GPi-DBS in Huntington's disease: results on motor function and cognition in a 72-year-old case.

Huntington's disease (HD) produces debilitating motor abnormalities that are poorly responsive to medical therapy. Deep brain stimulation (DBS) of the posteroventral globus pallidus internus (GPi) may offer a treatment option for patients with diskinetic phenotype and minimal cognitive impairment, but its role in the management of HD remains unclear and to date only two cases have been reported. We report the outcome of GPi-DBS in a 72-year-old man with HD. Stimulation at 130 Hz caused a rapid amelioration of chorea producing the worsening of bradykinesia, whereas 40 Hz stimulation (maintaining constant the total electrical energy delivered) improved chorea while preserving the ability to walk. At 1-year follow-up, chorea has completely disappeared; however, the patient was unable to stand and walk. The cognitive profile showed a progressive deterioration, with an extension of deficit from the mainly dysexecutive alterations at baseline to a more diffused cognitive deterioration.