Motor cortex excitability in vascular depression.

The aim of this study was to evaluate excitatory/inhibitory intracortical circuit changes in patients with vascular depression, and whether there are any interhemispheric differences of motor cortical excitability. Fifteen vascular depressed elderly (VD), ten nondepressed subcortical vascular disease patients (SVD) and ten age-matched controls underwent bilateral motor threshold and paired-pulse studies. They were also assessed for their brain vascular burden at MRI and neuropsychological profile. Executive dysfunction and apathy were significantly higher in VD; we were unable to find significant differences in resting motor threshold, cortical silent period and paired-pulse curves between VD, SVD and controls, and between the two hemispheres in the VD group. Our findings might suggest that neurophysiological mechanisms underlying VD differ from those previously reported in Major Depression (reduced excitability in the left hemisphere) and seem to be similar to those of patients with SVD. Our findings also, support the "vascular depression" hypothesis, suggesting that in VD patients the depressive syndrome is not the primary disease but can be considered as one of the clinical manifestations in the wide symptom spectrum of the cerebral small vessel disease.