Longitudinal Cognitive and Affective Outcomes Following Unilateral MR-Guided Focused Ultrasound Vim Thalamotomy in Essential Tremor and Parkinson’s Disease: A Real-World Cohort

Background/Objectives: Magnetic resonance-guided focused ultrasound (MRgFUS) ventral intermediate nucleus (Vim) thalamotomy is an established treatment for medication-refractory tremor, but longitudinal cognitive and affective data remain limited. We described global cognition, depressive symptoms, and anxiety after unilateral MRgFUS Vim thalamotomy in essential tremor (ET) and tremor-dominant Parkinson’s disease (PD). Methods: This exploratory, descriptive analysis of a retrospective single-center cohort included 25 participants (ET n = 11; PD n = 14). Montreal Cognitive Assessment (MoCA), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) scores were analyzed from baseline to the final available complete follow-up. Random-intercept mixed-effects models used all 54 complete observations. Sensitivity analyses examined first follow-up (W2), baseline-adjusted BDI comparisons, and random slopes. Holm correction addressed primary-outcome multiplicity; exploratory cognitive tests used false-discovery-rate correction. Results: Median assessment follow-up was 12.7 months (interquartile range 9.0–15.2; maximum 22.6). No significant whole-cohort change was detected in MoCA (mean change −0.12, 95% CI −1.33 to 1.09; Holm-adjusted p = 0.927), BDI (−0.36, −1.99 to 1.27; p = 0.927), or BAI (−2.60, −5.24 to 0.04; p = 0.188). The exploratory ET BDI change was −2.73 points at final follow-up (95% CI −4.51 to −0.95; Holm-adjusted p = 0.029) and −1.45 at W2 (−4.72 to 1.81; p = 0.262). The random-intercept time-by-diagnosis interaction for BDI was significant (β = 0.365 points/month, 95% CI 0.124 to 0.607; Holm-adjusted p = 0.009), whereas the four baseline-adjusted diagnostic contrasts did not survive joint Holm correction. No individual cognitive test remained significant after false-discovery-rate correction. Conclusions: These findings are descriptive and exploratory. No statistically significant cohort-level cognitive or affective change was detected. Diagnosis-related BDI findings were sensitive to endpoint definition and baseline adjustment and cannot be attributed causally to MRgFUS in this uncontrolled cohort.