Twenty patients with thyroprivic hypothyroidism with a mean age of 34.8 years (range: 15-50 years) were investigated. Peripheral/central functions of the auditory system were assessed in the hypothyroid state and they were re-evaluated in the euthyroid state after treatment with levothyroxine. The mean observation period for re-evaluation was 3.7 months (range 3-7 months). Sixteen patients with hypothyroidism (80%) demonstrated hearing loss when compared with randomly selected age- and sex-matched normal subjects. Twelve of the hypothyroid patients had sensorineural hearing loss and 4 had mixed loss. Special hearing tests revealed a cochlear type of hearing loss. The tympanogram curve was of Type B in one ear of each of the 4 patients. Brainstem electric response audiometry showed prolonged, absolute latency of wave V and interpeak latencies I-III and I-V. The amplitudes of waves I, II and V were reduced. Following treatment with levothyroxine a statistically significant improvement in hearing thresholds was observed by pure-tone audiometry. Tympanogram curves returned to normal in 3 out of 4 patients. Brainstem electric response parameters did not show significant reversibility to normalcy following treatment. The results of auditory investigations suggest a causal relationship between hypothyroidism and hearing loss. The site of lesion in the auditory system is probably at several levels, viz. in the middle ear, and at cochlear and retrocochlear sites.
\s=b\ Congenital aural atresia poses a great challenge, even to a competent otologic surgeon, due to innumerable types of malformations affecting the conduction and perception of sound. Roentgenographic evaluation by plain roentgenography is inconclusive in most cases; polytomography is helping to some extent. Recent generations of high-resolution computed tomographic (CT) scanners are probably the best. Seven cases of unilateral and three cases of bilateral congenital aural atresia were evaluated with high-resolution CT. Subsequently, ten ears were operated on. Surgical findings were correlated with CT scan findings with respect to atresia plate, extent of pneumatization, ossicular anomalies, bony facial nerve canal, and inner ear.Use of CT scans bears considerable importance in the management of these types of cases. High-resolution CT scan, when targeted for maximal bony detail, is possibly the method of choice in congenital aural atresia when surgical correction is contemplated.
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