1. Connected Speech Deficit as an Early Hallmark of CSF-defined Alzheimer’s Disease and Correlation with Cerebral Hypoperfusion Pattern
- Author
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Tatiana Cattaruzza, Sandro Sorbi, Franca Dore, Giulia Mazzon, Miloš Ajčević, Andrea Marini, Valentina Pesavento, Paolo Manganotti, Selene Capitanio, Alina Menichelli, Michele Guerriero, Mazzon, G., Ajcevic, M., Cattaruzza, T., Menichelli, A., Guerriero, M., Capitanio, S., Pesavento, Valentina, Dore, F., Sorbi, S., Manganotti, P., and Marini, Andrea
- Subjects
Single Photon Emission Computed Tomography Computed Tomography ,Lexical impairments ,Prodromal Symptoms ,Lexical impairment ,tau Proteins ,Disease ,Left inferior frontal gyrus ,Speech Disorders ,Correlation ,Alzheimer Disease ,Functional neuroimaging ,Humans ,Medicine ,Cognitive Dysfunction ,Episodic memory ,Connected speech ,Amyloid beta-Peptides ,Cerebral hypoperfusion ,business.industry ,Healthy subjects ,Mild cognitive impairment ,Brain ,Language disorder ,Early Diagnosis ,Neurology ,Alzheimer’s disease ,Language disorders ,Cerebrovascular Circulation ,Neurology (clinical) ,business ,Neuroscience ,Biomarkers - Abstract
Background: Diagnosis of prodromal Alzheimer's disease (AD) still represents a hot topic and there is a growing interest for the detection of early and non-invasive biomarkers. Although progressive episodic memory impairment is the typical predominant feature of AD, communicative difficulties can be already present at the early stages of the disease. Objective: This study investigated the narrative discourse production deficit as a hallmark of CSFdefined prodromal AD and its correlation with cerebral hypoperfusion pattern. Method: Narrative assessment with a multilevel procedure for discourse analysis was conducted on 28 subjects with Mild Cognitive Impairment (15 MCI due to AD; 13 MCI non-AD) and 28 healthy controls. The diagnostic workup included CSF AD biomarkers. Cerebral hypoperfusion pattern was identified by SPECT image processing. Results: The results showed that the discourse analysis of global coherence and lexical informativeness indexes allowed to identify MCI due to AD from MCI non-AD and healthy subjects. These findings allow to hypothesize that the loss of narrative efficacy could be a possible early clinical hallmark of Alzheimer’s disease. Furthermore, a significant correlation of global coherence and lexical informativeness reduction with the SPECT hypoperfusion was found in the dorsal aspect of the anterior part of the left inferior frontal gyrus, supporting the hypothesis that this area has a significant role in communicative efficacy, and in particular, in semantic selection executive control. Conclusion: This study contributes to the understanding of the neural networks for language processing and their involvement in prodromal Alzheimer's disease. It also suggests an easy and sensitive tool for clinical practice that can help identifying individuals with prodromal Alzheimer’s disease.
- Published
- 2019