Hearing loss in multiple sclerosis patients

Multiple sclerosis is one of demyelinating disorder of CNS that is an uncommon cause of the sensorineural hearing loss. This study was done to determine the hearing loss in multiple sclerosis patients. This case-control study was performed on 60 (44 women, 16 men) multiple sclerosis patients and 38 (27 women, 11 men) normal subjects by pure tone audiometery, otoacustic emissions and auditory brainstem responses in Gilan provine, Iran during 2010-11. Data was analyzed by using SPSS-17, Chi-Square and Fischer tests. 12.5% of case and 3.9% of the control ears had abnormal pure tone audiometery (P<0.05). The frequencies of abnormal HF-pure tone audiometery and two modalities of otoacustic emission did not show any significant differences in two groups. Abnormal autidory brainstem response of ears were observed in 20% and 9.2% of cases and controls, respectively (P<0.05). 20% of case and 9.2% of the control ears had abnormal auditory brainstem response (P<0.05). The absolute latencies of waves I, II and V had not significant differences between two groups. Inter peak latencies of I-III and III-V waves were observed in 10% and 11.7% in cases ears and 1.3% and zero percent in controls, respecticely. 6.7% of cases and 2.6% of control ears had retrocochlear abnormality. Hearing loss detected by pure tone audiometery and auditory brainstem response is more common in multiple sclerosis compared to normal population.