Structural and functional papez circuit integrity in amyotrophic lateral sclerosis

Author(s)

Arantes Bueno, Ana Paula ^[1] ; Pinaya, Walter Hugo L. ^[1] ; Moura, Luciana M. ^[1] ; Bertoux, Maxime ^[2] ; Radakovic, Ratko ^{[3, 4, 5]} ; Kiernan, Matthew C. ^{[6, 7]} ; Teixeira, Antonio Lucio ^[8] ; de Souza, Leonardo Cruz ^[8] ; Hornberger, Michael ^[2] ; Sato, Joao Ricardo ^[1]

Affiliation

^[1] Univ Fed ABC, Ctr Math Computat & Cognit, Santo Andre - Brazil

^[2] Univ East Anglia, Dept Med, Norwich Med Sch, Norwich Res Pk, James Watson Rd, Norwich NR4 7TJ, Norfolk - England

^[3] Univ East Anglia, Sch Hlth Sci, Norwich Med Sch, Norwich, Norfolk - England

^[4] Univ Edinburgh, Alzheimer Scotland Dementia Res Ctr, Edinburgh, Midlothian - Scotland

^[5] Univ Edinburgh, Ctr Cognit Ageing & Cognit Epidemiol, Edinburgh, Midlothian - Scotland

^[6] Univ Sydney, Sydney Med Sch, Sydney, NSW - Australia

^[7] Univ Sydney, Brain & Mind Ctr, Sydney, NSW - Australia

^[8] Univ Fed Minas Gerais, Dept Internal Med, Belo Horizonte, MG - Brazil

• Document type: Journal article
• Source: BRAIN IMAGING AND BEHAVIOR; v. 12, n. 6, p. 1622-1630, DEC 2018.
• Web of Science Citations: 6

Abstract

Cognitive impairment in amyotrophic lateral sclerosis (ALS) is heterogeneous but now recognized as a feature in non-demented patients and no longer exclusively attributed to executive dysfunction. However, despite common reports of temporal lobe changes and memory deficits in ALS, episodic memory has been less explored. In the current study, we examined how the Papez circuita circuit known to participate in memory processesis structurally and functionally affected in ALS patients (n=20) compared with healthy controls (n=15), and whether these changes correlated with a commonly used clinical measure of episodic memory. Our multimodal MRI approach (cortical volume, voxel-based morphometry, diffusion tensor imaging and resting state functional magnetic resonance) showed reduced gray matter in left hippocampus, left entorhinal cortex and right posterior cingulate as well as increased white matter fractional anisotropy and decreased mean diffusivity in the left cingulum bundle (hippocampal part) of ALS patients compared with controls. Interestingly, thalamus, mammillary bodies and fornix were preserved. Finally, we report a decreased functional connectivity in ALS patients in bilateral hippocampus, bilateral anterior and posterior parahippocampal gyrus and posterior cingulate. The results revealed that ALS patients showed statistically significant structural changes, but more important, widespread prominent functional connectivity abnormalities across the regions comprising the Papez circuit. The decreased functional connectivity found in the Papez network may suggest these changes could be used to assess risk or assist early detection or development of memory symptoms in ALS patients even before structural changes are established. (AU)

• FAPESP's process: 16/19376-9 - Structural and functional Papez circuit integrity and its relations to symptomology in Amyotrophic Lateral Sclerosis
• Grantee: Ana Paula Arantes de Andrade Bueno
• Support Opportunities: Scholarships in Brazil - Doctorate