Evaluating the Incidence of Audiological Derangement in Cases of Thyroid Hormone Imbalance

Thyroid hormone disorders are both congenital as well as acquired. According to a projection from several studies on thyroid diseases, it has been estimated that about 42 million people in India suffer from various kind of thyroid diseases (1) Thyroid hormone is closely associated with the development of the cognitive functions, thus deficiency of this hormone is said to have effect an overall impact on proper functioning of the body. The normal functioning of the thyroid gland and adequate levels in the blood are Needed for the formation and functioning of the middle ear, inner ear and the central auditory pathway. Thus, congenital hypothyroidism (CH) can be a potential risk factor for hearing impairment (2) if the hormones decrease or are absent during the development of the peripheral and central auditory system structures. This study was undertaken with the objective of studying the pattern of hearing loss in patients who have a deranged thyroid profile. The study was conducted among 50 patients who were known cases of thyroid disorder in the Otorhinolaryngology Department of our institute. The study was hospital based observational clinical study. The patients were subjected to thyroid profile test After this, those who satisfied the inclusion and exclusion criteria and were included, after detailed history and examination, patients were subjected to PTA, hearing loss was classified according to WHO guidelines. The age group of the patients was from 30-55 yrs. with the mean age being 42. On the basis of the t3, t4 and tsh levels, in the current study out of 50 patients,40 were hypothyroid (80%),with male to female ratio of 6:4. On pure tone audiometry, 15 patients had decreased hearing. The other 25 had normal hearing. The incidence of hearing loss in hypothyoroid patients in our study is 37.5%. On analaysis the PTA reports of these patients,9 patients (22.5%) had conductive hearing loss of mild variety, the mean value of hearing loss being 26.2 decibels. 2 (5%) patients had mixed variety of hearing loss, with sensorineural hearing loss at higher frequencies. All the remaining patients had sensorineural type of hearing loss, i.e., 10%. Of the 10 patients, that have hyperthyroidism 8 were female and 2 were male. 3 patients (30%) had hearing loss, all these 3 patients reported hearing losses at high frequencies and had moderate type of sensorineural hearing loss. Conclusion- From our current study, we could see that hearing loss is present in both extremes of thyroid hormone imbalance The dominant variety of hearing loss in thyroid disorder is sensorineural type, because thyroid hormone imbalance affects the inner ear function.