Objective: To assess 7-year outcomes of unilateral MRI-guided focused ultrasound (MRgFUS) ventral intermediate nucleus thalamotomy in tremor-dominant Parkinson’s disease (TDPD) patients with levodopa-unresponsive tremor, and to relate outcomes to lesion location using tractography.
Background: Long-term (>5 years) data on MRgFUS outcomes in TDPD are scarce.
Methods Four TDPD patients who completed 7-year follow-up were included (n=4). Tremor was assessed with the Clinical Rating Scale for Tremor (CRST); motor function with the Unified Parkinson’s Disease Rating Scale Part III (UPDRS III), overall and in the treated hemibody (hemi-CRST and hemi-UPDRS). Levodopa equivalent daily dose (LEDD) was calculated. Lesion location was evaluated with tractography.
Method: Four TDPD patients who completed 7-year follow-up were included (n=4). Tremor was assessed with the Clinical Rating Scale for Tremor (CRST); motor function with the Unified Parkinson’s Disease Rating Scale Part III (UPDRS III), overall and in the treated hemibody (hemi-CRST and hemi-UPDRS). Levodopa equivalent daily dose (LEDD) was calculated. Lesion location was evaluated with tractography.
Results: Median age at treatment was 61 years (range 51–66) and median disease duration was 6.5 years (range 2–10). Tremor improved immediately after MRgFUS in all patients. At 7 years, mean hemi-CRST was significantly improved versus baseline (baseline mean 20, range 10–20; 7-year mean 4.5, range 0–7; p = 0.04). Mean total CRST and hemi-UPDRS were also significantly improved at 7 years (p = 0.04), while total UPDRS was not. LEDD increased significantly at 7 years (p = 0.03). Lesions that involved the dentatorubrothalamic tract were associated with sustained tremor improvement. No adverse events were reported.
Conclusion: In this small case series, unilateral MRgFUS thalamotomy produced sustained tremor improvement at 7 years in TDPD patients without procedure-related adverse events. Lesions involving the dentatorubrothalamic tract were associated with long-term benefit; LEDD increased over time as expected.
To cite this abstract in AMA style:
M. Nassar, I. Senderova, M. Katson, A. Sinai, I. Schlesinger. Seven-Year Outcome of Focused Ultrasound Thalamotomy in Tremor Dominant Parkinson’s Disease Patients [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/seven-year-outcome-of-focused-ultrasound-thalamotomy-in-tremor-dominant-parkinsons-disease-patients/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/seven-year-outcome-of-focused-ultrasound-thalamotomy-in-tremor-dominant-parkinsons-disease-patients/