Etiologies of mild cognitive impairment subtypes in Parkinson's disease Lead Investigator: Brandy Callahan Institution : University of Calgary E-Mail : brandy.callahan@ucalgary.ca Proposal ID : 1097 Proposal Description: Cognitive impairment in Parkinson's disease (PD) is associated with other clinical aspects of the disease (i.e., rapid symptomatic progression, a non-tremor-dominant motor profile, anosmia), suggesting that it is associated with specific underlying pathologic changes independent of motor symptomatology. In support of this, pathological studies have revealed Lewy body accumulation spreading from the brainstem to the cortex in demented PD patients only, whereas in cognitively spared patients pathology is confined to the brainstem. Subtypes of cognitive impairment in PD (i.e., single-domain amnestic vs. multi-domain impairment) may also be associated with distinct pathological mechanisms, but this has never been investigated. The goals of the proposed research are to: 1) Characterize the cognitive subtypes of mild cognitive impairment in PD (i.e., PD-MCI) using a battery of cognitive tests expanding beyond what is typically used in PD, to assess a wide range of cognitive abilities not confounded by motor symptoms 2) Determine how PD-MCI subtypes are captured by the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) 3) Quantify in-vivo clinical and biomarker characteristics associated with PD-MCI subtypes 4) Quantify postmortem neuropathological characteristics associated with PD-MCI subtypes. It is expected that this work will yield new knowledge regarding the causes of specific types of cognitive impairment in PD.