The Parietal Lobe in Alzheimer’s Disease and Blindness

Article type: Research Article

Authors: Ahulló-Fuster, Mónica Alba^{a; *} | Ortiz, Tomás^b | Varela-Donoso, Enrique^a | Nacher, Juan^{c; d; e} | Sánchez-Sánchez, M. Luz^f

Affiliations: [a] Department of Radiology, Rehabilitation and Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University Complutense of Madrid, Madrid, Spain | [b] Department of Legal Medicine, Psychiatry and Pathology, Faculty of Medicine, University Complutense of Madrid, Madrid, Spain | [c] Neurobiology Unit, Institute for Biotechnology and Biomedicine (BIOTECMED), University of Valencia, Valencia, Spain | [d] CIBERSAM, Spanish National Network for Research in Mental Health, Spain | [e] Fundación Investigación Hospital Clínico de Valencia, INCLIVA, Valencia, Spain | [f] Physiotherapy in Motion, Multispeciality Research Group (PTinMOTION), Department of Physiotherapy, University of Valencia, Valencia, Spain

Correspondence: [*] Correspondence to: Mónica Alba Ahulló-Fuster, Department of Radiology, Rehabilitation and Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University Complutense of Madrid, Pl. Ramón y Cajal s/n Ciudad Universitaria, 28040 Madrid, Spain. Tel.: +34 91 394 15 00; E-mail: mahullo@ucm.es.

Abstract: The progressive aging of the population will notably increase the burden of those diseases which leads to a disabling situation, such as Alzheimer’s disease (AD) and ophthalmological diseases that cause a visual impairment (VI). Eye diseases that cause a VI raise neuroplastic processes in the parietal lobe. Meanwhile, the aforementioned lobe suffers a severe decline throughout AD. From this perspective, diving deeper into the particularities of the parietal lobe is of paramount importance. In this article, we discuss the functions of the parietal lobe, review the parietal anatomical and pathophysiological peculiarities in AD, and also describe some of the changes in the parietal region that occur after VI. Although the alterations in the hippocampus and the temporal lobe have been well documented in AD, the alterations of the parietal lobe have been less thoroughly explored. Recent neuroimaging studies have revealed that some metabolic and perfusion impairments along with a reduction of the white and grey matter could take place in the parietal lobe during AD. Conversely, it has been speculated that blinding ocular diseases induce a remodeling of the parietal region which is observable through the improvement of the integration of multimodal stimuli and in the increase of the volume of this cortical region. Based on current findings concerning the parietal lobe in both pathologies, we hypothesize that the increased activity of the parietal lobe in people with VI may diminish the neurodegeneration of this brain region in those who are visually impaired by oculardiseases.

Keywords: Aging, Alzheimer’s disease, blindness, dementia, metabolism, neurodegeneration, neuroplasticity, parietal lobe, visual impairment

DOI: 10.3233/JAD-220498

Journal: Journal of Alzheimer's Disease, vol. 89, no. 4, pp. 1193-1202, 2022