gms | German Medical Science

GPI (globus pallidus internus) deep brain stimulation offers a very interesting stereotactic neurosurgical therapy for medically intractable dystonia (generalised, segmental, focal). Immediate post-operative results and clinical follow-up for 15 patients are reported.

GPI-deep brain stimulation was performed in 15 patients (age 12-78 years) suffering from primary generalised (3), segmental (10) or focal (2) dystonia. Electrode-implantation (DBS 3387, Medtronic) was performed under propofol anaesthesia with MRI-guided stereotaxy using a modified Leksel/Lerch system. The lowest possible electrode was chosen for stimulation and intensity was set relatively high from the beginning (mean 80µA). After one week of successful stimulation by an external test stimulation system, permanent implantation of the stimulation system (Soletra, Medtronic) was performed. Clinical outcome was assessed using the Burke-Fahn-Mardsen (BFM) motor and disability scores. Median follow-up was 36 months.

All patients experienced a significant improvement of symptoms during the first week. After 3 months, symptom reduction was considered excellent in 6, fair in 5 and moderate in one patient. No improvement was observed in three patients. The BFM movement scores had improved in the range from 0 to 82% compared to preoperatively. After 30 months, relief of symptoms was unchanged compared to the 3-month status in 12, slightly reduced in two and severely reduced in one patient. Local infection occurred in one patient, making electrode-explantation necessary. Re-implantation was performed three months later without further complications. No other therapy-related morbidity was observed.

GPI deep brain stimulation offers a very effective and safe therapy for patients suffering from primary generalised, segmental or focal dystonia. Stable relief of symptoms can be achieved in the majority of patients.