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Yasuhiko Kaku, Yasuhiro Yonekawa, Tetsuya Tsukahara and Kiyoshi Kazekawa

✓ This report describes the successful treatment of cerebral vasospasm after subarachnoid hemorrhage with superselective intra-arterial infusion of papaverine hydrochloride. Thirty-seven vascular territories in 10 patients with symptomatic vasospasm were treated according to the following protocol. Percutaneous transluminal angioplasty was performed in two steps. First, a silicone balloon was used for dilation of the internal carotid artery and the proximal portions of the middle cerebral artery. A silicone leak balloon or Tracker-18 catheter was then introduced into or just proximal to the site of vasospasm not accessible to the angioplasty balloon catheter for superselective infusion of 0.2% papaverine. Thirty-four of 37 vascular territories were successfully dilated, and eight of 10 patients showed improvement in neurological function after the procedure. There were no serious side effects due to infusion of papaverine. It is essential to infuse the papaverine just proximal to the spastic vessels in order to deliver sufficient concentration of drug, and infusion should be carried out as early as possible before the artery loses its ability to return to a normal luminal size. Superselective intra-arterial infusion of papaverine is an alternative method of treatment for symptomatic vasospasm.

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M. Gazi Yasargil, Yasuhiro Yonekawa, Bruno Zumstein and Hans-Jürgen Stahl

✓ Twenty-eight cases of communicating hydrocephalus after subarachnoid hemorrhage (SAH) due to ruptured intracranial aneurysms are reported. The relationship between the incidence of this complication and the various clinical features of SAH is discussed. The findings of RISA cisternography have little relationship to the findings of pneumoencephalography or the results of shunting procedures. The availability and value of echoencephalography in treating such patients is emphasized.

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Javier Fandino, Yasuhiko Kaku, Bernhard Schuknecht, Anton Valavanis and Yasuhiro Yonekawa

Object. The purpose of the present study was to assess cerebral oxygenation patterns and brain lactate concentration changes before, during, and after intraarterial infusion of papaverine with or without balloon angioplasty in patients with symptomatic vasospasm.

Methods. A total of 23 vascular territories were successfully treated in 10 patients. In three patients balloon angioplasty was performed before the papaverine infusion. Continuous monitoring of jugular bulb vein oxygen saturation with a fiberoptic catheter and blood sampling allowed the assessment of the cerebral arteriovenous oxygen and lactate differences. A significant and rapid improvement in jugular bulb oxygen saturation was observed in all cases, with critical values reflecting an improvement in cerebral oxygenation after endovascular treatment of vasospasm (p = 0.005). Lactate concentration in the jugular bulb normalized within 4 hours in all patients who had evidence of brain lactic acidosis before superselective intraarterial infusion of papaverine. Recurrence of abnormal metabolic and oxygenation patterns were observed in one case in which an optimal hypertension and hypervolemic therapy could not be achieved after the procedure.

Conclusions. Improvement in cerebral oxygenation as well as prevention of cerebral lactic acidosis can be successfully achieved after intraarterial infusion of papaverine. Normalization of the oxygen supply after endovascular treatment has to be supported by optimal and well-monitored hypertension and hypervolemic hemodilution.

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H. Gregor Wieser, Marcos Ortega, Alon Friedman and Yasuhiro Yonekawa

Object. Analyses of the results of surgery for epilepsy are hindered by inconsistent classifications of seizure outcome, small numbers of patients, and short postoperative follow-up periods. The authors conducted a retrospective study with a reassessment of the long-term seizure outcomes in patients who underwent selective amygdalohippocampectomy (SelAH) for pharmacotherapy—resistant mesial temporal lobe epilepsy (MTLE) at the Zurich University Hospital from 1975 to 1999.

Methods. Year-by-year data and the last available data on seizure outcomes were retrospectively assessed for 369 consecutively surgically treated patients who had participated in a follow-up period longer than 1 year as of 1999 and whose outcomes were classified according to the Engel scale and the proposed new International League Against Epilepsy (ILAE) scale. Patients were grouped into nonlesional and lesional MTLE groups depending on whether they harbored a gross anatomical lesion that caused the MTLE. Differentiation was made between curative and palliative operations. Complications related to surgery are reported for 453 patients who underwent SelAH and participated in more than 3 months of follow-up review.

The last available outcome data according to the Engel scale were found to be generally similar to those of the new ILAE classification, with 66.9% of patients free from disabling seizures (Engel Class I) compared with 57.1% who were completely seizure and aura free (ILAE Class 1). The last available data on seizure outcome were not significantly different between patients in the lesional and nonlesional MTLE groups. In the lesional group, seizure outcomes were significantly better when patients underwent surgery early in the course of the disease. Overall, 70% of the patients received reductions in their antiepileptic drug treatment at the time of the last available follow-up review. Complications related to the surgical procedures were rare.

Conclusions. The authors conclude that SelAH is a safe and effective surgical procedure for MTLE.

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Kyo Huang Niijima, Yasuhiro Yonekawa, Hajime Handa and Waro Taki

✓ Anastomosis of rat common carotid artery was performed without sutures, using a neodymium (Nd)-YAG laser at 20 W for 100 msec; this power and exposure had been found optimal in preliminary experiments. An intraluminal intervascular splint made of water-soluble polyvinyl alcohol, which dissolved and disappeared within a few minutes after recirculation of blood, was used for precise “intima-to-intima” coaptation. No stay sutures or glue were required during the procedure.

There was a 92% patency rate 24 hours after surgery, and the anastomosed vessels were still patent on the 7th and 30th postoperative days. Complications such as aneurysm formation or stenotic change were negligible. The fusion of the muscle layer and collagen fibers of the media in the anastomosis was confirmed histologically. A tensile strength test immediately following operation and 1 week later showed that this anastomosis was significantly better than that achieved with the usual manual suture method. The major advantages of this technique, combined with use of a water-soluble polyvinyl alcohol splint, are rapidity, consistency of results, and firm fusion with no residual foreign body.

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Javier Fandino, Spyros S. Kollias, Heinz Gregor Wieser, Anton Valavanis and Yasuhiro Yonekawa

The purpose of the present study was to compare the results of functional magnetic resonance (fMR) imaging with those of intraoperative cortical stimulation in patients who harbored tumors close to or involving the primary motor area and to assess the usefulness of fMR imaging in the objective evaluation of motor function as part of the surgical strategy in the treatment of these patients.

A total of 11 consecutive patients, whose tumors were near to or involving the central region, underwent presurgical blood oxygen level-dependent fMR imaging while performing a motor paradigm that required the patients to clench and spread their hands contra- and ipsilateral to the tumor. Statistical cross-correlation functional maps covering the primary and secondary motor cortical areas were generated and overlaid onto high-resolution anatomical MR images. Intraoperative electrical cortical stimulation was performed to validate the presurgical fMR imaging findings. In nine (82%) of 11 patients, the anatomical fMR imaging localization of motor areas could be verified by intraoperative electrical cortical stimulation. In seven patients two or more activation sites were demonstrated on fMR imaging, which were considered a consequence of reorganization phenomena of the motor cortex: contralateral primary motor area (nine sites), contralateral premotor area (four sites), ipsilateral primary motor area (two sites), and ipsilateral premotor area (four sites).

Functional MR imaging can be used to perform objective evaluation of motor function and surgical planning in patients who harbor lesions near or involving the primary motor cortex. Correlation between fMR imaging findings and the results of direct electrical brain stimulation is high, although not 100%. Based on their study, the authors believe that cortical reorganization patterns of motor areas might explain the differences in motor function and the diversity of postoperative motor function among patients with central tumors.

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René L. Bernays, Spyros S. Kollias, Nadia Khan, Sebastian Brandner, Sonja Meier and Yasuhiro Yonekawa

Object. The authors undertook a prospective study of frameless, magnetic resonance (MR)—guided stereotactic brain biopsy procedures performed with the aid of an open MR system. Morbidity and mortality rates, frequency of postoperative hemorrhage, and histological yield were evaluated, as well as the size and location of the lesions under investigation.

Methods. During a period of 51 months (July 1996–November 2000), 114 consecutive frameless stereotactic biopsy procedures were performed with the aid of an open intraoperative MR system to investigate supratentorial lesions in 113 patients. The median volume of the lesions was 33.5 cm3, and 31.9% were deep seated. All biopsy samples comprised pathological tissue and in 111 (97.4%) of 114 a specific neuropathological diagnosis was made. A follow-up computerized tomography (CT) scan was obtained on the 1st postoperative day in all patients to evaluate postoperative complications. In two cases (1.8%), a hemorrhage was found on postoperative CT scans, with no neurological worsening of the patients. Morbidity with neurological worsening was seen in three patients; it was transient in two of them (1.8%), and in one (0.9%) subsequent emergency craniotomy was necessary because of increased edema. There were no infections, but there was one death (0.9%)

Conclusions. Open intraoperative MR imaging transforms a blind conventional stereotactic procedure into a visually controlled procedure that is adaptable to dynamic anatomical changes. Routine postprocedural MR imaging makes follow-up CT scanning obsolete. This largest reported series of intraoperative MR—guided biopsy procedures shows results that are at least comparable with those in reports of larger series of conventional stereotactic biopsy sampling. The mean procedure time was 60 minutes including planning, and this method produced low morbidity and complication rates and a high histological yield.

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Kevin N. Strommer, Sebastian Brandner, Ali C. Sarioglu, Ulrich Sure and Yasuhiro Yonekawa

✓ This case report contains a description of a 61-year-old patient who presented with a progressive truncal ataxia 22 years after complete removal of a small paraganglioma of the cauda equina. Magnetic resonance imaging of the neuraxis revealed a large cystic lesion in the cerebellar midline, three small cortical-to-subcortical nodular tumors in the posterior fossa, and local recurrences of the paraganglioma of the cauda equina. Pathological examination showed the cerebellar midline lesion to be a paraganglioma, most likely a metastasis from the cauda equina localization.

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Intraoperative validation of functional magnetic resonance imaging and cortical reorganization patterns in patients with brain tumors involving the primary motor cortex

Javier Fandino, Spyros S. Kollias, Heinz Gregor Wieser, Anton Valavanis and Yasuhiro Yonekawa