SUMMARY Three Japanese families with moya-moya disease in six patients are presented. These six patients were among 49 cases of confirmed moya-moya disease in our experience, and the familial incidence was more than 12%. A relatively high familial incidence (7%) was found in the total Japanese scries emphasising the important hereditary components in the pathogenesis of the disease. (Fig. 2) and WISC were essentially the same as in the previous studies.Case 1.2 This 11 year old girl was the younger sister of case 1

The treatment and prognosis of 4 cases of primary middle fossa arachnoid cyst in children were analyzed with computed tomography, carotid angiography and Radio isotope cisternography at preoperative and postoperative states. In 2 of 4 cases the cysts reduced their sizes and in the other 2 cases they disappeared after operation. Three surgical methods were performed. The postoperative courses of all cases were good. The disappearance of cysts does not depend on the surgical methods.

Five hundred cases of acute head injury were analyzed on the basis of clinical severity, CT findings and outcome. Parenchymal lesions, which were the most important information in predicting the outcome, were classified into six categories: Isodensity WITHOUT Mass Effect, Isodensity WITH Mass Effect, High Density, High and Low Density Complex, Low Density, and Acute Diffuse Cerebral Swelling. Isodensity WITH Mass Effect was related to the worst outcome (59% mortality and 24% functional recovery). This finding was obtained 2 and a half hours following trauma and High and Low Density Complex eventually appeared in repeated CT. Epidural hematoma was associated with parenchymal lesions in only six (40%) out of 15 cases and acute subdural hematoma was accompanied by parenchymal lesions in 21 (84%) out of 25 cases. The remarkable differences in the outcome of those two extracerebral hematomas were entirely dependent on the associated parenchymal lesions. In the minor head injury group, parenchymal lesions were not rare (8.5%) in patients with a loss of consciousness even for a brief period. To follow the rapid dynamic changes in parenchymal lesions, the importance of repeated CT was emphasized.