Structural neuroimaging of social cognition in progressive non-fluent aphasia and behavioral variant of frontotemporal dementia

Abstract

Social cognition impairments are pervasive in the frontotemporal dementias (FTD). These deficits would be triggered by (a) basic emotion and face recognition processes as well as by (b) higher level social cognition (e.g., theory of mind, ToM). Both emotional processing and social cognition impairments have been previously reported in the behavioral variant of FTD (bvFTD) and also in other versions of FTDs, including primary progressive aphasia. However, no neuroanatomic comparison between different FTD variants has been performed. We report selective behavioral impairments of face recognition, emotion recognition, and ToM in patients with bvFTD and progressive non-fluent aphasia (PNFA) when compared to controls. Voxel-based morphometry (VBM) shows a classical impairment of mainly orbitofrontal (OFC), anterior cingulate (ACC), insula and lateral temporal cortices in patients. Comparative analysis of regional gray matter related to social cognition deficits (VBM) reveals a differential pattern of fronto-insulo-temporal atrophy in bvFTD and an insulo-temporal involvement in PNFA group. Results suggest that in spite of similar social cognition impairments reported in bvFTD and PNFA, the former represents an inherent ToM affectation whereas in the PNFA these deficits could be related to more basic processes of face and emotion recognition. These results are interpreted in the frame of the fronto-insulo-temporal social context network model (SCNM).

Functional Connectivity and Temporal Variability of Brain Connections in Adults with Attention Deficit/Hyperactivity Disorder and Bipolar Disorder

“…Connections that were stronger in the BD group than in the CT group, while more diffusely distributed, showed a similar pattern. Our data are consistent with abnormal frontotemporal and fronto-occipital networks observed in several neuropsychiatric conditions [4,31,35,40,42]. These observations did not change qualitatively when changing the thresholds of the binary difference matrix or the activation mask.…”

Feeling, learning from and being aware of inner states: interoceptive dimensions in neurodegeneration and stroke

“…Images were preprocessed with the DARTEL Toolbox from Statistical Parametric Mapping software (SPM12) and analysed following previous procedures [56,57]; see electronic supplementary material, §1.3.2.…”

“…For instance, according to the social context network model [37,75], damage to interoceptive hubs in bvFTD may affect salience attribution during social cognition deficits (e.g. [57,[76][77][78]). Moreover, interoceptive tasks and the HEP have been linked to emotion and social cognition [5,79].…”

Cardiac responses to viewing facial emotion differentiate frontotemporal dementias

“…This classification admits considerable heterogeneity; in particular, bvFTD comprises several clinico‐anatomical subsyndromes, of which the most distinctive is the variant with predominant right temporal lobe atrophy (right temporal variant; rtvFTD) 2, 3. Deficits in emotion processing and empathy are prominent in all FTD syndromes,4, 5 but remain poorly characterized and difficult to quantify. Conventional neuropsychological instruments emphasize the cognitive categorization of emotions, which is potentially confounded by coexisting semantic deficits.…”