[Brainstem acoustic evoked potentials in children with developmental disabilities--a useful tool for differential...

In a retrospective study brainstem acoustic evoked potentials (BAEP) were evaluated in 222 children with psychomotor retardation or dysmorphic signs. Registrations were done, when no clear response to acoustic stimuli of medium intensity (60-80 dBA) could be obtained during clinical examination. Only 118 children (53%) had normal BAEP. 50 patients (22%) suffered from hearing impairment. 39 children (17%) showed disturbances of neuronal conduction. In 15 cases (7%) a combination of both conditions occurred. The mean age of our children with hearing impairment was 33.1 months, no case having been diagnosed before. In 57% the impairment was of the conductive type with an amount of less than 40 dB nHL This type was predominant in children with skeletal dysplasias (43%), chromosomal aberrations (43%) and malformation syndromes (40%). Severe hearing deficits of the sensorineural type with more than 69 dB nHL were found in children with malformation syndromes (28%), perinatal injuries (23%) and cns malformations (16%). As far as reference data were available, the hearing impairment in the BAEP was confirmed in 92% by our pedaudiologists. As a consequence hearing aids were first prescribed in 10 children, their medium age being 33.6 months. In 18 cases grommets were inserted. 9 children required paracentesis and 4 adenotomy. Disturbances of neuronal conduction with increased interpeak latencies and deformed potentials were predominantly found in the group of children with neurometabolic diseases (67%) and cns malformations (32%). Early diagnosis of hearing impairment in children with psychomotor retardation remains a problem as it is in the general population. More attention in clinical examination and appropriate screening is necessary. BAEP provide a powerful tool for hearing screening and additional information for differential diagnosis especially in children with neurometabolic diseases.