Iranian Journal of Pediatrics
Tehran University of Medical Sciences Press
Vol. 22, No. 1, 2012, pp. 92-96
Bioline Code: pe12015
Full paper language: English
Document type: Research Article
Document available free of charge
Iranian Journal of Pediatrics, Vol. 22, No. 1, 2012, pp. 92-96
© Copyright 2012 - Iran Journal of Pediatrics
Hearing Impairment in Congenitally Hypothyroid Patients|
Hashemipour, Mahin; Hovsepian, Silva; Hashemi, Mostafa; Amini, Massoud; Kelishadi, Roya & Sadeghi, Somaye
Objective: Thyroid hormone is necessary for normal development of the auditory system. The aim of this
study was to investigate the rate of hearing impairment in congenitally hypothyroid (CH) patients, and its
relation with factors such as CH severity and age at starting treatment, during CH screening program in
Methods: Hearing acuity was assessed in two groups of children with (94 patients aged 4 months – 3 years)
and without CH (450), between 2000-2006. Otoacostic emission (OAE) was performed by a two step method.
After two tests without OAE signals bilaterally, they were referred for auditory brainstem response (ABR)
test. Subjects with both OAE and ABR abnormal test results were considered to have hearing problem.
Obtained data was compared in case and control group and also CH patients with and without hearing
Findings: Three (3.2%) of patients and 1 of control group (0.2%) were diagnosed with sensorineural hearing
loss. The rate of hearing loss was not different significantly in two studied groups (P>0.05). There was no
difference between age of starting treatment and first T4 and TSH level in CH patients with and without
hearing loss (P>0.05). CH neonates with hearing impairment had thyroid dyshormonogenesis according to the
follow up results.
Conclusion: The rate of hearing loss was low among our studied CH patients. It may be due to proper
management of CH patients. In view of the fact that all CH neonates were dyshormonogentic and considering
the relation between certain gene mutations and hearing impairment in CH patients, further studies with
larger sample size, with regard to different etiologies of CH should be investigated to indicate the possible
gene mutations related to hearing loss in CH.
Hearing impairment; Auditory Brain Stem Response; ABR; Oto Acostic Emission; OAE
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