Differential insular cortex sub-regional atrophy in neurodegenerative diseases: a systematic review and meta-analysis

• Published in: Brain imaging and behavior Vol. 14; no. 6; pp. 2799 - 2816
• Main Authors: Fathy, Yasmine Y., Hoogers, Susanne E., Berendse, Henk W., van der Werf, Ysbrand D., Visser, Pieter J., de Jong, Frank J., van de Berg, Wilma D.J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2020; Springer Nature B.V
• Subjects: Activities of Daily Living; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - pathology; Alzheimer's disease; Atrophy; Atrophy - pathology; Biomedical and Life Sciences; Biomedicine; Brain; Cerebral Cortex - diagnostic imaging; Cerebral Cortex - pathology; Cognitive ability; Cortex (insular); Degeneration; Dementia; Dementia disorders; Disease; Frontotemporal dementia; Functional analysis; Humans; Lewy bodies; Lewy Body Disease; Magnetic Resonance Imaging; Mental disorders; Meta-analysis; Morphometry; Movement disorders; Neurodegeneration; Neurodegenerative diseases; Neurodegenerative Diseases - diagnostic imaging; Neurodegenerative Diseases - pathology; Neurological diseases; Neuropsychological Tests; Neuropsychology; Neuroradiology; Neurosciences; Parkinson's disease; Psychiatry; Review; Review Article; Speech perception; Systematic review; Voxel based morphometry; Alzheimer’s disease; Neurodegeneration; Perception; Cognition; Emotion; Frontotemporal dementia; Anatomic likelihood estimation; Insular cortex; Parkinson’s disease
• ISSN: 1931-7557; 1931-7565; 1931-7565
• DOI: 10.1007/s11682-019-00099-3

The insular cortex is proposed to function as a central brain hub characterized by wide-spread connections and diverse functional roles. As a result, its centrality in the brain confers high metabolic demands predisposing it to dysfunction in disease. However, the functional profile and vulnerability to degeneration varies across the insular sub-regions. The aim of this systematic review and meta-analysis is to summarize and quantitatively analyze the relationship between insular cortex sub-regional atrophy, studied by voxel based morphometry, with cognitive and neuropsychiatric deficits in frontotemporal dementia (FTD), Alzheimer’s disease (AD), Parkinson’s disease (PD), and dementia with Lewy bodies (DLB). We systematically searched through Pubmed and Embase and identified 519 studies that fit our criteria. A total of 41 studies ( n  = 2261 subjects) fulfilled the inclusion criteria for the meta-analysis. The peak insular coordinates were pooled and analyzed using Anatomic Likelihood Estimation. Our results showed greater left anterior insular cortex atrophy in FTD whereas the right anterior dorsal insular cortex showed larger clusters of atrophy in AD and PD/DLB. Yet contrast analyses did not reveal significant differences between disease groups. Functional analysis showed that left anterior insular cortex atrophy is associated with speech, emotion, and affective-cognitive deficits, and right dorsal atrophy with perception and cognitive deficits. In conclusion, insular sub-regional atrophy, particularly the anterior dorsal region, may contribute to cognitive and neuropsychiatric deficits in neurodegeneration. Our results support anterior insular cortex vulnerability and convey the differential involvement of the insular sub-regions in functional deficits in neurodegenerative diseases.