In Deep Brain Stimulation for treatment resistant depression with stimulation of Broadman area 25 (Cg 25) no consistent declines in memory for either verbal or visual material were noted after onset or maintenance of DBS over baseline. This makes DBS a procedure with out apparent cognitive side effects in treatment resistant depression. In a recent publication with DBS in the Subthalamic Nucleus for treatment resistant Obsessive Compulsive Disorder (OCD) no cognitive decline was found. The ratings of neuropsychological measures were not modified by stimulation.
In 17 patients participating in this 10-month, crossover, double-blind, multicenter study assessing the efficacy and safety of stimulation of the subthalamic nucleus one patient had a parenchymal brain hemorrhage (bleeding) resulting in a permanent finger palsy. Two patients had an infection leading to removal of the pulse generator. Seven transient motor and psychiatric symptoms induced by active stimulation occurred in the first month of stimulation and resolved spontaneously or rapidly after adjustment of the setting. Ten other patients also had serious but transient side-effects.Three patients became hypomanic, three suffered from anxiety, two of depressive symptomps the others suffered from transient neurological side-effects such as dyskinesia, trouble walking, dysarthria, dysphagia and facial asymmetry.
Deep Brain Stimulation of the subthalamic nucleus significantly reduced the symptoms of severe forms of OCD.
In conclusion, findings from this 3-month crossover study suggest that stimulation of the subthalamic nucleus may lessen the severity of obsessive–compulsive symptoms and improve global functioning in patients with refractory, severe OCD. Serious adverse events occurred in 11 of the 17 patients in whom stimulators were implanted. The occurrence of severe adverse events, the small number of patients, and the short duration of the study highlight the risks of stimulation of the subthalamic nucleus and the need for larger studies with longer follow-up. In addition to assessment in a larger number of patients, a comparison with other stimulation targets and surgical procedures would be desirable, as would an evaluation of the long-term benefits of stimulation of the subthalamic nucleus in patients with OCD, notably with respect to their quality of life and their ability to function in social and work environments.