From Cognition and Brain Plasticity Unit, Diffusion MRI and brain connectivity
will present the talk titled
The multidimensional pattern of apathy in Huntington’s disease: gray matter underpinnings of apathy subtypes
Abstract
Apathy, a prevalent feature of neurological disorders such as Huntington’s disease (HD), is characterized by a reduction in goal-directed behavior across cognitive, emotional, and auto-activation domains. Comprehensive measures such as the short-Lille Apathy Rating Scale (LARS-s) bear potential to parse apart such subtypes, thereby eclipsing evaluations of apathy as a uniform construct. Neurobiologically, apathy has been attributed to large-scale dysfunctions of frontal cortico-striatal circuits. However, whole-brain analyses of apathy are limited, and no study has yet investigated the gray matter correlates of apathy subtypes in HD. Methods: Forty HD individuals were scanned and evaluated for global apathy using the short-Lille Apathy Rating Scale (LARS-s), assessed for reliability and validity in HD, and the short-Problem Behavior Assessment (PBA-s). In order to study the dimensional structure of apathy subtypes, a principal component analysis of the seven LARS-s domain scores was implemented. Gray matter volume was then associated with global apathy and the resulting factors, representative of apathy subtypes, through whole-brain level voxel-based morphometry. Results: The LARS-s shared convergent validity with the PBA-s. Principal component analysis resulted in three factors that significantly related with theoretical apathy subtypes. Both global apathy and the cognitive factor were significantly associated with markers of disease progression. Anatomically, global apathy was significantly related with middle temporal gyrus, anterior cingulate cortex, dorsolateral prefrontal cortex, and insula, which extended to subcortical regions. Regarding apathy subtypes, the cognitive factor corresponded with dorsal regions (supplementary motor area, anterior cingulate), the emotional factor with limbic regions (insula, orbitofrontal cortex), and the auto-activation factor with subcortical and motor-related regions (putamen, caudate, supplementary motor area). Conclusions: This study corroborates the multidimensional nature of apathy in HD, as measured by factors of the LARS-s, while highlighting that apathy subtypes are underpinned by a complex neural network involving both cognitive and limbic territories. Such findings promote the continued study of apathy subtypes in an effort to pinpoint more precise therapeutic targets, which are currently lacking.
Location: Online (ZOOM)
The link will be send the same day of the seminar