Kohichiro Shigeno

Interferon-lnduced Sudden Hearing Loss: Original Paper

With the increasing long-term use of interferon (IFN), several new adverse effects have been recognized. Very little attention, however, has been paid to auditory acuity. We encountered 3 cases of sudden hearing loss associated with IFN. We then co nducted a prospective study to assess the auditory function of 73 patients receiving IFN. Auditory disability (tinnitus and/or hearing loss) occurred in 32 patients (43.8%) during IFN therapy, among which audiometry documented sensorineural hearing loss in 27 cases (36.9%); 17 (48.6%) of the 35 patients receiving IFN-β had auditory disability, including hearing loss in 13 cases (37.1%), and 15 (39.5%) of 38 patients receiving IFN-α suffered from auditory disability. There was not much difference between the influences of IFN-α and -β. Auditory disability frequently developed in the later stages of treatment, and most patients recovered 7-14 days after the discontinuation of IFN. The results demonstrate that sudden hearing loss can occur as a side effect of trea...With the increasing long-term use of interferon (IFN), several new adverse effects have been recognized. Very little attention, however, has been paid to auditory acuity. We encountered 3 cases of sudden hearing loss associated with IFN. We then conducted a prospective study to assess the auditory function of 73 patients receiving IFN. Auditory disability (tinnitus and/or hearing loss) occurred in 32 patients (43.8%) during IFN therapy, among which audiometry documented sensorineural hearing loss in 27 cases (36.9%); 17 (48.6%) of the 35 patients receiving IFN-beta had auditory disability, including hearing loss in 13 cases (37.1%), and 15 (39.5%) of 38 patients receiving IFN-alpha suffered from auditory disability. There was not much difference between the influences of IFN-alpha and -beta. Auditory disability frequently developed in the later stages of treatment, and most patients recovered 7-14 days after the discontinuation of IFN. The results demonstrate that sudden hearing loss can occur as a side effect of treatment with IFN. This may reveal the association between autoimmunity and sudden hearing loss.

Otolith dysfunction during vertiginous attacks in Ménière's disease

Objective—Vertiginous attacks of Ménières disease (MD) are characterized by various types of vertigo, namely rotatory vertigo, dizziness and drop attack. When a patient complains of dizziness without spontaneous nystagmus, otolith dysfunction cannot be ruled out. The purpose of this study was to evaluate otolith dysfunction during vertiginous attacks of MD or delayed endolymphatic hydrops. Material and Methods—Vestibular function tests were carried out daily for several days in 11 patients (MD, n = 9; delayed endolymphatic hydrops, n = 2) during vertiginous attacks. Otolith function was evaluated by means of the static torsional position of both eyes [static ocular torsion (OT)] whilst in an upright position. We defined otolith dysfunction as an abnormal change (range) in OT without spontaneous nystagmus or as an abnormal change in OT without a change in spontaneous nystagmus. Results—Four patients had an abnormal change (range) in OT without spontaneous nystagmus or an abnormal change in OT without a change in spontaneous nystagmus during vertiginous attacks of MD. Conclusions—Otolith dysfunction occurs in patients during vertiginous attacks of MD. In cases of ataxia without spontaneous nystagmus, otolith dysfunction most likely causes atypical attacks of MD.

Positional Nystagmus due to Alteration of the Specific Gravity in the Labyrinth

Horizontal positional nystagmus having characteristics similar to ice water caloric nystagmus was induced by injecting heavy water into the rabbit middle ear cavity or facial nerve through the stylomastoid foramen. Furthermore, with general administration of glycerol to normal subjects, horizontal positional nystagmus as with general administration of heavy water to experimental animals was observed. It is possible that alteration of the specific gravity arising from infiltration of heavy water or glycerol into the labyrinth accounts for the manifestation of positional nystagmus. These studies on positional nystagmus may be one of the means to elucidate the mechanism of caloric nystagmus and to examine the function of the human blood-labyrinth-barrier.