The study group consists of patients with advanced Parkinson's disease treated with directional deep brain stimulation in Helsinki University Hospital between 2017 - 2020. The study is a registry-based follow-up study. The aim of the study is to assess the clinical outcome and possible adverse effects of the dDBS treatment. The data will be collected from the patient records. The observed time points are 6-month's, 12-month's and 18-month's postoperative visits.~The following data will collected: the scores of Unified Parkinson's disease questionnaire part III (UPDRS-III), Non-Motor Symptoms Questionnaire (NMS-quest), Beck Depression Inventory (BDI), Mini-Mental State Examination (MMSE), Abnormal Involuntary Movement Scale (AIMS) evaluated in the screening phase for dDBS treatment and at 6-months' follow-up. Possible levodopa equivalent dose changes, LEDDs, will also be assessed at these time points.
The aim of the study is to assess the clinical outcome in patients with Parkinson's disease treated with directional deep brain stimulation (dDBS). The patients have been selected for the dDBS treatment by their treating neurologist. The study is a registry-based follow-up study.