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 mho suffered from depress ive disorders. Background: Recent studies indicate a biological origin of p oststroke depressive disorders. Due to differences in times of investigatio n, methods applied, and patient selection, most data are not comparable. Fu rthermore, only a few studies of poststroke depression report detailed neur opsychologic assessments. Methods: We investigated 20 consecutive patients who were diagnosed as depressive according to DSM-III-R criteria and exhibi ted no other severe illness, had no history of neurologic or psychiatric di sease, and who were either not aphasic, or only mildly aphasic. A structure d clinical interview, self-based and observer-based depression rating scale s, a comprehensive neuropsychologic and neurologic examination and ADL-meas urement were applied. Neuroradiologic analysis was based on standardized co mputed tomography scans. Results: Nine of 10 subjects with left hemisphere strokes exhibited a major depression and 7 of 10 subjects with right hemisp here infarcts a minor depression. The most prominent neuropsychologic defic its were found in frontal lobe associated tasks. Type and severity of depre ssion were not related to the severity of neurologic symptoms or impairment in activities of daily living. For both major and minor depression the max imal overlap of lesions was found in subcortical areas, including parts of the caudate nucleus, posterior parts of the putamen, and the deep white mat ter. Conclusions: The findings support the theory that poststroke depressio n is related to the dysfunction of (cortico-) striato-pallido-thalamic-cort ical projections that modulate cortico-thalamo-cortical loop systems.