Benefit of chronic electrical stimulation of the globus pallidus internus in the treatment of dystonia

Abstract

Dystonia is a movement disorder characterized by sustained muscle contractions leading to twisting movements and abnormal postures. There is no certain medical treatment such as ablative surgical treatment, which has often been disappointing. Recently, deep brain stimulation has become well established as a safe and effective therapy in the treatment of movement disorders. In this study, five cases of dystonia underwent the deep brain stimulation (DBS) targeted in globus pallidus internus (GPi); these cases shall be reported on. Among them, two cases were generalized dystonia and three cases of them were cervical dystonia. The electrode for chronic stimulation was inserted by a stereotactic surgical procedure. During the surgery, unitary potentials were recorded in order to decide the appropriate electrode location. The results were evaluated with Fahn–Marsden dystonia movement scales for generalized dystonia and a modified Toronto Western Spasmodic Torticollis Rating Scale for cervical dystonia. As a result, no complication caused by surgery and/or electrical stimulation was noted in these cases. The averages of the scale change, 6 months after the surgery, improved both types of dystonia. The chronic GPi stimulation therapy would be expected as an effective treatment for dystonia.