{'fraction_non_alphanumeric': 0.0213903743315508, 'fraction_numerical': 0.010160427807486631, 'mean_word_length': 5.21594684385382, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Neocortical Lewy body pathology parallels Parkinson's dementia, but not always.

OBJECTIVE
To evaluate the relationship between Parkinson's disease (PD) with dementia and cortical proteinopathies in a large population of pathologically confirmed PD patients.


METHODS
We reviewed clinical data from all patients with autopsy data seen in the Movement Disorders Center at Washington University, St. Louis between 1996 and 2019. All patients with a diagnosis of PD based on neuropathology were included. We used logistic regression and MANCOVA to investigate the relationship between neuropathology and dementia.


RESULTS
A total of 165 PD patients met inclusion criteria. Among these, 128 had clinical dementia. Those with dementia had greater mean ages of motor onset and death but equivalent mean disease duration. The delay between motor symptom onset and dementia was one year or less in 14 individuals, meeting research diagnostic criteria for possible or probable dementia with Lewy bodies (DLB). Braak Lewy body stage was associated with diagnosis of dementia, whereas severities of Alzheimer disease neuropathologic change (ADNC) and small vessel pathology did not. Pathology of individuals diagnosed with DLB did not differ significantly from that of other PD patients with dementia. 6% of individuals with PD and dementia did not have neocortical Lewy bodies; 68% with PD but without dementia did have neocortical Lewy bodies.


INTERPRETATION
Neocortical Lewy bodies almost always accompany dementia in PD; however, they also appear in most PD patients without dementia. In some cases, dementia may occur in PD patients without neocortical Lewy bodies, ADNC, or small vessel disease. Thus, other factors not directly related to these classic neuropathologic features may contribute to PD dementia. This article is protected by copyright. All rights reserved.