Illusory Responses across the Lewy Body Disease Spectrum

Abstract

Objective: This study was undertaken to study pareidolias, or perceived meaningful objects in a meaningless stimulus, in patients across the Lewy body (LB) disease spectrum, where most do not report hallucinations or delusions. Methods: We studied illusory responses on the Noise Pareidolia Task in 300 participants (38 cognitively impaired LB, 65 cognitively unimpaired LB, 51 Alzheimer disease spectrum [AD-s], 146 controls). Pairwise between-group comparisons examined how diagnosis impacts the number of illusory responses. Ordinal regression analysis compared the number of illusory responses across diagnosis groups, adjusting for age, sex, and education. Analyses were repeated after removing participants with reported hallucinations or delusions. Results: Cognitively impaired LB participants were 12.3, 4.9, and 4.6 times more likely than control, cognitively unimpaired LB, and AD-s participants, respectively, to endorse illusory responses. After adjusting for age, sex, and education, the probability of endorsing 1 or more illusory responses was 61% in the cognitively impaired LB group, compared to 26% in AD-s, 25% in cognitively unimpaired LB, and 12% in control participants. All results were similar after repeated analysis only in participants without hallucinations or delusions. In LB without hallucinations or delusions, 52% with mild cognitive impairment and 66.7% with dementia endorsed at least 1 illusory response. Interpretation: We found illusory responses are common in cognitively impaired LB patients, including those without any reported psychosis. Our data suggest that, prior to the onset of hallucinations and delusions, the Noise Pareidolia Task can easily be used to screen for unobtrusive pareidolias in all LB patients.

Pareidolias are a function of visuoperceptual impairment

“…This interpretation finds considerable resonance with recent studies. One reported that, while pareidolias were common in cognitively impaired Lewy body patients, this was equally the case in the subgroup with no history of hallucination [ 34 ]. Another found that hallucinating PD patients reported more pareidolic responses but also showed greater impairments on visuoperception tests compared to PD without hallucination [ 35 ].…”

Plasma pTau181 reveals a pathological signature that predicts cognitive outcomes in Lewy body disease

“…We selected research participants with available plasma from the Iqbal Farrukh and Asad Jamal Stanford Alzheimer’s Disease Research Center (ADRC) and Pacific Udall Center (PUC) 18 cohorts. Diagnostic procedures are described in detail elsewhere 19 .…”

“…We selected research participants with available plasma from the Iqbal Farrukh and Asad Jamal Stanford Alzheimer's Disease Research Center (ADRC) and Pacific Udall Center (PUC) 18 cohorts. Diagnostic procedures are described in detail elsewhere 19 . Briefly, each participant underwent a comprehensive evaluation, encompassing clinical history, physical and neurological examination, and neuropsychological assessments.…”

Mag-Net: Rapid enrichment of membrane-bound particles enables high coverage quantitative analysis of the plasma proteome

“…Plasma samples previously banked at Stanford as part of longitudinal studies on neurodegenerative diseases of aging were selected. Diagnostic criteria for ADD and PD and the assessments for the cognitive status determination have previously been described 89 . Ten age- and sex-matched samples were selected from each of four categories: 1) Alzheimer’s disease dementia (ADD), 2) Parkinson’s disease with dementia (PDD), 3) Parkinson’s disease cognitively normal (PDCN), and 4) healthy cognitively normal (HCN).…”