Prenatal Cochlear Disorders

Michel aplasia

Complete failure of development of inner ear, aud nerve, and facial nerve

deafness or profound SNHL

cochlear aplasia

absence of cochlea

profound HL

similar to Michel aplasia

Common cavity

vestibule and cochlea are touching, could be no chambers in the cochlea

profound HL (possible low freq)

Incomplete partition type I

No separation of chambers in the cochlea, no modiolus, no membrane to separate chambers

Severe to profound HL

Could benefit from CI

Incomplete partition type II

Not fully developed cochlea

Apical turn does not have a lot of separation

Mondini Dysplasia

Incomplete partition type II

1.5 turns of cochlea

Apical part of the modiolus and the corresponding interscalar septa are defective 

Mostly profound HL, air-bone gap may be present at low freq

CI electrodes may be too long to use, pt can use HAs

Scheibe Dysplasia 

Limited membranous labyrinthine dysplasia

cochleasaccular dysplasia, major damage in basal turn of cochlea, cochlear duct and saccule collapsed, organ of Corti partially or completely missing 

Waardenburg Syndrome

Rare disorder

HL could be unilateral or bilateral

premature graying hair, two different colored eyes, widely spaced eyes and high nasal bridge 

abnormalities of vestibular system are common

Bracnchio-oto-renal (BOR) syndrome

HL can be CHL or SNHL

usually stable hearing 

Malformations of the external ear, branchial arch anomalies, renal abnormalities 

Neurofibromatosis type 2 (NF2)

Progressive SNHL leading to possible deafness

cafe-au-lait spots

vestibular schwannomas/acoustic neuromas 

Usher syndrome

Combined deafness-blindness

Type I: congenital severe to profound SNHL; vestibular dysfunction

Type II: congenital mild to severe SNHL with progressive loss; no balance issues

Type III: congenital normal hearing with progressive SNHL; variable vestibular dysfunction 

CHARGE syndrome

Coloboma

Heart anomalies

Atresia of the choanae

Retardation of development 

Genital and urinary abnormalities

Ear abnormalities with hearing loss; 85% of children ranging from mild to profound

Toxoplasmosis

Bilateral moderate to severe SNHL

Transmission: food borne illness, animal to human, mother to child

Syphilis

STI

SNHL in 30%-40%

Childhood onset: bilateral hearing loss, symmetrical, severe to profound with no vestib sx

adult onset: bilateral, asymm, fluctuating HL, accompanied by tinnitus and vertigo

Rubella

Bilateral, flat, uniform mild to severe SNHL

Transmission: airborne

Other sx: congenital heart disease, microcephaly, congenital cataracts, cognitive impairment 

cytomegalovirus (cmv)

unilateral or bilateral mild to profound SNHL

transmission: close and prolonged contact with bodily fluids 

herpes simplex virus (hsv)

unilateral or bilateral severe to profound SNHL

transmission: STI, babies can contract with contact to birth canal during delivery

hyperbilirubinemia

increased levels of bilirubin in the blood

can cause brain damage, lead to HL intellectual disability, and behavior problems

Low birth rate

Increased risk of SNHL

ears may not fully develop

Premature and low birth weight usually occur together 

fetal alcohol syndrome

SNHL, CHL due to recurrent OM

growth defects, CNS anomalies or dysfunction