Establishing and developing a magnetic resonance-guided focused ultrasound program in a resource-limited setting: the...

Magnetic resonance-guided focused ultrasound (MRgFUS) is a non-invasive lesioning technique used to treat movement disorders such as essential tremor (ET), Parkinson's disease (PD), and X-linked dystonia-parkinsonism (XDP). We would like to report our experience in establishing and developing our MRgFUS program and preliminary results. Adult patients with tremor-dominant PD (TDPD), ET, and XDP were considered for initial screening (neurologic evaluation, skull density ratio [SDR] determination). Eligible patients underwent secondary screening (neurosurgical and neuropsychological evaluation, psychiatric and medical clearance). During the procedure, a neuro-anesthesiologist and neurologist were also present to monitor the patient and perform neurologic evaluation, respectively. Clinical follow-up was scheduled at 2 weeks post-treatment, then at every 3 months. A total of 30 patients underwent MRgFUS treatment: 22 TDPD, 6 XDP, and 2 ET. The mean age was 55.7 years, and majority were male (86.7%). Mean disease duration was 8.6 years. Mean SDR was 0.46. The targets for TDPD and ET were the contralateral ventral intermediate nucleus of the thalamus; for XDP, it was the pallidothalamic tract. The mean maximum temperature was 59.8^oC; number of sonocations, 7.3; and treatment time, 64.6 min. Majority of patients improved after the procedure. Transient intraprocedural adverse events (headache, dizziness) were reported in 20% of patients while post-procedural events (mild weakness, numbness) were seen in 16.7%. Only 26.7% of patients had follow-up data. Despite the unique challenges encountered, MRgFUS treatment is feasible in resource-limited settings. Additional steps would have to be made to develop and improve the program.