Examining eardrum of infants with Down syndrome

August 2002

Congenital and acquired otologic problems contribute to the relatively high incidence of hearing loss in Down syndrome patients. The nature of the anomalies varies with the severity of the patient’s phenotypic expression. It usually takes years of practice as a house officer, optimally coached by an expert in otoscopy, for a physician to become proficient in the pneumatic otoscopic examination of an infant or young child with Down syndrome.

There are multiple reasons for the difficulties in the physical examination of children with Down syndrome. They are easily frightened and require more time than normal children to develop a trusting relationship with their physician. They often have an aversion to physicians. They are extraordinarily fearful of being restrained, whether in the mother’s lap or on an examination table.

Most children with Down syndrome have an aversion to insertion of anything into their tiny ear openings, particularly aural specula. The pinna size of children with Down syndrome has been found by Schwartz to be two standard deviations below normal, limiting the localization of sound. The diameter of the external auditory canal is also decreased. These two congenital features contribute to the overall increased incidence of conductive hearing loss among children with Down syndrome. The stenotic ear canal predisposes to otitis externa and cerumen impactation which is seen frequently in patients with Down syndrome. Moreover, most infants with Down syndrome have tiny ear entrances and sagging cartilaginous portions of the ear canals which often accept only the smallest (2 mm) aural speculum. Children with Down syndrome often have dry, flaky earwax which is difficult to remove. Even small accumulations of earwax in tiny ear canals impede the otoscopic examination. Earwax removal is difficult and traumatic for patient, mother and physician.

Finally, these remarkable children cry loudly and sweat profusely, making them ever more slippery and difficult to restrain. Because of their floppy and stenotic ear canals, it is difficult to perform tympanometry on most children with Down syndrome until they are at least 1 year old. The otoscopic examine of infants and young children with Down syndrome is not a task for new house officers.

I find it best to perform pneumatic otoscopy at the end of the physical examination of young children with Down syndrome. It is a rare child who will remain still while being restrained in the mother’s lap. I explain to the parent that it is necessary to firmly restrain the child on the examination table to optimally visualize the tympanic membrane (TM). Two assistants are necessary for the examination. Restraint is accomplished by an experienced nurse or nurse’s assistant who immobilizes the infant’s head with her/his thumbs at the same time that she/he immobilizes the infant’s extended arms against the occiput and face with the nurse’s fingers encircling the infant’s elbows. The other assistant, perhaps a cooperative parent, applies firm pressure over the infant’s thighs pressing them against the examination table. The assistant assigned to immobilize the infant’s lower extremities can also lie across the infant’s thighs pressing them to the table. Alternatively, a restraint board or infant swaddle wrap can be used to immobilize the infant’s thighs, leg and body.

Mechanical removal of obstructing earwax is done by the use of a well-designed cerumen spoon (blunt aural curette), size 0 or 1. Because the ear canals are stenotic, it is common to traumatize the canal wall and cause minor capillary bleeding into the ear canals.

Preliminary instillation of vegetable oil into each external auditory meatus may be useful to lubricate the dry wax and facilitate removal. Any accumulated water overlying the TM must be removed. I accomplish this by instilling a thin wick of absorbent cotton introduced into the ear canal with the aid of a thin nasopharyngeal swab with an aluminum shaft. By this time the infant’s head and the nurse restraining the infant’s head and arms are sweating profusely.

At least 50% of the external auditory meati and ear canals of infants with Down syndrome cannot tolerate aural specula larger than the 2 mm size. It is important to use the permanent 2 mm size (or 3 mm size if it will fit) aural specula that are original equipment for diagnostic otoscopes. This is needed because infants with Down syndrome have poor cartilaginous support for the proximal two-thirds of the ear canal. The walls of the cartilaginous portion of their ear canals sag laterally, narrowing even further, the stenotic canals to a space of about 1 mm. A properly designed aural specula acts as a strut, lifting the sagging canal walls and allowing light to illuminate the TM. Disposable aural specula are poorly designed because the initial straight portion of the speculum measures only 2 mm to 3 mm before it flares outward. Therefore, the straight portion is too short to be inserted deeply into the stenotic ear canals of infants with Down. Only the original specula have a sufficiently long straight portion (5 mm-7 mm) to enter deep enough to permit visualization of the infant’s eardrum.

Visualization without performance of pneumatic otoscopy is unlikely to allow an accurate assessment of the TM. The most important criteria are translucency vs. opacification and position of the TM. Almost 25 years ago, Schwartz and Schwartz published a study of 38 young children with Down syndrome. Even though these children were examined during the summer, 60% of them had evidence of middle ear effusion. These findings have been replicated by others. According to the 2001 AAP Guidelines for Health Supervision for Children with Down Syndrome, the risk of middle ear effusion in infants with Down syndrome is at any given time 50%-70%. If the TMs cannot be visualized, refer the infant to an otolaryngologist.

Conductive hearing loss in Down syndrome is also caused by middle ear disease, particularly otitis media. The major predisposing factors are congenital in origin and are thought to result from defective Eustachian tube cartilage and musculature. In addition to histologically abnormal cartilage, the diameter of the Eustachian tube has been observed to be significantly smaller than normal. Hypotonicity and muscular defects of the tensor veli politini and dilator tubae were described as causative factors by Schwartz et al.

Tympanostomy tubes

In my area, infants with Down syndrome usually are candidates for insertion of tympanostomy tubes. Pediatricians should expect that 15% or more of such children will have persistent hearing loss after tube insertion. A behavioral audiogram or otoacoustic emissions test should be performed on all such children by their first birthday. Careful otoscopic examinations should be performed twice each year after the first year of life because there is a higher than normal incidence of premature extubation of the tympanostomy tubes. Moreover, children with Down syndrome suffer more episodes of acute and chronic otorrhea through the tympanostomy tubes and most of them have multiple insertions of tubes during childhood.

It is a frustrating experience for pediatricians who are inexperienced in the proper otoscopic examination of an infant with Down syndrome when the baby presents with a fever and fussiness. Obtain and use the proper equipment, don’t be afraid to firmly restrain the baby, learn how to efficiently remove earwax that obstructs a full view of the TM (forewarn the parent that there may be some bleeding and be prepared to handle it), choose the proper size and design of aural speculum, and practice the technique of pneumatic otoscopy. Aggressive, meticulous and compulsive diagnosis and treatment of the ear in children with Down syndrome provide significantly improved hearing levels.

For more information:

• AAP, Committee on Genetics, 2000-2001. Health supervision for children with Down syndrome. Pedratrics. 2001:107.
• Schwartz DM, Schwartz RH. Acoustic impedance and otoscopic findings in young children with Down’s syndrome. Arch Otolaryngol. 1978;104:652-656.
• Balkany TJ, Downs MP, Jafek BW, et al. Hearing loss in Down’s syndrome: A treatable handicap more common than generally recognized. Clin Pediatr. 1979;18:116-118.
• Roizen NJ, Wolters C, Nicol T, et al. Hearing loss in children with Down syndrome. J Pediatr. 1993;123:S9-12.
• Selikowitz M. Short-term efficacy of tympanostomy tubes for secretory otitis media in children with Down syndrome. Dev Med Child Neurol. 1993;35:511-515.
• Iino Y. Efficacy of tympanostomy tube insertion for otitis media with effusion in children with Down syndrome. Int J Pediatr Otorhinolaryngol. 1999;49:143-149.
• Hassman E, Skotnicka B, Midro AT, et al. Distortion products otoacoustic emissions in diagnosis of hearing loss in Down syndrome. Int J Pediatr Otorhinolaryngol. 1998;45(3):199-206.