Hearing loss with craniofacial syndromes

Hearing loss with craniofacial syndromes is a common occurrence. Many of these multianomaly disorders involve structural malformations of the outer or middle ear, making a significant hearing loss highly likely.

Individuals with Treacher Collins syndrome often have both cleft palate and hearing loss, in addition to other disabilities. Hearing loss is often secondary to absent, small, or unusually formed ears (microtia), and commonly results from malformations of the middle ear. Researchers have found that most patients with Treacher Collins syndrome have symmetric external ear canal abnormalities and symmetrically dysmorphic or absent ossicles in the middle ear space. Inner ear structure is largely normal. Most patients show a moderate hearing impairment or greater, and the type of loss is generally a conductive hearing loss. Patients with Treacher Collins syndrome exhibit hearing losses similar to those of patients with malformed or missing ossicles (Pron et al., 1993).

Persons with Pierre Robin sequence (PRS) are at greater risk for hearing impairment than persons with cleft lip and/or palate without PRS. One study showed an average of 83% hearing loss in PRS, compared to 60% in cleft individuals without PRS (Handzic et al., 1995). Similarly, PRS individuals typically exhibit conductive, bilateral hearing losses that are greater in degree than in cleft individuals without PRS. Middle ear effusion is generally apparent, with no middle ear or inner ear malformations. Accordingly, management by ear tubes (myringotomy tubes) is often effective and may restore normal levels of hearing (Handzic et al., 1995).

The hearing loss most typical in patients with Stickler syndrome is a sensorineural hearing loss, indicating that the source of the deficit lies in the inner ear, the vestibulocochlear nerve, or the processing centers of the brain. Szymko-Bennett et al. (2001) found that the overall hearing loss in Type I Stickler Syndrome is generally mild and is not significantly progressive. Hearing loss is more common in the higher frequencies, from about 4000–8000 Hz (Szymko-Bennett et al., 2001). This mildly progressive sensorineural loss, or more significant losses (associated with Types II and III Stickler syndrome) is present in about 80% of patients with Stickler syndrome. However, other patients are also susceptible to conductive losses, similar to nonsyndromic cleft patients (Peterson-Falzone et al., 2001).

...
Wikipedia