Fronto-parietal contributions to episodic retrieval-evidence from neurodegenerative disorders.
Learn Mem
; 26(7): 262-271, 2019 07.
Article
in En
| MEDLINE
| ID: mdl-31209121
ABSTRACT
Converging evidence suggests a critical role for the parietal cortices in episodic memory retrieval. Here, we examined episodic memory performance in Corticobasal Syndrome (CBS), a rare neurodegenerative disorder presenting with early parietal atrophy in the context of variable medial temporal lobe damage. Forty-four CBS patients were contrasted with 29 typical Alzheimer's disease (AD), 29 healthy Controls, and 20 progressive supranuclear palsy patients presenting with brainstem atrophy as a disease control group. Participants completed standardized assessments of verbal episodic memory (learning, delayed recall, and recognition), and underwent structural and diffusion-weighted MRI. Selective delayed recall deficits were evident in the CBS group relative to Controls, at an intermediate level to the stark amnesia displayed by AD, and Control-level performance noted in progressive supranuclear palsy. Considerable variability within the CBS group on delayed recall performance led to the identification of memory-spared (N = 19) and memory-impaired (N = 25) subgroups. Whereas CBS-Spared showed no significant memory deficits, the CBS-Impaired subgroup were indistinguishable from typical AD across all episodic memory measures. Whole-brain voxel-based morphometry analyses implicated fronto-parietal and medial temporal regions in delayed recall performance in both the CBS-Impaired and AD groups. Furthermore, diffusion tensor imaging analyses revealed correlations between delayed recall performance and altered structural connectivity between fronto-parietal and frontotemporal regions in the CBS-Impaired group. Our findings underscore the importance of a distributed brain network including frontal, medial temporal, and parietal brain regions in supporting the capacity for successful episodic memory retrieval.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parietal Lobe
/
Neurodegenerative Diseases
/
Memory, Episodic
/
Frontal Lobe
/
Memory Disorders
Type of study:
Prognostic_studies
Limits:
Aged
/
Female
/
Humans
/
Male
Language:
En
Journal:
Learn Mem
Journal subject:
NEUROLOGIA
Year:
2019
Document type:
Article
Affiliation country:
Australia