Seven cases of parietal cephalocele and three cases of occipital cephalocele associated with abnormal venous drainage were evaluated, and the mechanism of the development for venous system was discussed from the embryological viewpoint. In parietal cephaloceles the abnormally draining vein, which corresponds to the straight sinus, ascended along the interhemisphere apart from the tentorium and emptied into the superior sagittal sinus below the cephalocele. The superior sagittal sinus formed the confluence, which was positioned high up. Intraoperative findings revealed that cephalocele penetrated the superior sagittal sinus at the midline. In the case of occipital cephalocele, the straight sinus followed a postero-superior course, to drain into the confluence just above the neck of cephalocele. The results of our study suggest that the causation of abnormal venous drainage in the great vein of Galen, the straight sinus and the superior sagittal sinus may be secondary, through interaction with a developmentally pre-existing cephalocele.

We encountered unexpected accumulation of thallium-201 in a patient with thalamic dementia resulting from bithalamic venous infarction induced by arteriovenous fistula in the posterior fossa The site and degree of abnormal accumulation varied between early and delayed thallium-201 SPECT images. This unexpected and complicated accumulation of thallium-201 appeared to depend on not only breakdown of the blood-brain barrier but also on the hemodynamics of this type of venous infarction.

Achondroplasia is often associated with cervicomedullary dysfunction. MRI sagittal imaging was performed to determine whether surgical intervention was necessary to relieve cervicomedullary compression. Cervicomedullary compression was classified into severe and mild types based on the ratios of the brain stem diameter at the foramen magnum, the site of the most severe stenosis to the diameter at the pontomedullary junction and C3 level, where it is normal. This classification was found to be closely correlated with the severity of clinical symptoms and important in determining whether surgical intervention is necessary. Moreover, since the incidence of sudden death is high in patients aged 4 years or younger with achondroplasia, surgical intervention should be considered in all such patients if cervicomedullary compression is present.

This study investigated the relationship between neurotransmitters and improvement of symptoms af ter ventriculoperitoneal shunting in congenital hydrocephalus (LEW-HYR) rats. Twenty-four patent hydrocephalus rats, aged 12-14 days, were randomly assigned to the following four groups: ven triculoperitoneal shunt group, obstructed shunt group, burr hole group, and no treatment group. In addi tion, six normal rats served as control group. Head to body length ratio was measured before and 7 days after the procedures. Coordination movement was evaluated on the 7th postoperative day. High per formance liquid chromatography (HPLC) was used to measure the concentrations of dopamine (DA), norepinephrine (NE), serotonin, homovanillic acid (HVA), 3-methoxyl-4-hydroxyphenylenglycol, 5 -hydroxy-indolacetic acid (5-HIAA), and 3,4-dihydroxyphenylacetic acid in the whole cerebral cortex, the thalamus and hypothalamus, the midbrain, the lower brainstem, the cerebellum, and the striatum. Fluorohistochemical studies were also performed. Significant improvements were observed in body proportion and coordination movement in the ventriculoperitoneal shunt group compared to the burr hole group and the no treatment group. HPLC and fluorohistochemical studies revealed that concen trations of NE in the thalamus and hypothalamus and DA in the striatum were significantly lower in the burr hole group and the no treatment group. Concentrations of HVA and 5-HIAA in the cerebellum were significantly lower in the control group. The present study indicates that ventriculoperitoneal shunting may improve the changes in concentrations of neurotransmitter in specific neurons caused by hydrocephalus, and this may contribute to the improvement of the symptoms.

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