The Vestibular Aqueduct in Patients with Menière's Disease A Tomographic and Clinical Investigation

Abstract

The vestibular aqueduct was identified on tomograms in all healthy subjects. In patients with severe Menière's disease the visibility was affected. The aqueduct was visible in 65% of the non-diseased ears and in 59% of the diseased ears of patients with unilateral Menière's disease, whereas the corresponding figure for bilaterally diseased ears was only 53%. Longstanding disease can impair the visibility, while it does not seem to be affected by advanced age per se No obvious relationship was found between the visibility on tomograms and the results of hearing tests and caloric tests. The vestibular aqueduct is shorter in patients with Menière's disease than in healthy subjects. The pneumatization of the pyramid, which varies in normal individuals as well as in patients with Menière's disease, influences the length of the aqueduct. The longest aqueducts in healthy subjects were found in those with large cell pneumatization in the vicinity of the aqueduct. Most patients with Menière's disease lacked pneumatization of the pyramid, and the shortest aqueducts were found amongst them. The vestibular aqueduct and the adjacent para-vestibular canaliculus have been demonstrated by means of plastic moulding. Minute communicating channels, probably housing parts of the blood supply to the endolymphatic duct and sac, have been revealed. The para-vestibular canaliculus, which lies at the borderline of the tomo-graphically demonstrable structures, could be discerned in the tomograms of 10 of the 32 ears of healthy individuals and 10 of the 86 ears of patients with Menière's disease.