Early chronic Globus pallidus internus stimulation in paediatric and juvenile patients suffering from intractable primary dystonia

Objective: Globus pallidus internus (GPI) deep brain stimulation (DBS) offers a very effective stereotactic neurosurgical therapy for medically intractable dystonia. Although generalized dystonia is presenting mainly at young age and might be severely disabling, GPI-DBS is still usually not applied in the early course of the disease. We here present the immediate post-operative results and clinical follow for 5 paediatric/juvenile patients undergoing GPI-DBS.

Methods: All patients (mean age 13 years (range 8–16 years), 3 female/2 male, 2 DYT1-positive) were suffering from intractable primary generalized dystonia. Electrode-implantation (DBS 3389, Medtronic) was performed under propofol anaesthesia with MRI-guided stereotaxy using a modified Leksel/Lerch system. The lowest possible electrode was chosen for stimulation. After 5–7 days of successful stimulation by an external test stimulation system, permanent implantation of the stimulation system (Soletra/Kinetra, Medtronic) was performed. Electrode position was verified by MRI and clinical outcome was assessed using the Burke-Fahn-Marsden (BFM) motor and disability scores.

Results: Follow-up ranged between 16 and 68 months (mean 38.4 months). There was a significant improvement of symptoms in all patients already during the first week. After 3 months, the BFM scores had improved in the range from 47% to 85% (mean 58%). At 12 months follow-up the mean improvement of the BMF motor and disability scores was 75% (range 71–88%, p 0.001) and 71% (range 50–90%, p 0.003), respectively. The 2 patients with longterm-follow up (>60 months) showed a stable and significant relief of symptoms (p<0.001). Revision of the abdominal-IPG-pouch due to imminent percutaneous cable-perforation was necessary in one patient. No other surgery or therapy-related morbidity was observed.

Conclusion: GPI deep brain stimulation offers a very effective and safe therapy in paediatric and juvenile patients suffering from primary dystonia. Stable relief of symptoms can be achieved. Early neurosurgical intervention is crucial to prevent irreversible impairment of motor function.