Association of Preoperative Linear MRI Measures with Domain-Specific Cognitive Change After Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease

<b>Background/Objectives</b>: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an effective treatment for motor symptoms in Parkinson's disease (PD), but concerns remain regarding its impact on cognitive function. Identifying neuroanatomical predictors of postoperative cognitive decline could improve patient selection and outcomes. This study aims to investigate the relationship between preoperative brain morphology and postoperative neuropsychological outcomes in PD patients undergoing bilateral STN-DBS. <b>Methods</b>: Thirty-eight PD patients underwent standardized neuropsychological testing and preoperative MRI before and 3-24 months after STN-DBS. Manual MRI morphometric measurements were obtained for 42 cortical, subcortical, and ventricular parameters. Changes in cognitive domains-including executive function, memory, language, visuospatial abilities, attention, and global cognition-were analyzed, and correlations between structural metrics and cognitive changes were assessed using Spearman's coefficients. <b>Results</b>: Significant postoperative declines occurred selectively in language functions: verbal fluency (phonemic and semantic, d = -0.49 to -0.84) and confrontation naming (d = -0.47). Memory, executive functions, attention, and global cognition remained preserved. Enlarged lateral ventricles were consistently associated with poorer outcomes across multiple domains, while increased left precentral gyrus width correlated with executive and memory decline. Additionally, smaller midbrain and cingulate gyrus width were associated with greater executive impairment. <b>Conclusions</b>: STN-DBS in PD is associated with selective postoperative cognitive changes, most prominently in verbal fluency. Simple preoperative MRI morphometric measures, including ventricular size, limbic structure volumes, and specific cortical parameters, may serve as clinically feasible predictors of cognitive risk. Incorporating such measures into preoperative assessments could enhance patient selection, counseling, and individualized surgical planning.