The role of summating potential in the diagnosis and management of Menière's disease.
To assess the role of a negative summating potential (-SP) in the clinical diagnosis and management of Menière's disease, the relationship of -SP abnormality to clinical symptoms, hearing level and caloric test results was examined in 70 patients with unilateral Meniere's disease. The click-induced -SP and action potential (AP) were recorded by extratympanic electrocochleography. When SP/AP ratio exceeded 0.43, the -SP was considered to be abnormal. No significant relationship was found between abnormal -SP and clinical symptoms (the duration of cochlear and vestibular symptoms, recent hearing fluctuation and recent vertigo attack). Ears with abnormal -SP had a significantly worse hearing loss at high frequencies (2-8 kHz) than ears with normal -SP, whereas there was no significant difference in hearing loss at low frequencies (0.25-1 kHz) between both ears. No significant relation was found between abnormal -SP and abnormal unilateral weakness in caloric test. The results indicate that the click-induced -SP reflects the pathophysiology of Menière's disease basically in the cochlear partition at high frequencies.
Mori
N
N
Department of Otolaryngology, Kagawa Medical School, Japan.
Asai
H
H
Sakagami
M
M
D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001300:Audiometry, Evoked Response / Q000379:methods; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D002150:Caloric Tests; D003051:Cochlea / Q000503:physiopathology; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006309:Hearing / Q000502:physiology; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D008875:Middle Aged; D014722:Vestibule, Labyrinth / Q000503:physiopathology