EPISODIC MEMORY IMPAIRMENT IN PROGRESSIVE SUPRANUCLEAR PALSY (PSP): A NEUROIMAGING INVESTIGATION

Abstract

Background: Progressive supranuclear palsy (PSP) has been classically considered a “subcortical dementia” with a frontal pattern of cognitive decline, but episodic memory dysfunction also occurs in most patients. However, it remains uncertain whether this is due to executive dysfunction or to the involvement of key brain areas responsible for memory processes. Objective: We aim to identify the specific brain regions underlying episodic memory impairment in PSP. Methods: In this cross-sectional study, we included 21 patients with PSP and 20 healthy controls matched for age, sex, and schooling. Participants underwent the Brief Cognitive Battery (BCB, including the Figures Test for episodic memory) and had brain MRI. Both standard exploratory voxel‐based morphometry and region of interest analyses were performed with FSL software. Results: Compared to controls, PSP patients performed worse (p < 0.001) on the BCB (delayed recall). Adjusting for both age and Frontal Assessment Battery scores, neuroimaging analyses of the correlation between delayed recall (5 minutes) and grey matter volumes yielded significant clusters on medial temporal structures, including the hippocampus, entorhinal cortex, and parahippocampal gyrus (FWE, p < 0.05). Conclusion: Our results suggest that atrophy of medial temporal structures may play a role in episodic memory impairment in PSP, indicating that amnesia in PSP is not due to executive dysfunction.