Restoration of erect posture by deep brain stimulation of the globus pallidus in disabling dystonic spinal hyperextension

Abstract

Dystonia is a movement disorder notoriously difficult to treat. While primary dystonia is classically considered to respond well to deep brain stimulation (DBS), treatment of secondary dystonia yields variable results. Patient selection should be done on a case-by-case basis. Clearly, there is a need to accumulate additional information with regard to prognostic factors that may aid neurosurgeons in selecting those patients in whom the disorder is most likely to respond favorably to pallidal DBS. The authors report the case of a 29-year-old man with secondary dystonia due to perinatal hypoxia. The most prominent symptom was what we have termed ectatocormia-that is, severe, fixed truncal hyperextension and retrocollis, exacerbated by phasic, twisting movements of the trunk and head. This made it impossible for the patient to maintain a normal upright posture or to walk. The patient underwent bilateral DBS of the globus pallidus internus (GPi), and the authors observed impressive improvement in motor abilities and function. The patient's body adopted the normal upright posture and he became able to walk again, 4 months after the commencement of GPi stimulation. This report, along with others, emphasizes that the GPi as an ideal target for alleviating axial tonic symptoms. The presence of normal MR imaging findings, a phenotypical purity of predominantly dystonic symptoms, and a younger age seem to favor a positive outcome.