stimulation was applied for 5 minutes every 30 minutes during the daytime at an intensity that produced motor twitches of the upper extremities. We used 5 Hz for SCS, considering that the induced muscle twitches can be a useful functional neurorehabilitation for MCS patients. Eight of the 10 MCS patients satisfied the electrophysiological inclusion criteria, which we proposed on the basis of the results of deep brain stimulation for the treatment of patients in the VS. Seven patients recovered from MCS following SCS therapy, and were able to carry out functional interactive communication and/or demonstrate the functional use of two different objects. Cervical SCS increased cerebral blood flow (CBF) diffusely in the brain, and CBF increased by 22.2% during the stimulation period compared with CBF before stimulation in MCS patients (p < 0.0001, paired t-test). Five-Hz cervical SCS could increase CBF and induce muscle twitches of the upper extremities. This SCS therapy method may be suitable for treating MCS.Neurologia medico-chirurgica 01/2012; 52(7):475-81. · 0.61 Impact Factor -
Article: The indication of DBS in Parkinosn's disease (from a neurosurgical standpoint).
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ABSTRACT: It is obvious that deep brain stimulation (DBS) is one of the useful treatment choices for progressive Parkinson disease (PD). The main targets for DBS for PD are the thalamic Vim nucleus, globus pallidus interna (GPi), and subthalamic nucleus (STN). Vim-DBS is useful for tremor but not very effective for other Parkinson symptoms. Therefore, presently, STN and GPi are the common targets for DBS for PD. Diminishing the dose of anti-PD drugs is possible usually only after STN-DBS. However, no evident differences in the effect between STN-DBS and GPi-DBS are noted in the majority of studies. Appropriate indication should be decided on the basis of individual target's feature. Dopa responsiveness is a very important factor when considering the operative indications for both STN-DBS and GPi-DBS. CAPSIT protocol is usually used to evaluate the dopa responsiveness. DBS is considered to be characterized by the bottom-up and substitution effects. The disappearance of wearing-off is expected owing to the bottom-up effect and the disappearance of the side effects of anti-PD drugs is expected owing to the substitution effect. Age at surgery, duration of PD, and degree of dopa responsiveness are important factors for outcome prediction. On the other hand, the rate of complications such as cognitive decline, psychosis, and intracranial hemorrhage is relatively high in elderly patients.Rinshō shinkeigaku = Clinical neurology. 01/2012; 52(11):1095-7. -
Article: Decrease in doublecortin expression without neuronal cell death in rat retrosplenial cortex after stress exposure.
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ABSTRACT: Exposure to acute stress by forced swim impairs spatial learning and memory in rats. The retrosplenial cortex plays an important role in spatial learning and memory. A cell population that expresses immature neuronal markers, including doublecortin (DCX), plays a key role in plasticity of the adult brain through formation of new neurons. Here, we aimed to determine whether rats exposed to acute stress showed changes in DCX expression in retrosplenial cortex cells. Twelve male Sprague-Dawley rats were used. Six were subjected to acute stress by forced swim (group S), and the remaining six served as controls (group C). Immunohistochemical staining was performed for DCX, neuron-specific nuclear protein, parvalbumin, calbindin, calretinin, and somatostatin. Newly generated cells were immunohistochemically detected by daily administration of 5-bromo-2'-deoxyuridine for 1 week. Fluoro-Jade B staining was performed to detect cell death. Group S showed lower number of DCX-expressing cells than group C (P<0.001). The proportion of DCX-expressing cells showing neuron-specific nuclear protein co-localization (24% in group S; 27% in group C) or parvalbumin co-localization (65% in group S; 61% in group C) remained unchanged after acute stress exposure. Neither 5-bromo-2'-deoxyuridine-positive nor Fluoro-Jade B-positive cells were found in the retrosplenial cortex of groups S and C. DCX-expressing cells in the retrosplenial cortex decreases markedly without cell death after acute stress exposure. Neuronal differentiation of these cells toward gamma aminobutyric acidergic interneurons appears to be unaltered. The decrease in DCX expression may reduce plasticity potential within the retrosplenial cortex and attenuate spatial learning and memory function.Neuroreport 12/2011; 23(4):211-5. · 1.66 Impact Factor -
Article: Changes in motor function induced by chronic motor cortex stimulation in post-stroke pain patients.
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ABSTRACT: In well-designed multicenter studies, the protocol of continuing motor cortex stimulation (MCS) temporarily for 3-6 weeks was employed with rehabilitation therapy, and these studies showed some recovery of motor weakness in post-stroke patients. We aimed to clarify the effects of long-term MCS and the optimal stimulation conditions to improve motor weakness in post-stroke patients. We applied chronic MCS in 6 post-stroke pain patients with motor weakness. We then examined the correlation between the duration of daily MCS applied over 6 months and motor function assessed on the basis of the Fugl-Meyer Assessment (FMA) score of the patients. In the 6 patients with motor weakness, the FMA score of the upper extremity increased in 4 patients who underwent daily MCS for less than 4 h. On the other hand, 2 patients who continued excessive MCS to control their complicating post-stroke pain showed decreased FMA scores and worsened motor function owing to their increased rigidity and/or spasticity. These 2 patients recovered their motor function after their daily MCS was restricted to less than 4 h. These findings indicate that MCS could be a new therapeutic approach to improving motor performance after stroke by attenuating rigidity and/or spasticity. However, it may be important to define the appropriate number of hours and conditions of daily MCS.Stereotactic and Functional Neurosurgery 11/2011; 89(6):381-9. · 1.85 Impact Factor -
Article: [Stereotactic and functional neurosurgery: frame-based and frameless].
No shinkei geka. Neurological surgery 11/2011; 39(11):1033-44. · 0.13 Impact Factor -
Article: Subthalamic nucleus stimulation for attenuation of pain related to Parkinson disease.
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ABSTRACT: The objective of this study was to evaluate the efficacy of chronic subthalamic nucleus (STN) stimulation for alleviating pain related to Parkinson disease (PD). Among 163 consecutive patients undergoing STN stimulation, 69 were identified as experiencing pain preoperatively that was related to their PD. All 69 patients suffering from pain were followed up prospectively for 12 months after surgery. All patients described the severity of their pain according to a visual analog scale (VAS) preoperatively and at 2 weeks, 6 months, and 12 months postoperatively. Pain unrelated to PD was not studied. Several types of pain related to PD, the categories of which were based on a modification of 2 previous classifications (Ford and Honey), can occur in such patients: 1) musculoskeletal pain, 2) dystonic pain, 3) somatic pain exacerbated by PD, 4) radicular/peripheral neuropathic pain, and 5) central pain. The overall mean VAS score was significantly decreased postoperatively by 75% and 69% at 2 weeks and 6 months, respectively (p < 0.001). The mean VAS score at 12 months was also decreased by 80%, but 6 instances of pain (3 reports of somatic back pain and 3 reports of radicular/peripheral neuropathic pain) required additional spinal surgery to alleviate the pain severity. The results were analyzed using the Wilcoxon signed-rank test and demonstrated a significant reduction in VAS scores at all follow-up assessments (p < 0.001). Musculoskeletal pain and dystonic pain were well alleviated by STN stimulation. In contrast, somatic pain exacerbated by PD and peripheral neuropathic pain originating from lumbar spinal diseases, such as spondylosis deformans and/or canal stenosis, often deteriorated postoperatively despite attenuation of the patients' motor disability. Patients with central pain were poor responders. This study found that STN stimulation produced significant improvement of overall pain related to PD in patients with advanced PD, and the efficacy continued for at least 1 year. The present results indicate that musculoskeletal pain and dystonic pain responded well to STN stimulation, but patients with back pain (somatic pain) and radicular/peripheral neuropathic pain originating from spinal disease have a potential risk for postoperative deterioration of their pain.Journal of Neurosurgery 09/2011; 116(1):99-106. · 2.96 Impact Factor -
Article: DBS candidates that fall short on a levodopa challenge test: alternative and important indications.
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ABSTRACT: Candidacy for deep brain stimulation (DBS) in Parkinson disease (PD) is typically assessed by the preoperative motor response to levodopa along with an interdisciplinary evaluation. However, recent cases treated at our institution have achieved good outcomes with DBS despite a sub-30% improvement in motor scores. The aim of this study was to examine the outcomes of DBS in a subset of patients who failed to reach the 30% motor improvement threshold. A review of all DBS patients treated at the University of Florida Movement Disorders Center between 2002 and 2009 was performed utilizing a DBS database. All patients with sub-30% improvement in Unified Parkinson Disease Rating Scale Part III after dopaminergic medication administration were included. Nine patients were identified; DBS was performed for severe dyskinesia (n=5), "on/off motor" fluctuations (n=1) and medication-refractory tremor (n=3). The target symptoms were improved in all patients. Postoperatively, scores on the Unified Parkinson Disease Rating Scale Part II and III and subscores on Parkinson disease questionnaire-39 improved (P<0.05). Although motor response to levodopa remains the primary selection criteria for DBS candidacy in Parkinson disease, patients who do not meet the 30% threshold and have disabling symptoms may still benefit from DBS. Select patients with severe dyskinesia, "on/off" motor fluctuations, and/or medication-refractory tremor may experience significant benefits from DBS and should be considered on a case by case basis through an interdisciplinary team evaluation.The Neurologist 09/2011; 17(5):263-8. · 1.26 Impact Factor -
Article: Corticospinal descending direct wave elicited by subcortical stimulation.
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ABSTRACT: Recent studies have indicated the importance of subcortical mapping of the corticospinal tract (CT) during tumor resection close to the primary motor area. It is substantial evidence that the corticospinal descending direct wave (D-wave) can be used as a guide for mapping of the primary motor cortex (M1) and for monitoring of the CT functional integrity. In the present study, the authors investigated the feasibility of D-wave recordings after subcortical stimulation. The authors examined 14 patients with brain tumors close to the M1 and/or CT, who exhibited no obvious motor deficit before surgery. Subcortical white matter was electrically stimulated in monopolar or bipolar fashion by recording the descending wave (D-wave) from the spinal epidural space using a catheter-type electrode. Subcortical D-wave was more clearly recorded after monopolar stimulation than after bipolar stimulation. The features of the subcortical D-wave, including its waveform, conduction velocity, and latency, were nearly identical to those of the corticospinal D-wave recorded after M1 stimulation. Subcortical D-wave amplitude was prone to change depending on the distance from the stimulation points to the CT. Changes in parameters of subcortical D-wave may provide valuable information to prevent postoperative motor deficit. Further studies are required to clarify the relationship between the distance from the stimulating point to the CT and the amplitude of the subcortically elicited D-wave.Journal of clinical neurophysiology: official publication of the American Electroencephalographic Society 06/2011; 28(3):297-301. · 1.47 Impact Factor -
Article: MRI appearance of a cerebral cavernous malformation in the caudate nucleus before and after chorea onset.
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ABSTRACT: Movement disorders associated with cerebral cavernous malformations (CM) are seldom reported, and chorea, in particular, is rarely associated with a CM located in the caudate nucleus. Here we report a 78-year-old female patient with chorea, who presented with choreiform movements due to a CM in the contralateral caudate nucleus. A brain MRI was obtained and compared with that obtained before the onset of chorea. The new images did not reveal further extralesional hemorrhage from the CM when compared with the previous images. The choreiform movements showed spontaneous improvement and then disappeared completely. We reviewed previous reports of patients with chorea associated with a CM, and conclude that CM located in the caudate nucleus can cause chorea.Journal of Clinical Neuroscience 03/2011; 18(5):719-21. · 1.25 Impact Factor -
Article: Chronological changes in astrocytes induced by chronic electrical sensorimotor cortex stimulation in rats.
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ABSTRACT: Motor cortex stimulation (MCS) is a treatment option for various disorders such as medically refractory pain, poststroke hemiplegia, and movement disorders. However, the exact mechanisms underlying its effects remain unknown. In this study, the effects of long-term chronic MCS were investigated by observing changes in astrocytes. A quadripolar stimulation electrode was implanted on the dura over the sensorimotor cortex of adult rats, and the cortex was continuously stimulated for 3 hours, 1 week, 4 weeks, and 8 weeks. Immunohistochemical staining of microglia (ionized calcium-binding adaptor molecule 1 [Iba1] staining) and astrocytes (glial fibrillary acidic protein [GFAP] staining), and neuronal degeneration histochemistry (Fluoro-Jade B staining) were carried out to investigate the morphological changes following long-term chronic MCS. Iba1 staining and Fluoro-Jade B staining showed no evidence of Iba1-positive microglial changes or neurodegeneration. Following continuous MCS, GFAP-positive astrocytes were enlarged and their number increased in the cortex and the thalamus of the stimulated hemisphere. These findings indicate that chronic electrical stimulation can continuously activate astrocytes and result in morphological and quantitative changes. These changes may be involved in the mechanisms underlying the neuroplasticity effect induced by MCS.Neurologia medico-chirurgica 01/2011; 51(7):496-502. · 0.61 Impact Factor -
Article: Deep brain stimulation for the treatment of vegetative state.
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ABSTRACT: One hundred and seven patients in vegetative state (VS) were evaluated neurologically and electrophysiologically over 3 months (90 days) after the onset of brain injury. Among these patients, 21 were treated with deep brain stimulation (DBS). The stimulation sites were the mesencephalic reticular formation (two patients) and centromedian-parafascicularis nucleus complex (19 cases). Eight of the patients recovered from VS and were able to obey verbal commands at 13 and 10 months in the case of head trauma and at 19, 14, 13, 12, 12 and 8 months in the case of vascular disease after comatose brain injury, and no patients without DBS recovered from VS spontaneously within 24 months after brain injury. The eight patients who recovered from VS showed desynchronization on continuous EEG frequency analysis. The Vth wave of the auditory brainstem response and N20 of the somatosensory evoked potential could be recorded, although with a prolonged latency, and the pain-related P250 was recorded with an amplitude of > 7 μV. Sixteen (14.9%) of the 107 VS patients satisfied these criteria in our electrophysiological evaluation, 10 of whom were treated with DBS and six of whom were not treated with DBS. In these 16 patients, the recovery rate from VS was different between the DBS therapy group and the no DBS therapy group (P < 0.01, Fisher's exact probability test) These findings indicate that DBS may be useful for the recovery of patients from VS if the candidates are selected on the basis of electrophysiological criteria.European Journal of Neuroscience 10/2010; 32(7):1145-51. · 3.63 Impact Factor -
Article: Effects of electrode implantation angle on thalamic stimulation for treatment of tremor.
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ABSTRACT: Introduction. Chronic thalamic stimulation has been confirmed as an effective treatment for tremor. The optimal target has been commonly accepted to be situated within the ventral thalamus, but a standard trajectory of the deep brain stimulation (DBS) electrode has not yet been established. Materials and Methods. A 53-year-old man with an 11-year history of essential tremor was treated by DBS of the thalamus. In this patient, we had a chance to compare the effects of different trajectory angles of the DBS electrode on tremor. Results. Intraoperative stimulation with the DBS electrode temporarily inserted at a high angle to the horizontal plane of the anterior commissure-posterior commissure (AC-PC) line to cover only the nucleus ventralis intermedius (Vim) was not effective. In contrast, stimulation with the DBS electrode permanently implanted at a low angle, covering a wide area extending from the nucleus ventralis oralis (Vo) to the Vim, reduced the tremor. Conclusion. We report on the case of a patient who showed different effects on tremor depending on the trajectory angle of the DBS electrode to the AC-PC line. The insertion trajectory of the DBS electrode may be an important factor for the treatment of tremor.Neuromodulation 01/2010; 13(1):31-6. · 1.19 Impact Factor
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Institutions
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2003–2011
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Nihon University
- • Department of Neurosurgery
- • Department of Neurological Surgery
Tokyo, Tokyo-to, Japan
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