title: White Matter Changes Associated with Resting Sympathetic Tone in Frontotemporal Dementia vs. Alzheimer's Disease.
abstract: Resting sympathetic tone, a measure of physiological arousal, is decreased in patients with apathy and inertia, such as those with behavioral variant frontotemporal dementia (bvFTD) and other frontally-predominant disorders.
  
  
  
  To identify the neuroanatomical correlates of skin conductance levels (SCLs), an index of resting sympathetic tone and apathy, among patients with bvFTD, where SCLs is decreased, compared to those with Alzheimer's disease (AD), where it is not.
  
  
  
  This study analyzed bvFTD (n = 14) patients and a comparison group with early-onset AD (n = 19). We compared their resting SCLs with gray matter and white matter regions of interest and white matter measures of fiber integrity on magnetic resonance imaging and diffusion tensor imaging.
  
  
  
  As expected, bvFTD patients, compared to AD patients, had lower SCLs, which correlated with an apathy measure, and more gray matter loss and abnormalities of fiber integrity (fractional anisotropy and mean diffusivity) in frontal-anterior temporal regions. After controlling for group membership, the SCLs were significantly correlated with white matter volumes in the cingulum and inferior parietal region in the right hemisphere.
  
  
  
  Among dementia patients, SCLs, and resting sympathetic tone, may correlate with quantity of white matter, rather than with gray matter or with white matter fiber integrity. Loss of white matter volumes, especially involving a right frontoparietal network, may reflect chronic loss of cortical axons that mediate frontal control of resting sympathetic tone, changes that could contribute to the apathy and inertia of bvFTD and related disorders.
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, 710 Westwood Plaza, Los Angeles, California, 90095, United States of America.|Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, 710 Westwood Plaza, Los Angeles, California, 90095, United States of America.
authors.forename: Mario F
authors.initials: MF
authors.lastname: Mendez
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, 710 Westwood Plaza, Los Angeles, California, 90095, United States of America.
authors.forename: Simantini J
authors.initials: SJ
authors.lastname: Karve
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, 710 Westwood Plaza, Los Angeles, California, 90095, United States of America.
authors.forename: Madelaine
authors.initials: M
authors.lastname: Daianu
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, 710 Westwood Plaza, Los Angeles, California, 90095, United States of America.
authors.forename: Elvira
authors.initials: E
authors.lastname: Jimenez
authors.affiliation: Imaging Genetics Center, Institute for Neuroimaging & Informatics, University of Southern California, Los Angeles, California, 90033, United States of America.|Department of Neurology, University of Southern California, Los Angeles, California, 90033, United States of America.|Department of Psychiatry, University of Southern California, Los Angeles, California, 90033, United States of America.|Department of Radiology, University of Southern California, Los Angeles, California, 90033, United States of America.|Department of Radiology, University of Southern California, Los Angeles, California, 90033, United States of America.
authors.forename: Paul
authors.initials: P
authors.lastname: Thompson
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology* / Q000523:psychology; D016880:Anisotropy; D005260:Female; D057180:Frontotemporal Dementia / Q000473:pathology* / Q000503:physiopathology* / Q000523:psychology; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D012307:Risk Factors; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D066127:White Matter / Q000473:pathology*