Auditory-evoked response analysis in Brazilian patients with sickle cell disease

Abstract

The objective of the present study was to evaluate the integrity of the peripheral and central auditory systems of sickle cell disease (SCD) patients, through electrophysiological evaluation utilizing auditory evoked potentials, and comparing the results obtained in SCD patients with individuals without SCD. A total of 80 individuals were evaluated: 40 SCD patients; and 40 healthy age- and sex-matched controls. Brainstem auditory evoked response (BAER) was used to check neural integrity and electrophysiological thresholds, and cognitive potential (P300) to analyse the auditory selective attention. Despite the exclusion of individuals with comorbidities typical of SCD, the predominance of hearing loss among the patients was detected in 16 ears (20%). The absolute latencies of the BAER were within the expected range but the SCD group showed a small but statistically significant reduction of the interpeaks I-V, indicative of cochlear alteration. P300 latency and amplitude were adequate for both groups suggesting the absence of central auditory system abnormalities. The present findings suggest that SCD causes variable degree of cochlear abnormalities without evidence of neural problems.

Hearing loss in Angolan children with sickle‐cell disease

“…All the present study's hearing‐impaired SCD children had mild impairment in the speech range, and only two children had (unilateral) impairment of a moderate degree, which involved the low frequencies. In agreement with previous studies, the present study thus suggests that even though children in developing countries with SCD are at high risk for hearing handicaps, severe hearing impairment among young SCD patients is rare …”

“…and Mgbor and Emodi, as well as 6% from Kenya by Tsibulevskaya et al . and 12.5% from Brazil by de Castro Silva et al ., detected in samples of 33–80 SCD children/adolescents. The present study documented hearing loss already in young SCD children aged 5–7 years, corroborating the findings of Alabi et al .…”

“…These children's bone conduction thresholds were not measured in PTA, but neither their otoscopic nor tympanometric evaluations showed middle‐ear pathology. Previous studies have shown that sensorineural hearing loss occurs in children with SCD, probably due to anoxia of the inner ear structures during vaso‐occlusive crises: involvement of both high and low frequencies have been described. Because a hearing handicap in the speech range endangers the child's ability to communicate, such a handicap requires prompt rehabilitation.…”

“…In SCD patients, repeated periods of inadequate circulation due to vaso‐occlusion in the cochlear region may cause progressive deterioration of hearing . In developing countries, the reported rate of bilateral hearing loss among children with SCD ranges from 6% to 27.5% (Table ) . In addition, such patients suffer from splenic dysfunction and susceptibility to pneumococcal infections, which may also increase the prevalence of otitis media.…”

Auditory processing disorder evaluations and cognitive profiles of children with specific learning disorder

“…When the child had difficulty counting, the evaluator followed the hand signaling coincident with the presentation of the deviant stimuli during the execution of the exam. Both tests were conducted in non-sedated subjects in a comfortable reclining position, utilizing the Navigator (Biologic Systems) coupled to a computer, with silver surface electrodes placed in positions based on the International 10–20 System ( Klem et al, 1999 ): an active electrode in Fz, two reference elements A1 and A2 and a ground electrode in Fpz3 was used ( Silva et al, 2010 ). The potential P1, N1, P2, N2 and P3 were analyzed.…”