title: Relationship of CD4 counts to neurophysiological function in HIV-1--infected homosexual men.
abstract: OBJECTIVE
  To explore the relationship of immune dysfunction to neurophysiological measures of brain-stem conduction time.
  
  
  METHODS
  Three-year longitudinal prospective cohort study; results of time 1 analyses reported.
  
  
  METHODS
  San Francisco (California) General Hospital, Departments of Psychiatry and Epidemiology.
  
  
  METHODS
  Volunteer sample of 55 human immunodeficiency virus (HIV)-positive and 37 HIV-negative homosexual men recruited from a larger cohort of homosexual men followed up since 1983 at San Francisco General Hospital as part of an ongoing study of the natural history and course of HIV type 1 infection.
  
  
  METHODS
  None.
  
  
  METHODS
  Auditory brain-stem responses and somatosensory evoked potentials for subjects stratified separately on HIV serostatus, Centers for Disease Control and Prevention symptom groupings, and absolute CD4 counts.
  
  
  RESULTS
  The HIV-positive subjects had an increased wave III-V interpeak latency of the right ear auditory brain-stem response compared with the HIV-negative subjects (t test, P < .05). There were no significant differences among the three Centers for Disease Control and Prevention groupings on any evoked potential measure. When HIV-positive subjects were stratified on a measure of immune functioning, ie, CD4 counts, individuals with greater immune suppression were more impaired on speed of auditory brain-stem conduction time (Mann-Whitney U test, P < .05). Furthermore, 85% of subjects impaired on this evoked potential measure had CD4 counts of less than 0.40 x 10(9)/L (400/microL), whereas only 15% of those impaired on this measure had CD4 counts of greater than 0.40 x 10(9)/L.
  
  
  CONCLUSIONS
  Asymptomatic HIV-positive subjects who do not have evidence of immune suppression do not appear to be at greater risk for neurophysiological impairment than HIV-negative subjects. The HIV-positive individuals who are immune suppressed (even while asymptomatic) appear to have an increased likelihood of central conduction time slowing as measured by evoked potential procedures.
authors.affiliation: Department of Psychiatry, San Francisco General Hospital, CA 94110.
authors.forename: A A
authors.initials: AA
authors.lastname: Boccellari
authors.forename: J W
authors.initials: JW
authors.lastname: Dilley
authors.forename: C D
authors.initials: CD
authors.lastname: Yingling
authors.forename: D B
authors.initials: DB
authors.lastname: Chambers
authors.forename: M A
authors.initials: MA
authors.lastname: Tauber
authors.forename: A R
authors.initials: AR
authors.lastname: Moss
authors.forename: D H
authors.initials: DH
authors.lastname: Osmond
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology; D015496:CD4-Positive T-Lymphocytes; D005071:Evoked Potentials; D015658:HIV Infections / Q000276:immunology* / Q000503:physiopathology; D015497:HIV-1; D006716:Homosexuality; D006801:Humans; D007108:Immune Tolerance; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged