Mild cognitive impairment reverters have a favorable cognitive prognosis and cortical integrity in Parkinson's disease

Abstract

This study aimed to investigate whether reversion to cognitively normal status (CogN) is related to afavorablecognitiveprognosisin Parkinson'sdiseasewithmildcognitiveimpairment(PD-MCI). We recruited 217 patients with PD-MCI who underwent serial neuropsychological assessments 3-5 times (mean interval, 1.84years). Thirty-six patients reverted to CogN (reverters) during follow-up, whereas the other 181 did not (nonreverters). We assessed the risk ofcognitiveworsening in PD-MCIreverters, nonreverters, and patients with PD-CogN (n= 88). In addition, we performed comparative analyses of comprehensive neuroimaging studies between the PD-MCI reverter (n= 17) and nonreverter (n= 34) subgroups. PD-MCIrevertershad a lower risk of dementia conversion than nonreverters. In addition, PD-MCIrevertershad similar risks ofcognitiveworsening with patients with PD-CogN. PD-MCIrevertersexhibited greatercorticalthickness in the right parahippocampal gyrus and less severely decreased functional connectivity in the default mode and executive control networks relative to nonreverters. Our results suggest that PD-MCIrevertershave relatively preserved structural and functionalintegrityand afavorablecognitiveprognosiscompared with nonreverters.