title: Relation of quantitative visual and neurologic outcomes to fatigue in multiple sclerosis.
abstract: BACKGROUND
  The relation of fatigue in multiple sclerosis (MS) to the visual system, an emerging structural and functional surrogate in MS, has not been well established.
  
  
  OBJECTIVE
  We examined how physical and cognitive fatigue could be associated with visual dysfunction and neurologic impairment.
  
  
  METHODS
  At a single time-point, we assessed 143 patients with: Low-contrast letter acuity (LCLA) and high-contrast visual acuity (VA) testing, the 25-Item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) and Neuro-Ophthalmic Supplement, the Modified Fatigue Impact Scale (MFIS), the MS Functional Composite (MSFC), and the Expanded Disability Status Scale (EDSS).
  
  
  RESULTS
  Worse binocular LCLA scores were associated with increased levels of total and physical fatigue (p≤0.026). Greater levels of fatigue were also associated with reduced vision-specific QOL (p<0.001). Patients with more physical, but not cognitive, fatigue had greater levels of impairment by the Timed 25-Foot Walk (T25W, r=0.39, p<0.001), 9-Hole Peg Test (9HP r=0.22, p=0.011) and EDSS (r=0.45, p<0.001).
  
  
  CONCLUSIONS
  Reduced vision in MS is highly associated with physical fatigue and could be used to capture more global, difficult to describe, symptoms. The potential differences in physical vs. cognitive fatigue and their correlates may begin to provide insight into their underlying mechanisms.
authors.affiliation: Department of Neurology, University of Pennsylvania, 3400 Spruce St. 3. W. Gates, Philadelphia, PA 19104, USA. Electronic address: salim.chahin@uphs.upenn.edu.
authors.forename: Salim
authors.initials: S
authors.lastname: Chahin
authors.affiliation: Department of Neurology, Cleveland Clinic Foundation, 1950 E 89th St, Cleveland, OH 44106, USA. Electronic address: millerd@ccf.org.
authors.forename: Deborah
authors.initials: D
authors.lastname: Miller
authors.affiliation: University of Vermont College of Medicine, 89 Beaumont Ave, Burlington, VT 05405, USA. Electronic address: reiko.sakai@med.uvm.edu.
authors.forename: Reiko E
authors.initials: RE
authors.lastname: Sakai
authors.affiliation: Department of Neurology, University of Pennsylvania, 3400 Spruce St. 3. W. Gates, Philadelphia, PA 19104, USA. Electronic address: jawilson@mail.med.upenn.edu.
authors.forename: James A
authors.initials: JA
authors.lastname: Wilson
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA. Electronic address: Teresa.Frohman@UTSouthwestern.edu.
authors.forename: Teresa
authors.initials: T
authors.lastname: Frohman
authors.affiliation: Department of Neurology, University of Pennsylvania, 3400 Spruce St. 3. W. Gates, Philadelphia, PA 19104, USA. Electronic address: cmarkowi@mail.med.upenn.edu.
authors.forename: Clyde
authors.initials: C
authors.lastname: Markowitz
authors.affiliation: Department of Neurology, University of Pennsylvania, 3400 Spruce St. 3. W. Gates, Philadelphia, PA 19104, USA. Electronic address: Dina.Jacobs2@uphs.upenn.edu.
authors.forename: Dina
authors.initials: D
authors.lastname: Jacobs
authors.affiliation: Department of Neurology, University of California at San Francisco, 1500 Owens St #320, San Francisco, CA 94158, USA. Electronic address: agreen@ucsf.edu.
authors.forename: Ari
authors.initials: A
authors.lastname: Green
authors.affiliation: Department of Neurology, Johns Hopkins School of Medicine, 600 N. Wolfe St, Baltimore, MD 21287, USA. Electronic address: pcalabr1@jhmi.edu.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Calabresi
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA. Electronic address: Elliot.Frohman@UTSouthwestern.edu.
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
authors.affiliation: Department of Neurology, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY 10016, USA. Electronic address: Steven.Galetta@nyumc.org.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Galetta
authors.affiliation: Departments of Neurology and Population Health, New York University School of Medicine, 240 East 38th Street, 20th Floor, New York, NY 10016, USA. Electronic address: Laura.Balcer@nyumc.org.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000150:complications / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005221:Fatigue / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000503:physiopathology*; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000150:complications / Q000503:physiopathology*; D014792:Visual Acuity
keywords: Disability; Fatigue; Low-contrast acuity; Multiple sclerosis; Quality of life; Vision