Huntington's disease patients display progressive deficits in hippocampal-dependent cognition during a task of spatial memory

• Published in: Cortex Vol. 119; pp. 417 - 427
• Main Authors: Harris, Kate L., Armstrong, Matthew, Swain, Rachel, Erzinclioglu, Sharon, Das, Tilak, Burgess, Neil, Barker, Roger A., Mason, Sarah L.
• Format: Journal Article
• Language: English
• Published: Italy Elsevier Ltd 01.10.2019
• Subjects: Adult; Cognition; Cognition - physiology; Female; Hippocampus; Hippocampus - physiopathology; Humans; Huntington Disease - psychology; Huntington's disease; Male; Memory, Short-Term - physiology; Middle Aged; Neuropsychology; Space Perception - physiology; Spatial memory; Spatial Memory - physiology; Cognition; Neuropsychology; Huntington's disease; Hippocampus; Spatial memory
• ISSN: 0010-9452; 1973-8102
• DOI: 10.1016/j.cortex.2019.07.014

Cognitive disturbances occur early in Huntington's disease (HD) and place a significant burden on the lives of patients and family members. Whilst these impairments are typically attributed to deterioration of the frontal-striatal pathways, accumulating evidence suggests that hippocampal dysfunction may also contribute to such impairments. Here, we employ a novel spatial memory task that has previously been shown to elicit impairments in individuals with focal hippocampal lesions, as a means to further investigate the role of hippocampal dysfunction in HD. Sixty-four individuals participated in the study, including 32 healthy controls, 11 patients with diagnosed HD and 16 premanifest HD gene carriers. We also included an additional control group of 5 individuals with focal unilateral basal ganglia lesions. Participants undertook a task that measured perception and short-term spatial memory using computer-generated visual scenes. HD patients experienced significant impairments in spatial perception and memory, which strongly correlated with disease burden score (DBS). Premanifest gene carriers performed at a similar level to healthy controls throughout all aspects of the task indicating that the effects seen in the HD patients represent a deterioration in function. Interestingly, basal ganglia lesion patients were not impaired in any aspects of the task. There is evidence of significant deficits in hippocampal-dependent spatial cognition in HD that cannot be explained as a function of degeneration to the basal ganglia. The impairments were greatest in individuals with higher DBSs, suggesting that deficits relate to the disease process in HD.