title: Evaluation of neurologic function in Gulf War veterans. A blinded case-control study.
abstract: OBJECTIVE
  To determine whether Gulf War-related illnesses are associated with central or peripheral nervous system dysfunction.
  
  
  METHODS
  Nested case-control study.
  
  
  METHODS
  Twenty-three veterans with factor analysis-derived syndromes (the cases), 10 well veterans deployed to the Gulf War (the deployed controls), and 10 well veterans not deployed to the Gulf War (the nondeployed controls).
  
  
  METHODS
  With investigators blinded to group identities, participants underwent objective neurophysiological, audiovestibular, neuroradiological, neuropsychological, and blood tests.
  
  
  METHODS
  Evidence of neurologic dysfunction.
  
  
  RESULTS
  Compared with the 20 controls, the 23 cases had significantly more neuropsychological evidence of brain dysfunction on the Halstead Impairment Index (P=.01), greater interside asymmetry of the wave I to wave III interpeak latency of brain stem auditory evoked potentials (P=.02), greater interocular asymmetry of nystagmic velocity on rotational testing, increased asymmetry of saccadic velocity (P=.04), more prolonged interpeak latency of the lumbar-to-cerebral peaks on posterior tibial somatosensory evoked potentials (on right side, P=.03, and on the left side, P=.005), and diminished nystagmic velocity after caloric stimulation bilaterally (P values range from .02 to .04). Cases (n=5) with syndrome 1 ("impaired cognition") were the most impaired on brain stem auditory evoked potentials (P=.005); those (n=13) with syndrome 2 ("confusion-ataxia") were the most impaired on the Halstead Impairment Index (P=.006), rotational testing (P=.01), asymmetry of saccadic velocity (P=.03), and somatosensory evoked potentials (P< or =.01); and those (n=5) with syndrome 3 ("arthro-myo-neuropathy") were the most impaired on caloric stimulation (P< or =.01).
  
  
  CONCLUSIONS
  The 3 factor-derived syndromes identified among Gulf War veterans appear to represent variants of a generalized injury to the nervous system.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, 75235-8874, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Haley
authors.forename: J
authors.initials: J
authors.lastname: Hom
authors.forename: P S
authors.initials: PS
authors.lastname: Roland
authors.forename: W W
authors.initials: WW
authors.lastname: Bryan
authors.forename: P C
authors.initials: PC
authors.lastname: Van Ness
authors.forename: F J
authors.initials: FJ
authors.lastname: Bonte
authors.forename: M D
authors.initials: MD
authors.lastname: Devous
authors.forename: D
authors.initials: D
authors.lastname: Mathews
authors.forename: J L
authors.initials: JL
authors.lastname: Fleckenstein
authors.forename: F H
authors.initials: FH
authors.lastname: Wians
authors.forename: G I
authors.initials: GI
authors.lastname: Wolfe
authors.forename: T L
authors.initials: TL
authors.lastname: Kurt
mesh_terms: D000328:Adult; D001259:Ataxia; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D016022:Case-Control Studies; D002493:Central Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D003072:Cognition Disorders; D005071:Evoked Potentials; D006403:Hematologic Tests; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D009759:Nystagmus, Pathologic; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D018923:Persian Gulf Syndrome / Q000175:diagnosis / Q000453:epidemiology; D015899:Tomography, Emission-Computed, Single-Photon; D014481:United States / Q000453:epidemiology; D014724:Vestibular Function Tests; D014728:Veterans