Ears and hearing
Ears and hearing
Typically, individuals with CdLS have ears that are set lower, are hairy and are atypically formed. Some individuals may have small and narrow ear canals (ear canal stenosis) (101). Ear canal stenosis is associated with external ear and middle ear abnormalities, such as:
- Atypically formed small bones in the ear
- Impaired function of the cochlea (portion of the ear that receives sound vibrations and sends them to the brain to interpret)
- Impaired function of the vestibules (which are important for a person’s sense of balance)
- An inflamed middle ear (102,103)
Scans of the ear indicate that increased ear abnormalities are associated with a higher degree of hearing loss in CdLS (103). Hearing loss is very common in CdLS and occurs in 85-90% of individuals (101,104,105). Usually hearing loss in CdLS affects both ears. It is typically present from infancy and can range from mild to severe (101). Loss of hearing in CdLS can be caused by abnormalities in the inner ear (sensorineural hearing loss) and outer ear (conductive hearing loss) (105). Persistent middle ear infections (otitis media) often results in conductive hearing loss (101,104,106).
Ear infections and infection of the sinuses (sinusitis) are common problems in adults with CdLS (107). Regular eye (ophthalmologic) and ear, nose and throat (otolaryngologic) assessments are recommended (R40).
As hearing loss is common in CdLS, all individuals should have their hearing assessed at an early age and hearing assessments should continue long-term (R39). Individuals with CdLS often find it difficult to have their ears inspected and sometimes sedation may be needed. Initial auditory assessment should test a person’s ability to hear sounds (standard audiometric testing) and how well the inner ear is working (otoacoustic emissions testing) (108). Occasionally, individuals with CdLS may experience severe hearing loss caused by an inner ear abnormality. These individuals should be assessed for auditory neuropathy, a hearing disorder in which the inner ears successfully detect sound but has trouble sending sound from the ears to the brain. Tests are available to assess whether the brain is receiving the correct information from the inner ear (auditory brainstem response audiometry) (106,108). It is important that hearing loss is identified quickly in individuals with CdLS to maximise communication skills (101). Hearing has been found to improve over time in 50% of adults with CdLS (106).
Treatment options for hearing loss vary according to the type and severity of the loss. Middle ear infections and sinusitis should be treated according to the national guidelines for the general population (R41). Treatment for infections usually involve relieving pressure or draining fluid from the middle ear. Sometimes treatment options may include mastoidectomy, a procedure which removes infected cells from the ear (102). Hearing loss may also be treated by using hearing aids, however, hearing aids are often poorly tolerated by individuals with CdLS (109). Other treatment options for hearing loss include a cochlear implant or surgical correction of small bones in the ear that have formed atypically. A cochlear implant is a device that replaces the function of the damaged inner ear by providing sound signals to the brain. Cochlear implantation has resulted in variable levels of hearing gain (110,111).