Deep Brain Stimulation Placement Using Intraoperative MRI for Dystonia: One Year Clinical Outcomes (S30.003)

OBJECTIVE: To evaluate clinical outcome in patients with dystonia who underwent deep brain stimulation (DBS) placement using intraoperative MRI (ClearPoint®, MRI interventions). BACKGROUND: DBS lead placement using intraoperative MRI (iMRI) is an alternative surgical technique utilizing real-time intraoperative neuroimaging to guide electrode placement. Unlike the traditional awake procedure, iMRI DBS is done under general anesthesia without microelectrode recording (MER) and electrical stimulation. However, there is limited literature on clinical outcomes. METHODS: Twenty-two consecutive dystonia patients underwent DBS surgery using iMRI. Of these, 13 patients (idiopathic, n=11; genetic, n=1, tardive n=1) were included in our analysis. Patients with secondary dystonia (n=7) and those with prior DBS placement using MER (n=2) were excluded. Pre- and post-DBS Burke-Fahn-Marsden dystonia rating scale (BFMDRS) movement scores and Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity scores were obtained at 6 and 12 months. RESULTS: The mean age of patients (M=6, F=7) was 55 years. Distribution of dystonia was variable with cervical dystonia as predominant component in 12 patients. All patients underwent bilateral GPi DBS placement. The mean BFMDRS and TWSTRS scores before DBS were 20 (95[percnt] CI: 12-28[percnt]) and 17.5 (95[percnt] CI: 14.7-20.2[percnt]) respectively and after DBS were 4.92 (95[percnt] CI: 3.2-6.7[percnt]) and 8.2 (95[percnt] CI: 4-12.5[percnt]) respectively at 12 months. There was a mean improvement in BFMDRS of 70.7[percnt] (95[percnt] CI: 63.8-79.5[percnt], p<0.01) and in TWSTRS of 56.4[percnt] (95[percnt] CI: 34.2 -78.6[percnt], p<0.01) at 12 months. Two patients had asymptomatic small intracranial hemorrhage, 1 had technical complications causing symptomatic intracranial hemorrhage/capsular infarct with partial hemiparesis and 1 had unilateral hardware infection/ lead fracture requiring revision. CONCLUSIONS: iMRI-guided DBS in dystonia patients showed improvement in clinical outcomes comparable to previously reported results using awake MER-guided DBS placement. This technique is particularly appropriate for children and patients where dystonia interferes with head fixation during wakefulness. Disclosure: Dr. Sharma has nothing to disclose. Dr. Naik has nothing to disclose. Dr. Triche has nothing to disclose. Dr. Buetefisch has nothing to disclose. Dr. Willie has nothing to disclose. Dr. Boulis received a royalty payment from Neuralstem Inc. Dr. Factor has received personal compensation for activities with Lundbeck, Chelsea Therapeutics, Auspex, Neurocrin, Up-To-Date, and UCB Pharma. Dr. Factor has received personal compensation in an editorial capacity for Neurotherapeutics. Dr. Factor has r Dr. Gross has received research support from Visualase Inc. Dr. DeLong has received personal compensation for activities with Medtronic Corporation, Boston Scientific and Effron Laboratories as a consultant.