[Clinical study of correlation pre-senile, senile depressive state with silent cerebral infarction--MRI findings and its distribution].

We examined the relationship between the pre-senile/senile depressive state and silent cerebral infarction using MRI. The subjects studied were 56 patients 50 years of age or older with a depressive state who underwent MRI and who were hospitalized and treated at the Department of Psychiatry or the Department of Neurology of Hiroshima Prefectural Hospital. We made a diagnosis of depression in patients who fulfilled the criteria of DSM-III-R for major depression. Patients in whom apoplectic attacks had occurred, or who had local neurologic symptoms or a history of evident cerebrovascular disorders, were not included in the study. Silent cerebral infarction was observed with pre-senile onset in 60.3% of patients with a pre-senile depressive state, and the complication rate was significantly higher than for cases with juvenile onset (20%). For patients with a senile depressive state, the complication of silent cerebral infarction was found in 53.6% of cases of pre-senile onset and in 100% of cases of senile onset. These rates were remarkably higher than the age-related complication rate of silent cerebral infarction in normal persons reported hitherto, we therefore suspect that nearly half of patients with depressive state of pre-senile onset and most of patients with that of senile onset might have an organic-depressive state complicated by silent cerebral infarction. Both perforating-type infarcts and cortical-type infarcts were found, suggesting that infarct-related foci of depressive states were polyphyletic. When we divided the depressive states complicated by cerebral infarction into 2 subtypes, those complicated by a perforating-type infarct and those by a cortical-type infarct, and compared the 2 types, we found possible differences in clinical symptoms and course between the subtypes. These differences seem worthy of further study. Among cortical-type lesions, parietal lesions were predominant, followed by frontal and then temporal lesions in incidence. There were significantly more left frontal lesions than right frontal lesions. Infarcts of both the parietal lobe and left frontal lobe may be related to the depressive state. Compared with cases not complicated by cerebral infarction, those with perforating- and mixed-type cerebral infarction were complicated with PVH significantly more frequently, similarity in risk factors and pathology between perforating-type cerebral infarction and PVH was suggested by these results.