Deep brain stimulation of the globus pallidus internus (GPI) for torsion dystonia--a report of two cases.

Generalized dystonia is known as a type of movement disorder in which pharmacotherapeutic options are very limited. Deep Brain Stimulation (DBS) is well established for Parkinson's disease (PD) and tremor dominant movement disorders. We report on two cases of generalized dystonia which were successfully treated by chronic high frequency stimulation in the Globus pallidus internus (GPI). Two 26 and 27 years old males suffered from severe torsion dystonia and multisegmental dystonia of the lower limbs. Case 1 is a familiar type of dystonia (DYT1 positive). The onset of symptoms in both cases was at age 7. The complaints were initially treated with orally administered benzodiazepines, anticholinergic drugs, later by baclofen and L-DOPA. However there was no response. Case 2 was a patient with a history of left side dominated dystonia since the age of 8. It was first diagnosed as a psychogenic movement disorder. Prior to surgery he was treated with L-DOPA, anticholinergics, Baclofen without any effect. There was only a limited effect on high doses of diazepam. The patient is DYT1 negative. The target point was on both sides the GPI. Intraoperative computerized tomography (CT) and ventriculography (VG) were used for target setting. Furthermore microrecordings were helpful to ensure the exact electrode position. Surgery was performed under analgosedation. Two weeks after surgery we first observed a relief of symptoms in both cases. A significant reduction in the Burke-Fahn-Marsden-Dystonia Movement Rating Scale was observed at the 6 month follow-up (case 1: 95%, case 2: 80%). In case 1 a slight dystonic movement of the left ankle was the only remaining symptom under stimulation. The medication was continuously reduced. At the 24 month follow-up the effect of stimulation remained unchanged. However high stimulation parameters are required to maintain an optimal effect (mean 3.5 V, 400 microseconds, 145 Hz).

Treatment of DYT1-generalised dystonia by stimulation of the internal globus pallidus.

In seven selected patients with dystonia musculorum deformans-1 generalised dystonia (DYT1), continuous bilateral stimulation of the globus pallidus internus was associated with substantial improvement of dystonia and functional disability.

Pallidal stimulation for generalized dystonia. Report of three cases.

Pallidal stereotactic surgery is a well-accepted treatment alternative for Parkinson's disease. Another indication for this procedure is medically refractory dystonia, especially generalized dystonia with abnormal axial and extremity movements and postures. Improvement of dystonia after pallidotomy has been reported in several recent papers. In this report the authors describe three patients with generalized dystonia (two primary, one secondary) and their improvement after bilateral pallidal stimulation at follow-up times of between 6 and 18 months.

[Treatment of early-onset generalized dystonia by chronic bilateral stimulation of the internal globus pallidus. Apropos of a case]. / Traitement de la dystonie généralisée à début précoce par stimulation chronique bilatérale des globus pallidus internes. A propos d'un cas.

Dystonia musculorum deformans is an inherited severe disease, with a wide clinical polymorphism. The most severe clinical forms with early onset carry a high risk of life-threatening complications. In the absence of any efficient medical treatment, bilateral pallidotomy has previously been reported to be of value in the management of this disease. We report the first clinical case of a severe early-onset generalized dystonia dramatically improved by a bilateral stimulation of the internal globus pallidus. In November 1996, we proposed this neurosurgical procedure for a 8-year-old girl, who had suffered since the age of 3 from severe generalized dystonia, and who progressively became totally dependent and bedridden. She had been under sedation and permanent controlled respiratory assistance for the last two months. The etiology of the disease remained unknown (the DYT1 mutation was absent). Under general anesthesia, we bilaterally implanted a four-contacts electrode in the internal globus pallidus, using the Leksell's stereotactic frame and a 1.5 tesla MRI control. A dramatic improvement was noted 6 weeks later and led us to connect the two electrodes to neurostimulators inserted under the abdominal skin.