The crucial role of frontostriatal circuits for depressive disorders in the postacute stage after stroke.

OBJECTIVE: This study analyzes lesion configuration in patients in the post-acute stage after first single unilateral stroke who suffered from depressive disorders.
BACKGROUND: Recent studies indicate a biological origin of poststroke depressive disorders. Due to differences in times of investigation, methods applied, and patient selection, most data are not comparable. Furthermore, only a few studies of poststroke depression report detailed neuropsychologic assessments.
METHODS: We investigated 20 consecutive patients who were diagnosed as depressive according to DSM-III-R criteria and exhibited no other severe illness, had no history of neurologic or psychiatric disease, and who were either not aphasic, or only mildly aphasic. A structured clinical interview, self-based and observer-based depression rating scales, a comprehensive neuropsychologic and neurologic examination and ADL-measurement were applied. Neuroradiologic analysis was based on standardized computed tomography scans.
RESULTS: Nine of 10 subjects with left hemisphere strokes exhibited a major depression and 7 of 10 subjects with right hemisphere infarcts a minor depression. The most prominent neuropsychologic deficits were found in frontal lobe associated tasks. Type and severity of depression were not related to the severity of neurologic symptoms or impairment in activities of daily living. For both major and minor depression the maximal overlap of lesions was found in subcortical areas, including parts of the caudate nucleus, posterior parts of the putamen, and the deep white matter.
CONCLUSIONS: The findings support the theory that poststroke depression is related to the dysfunction of (cortico-) striato-pallido-thalamic-cortical projections that modulate cortico-thalamo-cortical loop systems.