Auditory Involvement in Thalassemia Major

Abstract

The auditory function of 75 children affected by homozygous β°-thalassemia, managed with a low transfusion scheme and treated irregularly with low doses of desferrioxamine, and of 75 controls were examined. In 12 patients a mild bilateral conductive hearing impairment due to bony hypertrophy and/or adenoid hypertrophy was found. In 43 cases a moderate monolateral or bilateral sensory-neural hearing loss at high frequencies with recruitment phenomenon was observed. Ferritin levels were determined in a randomly chosen group of these patients with (14) and without hearing loss (11). In the subjects with sensory-neural hearing loss the mean ferritin levels were significantly higher than in those with no hearing defect. There was no obvious relation between sensory-neural damage on the one hand and Hb levels and unit of blood transfused on the other. The results of this study suggest that iron overload could be a cause of damage in the high frequency elements of the auditory mechanism. Intermittent hypoxia and slow 8th nerve compression due to bony hypertrophy as causes of auditory involvement are also discussed.

Brainstem auditory evoked potentials features in thalassemia major

“…From 57.33% patients with sensorineural hearing impairment, bilateral hearing impairment was found in 41.33% patients and unilateral hearing impairment in 16% patients. 4 Hearing impairment was mostly found in age group between 7 to 12 years, nine patients (13.9%), with means 9.9 (SD 4.5) years. Argioulu et al found hearing impairment in 15.5% patients with mean 11.5 (SD 3) years, 6 Kontzoglou et al demonstrated mean 9.66 (SD 3.1) years, 18 and Gallant demonstrated mean 12 years.…”

“…Gallant et al demonstrated mild hearing impairment in 7.86% patients and moderate hearing impairment in 16.85% patients, 8 whereas other investigator demonstrated moderate hearing impairment in all of their patients. 4 Regarding to sex proportion, males were close to females in proportion (DeVirgilis 4 and Bentur).…”

“…Argioulu et al found hearing impairment in 15.5% patients with mean 11.5 (SD 3) years, 6 Kontzoglou et al demonstrated mean 9.66 (SD 3.1) years, 18 and Gallant demonstrated mean 12 years. 4,19 In the current study, the causal factor of hearing impairment was not investigated.…”

“…4 In this study, the youngest of age can not be determine because we limited the age of patient between 3 to 18 years.…”

“…3 Hearing impairment in thalassemia is generally correlated to chronic anemia, 4 iron overload, 4-6 extramedullary hematopoiesis, 7 and the side effect of desferoxamine chelation therapy. 6,[8][9][10][11][12] Various diagnostic tools are used to detect hearing impairment, one of them is brainstem auditory evoked potential (BAEP).…”