Lecture 3- HL in children Flashcards
What are the JCIH recommendations for middle ear conditions?
Craniofacial anomalies identified as risk factor for persistent congenital, delayed onset or progressive HL in childhood
- Includes abnormalities of pinna, EAC, ear tags & pits, and temporal bone anomalies
Complete head and neck exam for craniofacial anomalies
Atypical findings on eye exam may signal stigmata of a syndrome that includes HL
- (e.g., Irises of 2 different colors, abnormal positioning)
Surveillance of middle ear status at all well-child visits using:
- Pneumatic otoscopy
- Tympanometry
Referral of children with persistent middle ear effusion lasting 3 months or longer for otologic evaluation
How can you inspect a child’s head for congenital aural atresia and microtia?
Inspect a child’s pinna for size, shape, landmarks, and position on head
- Ear should be rotated ~20 degrees posteriorly
- Low set ears are often rotated posteriorly 30 degrees or more (pinna rotates anteriorly and superiorly during fetal development)
What are the 4 grades of severity of microtia?
1) Pinna is smaller than normal but EAC is patent and all normal ear structures are present
2) External ear is malformed, EAC is present but stenotic, middle ear space is small and ossicles are malformed or fused
3) Severe malformation of the pinna, absence of complete stenosis of the EAC, absence or near absence of middle ear space and ossicles
4) Anotia, total absence of the ear canal
What conditions or abnormalities are associated with microtia?
- Atresia or stenosis of EAC more common in microtia (also occurs with persistent CHL)
Common abnormalities
- Stapes deformity
- Absence of oval/round windows
- Facial nerve absence
- Anomalous development
- Poor pneumatization of middle ear cells and space
- Fusion of malleus and incus
What conditions or abnormalities are associated with aural atresia?
Typically assoc w/ mod-severe CHL
What are the treatment options for congenital aural atresia?
Conventional hearing devices typically not an option
- Absent EAC &/or pinna malformations
Treatment options
- Bone-conduction HA
- CROS
- Osseointegrated devices
- Atresiaplasty to create an ear canal/middle ear
CT scanning of the temporal bone is important for the decision
- If well-developed middle and inner ear anatomy, child may be a good candidate for surgical aural atresia repair with chances of hearing improvement
- Opening and grafting an ear canal, creation of TM, mobilization of the ossicular chain
If inner and middle ear anatomy are poorly developed, prognosis is poorer for hearing improvement following surgery
Facial nerve must also be considered–often an atypical course
- May run through the ME space and mastoid compartment
- May be in direct path of surgical repair
What are the high risk populations for OM?
Indigenous populations
- OM prevalence is always highest in any native group (e.g., Alaskan inuit and Australian aboriginals)
Countries with high rates of poverty
Bottle feeding and poverty-related indices (low SES, malnutrition, crowding) are assoc. w/ higher rates of OM
Factors in high risk populations include:
- overcrowding in the home
- greater rates of smoking, or cooking smoke in the home
- Lack of protective factors: breastfeeding, vaccines, access to preventative care, high-quality daycare, clean water, hygiene practices
What are the AHRQ (Agency for Healthcare Research and Quality) guidelines for treating otitis media?
- Watchful waiting for 3 months
- Reduce risk factors
- Try medication if all else fails
- Try PE tubes
What are the medical aspects of ANSD?
ANSD is most common in the newborn population
- Particularly premature babies and those who have medical illness
Major Risk Factors
- Hyperbilirubinemia
- Hypoxia and accompanying metabolic acidosis
- Exposure to antibiotics that are toxic to hair cells
Genetic causes of ANSD
- Mutations of Connexin 26 and of otoferlin
Congenital disorders such as atresia of the auditory nerve
Genetic disorders affecting the auditory nerve as part of more general peripheral and cranial nerve involvement
- E.g., Friedreich’s Ataxia
- Deficits in auditory function may present before symptoms in other sensorimotor systems (Starr et al., 1996)
Immune disorders
- E.g., Guillain-Barre syndrome–affects the proximal nerve roots and proximal portions of the auditory nerve
How should screening be conducted for ANSD?
Majority of pediatric cases involve congenital or perinatal presentation
Most diagnoses are made following NBHS
- Programs using only OAEs will miss a high proportion of ANSD cases
JCIH (2007) recommends that ABR be used as the screening measure, at least for babies housed in the NICU
Berlin et al. (2005) suggested that the acoustic reflex screening could be used to ID children in need of ABR assessment for screening programs using OAE assessment.
What should audiologic follow-up include for managing ANSD?
Inability of ABR and ASSR to predict behavioral thresholds is a challenge of early management
Behavioral hearing thresholds can vary from normal to profound levels (Rance et al., 1999)
Sound audibility doesn’t predict degree of functional disability. However, access to sound is still the basis of early intervention strategies (e.g., hearing aid fitting)
Visual Reinforcement Audiometry
- 6 months of age onward
Younger or delayed children
- Behavioral observation audiometry
- Few published studies describing BOA results in ANSD population
Parent observation including formal assessment tools (questionnaires)
What is the ANSD Audiological Clinical Profile?
- Sound detection thresholds
- Most (>90%) show impaired sound detection–range from normal to profound levels
- Typically the same in both ears
- Unilateral ANSD most commonly assoc w/ auditory nerve hypoplasia
- Reverse slope configuration is common
- Fluctuations in audiometric thresholds is common
Day-to-day variations of 20+ dB have been reported - Middle Ear Muscle Reflex
- Modulated by the inner hair cells, CN VIII, and auditory brainstem pathways
- Consistently abnormal in cases of ANSD regardless of behavioral hearing levels - Cortical Auditory-Evoked Potentials
- Potentials from the auditory cortex are recordable in some affected adults and children
- May reflect the fact that they are less dependent on synchronous neural firing than ABR - Basic Auditory Processing
- Frequency resolution and intensity discrimination are usually unaffected because they depend on cochlear processing
- Distortion of neural firing patterns results in impaired temporal resolution - Functional Hearing
- Speech perception difficulty
- Higher degrees of everyday listening and communication difficulty than matched controls
