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

• DOI: 10.1016/j.cortex.2019.07.014
• Publication Date: 2019-08-13T11:49:43Z
• Authors: Kate L. Harris; Matthew Armstrong; Rachel Swain; Sharon Erzinclioglu; Tilak Das; Neil Burgess; Roger A. Barker; Sarah L. Mason
• Keywords: 0301 basic medicine; Adult; Male; Huntington's disease; Middle Aged; Hippocampus; 3. Good health; 03 medical and health sciences; Cognition; Spatial memory; Huntington Disease; Memory, Short-Term; 0302 clinical medicine; Neuropsychology; Space Perception; Humans; Female; Spatial Memory

BACKGROUND: 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. METHOD: 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. RESULTS: 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. CONCLUSION: 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.