Perimesencephalic nonaneurysmal subarachnoid haemorrhage (PN-SAH) is characterised by accumulation of blood around the midbrain, normal angiographic findings and an excellent prognosis. The etiology of PN-SAH has not yet been determined. Therefore we decided to compare the venograms of patients with PN-SAH with those of patients with aneurysmal SAH (A-SAH) in order to examine the relationship between PN-SAH and venous structures. We retrospectively studied 6 patients with PN-SAH and 102 cases of angiographically evaluated A-SAH during the past 12 years by reviewing their venograms for possible abnormalities in venous structures, particularly in the basal vein of Rosenthal (BVR). More abnormalities in venous structures were found in the patients with PN-SAH than in those with A-SAH. Most of the BVR in the patients with PN-SAH appeared to drain into various dural sinuses instead of the galenic system. The relationship between PN-SAH and abnormalities in venous structures was determined.

An efficient treatment option for CSF hypovolemia is provided by the new application method of EBP with the aid of an intravenous catheter as a slidable device, which enables infusion of a sufficient amount of autologous blood into multiple epidural areas with a single lumbar entry point.

While there have been a few reports on cases of intradural spinal arteriovenous fistula located on the filum terminale, no cases of its location in a nerve root of the cauda equina have been reported to date. We describe two such cases and describe the intraoperative findings. A 40-year-old man presented weakness of his left leg. Another 62-year-old man presented paraparesis dominantly in his left leg with urinary hesitation. In both cases, spinal T2-weighted magnetic resonance images showed edema of the spinal cord, indicating a flow void around it. Digital subtraction angiography disclosed an anterior radicular artery branching from the anterior spinal artery on the surface of the conus medullaris and a turnaround vein running in the opposite direction within the cauda equina. In the first patient, while the feeding artery running along a nerve root was detected, the draining vein and the fistula were not identified at first sight. An incision into the respective nerve root exposed their location within it. In the second patient, unlike the first case, the feeding artery and the fistula were buried in a nerve root, while the draining vein was running along the nerve's surface. In both cases, permanent clips were applied to the draining vein closest to the fistula. The recognition of a hidden fistulous point in a nerve root of the cauda equina is essential for successful obliteration of the fistula.

A 21-year-old man presented with extraneural metastases to the peritoneum, pleura, bone marrow, lymph nodes, and other organs from a pulvinar high grade glioma. He had undergone a shunt operation and three tumor removals during a 6-year period. He also received radiotherapy and adjuvant chemotherapy with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride and interferon-beta. Two and a half years after the last surgery, extraneural metastasis to the peritoneal cavity was discovered. He died 13 months after the occurrence of extraneural metastases and 10 years after the initial diagnosis. Autopsy revealed tumor masses in the peritoneum, pleura, bone marrow, lymph nodes, and other organs, but no recurrent tumor of the primary lesion or metastases to other areas in the central nervous system. Systemic metastases from primary intracranial tumors are rare, but are likely to become more frequent as the prognosis of patients with brain tumors improves and the duration of survival lengthens.

We studied the mechanism underlying seizure induction in patients with chronic subdural hematoma. In our study population of 1,009 patients with chronic subdural hematoma, 26 (2.6%) had seizure-related complications. Six of them had already been diagnosed with epilepsy (4 patients) or suspected of having secondary epilepsy (2 patients) after experiencing traffic accidents or cerebral bleeding. Twenty patients (seizure group) had been tentatively diagnosed as having hematoma-induced convulsion. Of the remaining 989 patients without convulsion, 40 randomly sampled patients were included in the non-seizure group by matching with clinical terms. Intergroup comparisons showed that patients with dementia were more common in the seizure group than in the non-seizure group; however, no intergroup differences were observed for other clinical parameters. Radiological examinations showed that bilateral hematomas were relatively more common and sulcal hyperintensity on FLAIR MR images was significantly more frequent in the seizure group than in the non-seizure group. Interestingly, many patients presenting with sulcal hyperintensity exhibited mixed-density hematomas on CT images. These findings suggest the mechanism by which hematoma content infiltrates into the brain parenchyma and the subsequent induction of convulsions by the stimulatory component.