title: Amyloid burden correlates with cognitive decline in Alzheimer's disease presenting with aphasia.
abstract: OBJECTIVE
  A subset of patients with Alzheimer's disease (AD) present with early and prominent language deficits. It is unclear whether the burden of underlying β-amyloid pathology is associated with language or general cognitive impairment in these subjects.
  
  
  METHODS
  The relationship between cortical β-amyloid burden on [(11) C]Pittsburgh compound B (PiB) positron emission tomography (PET) and performance on the Montreal Cognitive Assessment (MoCA), the Wechsler Memory Scale - Third Edition (WMS-III), the Boston Naming Test (BNT) and the Western Aphasia Battery (WAB) was assessed using regression and correlation analyses in subjects presenting with aphasia who showed β-amyloid deposition on PiB PET.
  
  
  RESULTS
  The global PiB ratio was inversely correlated with MoCA (P = 0.02) and the WMS-III Visual Reproduction (VR) subtest (VR I, P = 0.02; VR II, P = 0.04). However, the correlations between PiB ratio, BNT (P = 0.13), WAB aphasia quotient (P = 0.11) and WAB repetition scores (P = 0.34) were not significant.
  
  
  CONCLUSIONS
  This study demonstrates that an increased cortical β-amyloid burden is associated with cognitive impairment, but not language deficits, in AD subjects presenting with aphasia. The results suggest that β-amyloid deposition could be partly contributing to impaired cognition in such patients whilst language dysfunction may be more influenced by other pathological mechanisms, perhaps downstream pathways of β-amyloid deposition.
authors: Department of Neurology, Mayo Clinic, Rochester, MN, USA.
authors: Y
authors: Y
authors: Jung
authors: J L
authors: JL
authors: Whitwell
authors: J R
authors: JR
authors: Duffy
authors: E A
authors: EA
authors: Strand
authors: M M
authors: MM
authors: Machulda
authors: M L
authors: ML
authors: Senjem
authors: V
authors: V
authors: Lowe
authors: C R
authors: CR
authors: Jack
authors: K A
authors: KA
authors: Josephs
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D001037:Aphasia / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D002540:Cerebral Cortex; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D013844:Thiazoles
keywords: PET; PiB; aphasia; beta-amyloid; dementia