title: Characterising eye movement dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome.
abstract: BACKGROUND
  People who suffer from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report that their eye movements are sluggish and that they have difficulties tracking moving objects. However, descriptions of these visual problems are based solely on patients' self-reports of their subjective visual experiences, and there is a distinct lack of empirical evidence to objectively verify their claims. This paper presents the first experimental research to objectively examine eye movements in those suffering from ME/CFS.
  
  
  METHODS
  Patients were assessed for ME/CFS symptoms and were compared to age, gender, and education matched controls for their ability to generate saccades and smooth pursuit eye movements.
  
  
  RESULTS
  Patients and controls exhibited similar error rates and saccade latencies (response times) on prosaccade and antisaccade tasks. Patients showed relatively intact ability to accurately fixate the target (prosaccades), but were impaired when required to focus accurately in a specific position opposite the target (antisaccades). Patients were most markedly impaired when required to direct their gaze as closely as possible to a smoothly moving target (smooth pursuit).
  
  
  CONCLUSIONS
  It is hypothesised that the effects of ME/CFS can be overcome briefly for completion of saccades, but that continuous pursuit activity (accurately tracking a moving object), even for a short time period, highlights dysfunctional eye movement behaviour in ME/CFS patients. Future smooth pursuit research may elucidate and improve diagnosis of ME/CFS.
authors.affiliation: School of Psychology, College of Medicine, Biological Sciences and Psychology, University of Leicester, Leicester, UK, s.p.badham@warwick.ac.uk.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Badham
authors.forename: Claire V
authors.initials: CV
authors.lastname: Hutchinson
mesh_terms: D000328:Adult; D000368:Aged; D053483:Eye Movement Measurements; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000503:physiopathology*; D012438:Saccades / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
references.citation: Biol Psychiatry. 1991 May 15;29(10):1001-15
references.pmid: 2065136
references.citation: Brain Cogn. 2008 Dec;68(3):359-70
references.pmid: 18845372
references.citation: Biol Psychiatry. 1995 Mar 15;37(6):394-401
references.pmid: 7772648
references.citation: Neuroimage. 2007 May 15;36(1):108-22
references.pmid: 17408973
references.citation: Psychol Med. 2010 Aug;40(8):1253-67
references.pmid: 20047703
references.citation: Psychosom Med. 2008 Sep;70(7):829-36
references.pmid: 18606722
references.citation: Neuroimage. 2005 Jun;26(2):513-24
references.pmid: 15907308
references.citation: J Intern Med. 2011 Oct;270(4):327-38
references.pmid: 21777306
references.citation: Psychiatry Res. 2010 Feb 28;181(2):155-64
references.pmid: 20006474
references.citation: Optom Vis Sci. 1996 Jan;73(1):49-53
references.pmid: 8867682
references.citation: Eur J Clin Invest. 2010 Jul;40(7):608-15
references.pmid: 20497461
references.citation: Psychol Med. 1999 Jan;29(1):73-85
references.pmid: 10077295
references.citation: Psychol Aging. 2004 Mar;19(1):211-4
references.pmid: 15065945
references.citation: Autoimmun Rev. 2009 Feb;8(4):287-91
references.pmid: 18801465
references.citation: J Int Med Res. 2008 Sep-Oct;36(5):867-74
references.pmid: 18831878
references.citation: Neuropsychopharmacology. 2006 Aug;31(8):1777-84
references.pmid: 16395303
references.citation: Optom Vis Sci. 1992 Oct;69(10):811-4
references.pmid: 1437004
references.citation: J Int Neuropsychol Soc. 1998 Sep;4(5):456-66
references.pmid: 9745235
references.citation: Ann Intern Med. 1994 Dec 15;121(12):953-9
references.pmid: 7978722
references.citation: Prim Care Companion J Clin Psychiatry. 2008;10(2):120-8
references.pmid: 18458765
references.citation: Brain Cogn. 2008 Dec;68(3):341-58
references.pmid: 18842328
references.citation: Psychophysiology. 2001 Mar;38(2):325-33
references.pmid: 11347877
references.citation: J Eval Clin Pract. 2012 Feb;18(1):25-31
references.pmid: 21029269