Efficacy and Safety of DBS of the GPi in Patients With Primary Generalized and Segmental Dystonia

Inclusion Criteria: * diagnosis of idiopathic multifocal, segmental or generalised dystonia * duration of disease \> 5 years * age between 14 and 75 years * relevant disability in activities of daily living despite optimal drug treatment * informed consent signed by the patient * For adolescents between 14 and 18 years: an additional informed consent signed by a legal guardian is necessary Exclusion Criteria: * Mattis-Score \< 120 * BDI \> 25 * previous stereotactic brain surgery * severe brain atrophy * increased bleeding risk * immunosuppression and increased risk of infection * relevant cerebrovascular disease * psychiatric disorders, which might interfere with the cooperation in the study * other contraindications for surgery