Behavioral and motor improvement after deep brain stimulation of the globus pallidus externus in a case of Tourette's syndrome.

ABSTRACT

OBJECTIVES: The objective of our paper is to show the partial decrease of therapeutic effect with battery exhaustion in a previously successfully treated patient with refractory Tourette's syndrome (TS). MATERIALS AND METHODS: We present a 47-year-old patient diagnosed with TS based on the TS Study Group Criteria and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Surgery was considered based on refractoriness to conservative management. Presurgical evaluation included magnetic resonance imaging (MRI), positron emission tomography scan, and neuropsychologic, neurologic, and psychiatric tests utilizing Yale Brown Obsessive Compulsive Scale, Yale Global Tics Severity Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Global Assessment of Functioning Scale, and Mini-mental State Examination. Target coordinates were obtained from inversion recovery MRI. Quadripolar deep brain stimulation (DBS) electrodes were implanted bilaterally in the globus pallidus externus (GPe) and connected to the pulse generator in the same procedure. To determine the clinical response to DBS, the scores of the scales obtained preoperatively were compared with those obtained postoperatively. RESULTS: No surgical complications were detected and according to the clinical scales the patient experienced a marked improvement of his symptoms, although he never showed obsessive-compulsive disorder components of any type. The battery was exhausted after two years with the subsequent significant partial loss of therapeutic effect. CONCLUSIONS: GPe seems to be a highly promising target of DBS for the treatment of medically refractory TS. After battery exhaustion, the patient experienced a marked partial decrease in the therapeutic effect, which confirms the beneficial action of this method.