Development of cerebral infarction was dependent on both time from stroke onset and residual cerebral blood flow (CBF), and cerebral tissue viability could not be preserved in a severe ischemic region even within 3 hours, but it could be preserved in a moderate ischemic region within 3-6 hours. Using ^<133>Xe-SPECT imaging, penumbral flow was estimated as 15-30 ml/100 g per mm within 3 hours from stroke onset and 20-30 ml/100 g per mm during 3-6 hours from stroke onset. The relationship between residual CBF (Y) and time from stroke onset (X) in an ischemic region with cortical hyperintensity area (HIA) on diffusion-weighted MRI (DWI) was expressed by linear regession(Y=3.12X+3.61, r=0.73, p<0.05), and cortical HIA on DWI was estimated as the ischemic core because cerebral tissue viability could not be preserved by residual CBF level in cortical HIA. Ischemic penumbra rescued by thrombolytic therapy was identified in a moderate ischemic region without cortical HIA on DWI within 6 hours from stroke onset.

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Stroke has never been as challenging or as exciting. The growing recognition and expanding knowledge of strokes will enable us to do something about it. Now is the time for recognizing stroke as medical emergency "brain attack". Awareness is a necessary prelude to action, already much can be done to prevent and treat strokes. Imaging, including CT, MRI, MR spectroscopy, SPECT and PET, allow us to peer into the brain, the blood vessels and the body with unprecedented acuity To diagnose and treat strokes using these state-of-the-art techniques within a narrow therapeutic time window, organized and multidisciplinary stroke care is mandatory.

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We studied the indication, usefulness, and seizure outcomes of tailored cortical resection for 41 patients with intractable neocortical epilepsy. There were 29 males and 12 female patients who ranged in age from 2 to 55 years at operation (average age 24.0 years). This series included 12 children less than 15 years of age. There were 19 patients with frontal lobe epilepsy, 14 with neocortical temporal lobe epilepsy, 3 with parietal lobe epilepsy, and 5 with multi-lobar epilepsy. MRI demonstrated focal cortical dysplasia (FCD) in 8 patients, neoplastic lesions in 10 patients, non-neoplastic lesions in 20 patients, and non-lesional areas in 11 patients. Chronic subdural recordings were performed in 83% of 48 operations performed with the resection surgery and were successfully completed in 3 days to 3 weeks (average : 2 weeks). Tailored cortical resection of the epileptogenic area was performed in all patients. Staged resection surgery was performed in 7 patients. Seizure outcomes were evaluated as class 1 in 66% of the patients and as class 2 in 17%. However, a postoperative seizure-free diagnosis was achieved in only 42% of the 12 children because of the lack of subdural recordings or multi-lobar foci. Postoperative neurological deficits consisted of upper quadrant hemianopsia in another case and mild leg paresis in one case. Satisfactory seizure outcomes were more readily achieved in patients with FCD or neoplastic lesions than in patients with non-lesional areas. Tailored cortical resection is a favorable surgical strategy not only for lateral cortices but also for medial and basal cortices. Ictal subdural recordings were indispensable for favorable outcomes in patients with neocortical epilepsy.

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We treated a series of 26 patients with hydrocephalus using a "dual switch valve (DSV)", which automatically changes its opening pressure relative to their posture. Post-operative changes in ventricle size, intraventricular pressure (IVP), and clinical course were examined in comparison with 33 hydrocephalic patients treated with the pressure adjustable valve Sophy (PAVS). The reduction rate of ventricular size was 9.0% in the DSV group and 15.6% in the PAVS group in a week post-operatively. The average IVP values were 43 mm H_2O in the supine position and -37 mm H_2O in the sitting position, both remained within the normal range, in patients treated by DSV No complication related to overdrainage occurred in the DSV group. Frequency of other complications was almost the same in both groups.

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It is common in Japan that surgical treatment for chronic subdural hematoma (CSDH) requires seven to ten days of hospitalization. The author set out to shorten the required hospitalization period about five years ago. This report shows the safety and fitness of our two-day hospital stay surgery for CSDH. We operated on 210 cases of CSDH in 195 adult patients, 130 males and 65 females with a mean age of 72.7±13.4 years, using one-burr hole and closed-system drainage from April 1997 through September 2001. The drain was removed on the following day of the operation and the patients were discharged on the next day. The stitches were removed at the outpatient office around 7 days after the operation. Mean hospitalization time was 5.3 (2-62) days and a 3-day stay was most common (45.7%). Hospitalization time was from 2 to 4 days in 149 cases (71.0%), from 5 to 9 days in 46 cases (21.9%), and over 10 days in 15 cases (7.1%). The mean hospitalization time of 7.1 days in 36 bilateral CSDHs was longer than that of 5.0 days in 174 unilateral CSDHs. The hospitalization period for patients in a low ADL (activity of daily living) state preoperatively tended to be long. Seven patients had postoperative complications, one died of pancreatitis and another one had acute hydrocephalus. Reoperation was required in 18 cases (9.2%). We had been anxious about the possible overlooking of complications, an increase in reoperations and wound infections. However, the present data showed no such problems. A two-day hospital stay surgery for CSDH is safe and appropriate for shortening a patient's hospitalization requirement.

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A 72-year-old female presented with a unique case of acoustic neurinoma with a cystic component followed by the chronic subdural hematoma manifesting as trigeminal neuralgia, facial palsy and trunchal ataxia 7 months after gamma knife radiosurgery Magnetic resonance imaging demonstrated a loss of central contrast enhancement at the postoperative residual tumor mass and a large cyst associated with a hematoma in the subdural space. A right suboccipital craniectomy was performed. A biopsy of the mass and the membrane was performed following aspiration of the brown-reddish fluid collection. The histological diagnosis was acoustic neurinoma with a hemorrhagic necrosis. The membranous tissue mimicked an outer membrane obtained from chronic subdural hematoma. The postoperative course was satisfactory and preoperative symptoms have been alleviated. In this case, the chronic subdural hematoma occurred at posterior fossa during the development of cysts caused by the radiosurgery, because the subdural space had been connected with the subarachnoid space after the first operation. The development of cysts or hematoma should be taken into consideration as possible complications following treatment with gamma knife radiosurgery for acoustic neurinomas.

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Peritoneal shunt is a common surgical procedure for hydrocephalus, and shunt revisions to deal with malfunction and/or complications are frequent. However, an abdominal cerebrospinal fluid pseudocyst is an infrequent complication of ventriculo-peritoneal shunt in children's peritoneal shunt procedures. We report here 12 cases of abdominal pseudocysts and examine their etiology diagnosis, clinical signs and symptoms and surgical management. In our hydrocephalus series, we found that the incidence of pseudocyst formation was 4.2%. The common presentation of those cases were abdominal signs such as vomiting, pain, distention in 11 cases, rather than neurological signs. In five of the children, symptoms or signs of increased intracranial pressure also appeared. Eight patients had a history of shunt revision. The diagnosis was based on findings obtained with abdominal computed tomography, where necessary, ultrasonography and shuntography. But in many cases, the latter two procedures were sufficient. Treatment of the cyst consisted of repositioning of the shunt tube (6 cases), of removal of the shunt tube and extraventricle drainage (5 cases), and of puncture of the cyst (1 case). Repositioning of the shunt tube in the abdominal cavity was not sufficient for the treatment. The patients who underwent extraventricle drainage of the shunt tube showed only one recurrence. Regardless of infection, removal of the shunt tube and extraventricle drainage of the shunt tube is thus considered to be the most reliable treatment of this complication.

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We report a case of recurrent chronic subdural hematoma initially treated by a burr-hole opening with irrigation. A 36-year-old man experienced headache about a month after head injury, which was diagnosed as a chronic subdural hematoma. He underwent burr-hole irrigation and the postoperative course was uneventful. A CT scan taken seven days after the operation revealed no residual subdural hematoma. And so he was discharged from hospital without neurological deficits. Four days after his discharge, he came to the hospital with a severe headache, and a CT scan demonstrated a recurrent chronic subdural hematoma. This time, we performed a craniotomy in order to investigate the cause of the recurrence. Right frontotemporoparietal craniotomy was performed, and an abnormal small artery arising from the cortical branch of the middle cerebral artery, which penetrated into the inner membrane of the chronic subdural hematoma, was confirmed. Pathological examination of the inner membrane adjacent to the abnormal small artery showed plenty of macrocapillaries in the sinusoidal channel layer, which were filled with red blood cells. Some of the macrocapillaries had ruptured, and so hematoma was noted in the sinusoidal channel layer and in the cavity of the hematoma, which had broken the fibrous layer. These findings suggest that a thin acute subdural hematoma was initially formed under the rupture of the cortical artery and changed into an unusual chronic subdural hematoma. And the re-growth of the subdural hematoma resulted mostly from the macrocapillaries of the outer membrane and partly from that of the inner membrane. So when we face such cases, we had better consider both the macrocapillaries of the outer and inner membranes before we choose the method of operation to avoid this type of the recurrence.

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