Objective: To explore whether pre-surgical white matter lesion volume, measured quantitatively on brain MR images, is predictive of cognitive outcomes following subthalamic nucleus deep brain stimulation (STN-DBS) in idiopathic Parkinson’s disease (iPD) patients.

Background: Studies evaluating cognitive outcomes following STN-DBS report significant declines in domains such as executive function, verbal fluency, and attention. However, few studies have assessed predictors of cognitive decline in iPD patients treated with STN-DBS. Thus, identification of pre-surgical MRI predictors might provide an important clinical tool for better risk-to-benefit assessment.

Methods: This retrospective study included data from 43 iPD patients with STN-DBS. For cognitive assessments, pre-surgical and ≥6 month post-surgical neuropsychological (NP) evaluation scores were collected. To quantify lesion volume, white matter hyperintensities were segmented from pre-surgical T2-FLAIR MRI. Mean pre/post NP test scores for measures of executive function, attention, verbal fluency, memory, and visuospatial function were analyzed. The correlation between log(lesion volume) and changes in performance on pre/post cognitive tests was investigated, covarying for age, education, and vascular risk factors.

Results: There were significant declines on cognitive measures of verbal fluency, executive function, attention, and visuospatial function. Pre/post change on tests of memory function were insignificant. Log(lesion volume) were weakly and not significantly correlated with cognitive outcomes for most cognitive measures, with and without adjusting for covariates. A significant negative correlation was observed between larger lesion volume and impaired performance on a visuospatial task, even when adjusting for covariates. Increased age and vascular risk factors were strongly correlated with larger lesion volume and impaired performance on NP tests.

Conclusions: Results of this study demonstrate that post-STN-DBS cognitive impairments are largely independent of pre-surgical lesion volume, suggesting that lesions, beyond any clinical vascular predictors, do not put DBS candidates at a significantly increased risk for cognitive impairments. Other quantitative measures of brain MRI, such as brain volume, may be correlated with STN-DBS cognitive impairments and warrant further investigation.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/quantitative-measures-of-brain-mri-as-a-predictive-factor-of-cognitive-outcomes-after-subthalamic-nucleus-deep-brain-stimulation-for-parkinsons-disease/