Treatment of early-onset generalized dystonia by bilateral chronic electrical stimulation of the internal globus pallidus. Case report.

Dystonia musculorum deformans is art inherited severe disease, with a wide clinical polymorphism. The most severe clinical forms with early onset carr y a high risk of life-threatening complications. In the absence of any effi cient 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 dysto nia 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 bee n under sedation and permanent controlled respiratory assistance for the la st two months. The etiology of the disease remained unknown (the DYT1 mutat ion was absent). Under general anesthesia, we bilaterally implanted a four-contacts electrod e in the internal globus pallidus, using the Leksell's stereotactic frame a nd a 1.5 tesla MRI control. A dramatic improvement was noted 6 weeks later and led us to connect the tw o electrodes to neurostimulators inserted under the abdominal skin. Thirty months after operation, the neurological examination was normal and revealed sustained alleviation of all dystonic symptoms. The girl experienc ed a progressive recovery of a useful strength and simultaneous improvement in her coordination and postural reaction. She went back to school and has splendidly recovered being self-sufficient for daily activities appropriat e for her age. Although her future remains uncertain, we believe that chron ic bilateral pallidal stimulation may prove to be the treatment of choice f or early outset generalized dystonia especially in children. Electrical sti mulation is a conservative adaptable and reversible neurosurgical procedure , and seems particularly worth while in children because of their ongoing b rain development.