The Results of a 12-Month Open-Label Follow-Up Study with MRI Monitoring of Patients with Parkinson’s Disease After MRI-Guided FUS

<b>Background:</b> Tremor-dominant Parkinson's disease (TDPD) is the most common subtype of PD. Tremor is difficult to treat and less than 50% of patients respond to dopaminergic medications. Magnetic resonance guided focused ultrasound (MRgFUS) thalamotomy is an incisionless noninvasive method for treating pharmacoresistant tremor in PD patients, but its effect on progression of PD is unknown. In this study, we investigate the efficacy of MRgFUS thalamotomy on progression of motor and non-motor symptoms, using a levodopa equivalent daily dose (LEDD) requirement. <b>Methods:</b> A total of 21 PD patients with ineffective tremor correction by medical therapy underwent MRgFUS thalamotomy. Assessments of motor and non-motor symptoms, adverse events (AE), changes in LEDD, and evolution of FUS (focused ultrasound) lesion were performed on the day before surgery, and then 2 days, as well as 3, 6, and 12 months, after the procedure. <b>Results:</b> On the 2nd day after FUS thalamotomy, 11 patients were tremor-free and, in 10 patients, tremor decreased by 80-90% with a concomitant reduction in hypokinesia and rigidity. By the end of the 12th month, 5 patients remained tremor-free; in 11 patients, mild/moderate tremor re-emerged; and in 5 patients, there was a relapse of severe tremor. Quality of life (QoL) and activities of daily living (ADL) improved significantly at 3 months and remained stable thereafter. Cognitive function improved in patients with baseline MoCA score < 26 points at 3 months after FUS. Anxiety progressed between baseline and end of follow-up. By the end of the follow-up period, LEDD was lowered or stable in 9 patients. Four patients had persistent mild AE. <b>Conclusions:</b> This open label study suggests a beneficial effect of MRgFUS in reducing tremor, hypokinesia, and rigidity and improving QoL, ADL, and cognitive function in TDPD patients in the short term, although long-term data needs to be collected in further studies.