Motor Gpi Deep Brain Stimulation for Huntington’s Disease: Long-Term Results

Unité multidisciplinaire “Pathologies cérébrales résistantes” – University Hospital of Montpellier – FRANCE

Unité de recherche sur les comportements et mouvements anormaux – IGF – INSERM U 661 – CNRS UMR 5203 – University of Monteplleir – France

Background : GPi DBS has been validated as a powerful tool for controlling symptoms in many dystono-dyskinetic syndroms. We proposed in 2002, to apply it to HD patients when chorea is the main symptom.

Patients and methods: Since 2003, January 22th, 16 patients suffering with HD have been selected for continuous electrical neuromodulation of the internal globus pallidus (motor GPi DBS) and followed up in the long term using UHDRS and Mattis DRS.

Results: Mean age at surgery was 46 Y-o. The mean FU was 4 years. Six patients died. The analysis of UHDRS “chorea” sub-score evolution shows a constant improvement. At 1 year, 57,2% (p 0.02) (ON-stimulation) and at 4 years, 52% (p 0.04). This was confirmed by the OFF-test in every patient. This improvement allows initially to alleviate medications’ dosages

Rigidity (dystonia) is influenced at a lower level.

With time dementia worsening limits the impact of chorea’s control coming with anosognosia. It seems that, at the initial phase (3 years), GPi neuromodulation positively influences Mattis scores.

Discussion: Chorea is a devastating symptom in HD. In this group of patients, the general condition constantly associated with a severe brain atrophy increases the risk of peri-operative complications. Using an MR- guided direct targeting method for leads implantation under general anesthesia, we could provide a sufficient level of security and accuracy, allowing to propose this symptomatic treatment in HD patients

Conclusion: We report on the efficacy of GPi neuromodulation on the choreic symptoms and on the transient multifactorial neuropsychological stabilization at the time HD patients can profit by a reduction of movement disorder in terms of quality of life, during at least 4 years.