Abstract
Deep brain stimulation (DBS) of the internal globus pallidus (GPi) is an established neurosurgical technique for the treatment of movement disorders. Despite the beneficial effects of GPi DBS in patients with primary generalized dystono-dyskinetic syndromes (DDS), the degree of improvement varies from one patient to another. We propose a computational anatomical model based on stereotactic MRI coupled with an electrical distribution model of DBS system that can be applied both pre- and postoperatively to patients already implanted. Thus, the model aims to optimize target localization at the time of surgical planning, allowing electrode localization after surgery and adjustment of electrical parameters in clinical practice for each patient. We applied the model to clinical records of patients with primary generalized DDS who had been treated by bilatéral GPi lead implantation. This thesis discussed the effects of clinical, anatomical (volume of the GPi) and electrical variables (stimulated volume) on the postoperative Burke-Fahn-Marsden Dystonia rating scale (BFMDRS) motor score in order to identify which factors may be predictive of the degree of improvement. Using these results, we designed a new electrode in order to optimize the electrical current delivery, to improve therapeutic benefit, to minimize side effects from DBS and to obtain a more homogenous electrical field distribution.