Modulation of motor cortex by subthalamic stimulation in Parkinson's disease

Following the classical model of basal ganglia organisation, STN deep brain stimulation (DBS) in Parkinson's disease (PD) induces a lesion like block of excessive activity of the STN and of its excitatory projections. This model neglects the influence of direct excitatory cortico-subthalamic projections from motor cortex. Previous studies revealed a decrease of resting rCBF in the primary sensorimotor cortex due to effective STN DBS. We therefore hypothesized that gradual increases in STN stimulation frequency correlate with the rCBF in the motor cortex. We studied 6 patients with bilateral DBS within the STN fo…