Auditory Functions in Raised Intracranial Pressure

A study of auditory functions was made in 25 cases of raised intracranial tension. It was noted that an average loss of 30 dB could occur due to raised intracranial pressure and that this improves after the return of normal pressure in the cranium, as seen in 16 cases submitted to surgery. Audiometric examination has been found to be a valuable diagnostic investigation in cases of raised intracranial tension. Whilst dealing with rather advanced cases of intracranial space-occupying lesions our neurosurgical colleagues were struck by a high incidence of symptoms referable to VIII nerve even when the cause or raised intracranial pressure was away from this nerve. We, therefore, instituted a collaborative study of the effects of raised intracranial pressure on cochlear and vestibular functions. During the last year we have studied 60 patients but for the purpose of this report we have selected first 25 cases to illustrate that the clinical impression finds significant confirmation from otoneuro-logical investigations. The auditory function tests revealed a significant impairment, although routine tests for vestibular functions (caloric test, rotation test, Fukuda's writing test and Fukuda's stepping test) were not much altered. This report, therefore, is restricted to the study of auditory functions only. Presented at the Scientific session of the annual conference of the Association of Oto-laryngologists of India, held at Poona in January 1967. This work was supported by a grant from the Council of Scientific and Industrial Research of India.