Deep brain stimulation in Parkinson's disease and paediatric DBS service

Idiopathic Parkinson’s disease (PD) is globally the most common neurodegenerative movement disorder and it affects not only physical and cognition but also the activities of daily living and social life. Deep brain stimulation (DBS) is the neurosurgical treatment in advanced PD and it is the most common indication of DBS surgery. In PD, the most common target area of stimulation is the subthalamic nucleus (STN) in order to alleviate motor symptoms, e.g., rigidity, tremor and bradykinesia. After STN DBS, PD-medication, which includes levodopa, can be reduced. Thus, levodopa-induced involuntary hyperkinetic movements, i.e., dyskinesias are alleviated and the PD patient’s condition becomes more stable.

Studies I-II were undertaken to evaluate the beneficial effects of bilateral STN DBS stimulation on PD patient’s motor symptoms and levodopa reduction 12 months after DBS surgery, when the DBS surgery was based on high-quality 3T MRI and the follow-up was conducted by the same DBS team. The results were compared with a previous study from OUH, which was presented by Tuomo Erola in his 2006 thesis. In Study II, the main interest was to study whether stimulation of the hyperdirective pathways between the lateral border of the STN and prefrontal cortex correlated with the motor outcome and levodopa reduction. The study implicated that diffusion tensor images (DTI) -based tractography can be applied in a clinically reasonable way for DBS targeting.

The paediatric population is the smallest and the most fragile DBS patient group and the usual indication is severe hyperkinetic movement disorder, e.g., dystonia. Paediatric DBS surgery (pDBS) is not an everyday procedure and the pre- and postoperative preparations are as important as the surgery itself. For this reason practical instructions are required when starting a pDBS centre. This is the topic of Study III.