title: Atrophy in distinct corticolimbic networks in frontotemporal dementia relates to social impairments measured using the Social Impairment Rating Scale.
abstract: Patients with frontotemporal dementia (FTD) often exhibit prominent, early and progressive impairments in social behaviour. We developed the Social Impairment Rating Scale (SIRS), rated by a clinician after a structured interview, which grades the types and severity of social behavioural symptoms in seven domains. In 20 FTD patients, we used the SIRS to study the anatomic basis of social impairments. In support of hypotheses generated from a prior study of healthy adults, we found that the relative magnitude of brain atrophy in three partially dissociable corticolimbic networks anchored in the amygdala predicted the severity of distinct social impairments measured using the SIRS. Patients with the greatest atrophy in a mesolimbic, reward-related (affiliation) network exhibited the most severe socioemotional detachment, whereas patients with the greatest atrophy in an interoceptive, pain-related (aversion) network exhibited the most severe lack of social apprehension. Patients with the greatest atrophy in a perceptual network exhibited the most severe lack of awareness or understanding of others' social and emotional behaviour. Our findings underscore observations that FTD is associated with heterogeneous social symptoms that can be understood in a refined manner by measuring impairments in component processes subserved by dissociable neural networks. Furthermore, these findings support the validity of the SIRS as an instrument to measure the social symptoms of patients with FTD. Ultimately, we hope it will be useful as a longitudinal outcome measure in natural history studies and in clinical trials of putative interventions to improve social functioning.
authors.affiliation: Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Bickart
authors.affiliation: Psychiatric Neuroimaging Research Program and Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.|Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Brickhouse
authors.affiliation: Psychiatric Neuroimaging Research Program and Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.|Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA.
authors.forename: Alyson
authors.initials: A
authors.lastname: Negreira
authors.affiliation: Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA.|Department of Speech and Language Pathology, Massachusetts General Hospital, Charlestown, Massachusetts, USA.
authors.forename: Daisy
authors.initials: D
authors.lastname: Sapolsky
authors.affiliation: Psychiatric Neuroimaging Research Program and Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.|Department of Psychology, Northeastern University, Boston, Massachusetts, USA.
authors.forename: Lisa Feldman
authors.initials: LF
authors.lastname: Barrett
authors.affiliation: Psychiatric Neuroimaging Research Program and Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.|Frontotemporal Disorders Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA.
authors.forename: Bradford C
authors.initials: BC
authors.lastname: Dickerson
mesh_terms: D000368:Aged; D001284:Atrophy / Q000473:pathology / Q000523:psychology; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D057180:Frontotemporal Dementia / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D006801:Humans; D008032:Limbic System / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012920:Social Behavior Disorders / Q000150:complications / Q000175:diagnosis* / Q000473:pathology* / Q000523:psychology