Objective: To ascertain the pattern of functional connectivity in PD patients with and without FOG in the absence of cognitive impairment

Background: Freezing of gait (FOG) is of the most debilitating symptoms in Parkinson’s disease (PD), being an important cause of falls and disability. Previous studies have showed reduced functional connectivity in executive and visual networks, however, cognitive dysfunction acted as an important cofounding factor. In the present study we analysed brain functional connectivity with resting state functional MRI in patients with PD and FOG without cognitive impairment

Method:
Forty-three PD patients, seventeen with FOG (FOG+) and twenty-six without FOG (FPG-) without cognitive impairment and twenty-four age-matched controls underwent resting-state fMRI. Seed-based correlation analysis from locomotor neural areas involved in FOG was performed using subtalamic nucleus (STN), pedunculopontine nucleus (PPN), supplementary motor area (SMA) and cerebellar locomotor region (CLR). Pairwise t-test between PD patients with and without FOG and controls was performed in order to obtain whole-brain connectivity analysis with threshold-free cluster enhancement statistics with p<0.05 corrected for multiple comparisons

Results:
In PD patients with FOG vs controls, we observed reduced functional connectivity between the right SMA and the bilateral sensorimotor, parietal and insular cortices and ipsilateral caudate. Additional reductions in functional connectivity in patients with FOG vs controls were showed between the left STN (in less degree in FOG-) and middle frontal premotor area, cuneus/precuneus, anterior cingulate cortex, cerebellum and basal ganglia. Functional hypoconnectivity was observed in right STN in FOG+ vs controls with cuneus, fusiform gyrus and sensorimotor cortex (in less degree in FOG-). Finally, reduced functional connectivity was showed between left PPN and bilateral lingual gyrus in PD patients FOG+ vs FOG-

Conclusion:
Our findings suggest a resting state functional connectivity disruption of STN and right SMA in PD patients with FOG(and less degree in FOG-) vs controls with cortical and subcortical regions involved with attention, response inhibition and conflict resolution in absence of cognitive impairment. In addition further hypoconnectivity of left PPN in PD FOG+ vs FOG- were observed with cortical regions associated with visual processing

« Back to MDS Virtual Congress 2020

MDS Abstracts - https://www.mdsabstracts.org/abstract/aberrant-resting-state-functional-connectivity-in-cognitively-unimpaired-patients-with-parkinsons-disease-and-freezing-of-gait/