Contribution of amyloid and putative Lewy body pathologies in neuropsychiatric symptoms

Abstract

ObjectivesNeuropsychiatric symptom could be useful for detecting patients with prodromal dementia. Similarities and differences in the NPSs between preclinical/prodromal Alzheimer's disease (AD) and prodromal Parkinson's disease dementia (PDD)/Dementia with Lewy bodies (DLB) may exist. This study aimed to compare the NPSs between preclinical/prodromal AD and prodromal PDD/DLB.MethodsOne hundred and three participants without dementia aged ≥50 years were included in this study. The mild behavioral impairment (MBI) total score and the MBI scores for each domain were calculated using the neuropsychiatric inventory questionnaire score. Participants were divided into five groups based on the clinical diagnosis by neurologists or psychiatrists in each institution based on the results of the amyloid positron emission tomography and dopamine transporter single photon emission computed tomography (DAT‐SPECT): Group 1: amyloid‐positive and abnormal DAT‐SPECT, Group 2: amyloid‐negative and abnormal DAT‐SPECT, Group 3: amyloid‐positive and normal DAT‐SPECT, Group 4: mild cognitive impairment unlikely due to AD with normal DAT‐SPECT, and Group 5: cognitively normal with amyloid‐negative and normal DAT‐SPECT.ResultsThe MBI abnormal perception or thought content scores were significantly higher in Group 1 than Group 5 (Bonferroni‐corrected p = 0.012). The MBI total score (Bonferroni‐corrected p = 0.011) and MBI impulse dyscontrol score (Bonferroni‐corrected p = 0.033) in Group 4 were significantly higher than those in Group 5.ConclusionThe presence of both amyloid and putative Lewy body pathologies may be associated with psychotic symptoms.

Relationship between Loneliness and Mild Behavioral Impairment: Validation of the Japanese Version of the MBI Checklist and a Cross-Sectional Study

“…Visual impairment may also be a symptom of Alzheimer’s disease [ 51 ], although a meta-analysis framed visual impairment as a risk factor for dementia [ 52 ]. A recent study reported that the presence of both amyloid and putative Lewy body pathologies may be associated with MBI abnormal thought and perception [ 53 ]. Therefore, both MBI abnormal thought and perception, and visual impairment may be early symptoms of dementia.…”

Mild Behavioral Impairment in Parkinson’s Disease: An Updated Review on the Clinical, Genetic, Neuroanatomical, and Pathophysiological Aspects

“…A recent study has indicated that among non-demented individuals with abnormal DAT-SPECT, scores in the MBI domain of abnormal perception and thought content were higher in individuals with positive amyloid positron emission tomography (PET), compared to those with negative amyloid PET, while total MBI scores did not significantly differ between these groups [121]. In accordance with this, reduced cerebrospinal fluid (CSF) beta-amyloid levels at the baseline have been associated with a higher risk of psychosis in PD [122], and early-onset formed hallucinations have been linked to cortical thinning in parietal, occipital, and frontal cortex, as well as decreased hippocampal volume.…”