Efficacy and safety of non-suture dural closure using a novel dural substitute consisting of polyglycolic acid felt and fibrin glue to prevent cerebrospinal fluid leakage-A non-controlled, open-label, multicenter clinical trial.

The objective of this study is to evaluate the efficacy and safety of non-suture dural closure using a novel dural substitute (GM111) consisting of polyglycolic acid felt with a fibrin-glue-coated area commensurate in size with the dural defect. This was a non-controlled, open-label, multicenter clinical trial. The efficacy evaluation endpoints were (1) GM111's intra-operative capability to close dural defects and (2) prevention of cerebrospinal fluid (CSF) leakage and subcutaneous CSF retention throughout the postoperative period (evaluated by diagnostic imaging). Patients meeting the following three preoperative and two intra-operative selection criteria were enrolled: (1) between 12 and <75 years of age; (2) the dura is surmised to be defective and in need of reconstruction; (3) informed written consent was obtained from the patient; (4) the surgical wound is class 1; and (5) the size of duraplasty is ≥0.2 cm2 to <100 cm2. Sixty patients were enrolled. The craniotomy site was supratentorial in 77.2%, infratentorial in 12.3% and sellar in 10.5%. The GM111 prosthesis size ranged from 0.24 to 42 cm2. To evaluate the efficacy, intra-operative closure was confirmed by Valsalva's maneuver, water infusion, etc., in all patients. CSF leakage and subcutaneous CSF retention throughout the postoperative period were found in four patients. Adverse events for which a causal relationship with GM111 could not be ruled out occurred in 8.8% of the patients. There were no instances of postoperative infection due to GM111. GM111 showed good closure capability and safety when used for non-suture dural closure.

Semiquantitative analysis of indocyanine green videoangiography for cortical perfusion assessment in superficial temporal artery to middle cerebral artery anastomosis.

BACKGROUND: Postoperative hyperperfusion may lead to severe neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. However, there are no reliable modalities to predict the occurrence of postoperative hyperperfusion during surgery. The purpose of this study is to evaluate whether a semiquantitative analysis of indocyanine green (ICG) videoangiography could be useful in predicting postoperative hyperperfusion after STA-MCA anastomosis. METHODS: This study included seven patients who underwent STA-MCA anastomosis due to occlusive carotid artery diseases. During surgery, ICG videoangiography was performed before and after bypass procedures, and ICG intensity-time curves were semiquantitatively analyzed to evaluate hemodynamic changes by calculating maximum intensity, time to peak (TTP), and blood flow index (BFI). RESULTS: Maximum intensity significantly increased from 252.6 ± 132.5 to 351.7 ± 151.9 after bypass (p < 0.001). TTP was significantly shortened from 12.9 ± 4.4 s to 9.8 ± 3.7 s (p < 0.001). Furthermore, BFI significantly increased from 33.9 ± 28.1 to 74.6 ± 88.4 (p < 0.05). Postoperative hyperperfusion was observed in five of seven patients 1 day after surgery. The ratio of BFI before and after bypass procedures was significantly higher in patients with postoperative hyperperfusion than those without, 2.5 ± 1.1 and 1.5 ± 0.4, respectively (p = 0.013). CONCLUSIONS: These findings suggest that semiquantitative analysis of ICG videoangiography is helpful in predicting occurrence of hyperperfusion after STA-MCA anastomosis in patients with occlusive carotid artery diseases.

Characteristics and distribution of somatosensory evoked potentials in the subthalamic region.

OBJECT: The aim of the present study is to evaluate the topographical distribution of somatosensory evoked potentials (SSEPs) in the subthalamic area, including the zona incerta (ZI). Determination of this distribution may help in the correct placement of deep brain stimulation (DBS) leads. METHODS: Intraoperative SSEPs were recorded from contacts of DBS electrodes at 221 sites in 41 patients: three patients with essential tremor and 38 with Parkinson disease who underwent implantation of DBS electrodes for the relief of severe tremor or parkinsonism. RESULTS: Two distinct SSEPs were recorded in the subthalamic area. One was a monophasic positive wave with a mean latency of 15.8 +/- 0.9 msec, which the authors designated subthalamic P16. Using both cephalic and noncephalic references, subthalamic P16 was only recorded in the ventral part of the ZI (mean 6.6 +/- 1.3 mm posterior to the midcommissure point, 4.8 +/- 1.2 mm inferior to the anterior commissure-posterior commissure line, and 9.7 +/- 0.6 mm lateral to the midline). When bipolar recordings were made, the traces showed a phase reversal at the caudal part of the ZI. The second potential is a positive-negative SSEP recorded throughout the entire subthalamic area. The mean latencies of the initial positive peak and the major negative peak were 13.6 +/- 1.1 msec and 16.4 +/- 1.1 msec, respectively. Several small notches were superimposed on the peaks, and their amplitudes were largest at the contact close to the medial lemniscus. CONCLUSIONS: The results indicate that intraoperative SSEPs from DBS electrodes are helpful in refining stereotactic targets in the thalamus and subthalamic areas.

[Deep brain stimulation of the posterior subthalamic area (Zi/Raprl) for intractable tremor].

Tremor in the proximal arm muscle, trunk, or legs is often resistant to the standard stereotactic surgery of the thalamic ventrointermediate nucleus. We have performed deep brain stimulation (DBS) of the posterior subthalamic area for those intractable tremors. The white matter area between the red nucleus and the subthalamic nucleus was targeted on the T2-weighted MR-CT fused image. Inhibitory effect on the tremor was tested with macrostimulation. The somatosensory-evoked potential recorded through DBS contacts demonstrated characteristic biphasic pattern. Eight cases with severe essential tremor and 18 of tremor-dominant Parkinson disease were treated with unilateral DBS of the area including the zona incerta and the prelemniscal radiation (Zi/Raprl). Tremors including the proximal part have been well controlled for 24 months after the operation. The stimulation parameters have been almost stable during the follow-up period. There was no obvious adverse effect of stimulation. We conclude that Zi/Raprl-DBS is a safe and effective treatment on Parkinsonian and essential tremor.

[Temozolomide in the treatment of recurrent malignant glioma].

Temozolomide (TMZ) has demonstrated activity and acceptable toxicity for the treatment of recurrent malignant gliomas in carious prospective phase II studies. No information is, however, available on TMZ treatment for recurrent malignant glioma in Japanese patients. We report Hokkaido University Hospital experience on 35 adult patients with a recurrent malignant glioma, including 13 glioblastomas, 9 anaplastic astrocytomas, and 13 anaplastic oligondendroglial tumors. The median age was 52 years. The starting dose of TMZ was 150 mg/m2/day for 5 days. When no remarkable toxicity was observed, the dose was increased to 200 mg/m2 for subsequent cycles, every 4 week. In the 35 patients, the overall objective response rate (partial response) was 12% and 74% of the patients achieved disease stabilization. The median progression-free survival was 28 weeks and the median overall survival was 43 weeks. Although hematological toxicity was the most frequent adverse event (CTC grade 3 or 4 in 6 patients), overall toxicity was generally mild. Four patients required hospitalization due to the toxicity, but 28 patients had been treated with TMZ at our outpatient clinic. These results suggested that the reported efficacy and toxicity profile of TMZ for the treatment of Japanese patients with recurrent malignant glioma is reproducible from the setting of clinical trials in the western countries.

Electrical stimulation of the posterior subthalamic area for the treatment of intractable proximal tremor.

OBJECT: Tremors, including its proximal component, are often refractory to standard thalamic surgery. In the 1960s the posterior part of the subthalamic white matter was reported to be a promising target in treating various forms of tremor, but was also found to be associated with adverse effects. Advances involving a less invasive method, that is, deep brain stimulation (DBS), has led to a reappraisal of this target. METHODS: Eight patients with severe essential tremor involving the proximal arm were treated using unilateral stimulation of the posterior part of the subthalamic white matter. The tentative target was situated in the area lateral to the red nucleus and posteromedial to the subthalamic nucleus. Macrostimulation was used to find the optimal site to suppress tremor. Through a quadripolar DBS lead, somatosensory evoked potentials (SSEPs) were recorded. Improvement of tremor was evaluated based on a modified clinical tremor rating scale. Anatomical locations of all contacts were assessed using stereotactic guidance and represented on the Schaltenbrand-Wahren atlas. CONCLUSIONS: A characteristic diphasic pattern of SSEPs reaffirmed the electrophysiological endorsement of this target. Tremors, both proximal and distal, were remarkably improved in all patients. The rate of improvement, as indicated by the total tremor score, was a mean of 81%. Axial tremors in the legs and head were also improved. Most of the contacts associated with remarkable improvement were located in the posterior part of the subthalamic white matter (the zona incerta and prelemniscal radiation). Neither major complications nor neurological deterioration was observed. The authors concluded that DBS of the posterior part of the subthalamic white matter together with SSEP recording is a safe and effective method to ameliorate severe intractable tremors.

Intraoperative dual monitoring during carotid endarterectomy using motor evoked potentials and near-infrared spectroscopy.

BACKGROUND: Carotid endarterectomy (CEA) is a useful procedure to prevent subsequent ischemic stroke in patients with severe stenosis of internal carotid artery. However, lowering of morbidity is still essential to keep its clinical significance. This study aimed to evaluate the validity of dual monitoring using transcranial motor evoked potential (MEP) and near-infrared spectroscopy (NIRS) during CEA. METHODS: Transcranial MEP and NIRS monitoring were conducted in 20 consecutive CEAs. MEP was recorded in the contralateral extremities. Regional cerebral saturation of oxygen (rSO(2)) was continuously measured in the ipsilateral forehead. The changes of MEP amplitudes and rSO(2) during cross-clamping of carotid artery were compared in each case. RESULTS: The amplitudes of MEP significantly decreased when rSO(2) reduced to more than 20% during carotid clamping. There was a significant correlation between the changes of MEP amplitude and rSO(2) during carotid clamping in a quadratic manner (P < .001, r = 0.821). However, NIRS could not detect critical cerebral ischemia in 1 patient with cerebral infarction in the ipsilateral frontal lobe. On the other hand, MEP could not identify it in 1 patient with severe motor deficit. No perioperative complication occurred. CONCLUSIONS: These findings strongly suggest that both MEP and NIRS can detect critical cerebral ischemia during CEA in most patients. Dual MEP and NIRS monitoring may further increase the sensitivity to identify it, being valuable to prevent perioperative complications due to cerebral ischemia during CEA.

Cystic meningioangiomatosis.

A case of cerebral meningioangiomatosis with rare cyst formation is reported. A 14-year-old boy without any stigmata of neurofibromatosis type 2 presented intractable complex partial and generalized seizures since the age of 12 years. Neuroradiological studies showed an abnormal cystic mass with calcification in the left frontal lobe of the cerebrum. The tumor was located in the leptomeninges and cerebral cortex. The patient underwent surgical treatment because medical treatment with phenytoin and sodium valproate was not sufficient to control the seizures. An intraoperative electrocorticogram revealed that epileptic foci were recorded from the cortex, which was adjacent to the lesion. Histopathology showed specific features of meningioangiomatosis with meningioma-like nodules. The patient did not have any seizures with anticonvulsants after surgery. It is important to distinguish meningioangiomatosis from other possible cortical lesions and epileptic foci should be carefully considered before resection, because it is a benign and surgically manageable cause of seizures.

Two-year follow-up of chronic stimulation of the posterior subthalamic white matter for tremor-dominant Parkinson's disease.

OBJECTIVE: To determine the efficacy and safety of unilateral deep brain stimulation on the posterior subthalamic white matter, including the zona incerta (ZI) and the prelemniscal radiation (PRL), for tremor-dominant parkinsonian patients and to determine the exact location of electrodes that were most effective. METHODS: Eight parkinsonian patients with severe resting tremor underwent unilateral stimulation of the ZI/PRL by use of stereotactic guidance. Electrophysiological targeting was obtained by macrostimulation and by somatosensory evoked potentials recorded directly through a quadripolar deep brain stimulation lead. Postoperative computed tomographic scans and magnetic resonance images were performed to confirm anatomic location of the electrode. Parkinsonian motor disabilities were evaluated by use of the Unified Parkinson's Disease Rating Scale in the medication-off state before surgery and every 6 months after electrode implantations. RESULTS: The mean location of the clinically effective contacts was in the posterior subthalamic white matter, including the ZI and the PRL (mean, 5.6 +/- 1.2 mm posterior to the midcommissural point, 3.2 +/- 1.1 mm inferior to the anterior commissure-posterior commissure line, and 10.5 +/- 1.2 mm lateral to the midline). At 24 months after operation, ZI/PRL stimulation resulted in significant improvement in mean Unified Parkinson's Disease Rating Scale motor score by 44.3%, contralateral tremor by 78.3%, contralateral rigidity by 92.7%, and contralateral akinesia by 65.7% above the "off-stimulation" scores. Handwriting, posture, and gait were also improved. There were no or only mild adverse events. CONCLUSION: Unilateral ZI/PRL stimulation is a reliable and long-term therapeutic modality and can be considered another surgical target for the treatment of tremor-dominant Parkinson's disease.