1. the establishment of an accurate diagnosis of hearing status,

2. effective family counseling conducted in parallel with the diagnostic process, and

3. timely service coordination

Four elements of pediatric practice:

1. Accessible, contiuous, comprehensive, coordinated and compassionate care

2. Family-centered/culturally competent care

3. Extensive knowledge of social-emotional, cognitive and communicatve development; development of whole child; provision of developmentally appropriate care

4. EBP

What is a medical home?

A family-centered medical home is an approach to providing primary care; works in partnership with a child and a child's family to assure that all of the medical and non-medical needs of the patient are met; the pediatric team can help the family/patient access, coordinate and understand care and services

Genetic or hereditary hearing loss

That which is inherited through a family.  It can be present at birth (i.e., congenital) or occur in later life

Heterozygote

If a person has ONE DEFECTIVE gene for hearing and ONE NORMAL gene (in the pair) then the person is called a heterozygote. 

If both genes (in the pair) are defective then the person is called a homozygote.

When only one defective gene (in the pair) is required for the trait to be expressed.

When both defective genes (in the pair) are required to express the trait.

Some genes for hearing loss are located on the X chromosome.  Males who have this gene are hearing impaired since they have only one X chromosome.  Females who have the gene for hearing impairment on one of their two X chromosomes are carriers.

The frequency with which a genetic abnormality is manifested among those who possess it is called penetrance.  A fully penetrant gene will produce its effec in every person who has it.  A gene with reduced penetrance will only produce its affect in a proportion of individuals who have it.

The variation in the clinical expressivity (manifestation) of a gene.

1. Origin of structure

2. Timing and development of structures

Ectoderm - outer

Mesoderm - middle

Endoderm - inner

Gives rise to external ear and membranous inner ear structures; also gives rise to outer skin layers, nervous system and sense organs

Gives rise to middle ear ossicles and bony portion of inner ear; also gives rise to skeletal structures, circulatory structures, reproductive organs and kidneys

Gives rise to tympanic cavity and eustachian tube; also gives rise to digestive canal and respiratory organs

External layer: ectoderm

Middle layer: mesoderm

Internal layer: endoderm

malleus

incus

tensor tympani muscle

stapes

stapedius muscle

1st and 2nd pharyngeal arches

and the

1st pharyngeal groove

1. Genetic factors (ex: mondini syndrome - only one turn of the cochlea)

2. Environmental factors (ex: maternal rubella)

No external ear canal;

Disorder of first and second brachial arch;

Ossicles are impaired;

Requires surgical intervention

1. genetic/hereditary

2. environmental/acquired

Mondini Dysplasia

a) what is it?

b) genetic causes?

c) non genetic causes?

Mondini Dysplasia

a) a single turn of the cochlea

b) Klippel Fiel syndrome, Arnold Chiari syndrome

c) Cytomegalovirus (CMV) or thalidomide injection by mother

Schiebe Dysplasia

a) what is it?

b) genetic causes?

c) non genetic causes?

a) impaired development of the cochlea and saccule

b) Ushers Syndrome, Waardenburgs Syndrome

c) Maternal Rubella

2003

Goals: to ID 20-25k genes in human DNA

Store information in databases

improve data analysis

transfer technologies to private sector

-->genetic testing to determine liklihood of different disorders

Syndromic vs Non-Syndromic genetic cases:

(percentages)

Autosomal (non-sex chromosomes) Dominant

Variable Expression

Penetrance for Deafness: 20%

White forelock: 17%

Lateral displacement of inner canthi: 99%

Hyperplasia of eyebrows: 99%

Gap Junction Beta 2 (GJB2).

Located on chromosome 13.

- autosomal dominant

- HL - reduced penetrance and variable expression

- shortening of neck, low posterior hairline, restricted head/neck movement

- cervical skeletal anomoly resulting from faulty segmentation of mesoderm during 3rd-7th fetal week

- stapedial malformations (MIDDLE EAR)

- incudo-malleal malformations

- preauricular tags, microtia of pinna, atresia/stenosis of EAC

- HL can be mild to profound

- CNS involvement

- Chromsomal aberration resulting from loss of one of the X chromosomes

- Occurs in females only

- Mixed or SNHL

- auricles are low set and elongated, exhibit thick lobules (often cup-shaped)

- middle ear anomolies

   - stapes malformation

   - stapes footplate fixation

   - absence of stapedial tendon

- reproductive organ and renal abnormalities

- autosomal dominant

- high penetrance

- variable expression

- skeletal disorder of ossification

- absense of clavicles, softness (be cautious doing BC testing) and bossing of skull

- atresia/stenosis of EAC, ossicular malformation (stapes fixation)

- usually congential conductive loss, occasionally progressive hearing loss is reported

- disorganization of collagen structure of the bone (brittle bone disease)

- autosomal dominant

- variable expression

- large skull; bowing of legs; multiple fractures of the bones

- progressive conductive loss

- degeneration of stapes suprastructure

- hearing loss does not occur until early adulthood

- autosomal recessive

- variable expression

- conductive loss

- incus and stapes malformations

- microtia / atresia of EAC

- cleft palate, tongue/teeth abnormalities

- short, thick digits

(*those with cleft palates need to be monitored for HL)

- autosomal recessive

- cardiovascular disorder

- profound congential bilateral SNHL

- atrophy of inner ear organs (organ of corti, spiral ganglia, large PAS deposits in stria vascularis)

- autosomal dominant

- variable expression

- SNHL

- congenital hand abnormality (wasting of finger muscles)

- extra chromosome during cell division

- 47 chromosomes often associated with increased maternal age

- low set ears, poorly differentiated pinnas, pre-auricular tags, absence of EAC, absense of ME, cleft/lip palate

- deformed ossicles, absence of stapedius muscle

- shortened cochlea, shortened endolymphatic valve, degeneration of the organ of corti, tectorial membrane, stria vascularis, and saccule

- prognosis is poor (95% die by age 3).

- autosomal dominant (mainly)

- osseous widening of bones; overgrowth of the craniofacial skeleton

- conductive, mixed or SNHL

- osseous invasion of tympanic cavity and/or cochlea

- ossicles are fixed at multiple sites and are large in size

- anomolies of first and second brachial arch

- mandibular disorders, microtia, EAC atresia/stenosis, ME malformation

- incudeomallear fusion, stapedial suprastructure malformation, stapes footplate fixation, absense of stapes

- low set cup-shapes auricles with or without pre-auricular tags

- conductive HL

Blood tests

Amniocentesis

Ultrasound

1. recognize etiology of HL

2. refer for genetic counseling

3. provide genetic counselor with necessary audiologic info

1. auricle

2. external auditory canal

- growns until 9 years of age

- look for abnormalities in the pinna

Only cartilaginous in infancy -- no bony growth

EAC is soft and compliant

-check for collapsing canals

-ensure that movement of the TM (not ear canal) is being recorded in tymps

Abnormal smallness of pinna

Type 1 - mildest anomoly

Type 2 - moderate anomoly

Type 3 - severe anomoly; pinna is absent (anotia) characterized by a tiny nubbin of tissue in its place

Must do ABR; most surgeries to correct pinna do not occur until age 3.

Abnormally smal ear canal opening

Type 1- mild anomoly (stenotic ear canal and normal ME)

Type 2 - moderate anomoly (EAC absent and ossicular malformation in common)

Type 3 - severe anomoly (EAC and ME space absent)

1. Fununculosis - infection of hair follicle in EAC

2. Swimmers ear - bacterial form of otitis externa occuring due to moisture

3. Viral otitis externa - herpes zoster virus causes blisters

4. Otitis Externa from trauma

Treatment can include drugs and surgical excision of blisters

1. benign tumors

2. cysts of sebaceous and ceruminous glands

3. keloids - growths following surgery or trauma

4. osteomas and extoses - single and multiple bony growths of bony portion of EAC

5. aural polyps - inflammed tissues

Treatment includes surgical excision.

- rare in children

- pinna is more frequently involved than EAC

- squamous cell carcinoma

- basal cell carcinoma

- treatment includes radical surgery; hearing conservation may be a secondary goal

- impaired pressure equalization btwn ME and outside

- impaired drainage of ME secretions

1. intrinsic ET dysfx - when lining of ET thickens to obstruct airflow

2. extrinsic ET dysfx - when opening of ET is occluded on the nasypharyngeal end

3. function ET dysfx - in infants the ET is almost horizontal so it does not facilitate drainage

4. circumstantial ET dysfx - even a normal ET under some circumstances may not be able to equalize sudden large changes in pressure

5. patulous ET dysfx - ET is open all the time

- the most common childhood infection

- inflammation of the ME (most commonly due to ET dysfx)

- most common in first two years of life

1. acute - 0-21 days (most painful)

2. subacute - 22 days-8 weeks

3. chronic - more than 8 weeks

- rapid onset bacterial infection

- otalgia, fever

- TM retracts into ME space because of neg pressure

- TM is stretched (atelactasis) -->

- blood vessels are dialated; fluid leaks into ME space