Overview of Literature Regarding Incidence of AN/AD

Authors (Year)NAge GroupRisk FactorsSummary of Results
Starr et al2 (1996)104–49 yHeterogeneous: Charcot-Marie-Tooth syndrome (3), slight sensory-motor neuropathy (5), no signs of neuropathy (2); vestibular (2) and visual (2) dysfunction notedVariable pure-tone audiograms (mild [2], moderate [7], and severe [1]); variable speech-recognition abilities (range: could not test [2], 0% [2] to 8–92%); 8 of the 10 patients had evidence of a peripheral neuropathy; hearing dysfunction earliest and major complaint; no benefit from amplification
Rance et al8 (1999)201–49 moFamily history (38%); birth weight < 1500 g (18%); parental concern (14%); hyperbilirubinemia (> 350 μmol/L [9%]); congenital malformation (9%); birth asphyxia (5%); other (7%)AN/AD was significantly higher in their NICU population than had been reported previously in the literature; 15% of those infants diagnosed with AN/AD had no risk factors; tests of cochlear function (CM in particular) became standard practice for all infants with absent or abnormal ABRs; effects of AN/AD on auditory function are idiosyncratic and not predictable from tests currently available; estimated incidence of 0.23% within the at-risk population and 11% of children with SNHL
Madden et al7 (2002)18 with AN/AD; 4 of those with AN/AD had CIs; various degrees of hearing loss; 12 of the 18 in the severe-to-profound deficits range; age of implantation: 12–39 mo (mean: 25 mo)1–60 mo (mean: 17 mo)Prematurity; hyperbilirubinemia; family history (ie, 3 sets of siblings); ototoxic medications; cerebral palsyAll children with implants showed improvement in auditory (pure-tone thresholds) and verbal (ie, closed-set speech recognition) development within 5 mo; auditory dysfunction in these children suggests either inner hair cell or inner hair cell-cochlear junction pathology that can be remediated with CIs; incidence of AN/AD in their SNHL population since 1996 is 10%
Rance et al4 (2002)18 with AN/AD, 18 with SNHL6–92 moJaundice; hypoxia; hydrocephalus; meningitis; middle-ear malformationPure-tone results varied from mild to profound; 14 of 18 children with AN/AD were diagnosed with hearing loss by 6 mo of age; 18 of 18 children were fit with hearing aids between 12 mo (13 children) and 2 y (5 children); 16 of 18 children with AN/AD were initially placed in an auditory/oral early intervention program: 6 of 16 were transferred to a total communication program, 2 of 18 were enrolled in a total communication or “signed English” program from the start, and speech-perception results were obtained on 15 of 18 children, all with poor open-set abilities in the unaided condition (8.1%; range: 2–20%); 8 of 15 children with AN/AD demonstrated benefit from amplification (67.2%); no correlation was found between degree of loss and aided speech-perception abilities; event-related potentials were present in children with AN/AD who showed open-set speech-perception ability; when event-related potentials were absent, speech-perception abilities were <10% despite hearing loss of less than profound degree
Dunkley et al9 (2003)3Newborn–6 moHyperbilirubinemia; extreme prematurity and/or its complications; unknownNewborn hearing screening based solely on OAE technology will fail to detect possible AN/AD in at-risk and non-risk populations; ongoing surveillance is critical to identify AN/AD
Wang et al10 (2003)12 (10 males, 2 females) from 4 families8–24 yHereditaryHearing loss ranged from mild to profound, predominantly in the low frequencies; children presented at ∼10 y; poor word-recognition score; absent acoustic reflex thresholds and ABRs; DPOAEs within normal limits; normal vestibular function, computed tomography scans, and electrocardiograms in 3 patients who underwent these examinations; 4 nonsyndromic inheritance patterns found in the 4 families: X-linked, recessive in 1 family (6 males affected in 4 generations) and autosomal recessive in 3 families
  • CI indicates cochlear implant; SNHL, sensorineural hearing loss.