Object: Subthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson disease (PD) and reduces antiparkinsonian medication. Therefore, STN DBS seems to be well indicated for patients suffering from medication-induced psychotic symptoms. However, there are few available data dealing with the effect of STN DBS in this kind of patient. The authors studied the effect of STN DBS in patients with PD and severe medication-induced hallucinations or delusions.
Methods: The authors retrospectively reviewed the clinical course of 10 patients who suffered from severe medication-induced hallucinations or delusions and underwent bilateral STN DBS. Patients whose preoperative thought disorder score (Unified Parkinson's Disease Rating Scale Part I, item 2) was 3 or more were enrolled in this study. All patients underwent cognitive function examination and brain perfusion SPECT preoperatively to exclude dementia with Lewy bodies.
Results: Subthalamic nucleus DBS yielded significant improvement of motor function in all patients. In 8 patients, psychotic symptoms completely disappeared with significant reduction of dopaminergic medication. In 2 patients, hallucinations and delusions deteriorated immediately after surgery despite complete withdrawal of antiparkinsonian medication. However, these psychotic symptoms completely disappeared after a few months with administration of antipsychotics, and no recurrence was observed afterward in either patient.
Conclusions: Subthalamic nucleus DBS is a good treatment option for patients with PD who are suffering severe medication-induced hallucinations or delusion. However, vigilance is needed, because temporary deterioration of psychotic symptoms may occur after surgery.