Cognitive impacts of unilateral MR-guided focused ultrasound thalamotomy: a meta-analysis and a call for systematic neuropsychological assessment.

Objective: Pharmacoresistant tremors, often seen in Parkinson disease and essential tremor, significantly impair patient quality of life. Although deep brain stimulation has been effective, its invasive nature limits its applicability. MR-guided focused ultrasound (MRgFUS) thalamotomy offers a noninvasive alternative, but its cognitive impacts are not fully understood. This meta-analysis aimed to evaluate the cognitive and emotional effects of unilateral MRgFUS thalamotomy in patients with pharmacoresistant tremors.

Methods: Adhering to PRISMA guidelines, a comprehensive literature search was conducted across PubMed, Web of Science, and the Cochrane Library. Studies were included if they involved unilateral MRgFUS thalamotomy and assessed cognitive functions pre- and postprocedure. The primary outcomes were changes in cognitive functions and emotional states postthalamotomy.

Results: Of 90 identified articles, 5 met the inclusion criteria, encompassing 112 patients (74 essential tremor, 38 Parkinson disease). The analysis revealed no significant deterioration in cognitive domains or emotional states postprocedure. Statistical heterogeneity among studies was small for cognitive outcomes but moderate for emotional states.

Conclusions: Unilateral MRgFUS thalamotomy appears to be a safe procedure with respect to cognitive and emotional outcomes in patients with pharmacoresistant tremors. However, the small number of studies and the short-term nature of assessments necessitate caution. Further research, especially on long-term cognitive effects and in the context of bilateral procedures, is essential for a comprehensive understanding of MRgFUS thalamotomy's neuropsychological impact. Systematic review registration no.: CRD42023491757 (www.crd.york.ac.uk/prospero).