Globus Pallidus Internus Deep Brain Stimulation for Traumatic Hemidystonia Following Penetrating Head Injury.

Abstract

Deep brain stimulation (DBS) has been a major advance in the treatment of dystonias. Outcomes are, however, less predictable for secondary dystonias, predominantly due to progression of disease or specific brain lesions. There are few cases reported of globus pallidus internus (GPi)-DBS for posttraumatic dystonia. We describe the successful use of unilateral GPi-DBS in a patient with hemidystonia following penetrating head injury. To our knowledge, this is the first description of the use of DBS following penetrating head injury. We present the case of a 47-year-old man with phasic hemidystonia. At the age of 3 years he suffered a penetrating head injury from a welding needle. The patient developed dystonic and phasic right-sided movements. Preoperative Burke-Fahn-Marsden score was 26. Magnetic resonance imaging showed a linear encephalomalacic track extending from the cortex in the left parieto-occipital region, traversing just superolateral to the left trigone into the left thalamus and ending in the region of left cerebral peduncle and subthalamic nucleus. There was no left GPi lesion. A left GPi-DBS electrode was inserted. At 6 months' follow-up, the patient's arm was more relaxed and his spasms lessened in their severity and frequency. Although the Burke-Fahn-Marsden score of 21 had improved modestly by 20%, pain and comfort levels had significantly improved with 50% improvement in visual analog scale score, translating in better quality of life. There were no complications. The clinical benefit persists at 5 years post surgery. Selected patients with posttraumatic hemidystonia, including following penetrating head injury, represent one group of secondary dystonias that might benefit from DBS surgery.