This is a single centre, controlled phase I study, which evaluates safety and efficacy of stimulation of lower caudal two contacts (GPI) vs. upper cranial two contacts (GPE) in Huntington´s disease (HD).

A total of 6 HD patients will be selected out of an existing larger HD patient cohort upon careful evaluation of the inclusion and exclusion criteria at month 0. Patients will be recruited if no significant cognitive deterioration is observed between month 0 and month 3. The preoperative clinical status will be evaluated twice including the United Huntington Disease Rating Scale (UHDRS), neuropsychological, neurophysiologic and neuroradiological assessments. At 4 weeks postoperatively an extensive evaluation of effects and side effects of every single contact of the bilateral quadripolar electrodes takes place.

All patients will receive a stereotactic placement of bilateral stereotactic insertion of two quadripolar electrodes into the Globus pallidus, two contacts reaching the GPE, two the GPI within both hemispheres. Surgery will be done under general anesthesia, The implantation of the stimulator (Kintera®) will take place in the same procedure. Postoperatively patients will be monitored at three and six months and regularly up to 60 months with a battery of clinical, neuropsychological, psychiatric, neurophysiological and neuroimaging tests.

We expect that this trial will provide a rational basis to conclude about the efficacy, safety, reproducibility and long-term effects of pallidal Deep Brain Stimulation (DBS) on motor symptoms of HD.

Inclusion Criteria:

• clinically symptomatic and genetically confirmed Huntington Disease (number of CAG repeats>= 36)
• age: > 18
• moderate stage of the disease (UHDRS motor>= 30)
• predominant movement disorder
• compliance of the patient, stable cognition during a 6 months phase prior to inclusion (MDS>/= 120)
• signed informed consent

Exclusion Criteria:

• advanced disease, precluding the ability to give informed consent
• very early stage of disease causing minor disability
• severe comorbidity that could compromise the life prognostic or preclude general anaesthesia or immunosuppression
• Mattis Dementia Rating Scale < 120
• psychiatric or personality disturbances that might compromise the follow-up
• participation at another trial (in particular transplantation)
• severe cortical atrophy seen on CT and MRI