The effects of chronic subthalamic stimulation on nonmotor symptoms in advanced Parkinson's disease, revealed by an...

This study was designed to detect and assess the frequency and severity of nonmotor symptoms (NMSs) in advanced Parkinson's disease (PD) and to investigate the effects of subthalamic nucleus deep brain stimulation (STN-DBS) on NMSs.

We developed an online PC-based questionnaire program to assess NMSs in PD. Twenty-six PD patients who underwent bilateral STN-DBS were assessed. The NMS questionnaire consisted of 54 NMSs in three categories, based on Witjas et al. (2002). For each NMS, the patients were asked whether or not it was present, whether or not the fluctuating manifestations correlated with the timing of levodopa-induced motor fluctuations, and how severe the NMS was. Patients were assessed by this system before surgery and at the follow-up visit, 3 to 6 months after surgery. At the postoperative assessment, patients were also assessed on preoperative NMSs using recall.

The most frequent preoperative NMSs were constipation and visual disorders, while the most frequent postoperative NMSs were difficulty in memorizing and pollakiuria. The ranking of most frequent NMSs changed from before to after surgery. NMSs of drenching sweats, dysphagia, and constipation were significantly ameliorated, while NMSs of dyspnea and slowness of thinking were significantly deteriorated after surgery. The preoperative assessment by postoperative recall gave very different results from that of the preoperative assessment.

An online questionnaire system to assess NMSs in patients with advanced PD suggested that STN-DBS might influence the frequencies of some kinds of NMSs.