Brain atrophy and cerebral infarction.

The subjects of the study (109 males, 48 females) were all diagnosed to have cerebral infarction by computerized tomography (CT). The cerebrospinal fluid (CSF) space volume and cranial cavity volume in the normal hemisphere of the patients were estimated using CT at the time from 1 to 3 weeks after the attack of cerebral infarction. The percentage of the CSF space volume to the cranial cavity volume was calculated as an indicator for brain atrophy and called brain atrophy index (BAI): BAI (%) = 100(%) X (CSF space volume/cranial cavity volume). The BAI immediately after the attack of infarction (6.6 +/- 2.2, n = 15), during which no detectable change occurred on CT examination, was the same as the BAI at the time from 1 to 332 days after the attack (6.6 +/- 2.4, n = 20). Therefore we compared the BAI in patients without infarction with the BAI in patients with infarction irrespective of secondary atrophy of the brain after the attack. The BAIs in males with infarction were significantly greater than the BAIs in males without infarction in the age of fifties, sixties and seventies. The BAIs in females with infarction were significantly greater than in females without infarction in the age of fifties, sixties and eighties.