The acute deafness of definite multiple sclerosis: BAEP patterns.

Area of Science:

• Neurology
• Neuro-otology
• Demyelinating Diseases

Background:

• Acute hearing loss is an infrequent symptom in multiple sclerosis (MS), occurring in approximately 3% of cases.
• This study investigates 12 patients with definite MS who experienced acute hearing loss during a relapse.

Purpose of the Study:

• To analyze the clinical and electrophysiological findings in patients with multiple sclerosis presenting with acute hearing loss.
• To determine the potential location of lesions responsible for hearing loss in MS using brain-stem auditory evoked potentials (BAEPs).

Main Methods:

• Retrospective analysis of 705 patients undergoing evoked potential recording over 5 years.
• Recording of brain-stem auditory evoked potentials (BAEPs) in 12 patients with definite MS and acute hearing loss.
• Comparison of BAEPs during acute relapse and post-relapse periods.

Main Results:

• 12 patients with definite MS experienced unilateral acute hearing loss during relapse, often with associated tinnitus.
• BAEP abnormalities were ipsilateral to the hearing loss during relapse.
• BAEPs showed significant improvement post-relapse in some patients, with persistent abnormalities on the affected side.
• Lesions may be located in the cochlear nerve or brain-stem entry zone.

Conclusions:

• Unilateral hearing loss in MS relapses is associated with BAEP abnormalities.
• BAEPs can aid in localizing auditory pathway lesions in MS.
• The cochlear nerve or brain-stem entry zone are likely sites for lesions causing hearing loss in MS.