title: [Reference values for the vestibulo-ocular reflex response to the head shaking and the bithermal caloric tests].
abstract: OBJECTIVE
  To obtain reference values for the vestibulo-ocular reflex response to the head-shaking nystagmus and the bithermal caloric test in the spanish population.
  
  
  METHODS
  
  
  
  METHODS
  A descriptive study. SET UP: General hospital.
  
  
  METHODS
  One hundred and seven healthy sex and age stratified voluntiers were included. The final sample included 97 individuals over 18 years of age.
  
  
  METHODS
  Spontaneous nystagmus (SN), head-shaking nystagmus (HSN) and caloric induced nystagmus were explored. The eyes movement was recorded by a video-oculographic system. The SN or HSN was considered significant when at least 6 consecutive beats with a slow phase velocity of 2 degrees/sec were detected. The caloric test was performed with water flow at 250mL/20 s at 30 degrees C and 44 degrees C with an interval of 10 minutes between irrigations. The percentage of canal paresis (CP) and directional preponderance (DP) was calculated using maximum slow phase velocity and the Jongkees index formula.
  
  
  METHODS
  Presence of SN, horizontal and vertical SHN, percentage of CP and DP.
  
  
  RESULTS
  SN was found in 10,3% individuals (6 women and 4 men). Horizontal HSN was also observed in 9 women and 10 men (19,5%), and vertical HSN in 8 women and 10 men (18,6%). The mean and 95 percentil for CP were 13,10 and 28,60 in women and 11,02 and 27,30 in men. For DP, the mean and 95 percentil were 11,76 and 35,80 in women and 11,58 and 28,65 in men. The 5 percentils for slow phase velocity of nystagmus after each irrigation were 6,30; 5,14; 5,96; 4,02 degrees/s (left ear 44 degrees, right ear 44 degrees, left ear 30 degrees, right ear 30 degrees, respectively) in the group of women; and 5,82; 6,99; 5,67; 4,55 degrees/s in men (with the same irrigation sequence).
  
  
  CONCLUSIONS
  Results presented should be considered as a population-based norms and may be useful as references for water bithermal test for VOG studies. The SN or HSN could be observed in subjects without vestibular pathology.
authors.affiliation: Grupo de Otología y Otoneurología, CTS495, Unidad de Otorrinolaringología, Area de Cirugía, Hospital de Poniente de Almería, El Ejido, Almería.
authors.forename: M I
authors.initials: MI
authors.lastname: Molina
authors.forename: C
authors.initials: C
authors.lastname: Zapata
authors.forename: M J
authors.initials: MJ
authors.lastname: Palma
authors.forename: J A
authors.initials: JA
authors.lastname: López-Escámez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002150:Caloric Tests; D004584:Electronystagmography; D005260:Female; D006257:Head / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D009760:Nystagmus, Physiologic / Q000502:physiology*; D012016:Reference Values; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012720:Severity of Illness Index; D014743:Videotape Recording