Depressive disorders following posterior circulation as compared with middle cerebral artery infarcts.

Patients with cerebrovascular lesions in the posterior circulation territory (PC) were compared with patients having middle cerebral artery territory (MCA) strokes for the presence of mood disorders. Both groups showed a similar profile of clinical symptoms of depression during the acute evaluation in hospital. Patients with posterior circulation lesions involving the brainstem and/or cerebellum demonstrated a significantly lower frequency of depression than patients with MCA lesions or patients with posterior circulation lesions involving the left cerebral hemisphere. Moreover, depression following brainstem and/or cellebellar infarcts was of significantly shorter duration than depression following MCA lesions. These differences in the frequency and duration of depression following brainstem/cerebellar as compared with MCA lesions were not explained by differences in lesion volume, physical impairment, cognitive deficits or quality of social support. They suggest that PC and MCA induced depression may have different aetiologies.