Rinshō shinkeigaku = Clinical neurology
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Eighteen autopsy cases of syringomyelia were studied neuropathologically. In 5 cases associated with Chiari type I malformation, the syrinx was irregular in shape and communicated with the subarachnoid space at the entry zone of the posterior nerve roots. The central canal above the level of the syrinx was patent in 2 but closed in 3 out of 5 cases. ⋯ In 6 cases associated with Chiari type II malformation, the syrinx central canal, and the central canal was patent from the 4th ventricle to the syrinx in all cases. In these cases, direct continuity between the 4th ventricle and the syrinx was essential for the development of the syrinx. In cases associated with posterior fossa or spinal canal tumors, the local circulatory disturbance and/or edema due to the tumors were thought to cause the syrinx.
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Previous studies have shown that migraine with aura is associated with the reduction of regional cerebral blood flow (rCBF). However, the question of whether the reduction of rCBF during migraine aura is caused by cerebral vasospasm or is secondary to the neural depression (spreading depression) is still disputed. We measured rCBF by high resolution SPECT method during the attack of migraine and examined whether the reduction in flow corresponds to the cerebral vascular territory. ⋯ Cerebral spinal fluid lactate level during the headache measured in one patient was higher (38 mg/dl) than the interictal period (12 mg/dl). Our data indicated that the reduction of rCBF during the aura is caused by ischemia probably due to the cerebral vasospasm and is not secondary to the neuronal depression. It was also suggested that the primary site of rCBF reduction during the visual aura is the occipital association cortex which is reported to be responsible for the visual hallucination.