Díez-Cirarda, M. 1 , Ibarretxe-Bilbao, N. 1 , Peña, J. 1 , Cabrera, A. 2 , Lucas-Jiménez, O. 1 & Ojeda, N. 1
1 Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain.
2 Department of Neurology, Galdakao Hospital, Galdakao, Spain
Introduction:
Mild cognitive impairment (MCI) is common in Parkinson´s disease (PD) but neuroanatomical description of MCI profiles is needed. The purpose of this study is to assess white matter (WM) fractional anisotropy (FA) differences in subtypes of MCI in PD.
Methods:
Thirty-three PD patients (mean age=67.64 ± 6.535) and 44 HC (age, gender and years of education-matched) underwent a neuropsychological battery and magnetic resonance imaging (DTI and T1) was acquired. Whole-brain voxel-wise and ROI analysis were performed using TBSS (Tract-Based Spacial Statistics) to assess FA. MCI diagnostic criteria were 1.5 SD below HC group.
Results:
Ten PD patients showed no_MCI, 6 showed single domain MCI (SD-MCI) and 17 multiple domain MCI (MD-MCI). Mean FA values: no_MCI group (m= .348; s.d.=.011), SD-MCI group (m=.345; s.d.= .010) and MD-MCI group (m=.336; s.d.=.012) but were not statistically different. WM FA significant differences were found between MD and no_MCI subtypes in right inferior longitudinal fasciculus (p=.020), inferior fronto-occipital fasciculus (p=.022), optic radiation (p=.010) and right (p=.025) and left (p= .026) corticospinal tract. In addition, differences were found between MD and SD-MCI subtypes in right (p=.35) and left (p=.004) corticospinal tract.
Conclusions:
WM principal tracts connecting the frontal, temporal, parietal and occipital lobe showed significant differences between MCI subtypes. These findings suggest the existence of different neuroanatomical substrates for MCI subtypes in PD.