title: Diagnosis and quantification of cognitive fatigue in multiple sclerosis.
abstract: OBJECTIVE
  To standardize a method to measure cognitive fatigue in patients with multiple sclerosis (MS).
  
  
  BACKGROUND
  Many patients with MS complain of cognitive fatigue, defined as a decline in cognitive performance during a task requiring sustained activity. Until now there has not been a standardized way to detect cognitive fatigue or determine its severity.
  
  
  METHODS
  We administered the Paced Auditory Serial Addition Test (PASAT) to 130 normal controls and 100 randomly selected patients with MS, and compared the number of correct responses between the first third and last third of the test.
  
  
  RESULTS
  The controls averaged 2 more correct responses in the last third of the PASAT than in the first third. The patients with MS averaged 2 to 3 fewer correct responses in the last third than the first third.
  
  
  CONCLUSIONS
  Our study showed that comparing responses between the first and last thirds of the PASAT is a reliable method to measure cognitive fatigue in patients with MS. We also present normative data to be used to determine whether patients with MS have cognitive fatigue.
authors: *London Health Sciences Center, London, Ontario, Canada Departments of †Clinical Neurological Sciences ‡Health and Rehabilitation Sciences, University of Western Ontario, London, Ontario, Canada.
authors: Sarah A
authors: SA
authors: Morrow
authors: Heather
authors: H
authors: Rosehart
authors: Andrew M
authors: AM
authors: Johnson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003071:Cognition; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000523:psychology*; D009483:Neuropsychological Tests; D012720:Severity of Illness Index