Pediatric Hearing Loss 2 and Blindness

Question 1

Medical Work up – History (10)

Answer 1

1. In taking a history, special attention is directed toward the perinatal period.
2. A history of maternal (gestational) infection (toxoplasma, rubella, cytomegalovirus, syphilis) raises the possibility of congenital infection as a cause for the SNHL.
3. Other historical factors that might help determine an etiology include factors related to prematurity such as prolonged ventilation, exposure to ototoxic medications, severe jaundice and extracorporeal membrane oxygenation (ECMO).
4. Late-onset hearing loss can be caused by head trauma, chemotherapy, and meningitis.
5. Approximately 90% of infants with hearing loss are born to parents who are hearing, and 50% are born full term.
6. A family history of hearing loss is also relevant, because upwards of 50-60% of children will eventually be found to have either a genetic and/or hereditary etiology to their deafness.
   a. Need to be getting fourth and fifth tier family histories
7. A careful inquiry into all immediate family members and first-degree relatives is a minimum for probing a possible hereditary hearing loss etiology.
8. Some specific syndromes can run in families that are previously undetected.
9. Asking about extended family members with premature graying(in their 20’s and 30’s), kidney failure, difficulties with night vision, thyroid function and sudden death may have relevance to specific syndrome(s) (Waardenburg, Alport, Usher, Pendred and Jervell-Lange- Nielson).
10. This extended family history is important to guide work-up.

Question 2

Syndromes Associated with Hearing Loss: Pendred Syndrome (5)

Answer 2

1. Associated with hearing loss (bilaterally) and goiter (not everyone get the thyroid glad enlargement
2. Hearing screen at birth maybe normal
3. Eventually child is completely deaf
4. Enlarged Vestibular Aquaduct
5. Needs MRI and thyroid study with Pendred syndrome

Question 3

Syndromes Associated with Hearing Loss: Alport Syndrome (5)

Answer 3

1. Progressive loss of kidney function— hematuria and proteinuria
2. Resulting in end-stage renal disease (ESRD).
3. Develop sensorineural hearing loss, which is caused by abnormalities of the inner ear, during late childhood or early adolescence.
4. Affected individuals may also have misshapen lenses in the eyes (anterior lenticonus)
   * Anterior lens that comes to a point – will have eye problems
5. Abnormal coloration of the light- sensitive tissue in the retina - seldom lead to vision loss.

Question 4

Medical Work-up Physical Exam: Overview (5)

Answer 4

1. Overall assessment of the patient.
2. The patient’s stature can indicate syndromes associated with hearing loss, such as Hurler syndrome (mucopolysaccharidosis) or abnormal body proportion (achondroplasia).
3. Skin lesions such as café-au-lait spots can suggest neurofibromatosis that can be associated with hearing loss and inner ear tumors (particularly in neurofibromatosis type 2).
   a. Children with neurofibromatosis type 2 gets acoustic neuromas
4. Presentation of hearing loss usually occurs in teens or adults secondary to the development of “acoustic neuromas” (correctly termed “vestibular schwannoma”)..
5. A methodical head and neck exam is also requisite to rule out a potential craniofacial syndrome.

Question 5

Medical Work-up Physical Exam: head and Neck Exam (4)

Answer 5

1. Facial asymmetry, micrognathia, hypoplastic zygomas, ocular abnormalities such as hypertelorism or heterochromic irides, and white forelock
   i. Goldenhar, Treacher-Collins or Waardenburg syndromes.
2. Abnormal skull morphology is seen in Apert and Crouzon syndromes.
3. A cleft palate is associated with hearing loss either conductive or sensorineural.
4. A systematic exam of the ears, including the auricle and the periauricular region, is necessary in evaluating pediatric SNHL. Any malformation of the pinna (eg, microtia), preauricular pits or skin tags may be the only feature pointing to congenital malformation of the middle or inner ear and possible associated abnormalities as might be seen in branchio-oto-renal syndrome (BOR).

Question 6

Medical Work-up Physical Exam: Brachio-oto-renal syndrome (3)

Answer 6

1. In the case of suspected BOR syndrome, a renal ultrasound and renal panel are indicated.
2. Careful examination of the ear canal and eardrum are also requisite to rule out potentially simple pathologies of the external or middle ear that could contribute to a hearing loss.
3. Occasionally, a deformity of the malleus can be noted on otoscopy or microscopy and suggest a congenital defect of the ear. This type of aural pathology may be diagnosed by high resolution computed tomography (CT) scanning.

Question 7

Medical Work-up: Diagnostics (4)

Answer 7

1. High resolution scanning of the temporal bones (inner ear region) has dramatically improved the ability to identify a cause for a child’s congenital sensorineural hearing loss (SNHL).
2. In roughly 35% of children scanned because of a confirmed SNHL, an abnormality of the inner ear can be identified as responsible for the hearing loss.
3. Enlarged vestibular aqueduct represents the most frequent inner ear anatomical defect.
4. The vestibular aqueduct is a bony conduit that houses the endolymphatic duct and sac of the inner ear, structures that are believed to play a role in the fluid homeostasis of the inner ear.

Question 8

Medical Work-up: High Resolution CT of temporal Bones (4)

Answer 8

1. If a child has bilaterally enlarged vestibular aqueduct syndrome, there could be a mutations of the Pendred syndrome gene in some patients with bilateral enlarged vestibular aqueduct syndrome.
2. The Pendred syndrome gene has been found to encode for an anion exchanger that likely plays a role in inner ear electrolyte regulation.
3. Therefore, it is reasonable to speculate that failure of normal inner ear electrolyte and fluid homeostasis may occur when the Pendred syndrome gene is mutated.
4. Other common defects of the inner
   a. Spectrum of cochlear hypoplasias,
   b. Early identification of these inner ear defects can provide the patient’s family with a reason for the child’s hearing loss, possibly provide insight as to whether the child’s hearing loss is likely to progress, and also has relevance toward cochlear implant candidacy if the family wishes to pursue this management option.

Question 9

Non-Syndromic Hearing Loss – GJB2 Mutation Screening (4)

Answer 9

1. The recognition of mutations in the gap junction beta 2 gene(GJB2) as one of the most common causes of nonsyndromic hearing loss.
2. GJB2 encodes for a gap junction protein (Connexin26) that forms intercellular channels that have been proposed to allow cell-to-cell communication and facilitate potassium recycling in the inner ear. Loss of normal Connexin expression is thought to compromise inner ear fluid regulation with concomitant hearing loss.
3. GJB2 mutations have been reported as causing upwards of 30% of cases of bilateral SNHL.
4. The frequency of persons carrying GJB2 mutations in the general population has been estimated to be 3% (i.e., the carrier rate for people with normal hearing who carry one abnormal GJB2 allele is 3%)

Question 10

Genetic Counseling of Families with Hearing Loss (8)

Answer 10

1. Family Planning
2. Identifying Hearing Loss in Siblings
3. Sensitivity in Counseling Families
4. GJB2 mutations have yet to be associated with any critical, life-threatening problems (i.e., hearing loss is the only result of GJB2 mutations). loss.
5. For all patients and families impacted by hearing loss, it is necessary to address the optional nature of genetic testing for deafness-causing genetic mutations. For some families, it may be unnecessary or undesirable to determine a cause for their child’s hearing loss.
6. Particular attention or sensitivity to such issues is needed in counseling families embracing the deaf culture.
7. In cases where there are no medical urgencies (health-threatening conditions) associated with the child’s hearing loss, there is no absolute requirement to pursue diagnostic genetic testing.
8. Drug use is high amongst deaf families

Question 11

Medical Work-up: Ophthalmology (5)

Answer 11

1. Infants with a hearing loss need to have an ophthalmologic examination in the first year of life to rule out associated eye findings affecting vision.
2. Longitudinal assessments of a child suspected of Usher are indicated because eye findings present with increasing age.
3. Surveillance with vision screening is critical, even with a normal eye exam in the first year of life.
4. Loss of vision or the threat of subsequent loss of vision are critical pieces of information for any child with a hearing loss because communication modalities (sign language and lip-reading) rely on vision to some degree.
5. An infant who uses sign to communicate and subsequently loses vision must adapt his/her communication mode to an extremely limiting tactile- only approach.

Question 12

A plan for a child with a bilateral sensorineural hearing loss (mild to moderate range) might include these steps (6)

Answer 12

1. Hearing aid evaluation/fitting with pediatric audiologists with routine hearing aid checks and management
2. Referral to an otolaryngologist for workup of the sensorineural hearing loss
3. Monitoring of child’s behavior once properly fitted with hearing aids
4. Consider ADHD specialist consultation if there is a hyperactive, impulsive behavior
5. Have parents inform school educators regarding patient’s hearing loss and implement appropriate in-class measures (preferential seating, regular hearing aid use and checks, acoustic accessibility with an FM system, educational audiologist on the IEP, etc.)
6. Refer for a speech-language evaluation

Question 13

Encouraging Communication in Children with Hearing Loss (18)

Answer 13

1. Establish face-to-face contact when speaking to the child
2. Limit background noise in the examination room
3. Speak clearly but naturally; repeat as needed
4. Provide feedback and visual cues (i.e., gestures)
5. Listen closely for the family’s concerns; provide understanding
6. Give hope and allow for expressions of grief
7. Ensure that the family is seeing an experienced audiologist who has experience
8. treating pediatric patients. If the audiologist has experience with infants with hearing loss, you may see that
9. Confirmatory diagnostic stages progress efficiently
10. Loaner hearing aids may be provided while steps are taken to prescribe hearing aids for the infant
11. Prescriptive methods are used to verify an appropriate hearing aid fitting for the infant
12. Parents are guided to be independent in management of the amplification devices
13. Help the family link to early intervention services in your community
14. Many states have a single point of entry to the EI system
15. Know who to contact in the local community for services for infants with hearing loss
16. Interpret diagnostic results in “action terms” for the parents
17. Instead of focusing on degree of hearing loss, help families understand the potential impact of hearing loss on the child’s development
18. Suggest ways that the family can promote the child’s development

Question 14

Amaurosis (5)

Answer 14

1. Partial or total loss of vision
2. Usually this term is reserved for profound impairment, blindness or near blindness
3. Child has congenital blindness
4. Consider developmental malformations secondary to gestational or perinatal infections, anoxia or hypoxia, prenatal trauma or genetic disease
5. Visual cortex is damaged/there is a problem with the visual cortex
   a. Central vision loss

Question 15

Congenital Blindness (6)

Answer 15

1. Cortical Blindness
2. Optic nerve hypoplasia (ONH) or aplasia
   a. Third most prevalent cause of visual impairment in kids under three years of age.
3. Most common congenital optic disc abnormality.
4. Most often presents bilaterally (75% of cases).
5. Among patients with ONH, approximately 10% will present with septo-optic dysplasia.
   a. 50% of these patients will have endocrine abnormalities
   b. Associated with multiple intracranial midline defects including an underdevelopment of the septum pellucidum and/or pituitary gland dysfunction - septo-optic dysplasia (de Morsier syndrome)
6. No socio-economic or racial correlations have been established

Question 16

Management of Optic Nerve Hypoplasia (5)

Answer 16

1. MRI due to the strong association with endocrine abnormalities and other structural malformations.
2. A normal MRI does not exclude pituitary abnormalities!
3. Referral to an endocrinologist is necessary since these children commonly have endocrine problem
4. Regular follow-up and attention to growth charts
5. Hormonal dysfunction may not present at the time of diagnosis

Question 17

Optic Coloboma (4)

Answer 17

1. Result of an incomplete closure of the embryonic fissure while in utero.
2. Varying amount of glial tissue typically fills the defect, manifests as a white mass
3. Causes low vision
4. Low vision is an ocular condition where the child has a visual acuity is 20/70 or poorer in the better- seeing eye and cannot be corrected or improved with regular eyeglasses

Question 18

Other Congenital Eye Problems (5)

Answer 18

1. Aniridia
2. Morning glory disc
3. Rieger anomaly
4. Hypoplastic Iris
   a. Rare congenital malformation of the optic nerve looks like a morning glory
   b. Associated with anterior lens problems
   c. Often have a pupil that is off-center (corectopia) or extra holes in the iris that can look like multiple pupils (polycoria)
5. Other system signs
   a. Extra fold of skin at umbilical area
   b. Congenital heart disease
   c. Hypospadias
   d. Anal steno

Question 19

Occurs in the anterior segment – lens, iris, and cornea (4)

Answer 19

1. The elements of the anterior segment usually form separate structures.
2. In Peters anomaly, development of the anterior segment is abnormal, leading to incomplete separation of the cornea from the iris or the lens.
3. Small ones on periphery may not be as significant as large central ones
4. As a result, the cornea is cloudy (opaque), which causes blurred vision.

Question 20

CNS Disorders that cause Congenital Blindness: Hydranencephaly

Answer 20

Brain’s cerebral hemispheres are absent to varying degrees and the remaining cranial cavity is filled with cerebrospinal fluid
*Extremely rare

Question 21

CNS Disorders that cause Congenital Blindness: Porencephaly

Answer 21

Involves encephalomalacia

Characterized by cysts or cavities within the cerebral hemisphere

Question 22

CNS Disorders that cause Congenital Blindness: Microencephaly

Answer 22

Head is much smaller than expected

Question 23

CNS Disorders that cause Congenital Blindness: Encephalocele, particularly occipital

Answer 23

1. Neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull.
2. Failure of the neural tube to close completely during fetal development.

Question 24

Genetic Disorders Which can be associated with Blindness: Sturge Weber Syndrome (3)

Answer 24

1. Get blindness on the affected side due to large pupils & tearing → congenital glaucoma
   * If they don’t get treated for the glaucoma then they wind up with blindness
2. Highest incidence of glaucoma in pediatric population is A.A. males
3. Also has port wine stain

Question 25

Genetic Disorders Which can be associated with Blindness: von Hippel-Landau Disease (3)

Answer 25

1. Rare genetic disorder
2. Visceral cysts and benign tumors in multiple organ systems that have subsequent potential for malignant change
   i. Retinal and central nervous system (CNS) hemangioblastomas (blood vessel tumors)
   ii. Pheochromocytomas
   iii. Multiple cysts in the pancreas and kidneys
   iv. Increased risk for malignant transformation of renal cysts into renal cell carcinoma
3. Variable penetrance and presentation ranges from infancy to age 90

Question 26

Amaurosis (3)

Answer 26

1. If child has useful vision and then loses it: Ocular disease
   i. Retinoblastoma
   ii. Retinitis pigmentosa
   iii. Cataract
   iv. Chorioretinitis

If not ocular disease, neurological and systemic disorders

2. Encephalopathies will be rapid in onset
   i. Hypertensive
   ii. Infectious vasculitis
   iii. Migraine
   iv. Leukemia with CNS involvement
   v. Toxins or trauma
3. Increase in ICP
   i. Brain tumor-optic gliomas and craniopharyngiomas
   ii. Pseudotumor cerebri

Question 27

Neurodegenerative diseases Leading to Blindness (6)

Answer 27

1. Cerebral storage
2. Gangliosidoses—Tay Sachs*
   a. Tay Sachs is most common leukodystrophy
3. Lipidoses and ceroid lipofuscinoses
4. Mucopolysaccharidoses (Hunter and Hurler syndrome)
5. Leukodystrophies
6. Demyeling sclerosis

Question 28

Management of the Blind Child (8)

Answer 28

1. Physical therapy
2. Medication for seizures
3. Placement of a shunt in the brain to remove excess fluid in the brain
4. Educational plan for both neurological problems and blindness
5. Multiple specialists—Care coordination
6. Sleep problems associated with blindness
7. Behavioral issues
8. Sensory problems