Association of MRI Measurements with Cognitive Outcomes After STN‐DBS in Parkinson's Disease

Abstract

Objectives Subthalamic nucleus deep brain stimulation (STN‐DBS) is an effective treatment for improving the motor symptoms of Parkinson's disease (PD). Overall, cognitive function remains stable after STN‐DBS in most patients. However, cognitive decline, specifically in the verbal fluency domain, is seen in a subset of STN‐DBS patients. Currently, predictors of cognitive decline in PD patients treated with STN‐DBS are not well known. Thus, identification of presurgical predictors might provide an important clinical tool for better risk‐to‐benefit assessment. This study explores whether whole brain white matter lesion (WML) volume, or hippocampal and forebrain volumes, measured quantitatively on MRI, are associated with cognitive changes following STN‐DBS in PD patients. Methods We conducted a retrospective study using presurgical, and ≥ 6‐month postsurgical neuropsychological (NP) evaluation scores from 43 PD patients with STN‐DBS. Mean pre/post NP test scores for measures of executive function, attention, verbal fluency, memory, and visuospatial function were analyzed and correlated with WML volume, and brain volumetric data. Results Although cognitive measures of verbal fluency, executive function, attention, memory, and visuospatial function showed declines following STN‐DBS, we observed limited evidence that white matter lesion burden or cortical atrophy contributed to cognitive change following STN‐DBS. Conclusions These results suggest that post‐STN‐DBS cognitive changes may be unrelated to presurgical WML burden and presence of cortical atrophy.

A systematic review of brain morphometry related to deep brain stimulation outcome in Parkinson’s disease

“…The involvement of HA in the progression of Lewy bodies contributes significantly to the development of dementia in PD, which is demonstrated in imaging, proteomics and biochemical analysis 62 – 64 . Four studies identified in our review noted the associations of reduced presurgical hippocampal volume with verbal memory decline or overall cognitive impairment after DBS, suggesting hippocampal atrophy as a preexisting risk factor for cognitive decline for patients receiving DBS surgery 28 , 30 – 32 . Connections between hippocampal subfields with cognitive functions and motor subtypes of PD patients have been proposed, the study of which might exert increased potential in patient selection with candidate stratified to different motor subtypes 65 , 66 .…”

“…↓ The right and left superior frontal gyrus thickness & The variation of the backward digit-span task. 1 yr Med off: 32 [8–70]; Med on: 10 [3–28] Med off: 21 [7–53]; Med on: 13 [2–41] Weinkle; 2018 32 43 (30/13) 29 BL STN 14 UL STN 9.4 ± 4.1 62.3 ± 7.3 ↑ WML & Declined performance on the Block design visuospatial task. ↑ Volume of the right hippocampus volume & Improvement in CVLT-II recognition hits score.…”

Brain morphometry is not associated with non-motor outcomes after deep brain stimulation in Parkinson’s disease

“…Previous studies found limited evidence of an association between cortical atrophy and postoperative changes in various cognitive functions. 18 Lower hippocampal volume, however, has been associated with a postoperative decline in verbal memory. 18,19 In the present study, lower hippocampal volumes were associated with less postoperative changes in the attention and memory domains, although these results did not survive TFCE correction.…”

“…18 Lower hippocampal volume, however, has been associated with a postoperative decline in verbal memory. 18,19 In the present study, lower hippocampal volumes were associated with less postoperative changes in the attention and memory domains, although these results did not survive TFCE correction. The lack of significant results in this domain might be attributed to the presumably low sensitivity of the NMSS to detect subtle changes in a single cognitive domain.…”