Driver‐Dunckley, Erika

AbstractBackgroundMild Cognitive Impairment (MCI) is a pre‐dementia state where impaired cognitive domains (memory, executive, visuospatial processing, language) may predict underlying pathology, e.g. Alzheimer’s disease(AD), Lewy body (LB), and other. Delineating neuropathological heterogeneity in MCI and their associations with neuropsychological profiles are important in identifying individuals at risk of further deterioration. We aimed to characterize the neuropathological heterogeneity in cases with a diagnosis of MCI.MethodCases with a final consensus cognitive diagnosis of MCI (n = 128) prior to death were selected from the Arizona Study of Aging and Neurodegenerative disorders (AZSAND). Groups were divided into amnestic (aMCI) and non‐amnestic MCI (naMCI), single and multi‐domain impairment, and specific domain impairment (executive, language, visuospatial) was explored. Presence and severity of neuropathology including AD, LB, cerebral white matter rarefaction (CWMR), cerebral amyloid angiopathy (CAA), cerebral infarcts and microinfarcts (cortical and subcortical), TAR DNA‐binding protein 43 (TDP‐43), and apolipoprotein E (ApoE) status were compared between MCI subtypes.ResultThe number of cases meeting neuropathological criteria for AD was not different between aMCI (36.4%) and naMCI (22.6%) while co‐existent PD was less frequent in aMCI (19.5% vs 38.7%). When compared to naMCI (n = 31), the aMCI (n = 85) group had an older age of death (p = 0.001), less educational years (p = 0.04), a higher number of subcortical infarcts (p = 0.012), a higher regional density of neurofibrillary tangles (p = 0.027) and a lower density of LB (p = 0.015) in the temporal lobe, and CWMR in tended to be more severe in the frontal lobe (p = 0.052). Those with single domain aMCI had less CWMR (p = 0.001) compared to the multidomain. Within the naMCI group, those with single domain MCI had higher proportions of CAA (p = 0.042), and lower LB density (p = 0.019) compared to multidomain. CWMR was more severe (p = 0.026) inConclusionA high heterogeneity was observed between MCI subtypes. While AD pathology was similar between groups, regional anatomical differences were observed. Vascular pathology including subcortical infarcts, CWMR and CAA appear to be commonly associated with both aMCI and naMCI respectively while CWMR was associated with executive dysfunctions. CWMR, CAA and LBs appear to be more frequent in multidomain aMCI and naMCI respectively.

AbstractBackgroundLewy body (LB) diseases can present with overlapping prodromal, cognitive, motor, autonomic or neuropsychiatric symptoms. Intuitively, greater symptom severity should correlate with greater pathological burden, but this has not been consistently shown. LB pathology does not translate to clinical expression in Incidental LB disease. While several composite scores/toolkits utilize overlapping schemes for diagnosis, a composite data‐derived score to predict LB pathologic burden is lacking. We aimed to utilize an autopsy‐confirmed cohort, and validated, brief, and standardized clinical, functional, pathologic assessments, and machine learning (ML)/quantitative modeling techniques to identify clusters and importance rankings among assessments/measures to predict LB pathologic severity and density.MethodA total of 234 subjects with neuropathological finding of LB at autopsy in the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) who were classified as Cognitively Unimpaired or Mild Cognitive Impairment after their first study clinical evaluation were included. Of these, 145 subjects had complete scores for 32 of 46 measures (clinical, cognitive, behavioral and functional) that were utilized as predictors of LB pathology. Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT). LB severity was assessed by the Unified Staging System for Lewy Body Disorders (USSLB). Several ML algorithms and quantitative prediction models were explored and compared: artificial neural network (ANN), partial least square regression (PLSR), support vector regression (SVR), relevance vector regression (RVR) and ensemble forest regression (EFR) with leave‐one‐out (LOO) scheme. Game‐theory based Shapley methods assessed the impact, including rankings, consistency and magnitude, of model predictors.ResultRVR predicted aggregate LB density with large effect size (R2 = 0.691, p<0.00001). ANN predicted USSLB severity stage with large effect size (R2 = 0.74, p<2.5e‐43). All other ML algorithms/models provided substantial prediction. Across all models, UPSIT was the most influential predictor (>65%), followed by Controlled Oral Word Association Test (COWAT) and age.ConclusionThese preliminary and exploratory results support the utilization of ML techniques/models to assess LB pathologic burden with key measures collected in relatively small samples. UPSIT was consistently ranked highest impactful among clinical and functional measures/predictors. Integrated together in ML/data‐derived composites, UPSIT, COWAT and other clinical characteristics may be of antemortem utility to predict USSLB stages.

AbstractBackgroundIdiopathic rapid eye movement sleep behavior disorder (RBD) is a strong known predictor of a final clinicopathological diagnosis of a Lewy type α‐synucleinopathy (LTS). Olfactory dysfunction is an early symptom of synucleinopathies and has been repeatedly associated with the presence of post‐mortem LTS.ObjectiveTo assess the combined value of a clinician diagnosis of probable RBD (PRBD) and hyposmia in predicting the post‐mortem presence of LTS in a broader, less‐selected, volunteer elderly population.MethodsWe studied 652 autopsied subjects from the Arizona Study of Aging and Neurodegenerative Disorders, which were evaluated for PRBD, had completed annual movement and cognitive assessments, and had at least one the University of Pennsylvania Smell Identification Test (UPSIT) olfactory test.ResultsHistological evidence of LTS was significantly more frequent in those who had PRBD (112/152: 73.7%) than those without (177/494: 35.8%) (P < 0.001). LTS was more frequent in cases with PRBD and a low UPSIT score (90.8%) compared to cases with PRBD only (73.7%) (P < 0.001) or cases with a low UPSIT score only (69.4%) (P < 0.001). Sensitivity of PRBD diagnosis for predicting LTS was 38.8% and specificity 88.8%, whereas sensitivity of a low UPSIT score was 74.4% and specificity 73.4% (Youden's index = 0.276 for PRBD, 0.478 for UPSIT). When combining both measures, sensitivity was 34.3% and specificity increased to 97.2%.ConclusionPRBD, diagnosed without sleep study confirmation, combined with a reduced olfactory performance is highly specific for predicting post‐mortem presence of LTS. The combination of both measures may provide a cost‐effective means of predicting LTS in a broader community.

AbstractBackgroundWhile preclinical studies have shown that alpha‐synuclein can spread through cell‐to‐cell transmission whether it can be transmitted between humans is unknown.ObjectivesThe aim was to assess the presence of a synucleinopathy in autopsied conjugal couples.MethodsNeuropathological findings in conjugal couples were categorized as Parkinson's disease (PD), dementia with Lewy bodies (DLB), Alzheimer's disease with Lewy bodies (ADLB), incidental Lewy body disease (ILBD), or no Lewy bodies.ResultsNinety conjugal couples were included; the mean age of death was 88.3 years; 32 couples had no Lewy bodies; 42 couples had 1 spouse with a synucleinopathy: 10 PD, 3 DLB, 13 ADLB, and 16 ILBD; 16 couples had both spouses with a synucleinopathy: in 4 couples both spouses had PD, 1 couple had PD and DLB, 4 couples had PD and ADLB, 2 couples had PD and ILBD, 1 couple had DLB and ADLB, in 3 couples both had ADLB, and 1 couple had ADLB and ILBD. No couples had both spouses with ILBD.ConclusionsThis large series of 90 autopsied conjugal couples found 16 conjugal couples with synucleinopathies, suggesting transmission of synucleinopathy between spouses is unlikely. © 2024 International Parkinson and Movement Disorder Society.

AbstractBackgroundNeuropsychiatric symptoms (NPS) are frequent in Alzheimer’s Disease dementia (ADD) but a higher NPS burden is found in dementia with Lewy bodies (DLB). Lewy body (LB) pathology frequently co‐occurs with AD pathology and may not meet neuropathological criteria for DLB (ADLB). Previous studies have shown that both ADLB and DLB cases have faster cognitive and/or functional decline compared to AD. However, the differences in NPS severity over disease course and survival in these pathologic subgroups is not well understood.MethodCases from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) with a final neuropathologic diagnosis of DLB (±AD co‐pathology; n = 65), ADLB (n = 89), AD (without LB) (n = 140), and controls (no neuropathological diagnosis) (n = 82) were included. Total NPI‐Q (scores ranging from 0‐36) at time of enrollment and within 2.5 years of death were calculated for all groups. Statistical analysis utilizing ANCOVA (adjusting for age, sex, baseline MMSE and cognitive symptom duration) with pairwise comparisons, and Kaplan‐Meier curves were completed.ResultAge at onset of cognitive symptoms was not different between pathology groups. NPI‐Q scores at enrollment were highest in ADLB (7.33 ± 4.85), and higher (p<0.001) than DLB (5.10 ± 3.37), AD (4.54 ± 3.63) and controls (1.78 ± 1.70). At final evaluation, NPI‐Q scores were highest in DLB (10.04 ± 6.28), followed by ADLB (8.0 ± 4.), and ADD (7.61 ± 5.05) when compared to controls (2.78 ± 3.97) (all p<0.001). DLB and AD demonstrated significant increases in NPI‐Q severity during follow up (p < 0.001). AD had longer survival time (5.8 years) compared to ADLB (4.0 years) and DLB (3.9 years). Subjects with NPS had a shorter median survival time (3.4 years) compared to subjects without NPS (6.5 years; p = 0.002).ConclusionA higher NPS burden and shorter survival is seen in both DLB and ADLB, as compared with AD. This suggests that diffuse neocortical LB pathology is not the major driver of either NPS or survival.

AbstractBackgroundPathological Lewy body disease (LBD) may commonly present clinically as Parkinson’s disease dementia (PDD), Dementia with Lewy bodies (DLB) or Alzheimer’s disease dementia (ADD). Neuropathological definitions also include a group in which ADD is present, but the postmortem Lewy pathology does not meet threshold density and distribution levels for the neuropathological diagnosis of DLB (ADLB). Little is known about the cognitive profiles of patients with ADLB and despite common underlying pathology, studies delineating neuropsychological profiles in LBD are fraught with inconsistencies. We characterized the longitudinal cognitive trajectories defined by neuropsychological profiles in cases along the pathological spectrum of LBD.MethodCases from the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND) with a cognitive diagnosis of dementia at death and who at minimum, had two neuropsychological evaluations were included. Final neuropathological diagnosis was determined as LBD (neocortical or limbic LB ± AD), ADLB, and AD pathology only. LBD cases were categorized by their cognitive clinical syndromes as PDD and DLB. Global cognition was evaluated using MMSE. Neuropsychological domains of Memory, Executive function, language, attention, and visuospatial were evaluated. Mixed linear methods were used to predict longitudinal change for a given baseline MMSE.Result287 participants and 1874 participant‐years of data were included in this study. LBD (n = 115), and ADLB (52) groups were predominantly male, while AD (n = 114) group was primarily female. Baseline MMSE was similar across all pathologic groups. Linear mixed modelling methods showed faster decrease in memory domain scores (decreasing 0.22 units/year – 0.42 units/year faster, p = 0.01) in ADLB group compared to other groups. Significantly faster decline was noted in LBD and ADLB group in clock drawing (p<0.001), fluency scores (declining 1.02 unit/year faster p<0.001) compared to AD group. There was no difference between PDD and DLB clinical subgroups.ConclusionIn autopsy confirmed cases, ADLB had an accelerated trajectory of decline in memory tasks, while AD, and LBD appeared to have similar trajectories. In contrast, all groups with Lewy bodies progressed faster and showed accelerated decline compared to AD in measures of frontal‐subcortical functions. These results may inform antemortem classification of patients and diagnostic accuracy in these groups.

Abstract INTRODUCTION We examined the progression of extrapyramidal symptoms and signs in autopsy‐confirmed dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and Alzheimer's disease dementia (AD). METHODS Longitudinal data were obtained from Arizona Study of Aging and Neurodegenerative Disease, with PDD ( n = 98), AD ( n = 47) and DLB ( n = 48) further sub‐grouped as with or without parkinsonism (DLB+ and DLB−). Within‐group Unified Parkinson's Disease Rating Scale (UPDRS) ‐II and UPDRS‐III trajectories were analyzed using non‐linear mixed effects models. RESULTS In DLB, 65.6% had parkinsonism. Baseline UPDRS‐II and III scores (off‐stage) were highest ( P < 0.001) for PDD (mean ± SD 14.3 ± 7.8 and 27.4 ± 16.3), followed by DLB+ (6.0 ± 8.8 and 17.2 ± 17.1), DLB− (1.1 ± 1.3 and 3.3 ± 5.5) and AD (3.2 ± 6.1 and 8.2 ± 13.6). Compared to PDD, the DLB+ group had faster UPDRS‐III progression over 8‐years (Cohen's‐ d range 0.98 to 2.79, P < 0.001), driven by gait ( P < 0.001) and limb bradykinesia ( P = 0.02) subscales. DISCUSSION Motor deficits progress faster in DLB+ than PDD, providing insights about expected changes in motor function. Highlights Dementia with Lewy bodies has faster motor progression than Parkinson's disease dementia Linear and non‐linear mixed modeling analysis of longitudinal data was utilized Findings have implications for clinical prognostication and trial design

AbstractBackgroundWe previously reported that in our autopsy‐confirmed cohort of Dementia with Lewy Bodies (DLB), Parkinson’s Disease Dementia (PDD) and Alzheimer’s Disease (AD), DLB with parkinsonism (DLB+Park) predicted faster progression of UPDRS‐III scores compared to PDD, DLB without parkinsonism (DLB‐Park), and AD. This study examined annualized rate of change of UPDRS‐III subscales in our cohort.MethodsData included were from participants in Arizona Study of Aging and Neurodegenerative Diseases (AZSAND) with clinicopathologic diagnosis of DLB (n = 48), PDD (n = 98) or pure AD (n = 48), and longitudinal movement exams. Mixed effects model (accounting for age, education, and sex) was used to determine predicted mean UPDRS‐III and subscale scores (0‐4) for all groups. Individual UPDRS‐III subscale scores were derived for: Body Bradykinesia, Limb Bradykinesia, Gait, Postural Instability, Limb Rest Tremor, Neck Rigidity and Limb Rigidity. Where applicable, scores for multiple limbs involved were averaged.ResultsLongitudinal data was analyzed for over 1430‐participant years. Parkinsonism was present in 65.6% of DLB participants. PDD participants were more likely to be treated with dopaminergic agents (87.8%) compared to (p<0.001) DLB+Park (57.6%), DLB‐park (0%) and AD (2.1%). Frequency (29.4% vs. 29.0%) and severity (mean±SE = 0.4±0.07 and 0.4±0.12) of Limb Rest Tremor was similar for PDD and DLB+park. Limb Bradykinesia frequency and severity were PDD: 100%, 2.4±0.11, DLB+Park: 96.8%, 2.1±0.18, DLB‐Park: 20%, 0.4±0.23, and AD: 62%, 1.1±0.16. Frequency of gait abnormality was 98.5% in PDD, 90.3% in DLB+park, 60% in DLB‐Park and 57.8% in AD. Rigidity was most frequent in the PDD group (88.2%), followed by DLB+Park (71%), AD (19.6%), and none DLB‐park (0%). Over 8 years trajectories for limb bradykinesia and gait were greater for DLB+park than PDD (Figure 1, Cohen’s d range 0.89‐2.18 and 0.63‐1.99 over 8 years, p<0.001).ConclusionOur results suggest that DLB+Park group have faster motor progression predominantly related to gait abnormalities and limb bradykinesia. Future analyses will explore more convergent data, integrated effects of various measures and their differential contributions in this cohort.