Kazuhiro Samura

Spectral Analysis of Field Potential Recordings by Deep Brain Stimulation Electrode for Localization of Subthalamic Nucleus in Patients with Parkinson’s Disease

Aims: Spectral analysis of local field potential (LFP) recorded by deep brain stimulation (DBS) electrode around the subthalamic nucleus (STN) in patients with Parkinson’s disease was performed. Methods: The borders of the STN were determined by microelectrode recording. The most eligible trajectory for the sensorimotor area of the STN was used for LFP recording while advancing the DBS electrode. Results: The low-frequency LFP power (θ- to β-band) increased from a few millimeters above the dorsal border of the STN defined by microelectrode recording; however, the low-frequency power kept the same level beyond the ventral border of the STN. Only high β-power showed close correlation to the dorsal and ventral borders of the STN. Conclusions: A spectral power analysis of LFP recording by DBS electrode helps with the final confirmation of the dorsal and ventral borders of the STN of Parkinson’s disease in DBS implantation surgery.

Subthalamic Nucleus Stimulation Does Not Cause Deterioration of Preexisting Hallucinations in Parkinson’s Disease Patients

Background: Among the neuropsychiatric symptoms in Parkinson’s disease (PD) patients, hallucination can result from the disease itself or medical treatment. Hallucination associated with subthalamic nucleus stimulation (STN-DBS) has been reported; however, it is still unclear whether PD patients with a history of hallucination are appropriate candidates for STN-DBS or not. Aims: We investigated the effect of STN-DBS on preexisting hallucination associated with advanced PD. Methods: Eighteen STN-DBS patients were investigated retrospectively. The severity of hallucination was assessed by the thought disorder score on the Unified Parkinson’s Disease Rating Scale (UPDRS, part 1-item 2) in the patients’ interviews; the score 6 months after the initiation of STN-DBS was compared with the highest score throughout the preoperative history and the score 2 weeks before surgery. Results: Hoehn-Yahr stage and motor score (UPDRS part 3) were significantly improved following STN-DBS. Six months after the initiation of STN-DBS, the severity of hallucination, assessed by thought disorder score, did not increase, but rather decreased compared with the preoperative level (p < 0.05 by McNemar’s test). The daily levodopa equivalent dose was increased in 2 patients without the development of hallucination. On the other hand, anti-parkinsonian drugs were totally withdrawn in 1 patient, but without improvement of hallucination. Conclusions: Our findings indicate that STN-DBS surgery does not always lead to deterioration of preexisting hallucination in PD. In advanced PD, hallucination involves a multifactorial pathogenesis and a history of hallucination is not a contraindication to STN-DBS surgery.

Surgical strategy for multiple huge spinal extradural meningeal cysts. Case report.

The authors describe the case of an 8-year-old boy who developed spastic paraparesis and hypalgesia below the middle thoracic level. Magnetic resonance (MR) imaging showed huge and multiple extradural cystic lesions posterior to the spinal cord from T-5 to S-1, which were associated with severe spinal cord compression, especially at the T5-8 level. Using constructive interference in steady state (CISS) MR imaging, many septa were visible that were dividing the cysts in a tandem arrangement, and the multiple cysts were distributed far laterally, extending to the root sleeves. Three transdural communications of cerebrospinal fluid into the cysts, including one that was located ventrally, were revealed by multiangled observation using CISS MR imaging and intraoperative inspection. The huge and multiple appearances of the extradural meningeal cysts on MR images suggested various stages of growth of these cysts. As this case demonstrates, cysts of this type (huge, multiple, extradural meningeal [arachnoid] cysts) need to be completely removed during one-stage surgery.

Effectiveness of Acute Phase Hybrid Assistive Limb Rehabilitation in Stroke Patients Classified by Paralysis Severity

The purpose of the present study was to investigate the effectiveness of acute phase hybrid assistive limb (HAL) rehabilitation training for patients after stroke by measuring the difference in the severity of paralysis. Fifty-three acute stroke patients were enrolled in this prospective cohort study. HAL training was administered about twice per week, and the mean number of sessions was 3.9 ± 2.7. The walking training was performed on a treadmill with individually adjustable body weight support and speed and there was a 10-m walk test (10MWT) before and after each session. Assessment at baseline and at endpoint consisted of the Glasgow Coma Scale (GCS), Revised Hasegawa’s Dementia Scale (HDS-R), Brunnstrom stage (Brs), Functional Independence Measure (FIM), Barthel index (BI), and 10MWT. We measured these assessments at the first walking training session and at the end of the final training session without the HAL. To evaluate the feasibility of training with the HAL, the outcome measures of BI, FIM, and speed and number of steps of 10MWT were compared before and after training using a paired Wilcoxon’s signed-rank test in different Brs. Except for Brs IV, the Brs III or higher subgroups displayed significant amelioration in BI, and the Brs III subgroup displayed significant amelioration in FIM. The Brs V and VI subgroups displayed significant amelioration in 10-m walking speed and steps. In acute phase rehabilitation after stroke, it is thought that the HAL is more effective for patients with less lower-limb paralysis, such as Brs III or higher.

Short circuit in deep brain stimulation

OBJECT The authors undertook this study to investigate the incidence, cause, and clinical influence of short circuits in patients treated with deep brain stimulation (DBS). METHODS After the incidental identification of a short circuit during routine follow-up, the authors initiated a policy at their institution of routinely evaluating both therapeutic impedance and system impendence at every outpatient DBS follow-up visit, irrespective of the presence of symptoms suggesting possible system malfunction. This study represents a report of their findings after 1 year of this policy. RESULTS Implanted DBS leads exhibiting short circuits were identified in 7 patients (8.9% of the patients seen for outpatient follow-up examinations during the 12-month study period). The mean duration from DBS lead implantation to the discovery of the short circuit was 64.7 months. The symptoms revealing short circuits included the wearing off of therapeutic effect, apraxia of eyelid opening, or dysarthria in 6 patients with Parkinson disease (PD), and dystonia deterioration in 1 patient with generalized dystonia. All DBS leads with short circuits had been anchored to the cranium using titanium miniplates. Altering electrode settings resulted in clinical improvement in the 2 PD cases in which patients had specific symptoms of short circuits (2.5%) but not in the other 4 cases. The patient with dystonia underwent repositioning and replacement of a lead because the previous lead was located too anteriorly, but did not experience symptom improvement. CONCLUSIONS In contrast to the sudden loss of clinical efficacy of DBS caused by an open circuit, short circuits may arise due to a gradual decrease in impedance, causing the insidious development of neurological symptoms via limited or extended potential fields as well as shortened battery longevity. The incidence of short circuits in DBS may be higher than previously thought, especially in cases in which DBS leads are anchored with miniplates. The circuit impedance of DBS should be routinely checked, even after a long history of DBS therapy, especially in cases of miniplate anchoring.

Intractable facial pain in advanced Parkinson’s disease alleviated by subthalamic nucleus stimulation

Pain may occur in about half of patients with Parkinson’s disease (PD).1–3 We describe a rare case who had intractable facial pain with allodynia as a result of long term levodopa replacement therapy, which was alleviated by subthalamic nucleus-deep brain stimulation (STN-DBS). A 55-year-old woman developed claudication in the right leg at the age of 37 years. One year later, she developed tremor in the right leg and clumsiness of the right hand, and she began to take levodopa. During the following 17 years, her parkinsonism gradually advanced, irrespective of medical control with pergolide, pramipexole and selegiline, as well as levodopa. Until 3 months prior to surgery, the levodopa dosage was progressively increased up to 1150 mg per day because of a wearing off phenomenon. She felt some diffuse numbness in the whole face, symmetrically, from 6 months prior to the surgery, which gradually turned into a piercing or tingling pain from 2 months prior to the surgery. On admission to our hospital, her facial pain was so severe that she could neither touch her face nor open her eyelids. In the “off” state, she could not even move from her bed because of her severe facial pain …

Hybrid Assistive Limb (HAL) Rehabilitation in Patients with Acute Hemorrhagic Stroke

The efficacy of hybrid assistive limb (HAL) rehabilitation in the acute phase of stroke remains unclear. The purpose of this study was to evaluate the outcomes of patients with acute intracranial hemorrhage (ICH) who were treated with or without HAL rehabilitation. Among 270 patients with acute ICH from 2009 to 2014, 91 patients with supratentorial ICH were included in this retrospective study. Of these, 14 patients (HAL group) received HAL rehabilitation at approximately 1 week after ICH occurrence, while the remaining 77 patients received usual rehabilitation without HAL (N-HAL group). We obtained various patient data from the hospitals where the patients were moved to for further rehabilitation. Statistical comparisons were performed for the characteristics of the ICH patients, and outcomes between the HAL and N-HAL groups. There were no differences in outcomes between the HAL and N-HAL groups. However, patients with right ICH in the HAL group exhibited a significant association with a functional independence measure (FIM) score of ≥ 110 compared with patients in the N-HAL group (HAL group: 81.8%, N-HAL group: 43.9%, P = 0.04). In patients with right ICH, HAL rehabilitation was associated with improved outcomes as evaluated by the FIM score. Thus, HAL rehabilitation may improve outcomes of acute ICH in appropriately selected patients.

Holocord hydrosyringomyelia with terminal myelocystocele revealed by constructive interference in steady-state MR imaging.

We report an operated case with terminal myelocystocele and holocord hydrosyringomyelia (syrinx). The patient exhibited a subcutaneous mass at the right lumbosacral region with multiple anomalies including scoliosis and hyperdactylia of the right foot and systemic disease such as hydronephroureter. Neurological examination revealed palsy of the left diaphragm, and left upper and right lower limbs. Constructive interference in steady-state (CISS) images demonstrated a terminal myelocystocele with a huge syrinx extending to the medulla. The curvilinear reconstruction of the CISS sequence depicted continuous cystocele and whole syrinx. At day 37, sac excision and untethering of the spinal cord were performed. The caudal part of the central canal was opened to the subarachnoid space (terminal ventriculostomy), resulting in a slight improvement of limb palsy and shrinkage of the holocord syrinx. CISS imaging is useful to detect the complicated pathology, and terminal ventriculostomy should be performed to improve associated syrinx.

Successfully Treated Isolated Posterior Spinal Artery Aneurysm Causing Intracranial Subarachnoid Hemorrhage: Case Report

There are very few published reports of rupture of an isolated posterior spinal artery (PSA) aneurysm, and consequently the optimal therapeutic strategy is debatable. An 84-year-old man presented with sudden onset of restlessness and disorientation. Neuroradiological imaging showed an intracranial subarachnoid hemorrhage (SAH) with no visible intracranial vascular lesion. Spinal magnetic resonance imaging (MRI) detected a localized subarachnoid hematoma at Th10–11. Both contrast-enhanced spinal computed tomography and enhanced MRI and magnetic resonance angiography revealed an area of enhancement within the hematoma. Superselective angiography of the left Th12 intercostal artery demonstrated a faintly enhanced spot in the venous phase. Thirteen days after the onset of symptoms, a small fusiform aneurysm situated on the radiculopial artery was resected. The patients postoperative course was uneventful and he was eventually discharged in an ambulatory condition. To our knowledge, this 84-year-old man is the oldest reported case of surgical management of a ruptured isolated PSA aneurysm. This case illustrates both the validity and efficacy of this therapeutic approach.

Double lumbosacral lipomas of the dorsal and filar types associated with OEIS complex - Case report

A female baby was born at 37 weeks and 6 days gestation by vaginal delivery with omphalocele, exstrophy of the cloaca, and imperforate anus, indicating the presence of OEIS complex, a rare combination of defects consisting of omphalocele (O), exstrophy of the cloaca (E), imperforate anus (I), and spinal deformity (S), associated with lumbosacral lipoma. The most common associated spinal deformity is terminal myelocystocele, and spinal lipoma is rare. Constructive interference in steady-state magnetic resonance imaging clearly revealed double lipomas, a dorsal-type lipoma, located dorsal to the low-lying conus medullaris, and a filar-type lipoma, revealed by a thickened and fatty filum terminale. After recovery from abdominogenital repairs, debulking of the dorsal-type lipoma and untethering of the spinal cord by sectioning of the filar-type lipoma were performed at the age of 14 months. Neurosurgical treatment for occult spinal dysraphism should be undertaken after recovery from the initial series of major abdominogenital procedures.