Papez Circuit Gray Matter and Episodic Memory in Amyotrophic Lateral Sclerosis and Behavioural Variant Frontotemporal Dementia

• Published in: Brain imaging and behavior Vol. 15; no. 2; pp. 996 - 1006
• Main Authors: Bueno, Ana Paula Arantes, de Souza, Leonardo Cruz, Pinaya, Walter Hugo Lopez, Teixeira, Antônio Lúcio, de Prado, Laura Godoy Rousseff, Caramelli, Paulo, Hornberger, Michael, Sato, João Ricardo
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2021; Springer Nature B.V
• Subjects: Amyotrophic lateral sclerosis; Amyotrophic Lateral Sclerosis - diagnostic imaging; Atrophy; Biomedical and Life Sciences; Biomedicine; Circuits; Cortex (entorhinal); Dementia; Dementia disorders; Frontotemporal dementia; Frontotemporal Dementia - diagnostic imaging; Frontotemporal Dementia - genetics; Gray Matter - diagnostic imaging; Humans; Magnetic Resonance Imaging; Medical imaging; Memory; Memory, Episodic; Neuroimaging; Neuropsychology; Neuroradiology; Neurosciences; Original Research; Parahippocampal gyrus; Psychiatry; Recall; Structure-function relationships; Substantia grisea; Temporal cortex; Temporal lobe; Amyotrophic lateral sclerosis; Papez circuit; Episodic memory; Behavioural variant frontotemporal dementia
• ISSN: 1931-7557; 1931-7565
• DOI: 10.1007/s11682-020-00307-5

Amyotrophic lateral sclerosis and behavioural variant frontotemporal dementia are two different diseases recognized to overlap at clinical, pathological and genetic characteristics. Both conditions are traditionally known for relative sparing of episodic memory. However, recent studies have disputed that with the report of patients presenting with marked episodic memory impairment. Besides that, structural and functional changes in temporal lobe regions responsible for episodic memory processing are often detected in neuroimaging studies of both conditions. In this study, we investigated the gray matter features associated with the Papez circuit in amyotrophic lateral sclerosis, behavioural variant frontotemporal dementia and healthy controls to further explore similarities and differences between the two conditions. Our non-demented amyotrophic lateral sclerosis patients showed no episodic memory deficits measured by a short-term delayed recall test while no changes in gray matter of the Papez circuit were found. Compared with the amyotrophic lateral sclerosis group, the behavioural variant frontotemporal dementia group had lower performance on the short-term delayed recall test and marked atrophy in gray matter of the Papez circuit. Bilateral atrophy of entorhinal cortex and mammillary bodies distinguished behavioural variant frontotemporal dementia from amyotrophic lateral sclerosis patients as well as atrophy in left cingulate, left hippocampus and right parahippocampal gyrus. Taken together, our results suggest that sub-regions of the Papez circuit could be differently affected in amyotrophic lateral sclerosis and behavioural variant frontotemporal dementia.