title: Pressure transfer between intracranial and cochlear fluids in patients with Meniere's disease.
abstract: OBJECTIVE
  To elucidate the pressure transfer between intracranial and labyrinthine fluids in patients with well-defined unilateral Meniere's disease.
  
  
  METHODS
  Eleven patients previously exposed to hypobaric pressure agreed to be investigated further with the tympanic membrane displacement (TMD) technique. TMD was used to indirectly analyze perilymph pressure changes as the result of changes in body position.
  
  
  METHODS
  Repeated measurements for both the diseased and the healthy ears were made with the patients supine and then in a sitting position. The TMD parameters for the maximum inward displacement, the Vi, and the mean volume displacement, the Vm, were calculated and compared.
  
  
  RESULTS
  The paired comparison showed statistically significant larger Vi values for both ears in the supine position. A similar tendency was observed for the Vm value. This difference of the Vi was significantly larger for the diseased ear compared with the currently healthy ear. The results were compared to the audiometric and electrocochleographic results previously obtained on the same patients when they were subjected to hypobaric pressure. Patients who experienced the largest differences in hearing level thresholds in the lower frequencies also showed the greatest differences in TMD values as the result of postural changes.
  
  
  CONCLUSIONS
  Despite the limited number, the statistically supported results suggest a relation between the efficiency of the routes of pressure transfer and the observed effect of hypobaric exposure. The results also indicate that for the patients tested, the routes of communication are more effective in the diseased ear than in the healthy ear--a condition that may relate to the pathogeneses of Meniere's disease.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University Hospital Lund, Sweden. konrad.konradsson@onh.lu.se
authors.forename: K S
authors.initials: KS
authors.lastname: Konrádsson
authors.forename: L H
authors.initials: LH
authors.lastname: Nielsen
authors.forename: B I
authors.initials: BI
authors.lastname: Carlborg
authors.forename: B
authors.initials: B
authors.lastname: Borgkvist
mesh_terms: D000328:Adult; D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D005260:Female; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D007761:Labyrinthine Fluids / Q000502:physiology*; D008297:Male; D008575:Meniere Disease / Q000503:physiopathology*; D008875:Middle Aged; D011312:Pressure