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Objectives Spinal cord stimulation (SCS) is not typically recommended for the treatment of central poststroke pain (CPSP). We examined whether the pharmacological evaluation of CPSP is useful for selecting the candidates for SCS. Materials and Methods Changes in visual analog scale (VAS) scores for pain following pharmacological evaluation using morphine, thiopental, and ketamine were compared with those following SCS in 22 CPSP patients. Results Twelve of the 22 (54.5%) patients in the ketamine test and thiopental test, and 5 (22.7%) of the 22 patients in the morphine test showed a more than 40% reduction in VAS score and were judged as “sensitive.” Pain relief by SCS was estimated as excellent (≧60% VAS score reduction) in three patients, good (30–59% reduction) in nine patients, and fair (10–29% reduction) in seven patients 24 months after the start of SCS. The remaining 3 patients evaluated as having poor pain relief (

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.

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.

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.

Objectives. Motor cortex stimulation has been used as a treatment for intractable pain. However, the mechanisms underlying its effects remain unclear. In this study, neuroplasticity induced by chronic sensorimotor cortex stimulation was investigated experimentally on the basis of c-Fos expression. Materials and Methods. The experimental animals employed were adult male Wistar rats. A quadripolar stimulation electrode was positioned over the sensorimotor cortex. We examined the neural activation in response to chronic stimulation using c-Fos immunopositivity. Results. The results are as follows: 1) c-Fos was significantly expressed immediately after the stimulation compared with that in the control; 2) c-Fos expression became extensive over the various regions with an increase in stimulation duration; and 3) after two months of stimulation, c-Fos was expressed not only on the stimulation side, but also within the contralateral cerebral hemisphere. Conclusions. Changes in c-Fos expression induced by long-term stimulation indicate the existence of a time-dependent neural plasticity.

Objectives. The aims of this study were to clarify the direction and degree of brain shift, and to determine the predictive factors for a brain shift during deep brain stimulation (DBS) of the subthalamic nucleus (STN). Materials and Methods. To evaluate the brain shift during bilateral STN-DBS, the position of the anterior commissure (AC), posterior commissure (PC), midcommissure point (MC), and tip of the frontal lobe and anterior horn of the lateral ventricle were calculated pre- and poststereotactic operations in the three-dimensional direction employing special software (Leksell SurgiPlan). To determine the predictive factors for a brain shift, patient's age, operation hours, width of the third ventricle, bicaudate index (BCI), and cella media index (CMI) were compared with the shift of MC. Results. In 50 patients, the MC shifted mainly in the posterior direction (y-axis: 1.27 ± 0.7 mm), and the shifts in the inferior direction (z-axis: 0.11 ± 0.43 mm) and lateral direction (x-axis: 0.02 ± 0.39 mm) were small. The shift of the MC in the posterior direction correlated well with the shift of the tip of the anterior lobe and anterior horn. Among the predictive factors examined, namely, the patient's age, operation hours, width of the third ventricle, BCI, and CMI, only the CMI showed a correlation with the shift of the MC (r = 0.42, p

Objective. Employing [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) to assess the correlation between the effect of deep brain stimulation (DBS) on the subthalamic nucleus (STN) and the regional cerebral metabolic rate of glucose (rCMRGlc) in advanced Parkinson's disease patients (N = 8). Materials and Methods. On the basis of patients’ diary records, we performed FDG-PET during the off-period of motor activity with on- or off-stimulation by STN-DBS on separate days and analyzed the correlation between changes in motor symptoms and alterations in the rCMRGlc. Result. When FDG-PET was performed, the motor score on the unified Parkinson's disease rating scale (UPDRS) was 64% lower with on-stimulation than with off-stimulation (p

Objective. To clarify the efficacy of subthalamic nucleus (STN) stimulation in young-onset Parkinson's disease (PD), we compared the effects of STN stimulation on the motor symptoms between young-onset PD (YOPD) and late-onset PD (LOPD). Methods. We analyzed the effects of STN stimulation on motor function and motor fluctuations in 15 patients with YOPD, and 113 patients with LOPD who underwent STN stimulation during the same period. The Unified Parkinson's Disease Rating Scale (UPDRS) was evaluated during the on-period and off-period, which are defined as the times at which the motor symptoms are the best and worst during the daily active time with sustaining anti-parkinsonian drugs. The dyskinesia severity rating scale (DSRS) also was employed to assess the severity of peak-dose dyskinesia. We analyzed the changes in levodopa equivalent daily dose (LED), motor fluctuations, DSRS, and UPDRS part 3 score after STN stimulation, and compared the changes in each score between the two groups (YOPD vs. LOPD). Results. The LED was reduced, and the on-off motor fluctuation index, dyskinesia rating scale score (on-period), and UPDRS part 3 score (on- and off-periods) were improved in both the YOPD and LOPD groups. The improvement rates of the UPDRS part 3 scores in both the on- and off-periods in the YOPD group were superior to those in the LOPD group. The results of multivariate logistic regression analysis demonstrated that YOPD itself is the best responder to STN stimulation. Conclusions. STN stimulation can reduce the LED and improve motor fluctuations in patients with YOPD. The effects of STN stimulation on the motor symptoms of YOPD patients are superior to those in LOPD. The present findings suggest that YOPD patients suffering from several problems related to pharmacological therapy are probably good candidates for STN stimulation.