Apathy and impulsivity in frontotemporal lobar degeneration syndromes

Abstract

Lansdall et al. reveal the structural brain changes leading to different types of apathy and impulsivity, across the spectrum of disorders caused by frontotemporal lobar degeneration, including frontotemporal dementia, progressive supranuclear palsy and corticobasal syndrome. The positive correlation between apathy and impulsivity indicates the need for a unified therapeutic strategy.

The neuroanatomical and neurochemical basis of apathy and impulsivity in frontotemporal lobar degeneration

“…Voxel-based-morphometry analyses revealed distinct white-matter or grey-matter correlates for patient related, carer related and task-related principal components (after [8]). Patient self-ratings correlated with white-matter atrophy in cortico-spinal circuits while carer ratings correlated with diffuse grey-matter deficits in fronto-striatal and fronto-temporal regions.…”

“…To overcome these limitations, we recommend multiple modes of assessment of apathy (e.g., behavioural tests, questionnaires from multiple sources, wearables technologies) as well as trans-diagnostic approaches that emphasize the commonality of the manifestation of apathy across the broad clinical spectrum of FTLD diagnoses. This enables a data-driven approach to interrogate the phenomenology and etiology of apathy and impulsivity [8,30]. For example, Lansdall et al used a principal components analysis of multiple questionnaires and laboratory tests, combined with structural magnetic resonance imaging [8,30].…”

“…This enables a data-driven approach to interrogate the phenomenology and etiology of apathy and impulsivity [8,30]. For example, Lansdall et al used a principal components analysis of multiple questionnaires and laboratory tests, combined with structural magnetic resonance imaging [8,30]. They found a positive correlation between measures of apathy and impulsivity (Fig.3) and a dissociation between patient ratings, carer ratings, and dissociable neural correlates of the different modes of apathy and impulsivity, depending on the rater (Fig.3)[8].…”

“…For example, Lansdall et al used a principal components analysis of multiple questionnaires and laboratory tests, combined with structural magnetic resonance imaging [8,30]. They found a positive correlation between measures of apathy and impulsivity (Fig.3) and a dissociation between patient ratings, carer ratings, and dissociable neural correlates of the different modes of apathy and impulsivity, depending on the rater (Fig.3)[8]. Carers’ observations of apathetic changes in behavior correlated with diffuse atrophy in fronto-striatal and fronto-temporal regions, while patients’ reports related to deficits in motor networks, suggesting that patients retain insight in some aspects of their disability.…”

“…These effects span animal models of impulsive disorders [34], neuroimaging data from individuals with impulsive neurodevelopmental disorders [35] and adult patients (e.g., obsessive-compulsive disorders and PD)[21,22,36]. The prevalence of impulsivity in these diverse conditions highlights the value of translational and trans-diagnostic approaches to elucidate the neural underpinnings of impulsivity [8,30]. In the study by Lansdall et al [12], the response-inhibition deficits observed during laboratory-based behavioral paradigms (e.g., the stop-signal task of response cancellation) correlated with focal atrophy in the inferior frontal gyrus and pre-SMA.…”