[Significance of periventricular hyperintensity on magnetic resonance images in stroke patients].

To clarify the significance of periventricular hyperintensity (PVH) on MRI-T2 images in stroke patients, clinical and experimental studies were performed. MRI (1.5 Tesla) was obtained in 153 patients with ischemic stroke. The PVH was observed in all the patients, although severe PVH was found only in 22% of the cases. Severe PVH was observed mainly in hypertensive elderly patients with multiple infarctions and impaired cognitive function. Regional cerebral blood flow was reduced in majority of these patients. The absence of aqueductal signal flow void, remarkable ventricular enlargement and abnormal RI cisternography+ were observed in 20% of the patients with severe PVH. In Wistar rats and gerbils, chronic low perfusion state was induced by occlusion or narrowing of both common carotid arteries, and histological studies were performed at 1 week, 1 month or 3 months after the surgery. Multiple infarctions, white matter changes and ventricular enlargement were observed in these animals. The results suggest that chronic low perfusion in the brain and/or abnormal cerebrospinal fluid circulation play a role in the development of PVH.