A – 113 Localized White Matter Fiber Density Correlates of Neuropsychological Performance in Parkinsonian Freezing of Gait

Abstract Objective Determine whether Parkinson’s Disease (PD) Freezing of Gait (FOG) is differentially correlated with white matter fiber density and neuropsychological task performance. Method We examined imaging data from 53 participants (Mean Age = 69.25; SD = 5.8) who were healthy controls (HC; n = 16), PD patients with no FOG (PD-nFOG; n = 21), or PD patients with FOG (PD-FOG; n = 16). Participants were administered a full cognitive testing battery including Dementia Rating Scale-2 (DRS-2), Brief Visuospatial Memory Test (BVMT), Rey Auditory Verbal Learning Test (RAVLT), and DKEFS verbal fluency tasks. Fiber density and cross section (FDC) measured micro- and macrostructural fibers and was mapped onto a population-based template. We then correlated FDC with neuropsychological performance both within and between participant groups via Mrtrix3. Results Significant correlations were found at family-wise error corrected p < .05 at specific loci which could point to differential performance. FOG FDC was correlated with lower DRS-2 Attention scores (p = .002), was differentiated from HC via lower DRS-2 Concept scores (p = .011) and greater BVM learning scores (p = .001) and significantly differentiated from PD-nFOG via lower AVLT recognition scores (p = .003). (See Figure for effect) Conclusion Neuropsychological testing differentially correlated with white matter tract fiber density in PD-FOG against other groups. Future research should assess whether task performance and FDC can consistently differentiate PD-FOG from PD-nFOG and HC groups.