Hearing Loss in Patients with Osteogenesis ImperfectaA Clinical and Audiological Study of 201 Patients

Abstract

Clinical otological features, hearing status and middle ear function in 201 patients with osteogenesis imperfecta are presented. The study covered 76% of the expected total number of patients with osteogenesis imperfecta in Denmark. 78% of the patients exhibited an autosomal dominant inheritance pattern with an almost 100% penetrance. In 39% of the ears examined, a conductive or mixed hearing loss was found. Sensorineural hearing loss or anacusis was seen in 11% of the ears. In most cases the onset of hearing impairment was noted in the second or third decade and progressing with increasing age, especially after the age of 60. Tympanometry and acoustic reflex measurements suggested that the cause of conductive or mixed hearing loss was stapedial fixation and in a few cases ossicular discontinuity due to aplasia or fracture of the stapedial crura. Findings during stapedectomy in 32 patients confirmed these assumptions.

Hearing loss in children with osteogenesis imperfecta

“…The onset may also occur in the ®rst decade. Cox and Simmons [5] observed a mild conductive type of hearing loss in a 9-year-old boy with normal tympanograms and Pedersen found ®ve children with conductive hearing loss in the ®rst decade [11]. Sensorineural hearing loss may also occur in children.…”

“…The hearing loss in OI is predominantly of the conductive type. The onset coincides closely with the time of life with the frequency of fractures decreasing in the late second decade of life [2,5,7,11,13]. The onset may also occur in the ®rst decade.…”

“…A population study of 201 Danish patients including all types of OI was carried out by Pedersen in 1984 [11]. Conductive hearing loss was observed in 22% of the children in the age group 4±9 years and a mainly conductive hearing loss in 28% in the age group 10±19 years; however, the median age at the onset of hearing loss was 25 years.…”

“…Normal hearing in children was de®ned as PTA 0.5±2 kHz equal to or better than 20 dB hearing level (HL). A de®nition for dierent types of hearing loss paralleling de®nitions given by Shapiro et al [14] and Pedersen [11] was used. Conductive hearing loss was de®ned as an average air-bone-gap for the frequencies 0.5, 1 and 2 kHz greater than 15 dB with corresponding bone conduction threshold better than 15 dB.…”

“…OI is most often caused by mutations in one of the two genes COL1A1 and COL1A2 that encode the synthesis of type I collagen [4]. The minimum prevalence of OI is estimated to be 1/10 000±1/30 000 [4,8,11]. Variable severity of clinical expression, non-reporting, and lack of patient registers are probably the major reasons for biased prevalence ®gures [4].…”