title: Asymmetry of cortical decline in subtypes of primary progressive aphasia.
abstract: OBJECTIVE
  The aim of this study was to provide quantitative measures of changes in cortical atrophy over a 2-year period associated with 3 subtypes of primary progressive aphasia (PPA) using whole-brain vertex-wise and region-of-interest (ROI) neuroimaging methods. The purpose was to quantitate disease progression, establish an empirical basis for clinical expectations, and provide outcome measures for therapeutic trials.
  
  
  METHODS
  Changes in cortical thickness and volume loss as well as neuropsychological performance were assessed at baseline and 2-year follow-up in 26 patients who fulfilled criteria for logopenic (8 patients), agrammatic (10 patients), and semantic (8 patients) PPA subtypes. Whole-brain vertex-wise and ROI imaging analysis were conducted using the FreeSurfer longitudinal pipeline.
  
  
  RESULTS
  Clinical deficits and cortical atrophy patterns showed distinct patterns of change among the subtypes over 2 years. Results confirmed that progression for each of the 3 subtypes showed left greater than right hemisphere asymmetry. An ROI analysis also revealed that progression was greater within, rather than outside, the language network.
  
  
  CONCLUSIONS
  Preferential neurodegeneration of the left hemisphere language network is a common denominator for all 3 PPA subtypes, even as the disease progresses. Using a focal cortical language network ROI as an outcome measure of disease progression appears to be more sensitive than whole-brain or ventricular volume measures of change and may be helpful for designing future clinical trials in PPA.
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL. erogalski@gmail.com.
authors.forename: Emily
authors.initials: E
authors.lastname: Rogalski
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Derin
authors.initials: D
authors.lastname: Cobia
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Adam
authors.initials: A
authors.lastname: Martersteck
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Alfred
authors.initials: A
authors.lastname: Rademaker
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Christina
authors.initials: C
authors.lastname: Wieneke
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Sandra
authors.initials: S
authors.lastname: Weintraub
authors.affiliation: From the Cognitive Neurology and Alzheimer's Disease Center (E.R., A.M., C.W., S.W., M.-M.M.), and Departments of Psychiatry and Behavioral Sciences (D.C., S.W.), Preventative Medicine (A.R.), and Neurology (M.-M.M.), Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: M-Marsel
authors.initials: MM
authors.lastname: Mesulam
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018888:Aphasia, Primary Progressive / Q000473:pathology* / Q000503:physiopathology; D001284:Atrophy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012660:Semantics