OWL Genetic Hearing Loss Flashcards
High risk register revisited Peri-natal insults and infections (non-genetic hearing loss) Genetic hearing loss with other features External ear abnormalities Musculoskeletal abnormalities
What are 5 High Risk Register for Hearing Loss?
- Caregiver concern (hearing, speech, language, developmental delay)
- Family history of permanent childhood HL
- NICU > 5 days, assisted ventilation, ototoxic drugs, hyperbilirubinemia
- Prenatal infections (TORCH)
- Craniofacial anomalies
What are 5 OTHER High-Risk Register for Hearing Loss?
- Physical findings associated with HL syndrome
- Syndromes with associated HL
- Neurodegenerative disorders associated with HL (eg Charcot-Marie Tooth syndrome)
- Postnatal infections associated with HL (eg meningitisto
Describe Non-Genetic Hearing Loss: (2)
- Not all congenital hearing loss is due to genetic causes
- Not all hearing loss detected early in life is congenital
- May be acquired very early in life (even during birthing)
What are 5 Intrauterine/Neonatal Infections? (TORCH)
Toxoplasmosis
Other (syphilis)
Rubella
Cytomegalovirus (CMV)
Herpes
What is Neo-Natal?
28 first days of life
What would be 2 non-genetic Hearing Loss causes?
- Intrauterine/neonatal infections
- Intrauterine/neonatal insults
Hyperbilirubinemia
Anoxia (low oxygen) NICU stay
Ototoxic medications
What is TORCH? (2)
- Part of the high risk register
- Congenital but non-genetic cause of infant hearing loss
In utero infection (vertical transmission from mom) or
Infection in early infancy
What are micro-organisms? (2)
- Organism of microscopic size
- Usually refers to bacteria, virus or protozoa
What are parasites? (2)
- An organism that lives on a different organism while contributing nothing to the survival of the host
- Host is usually harmed
What are protozoa? (3)
1- Diverse group of single-cell eukaryotic organisms
2- Usually motile
3- Human diseases
ex:
Malaria
Dysentery
Trichomoniasis
Toxoplasmosis
What are Virus? (3)
- An infectious agent found in most life forms (humans, animals, plants, fungi, and bacteria)
- 20-100 times smaller than bacteria
- 5000 viruses have been studied (millions more)
What are the characteristics of Viruses (3) ?
- Not free-living and cannot reproduce outside of a living cell (needs a host)
- After infection, viruses use the machinery and metabolism of a host cell to replicate
- Along the way, the host cell and system may be destroyed
What are human diseases you can get from Viruses? (5)
Cold
Flu
AIDS
Rabies
Yellow fever
Polio
HPV
Coronavirus
Cancers
What are bacteria? (2)
- Most common and ancient organism on earth and are connected to the lives of all organisms
- < 1 micron (1 millionth of a meter) but are considerably larger than viruses
What is Toxoplasmosis? (3)
Congenital infection
Caused by Toxoplasma gondii-a protozoan parasite
Not harmful to healthy children and adults
How does toxoplasmosis affect newborns?
- Risk of harm to newborns and immunocompromised individuals
- Transferred to fetus transplacentally by mothers
How can you get toxoplasmosis? 3
- Cats are the hosts (cat feces)
- Cat -> Mom -> Newborn
- Contaminated fruits and vegetables
- Raw or rare meat
- Unpasteurized milk
What are three areas that can get affected by Toxoplasmosis?
Ocular
Systemic (generalized)
Central nervous system
- May lead to spontaneous abortions if infected early in pregnancy
What are physical signs from toxoplasmosis?
Enlarged spleen and liver (hepatosplenomegaly)
What are conditions a patient may develop when toxoplasmosis affects the CNS? (5)
Microcephaly
Hydrocephaly
Motor and intellectual disability
Seizures
SNHL
How does toxoplasmosis affect hearing?
- Sensorineural hearing losss
Mild to moderate
Unilateral or bilateral
Calcification of stria vascularis and spiral ligament
Other sites of auditory pathway may be involved
How can we prevent toxoplasmosis? (7)
No raw or uncooked meat
Wash fruits and vegetables
Wear gloves when gardening
Wash hands, utensils and cutting boards
Keep cats indoors
Proper handling of cat litter
Get a dog, instead of a cat
What is syphilis? (2)
- Most commonly, syphilis is a sexually transmitted disease
- Caused by a spirochete bacterium Treponema pallidum
What is congenital syphilis? (4)
- Different than adult-onset syphilis
- Transplacental transmission of Treponema pallidum
- Many CNS and skin findings
- SNHL in up to 40% affected, often delayed significantly
What are the 4 stages of syphilis?
Primary
Secondary
Latent
Tertiary
What are the characteristics of the primary stage? (4)
- Contact to first symptom: 21 days
- Chancre sore (firm, round, small, painless) at contact sites
- Lasts 2-6 weeks
- If untreated, progresses to secondary stage
What are the characteristics of the second stage of syphilis? (7)
Non-pruritic rash in several areas
Rough, red, brown spots
Fever, weight loss, myalgias
Sore throat
Swollen lymph nodes
Patchy hair loss
Headaches
What are the characteristics of the latent stage of syphilis? (4)
- Becomes hidden or latent
- Begins to damage internal organs (brain, nerves, eyes, ears,…)
- In later years, this damage shows up without warning as paralysis, blindness, deafness,… (tertiary stage)
- Can lead to death
How does syphilis affect hearing? (4)
SNHL
Sudden onset
Bilateral and symmetrical
Progressive to profound
What is rubella? (3)
- Aka German measles caused by rubella virus
- Immunization and screening prevent most cases in developed nations (MMR vaccine)
- One of the most well-studied causes of hearing loss
How does rubella affect babies? (3)
- Intrauterine virus affecting the fetus before 20 wks gestation
- Congenital cateracts, glaucoma, heart defects, rash, jaundice, microcephaly
- SNHL common
How can rubella affect hearing? (4)
Sensorineural hearing loss
- Bilateral
- Can be progressive
- Audiogram configurations
Flat -> gradually sloping -> cookie-bite
- Sites of pathology
Stria vascularis and tectorial membrane
What is cytomegalovirus? (2)
- One of the herpes viruses (HHV5)
- CMV is the most important and common cause of infectious SNHL
1% of newborns
90% asymptomatic at birth
How can you get cytomegalovirus?
- Can be congenital or acquired
CMV antibodies detected in first 1-2 weeks of life is diagnostic of congenital CMV - If CMV is contracted during pregnancy, it may be transferred transplacentally to the fetus
What are the features of cytomegalovirus? (7)
Hepatosplenomegaly
Jaundice
Irritability/hyperactivity
Low birth weight
Microcephaly/intellectual disability
Anemia
SNHL
How can cytomegalovirus affect hearing? (4)
- Congenital CMV may account for 25% of congenital hearing loss
- 10% of CMV infections cause symptoms, of these 50% have SNHL
- Of asymptomatic cases, 10% have hearing loss
- Can be uni or bilateral, often progressive
When can hearing loss in cytomegalovirus-affected patients appear? (4)
May have no hearing loss or profound SNHL
Can have late onset (6 years) or progressive SNHL
Must diagnose viral shedding in the first 2 weeks of life
Early antiviral therapy may stabilize or improve hearing
What is Herpes? (3)
“The disease that keeps on giving”
HSV = herpes simplex virus
HHV = human herpes virus
What are the different types of herpes? (8)
HHV1 = HSV1 (cold sores)
HHV2 = HSV2 (genital herpes)
HHV3 = Herpes zoster (varicella)
HHV4 = Epstein Barr virus (mononucleosis)
HHV5 = Cytomegalovirus (CMV)
HHV6 = Roseola, MS
HHV7 = T-cell lymphoma
HHV8 = Kaposi sarcoma
HHV1 =
HSV1 (cold sores)
HHV2 =
HSV2 (genital herpes)
HHV3 =
Herpes zoster (varicella)
HHV4 =
Epstein Barr virus (mononucleosis)
HHV5 =
Cytomegalovirus (CMV)
HHV6 =
Roseola, MS
HHV7 =
T-cell lymphoma
HHV8 =
Kaposi sarcoma
What does herpes do in your body? (4)
*Infects the epithelial cells of skin and mucous membranes
*Eruption Blisters
* Sheds and spreads as a result of direct contact or bodily secretions
* Virus can lie dormant in the nervous system and cause repeated infections
How can herpes affect newborns? (2)
- Transmission is low to newborn unless the primary infection is during pregnancy
- Incurable disease and tends to recur
High risk registers refer to _____________, _____________ and _____________
High risk register refers to HHV1, HHV2, and HHV3
What are three variations of HHV1?
Herpes labialis
Keratitis and conjunctivitis
Gingivostomatitis
What are the symptoms of Herpes labialis?
cold sores or fever blisters
What are the symptoms of keratitis and conjunctivitis?
Inflammation of the cornea and conjunctiva
What are the symptoms of gingivostomatitis?
Lesions in mouth, fevers, sore throats, cold sores
How does the virus in HHV1 affect the inner ear (rare): (4)
- Virus enters the inner ear
- Associated with sudden onset hearing loss
- Also causes labyrinthitis
- Vertigo and SNHL
Do symptoms improve in HHV1?
Symptoms typically improve when the virus becomes dormant
Explain HHV2? (4)
- Most common in adults
STI - Newborns affected through infected mothers
Passed on during birth - Contagious when lesions are present
- Symptoms in adults
Blisters (genital), itchiness, burning, pain
Explain HHV2? (4)
- Most common in adults
STI - Newborns affected through infected mothers
Passed on during birth - Contagious when lesions are present
- Symptoms in adults
Blisters (genital), itchiness, burning, pain
What are the symptoms of HHV2 in newborns? (4)
- Fatal in over half of untreated cases
- Systemic organ and CNS damage
- CNS damage -> developmental, learning, and hearing problems (SNHL)
- Ear canal lesions -> CHL
Describe HHV3- Varicella Zoster: (2)
- Primary infection
Chicken pox - Reactivation
Shingles
Ramsay Hunt syndrome
Describe HHV3 chicken pox:
Chickenpox
Vaccination available
Immunity passed on passively during childhood
Much more severe when affected as an adult
No direct association with hearing loss but precursor to other diseases that can cause hearing loss
Explain HHV3 and shingles:
Shingles (Herpes zoster)
Follows chickenpox
Virus becomes inactive (dormant) in ganglion of nerves
Which age range is HHV3 common? (3)
- Common in adults over 55 years old
- Tends to infect single nerves
- Disease can be unilateral or in a dermatomal distribution
- Rash leads to blisters, tingling sensation, itching and severe pain
What is Herpes Zoster Oticus? (3)
- Viral infection caused by varicella zoster
- Affects one or more cranial nerves
Dermatomal distribution like shingles - Ramsey Hunt syndrome
Herpes zoster infection of cranial nerves
SNHL and vertigo
When does Herpes Zoster Oticus occur? (2)
Occurs when virus has been dormant after chickenpox, then reactivates
Typically only a single attack-no repeats
What are the physical features of ramsey hunt syndrome? (8)
Early: burning pain of ear, headache, malaise, fever
Late (3-7 days): vesicles, facial nerve paralysis
SNHL (7% of those with CN7 involvement)
CHL (vesicular lesions)
Vertigo
Tinnitus
Loss of taste
Dry mouth and eyes (xerostomia and xerophthalmia)
What are other infectious causes of HL?
Bacterial meningitis
Measles
HIV
What is Anoxia?
no oxygen
Up to 40% of significant birth anoxia have SNHL
Often progressive
What is hypoxia?
reduced oxygen
What is bilirubin and what condition is associated with this?
The breakdown product of hemoglobin
Hyperbilirubinemia = too much bilirubin
What is hemoglobin?
Oxygen carrying protein in red blood cell
What is the process of bilirubin? (3)
Hemoglobin breaks down into heme and globin
Heme is converted to bilirubin and carried by albumin in the liver, then gets chemically altered and excreted via bile
What is the process that causes Hyperbilirubinemia? (3)
When hemoglobin is being broken down at a faster rate than the liver processing rate, bilirubin accumulates in the body
Hyperbilirubinemia leads to jaundice
Jaundice is yellowish discoloration of skin and eyes
Liver disease can cause:
adult jaundice
Extreme hyperbilirubinemia leads to:
kernicterus
- a type of brain damage
- Causes athetoid cerebral palsy and hearing loss.
What is kernicterus? (3)
Kernicterus is a neurological condition due to bilirubin deposits into the CNS
High frequency sloping SNHL
Not a common cause of HL currently
What are 8 classification of abnormalities/disorders?
- No associated abnormalities
- External ear abnormalities
- Musculoskeletal abnormalities
- Ocular abnormalities
- Integumentary system abnormalities
- Metabolic and renal disorders
- Nervous system disorders
- Cleft and craniofacial disorders
What is a syndrome?
- Single anomaly leads to other anomalies
- Associated with Multiple congenital anomalies occurring at high frequency
- Predictable pattern of anomalies due to a specific cause/trigger/insult
What is important to remember between overlaps of syndromes?
There are many overlaps between syndromes
E.g., microtia can be seen in Goldenhar syndrome and by itself
What are preauricular pits and tags? (5)
- Hillocks fusion abnormalities
- Very common in newborns and is not usually associated with hearing loss or other anomalies
- Rarely, pits and tags are associated with other anomalies or syndromes (Branchio-oto-renal)
- Pits-excision if recurrent infections
- Tags-excision for cosmetic reasons
What is this condition?
Accessory Auricle
Give important descriptions of microtia: (6)
- 1 in 4000 newborns
- M > F (2:1)
- Unilat > Bilat (9:1)
- Right > Left (2:1)
- Usually occurs with ear canal abnormalities
- Inner ear is rarely affected
What are the 3 categories of Microtia?
Sporadic
Syndromic
( Hemifacial microsomia, Treacher Collins, Branchio-oto-renal, Crouzon)
Familial
What is aural atreasia? (2)
Absence of EAC
Congenital
What is aural stenosis? (2)
Narrowing of external auditory canal
Congenital or acquired
What are results from Aural Atresia-Hearing Assessments? (2)
- NBHS failures (unable to test)
- ABR at 2-3 mos
Normal bone conduction level
Maximal CHL (ABG 60 dB)
If normal contralateral hearing no urgent intervention
What are reconstruction surgeries for Microtia and Aural Atresia-Management?
Canaloplasty
(Microtia repair)
What hearing aids recommended if you have Microtia or Aural Atresia-Management?
Bone conduction/anchored hearing aids
Which type of BAHA is this?
Transcutaneous BAHA
What are IE Malformations in the Embryology context? (3)
- Inner ear formed from otic capsule starting at 3 weeks
- (Middle and external ear form from branchial arches starting 5-6 weeks)
- Early insults during pregnancy leads to inner ear anomalies (middle/ext ear may be normal)
- Inner ear formed by 9-10th week of gestation
- Arrest in development or aberrant development may lead to hearing loss
- Up to 20% of children with congenital SNHL have inner ear anomalies
What are the 3 parts of the labyrinth in the inner ear? (3)
- 3 SSC (orthogonal)
- Vestibule (utricle, saccule)
- Cochlea
(Bony labyrinth covers membranous labyrinth
Perilymph is in between bony and membranous portions)
Inner Ear Malformations are divided into __________________________ vs ____________________________ labyrinth and most are _________________ and _________________.
Inner Ear Malformations are divided between membranous vs osseous labyrinth and most are bilateral and symmetric.
Types of congenital inner ear malformations:
________________
________________
________________
________________
________________
and can appear as part of a syndrome or on their own
Types of congenital inner ear malformations:
Michel aplasia
Mondini anomaly
Scheibe anomaly
Alexander anomaly
Enlarged vestibular aqueduct
and can appear as part of a syndrome or on their own
What is Michel Aplasia? (6)
Complete agenesis of petrous portion of temporal bone
Very early insult
AD
External/middle ear may be normal
Anacusis
Vibrotactile devices for bilateral cases
What is Mondini anomaly?
Developmental arrest of bony and membranous labyrinth around 6th week gestation
Progressive or fluctuating SNHL
CT: only basal turn of cochlea is present
Wide vestibular aqueduct may occur
Amplification, CI
Mondini anomaly can be seen in ___________________________
ex: (6)
Can be seen in syndromic hearing loss
Waardenbug
Treacher Collins
Branchial-oto-renal
Pendred
Wildervanks
What is Scheibe Anomaly? (6)
(cochleosaccular dysplasia)
- Failed development of membranous cochlea and saccule (pars inferior) and normal SSC and utricle (pars superior)
- AR
- CT normal; MRI abnormal
- SNHL
- Amplification
Scheibe Anomaly is most common type of ______________________________ malformations and can be seen in _____________________, _________________ and _________________________________________
Most common type of congenital cochlear malformations
Can be seen in syndromic hearing loss
Usher
Waardenburg
Jervell-Lange and Nielson syndrome
What is Alexander Anomaly?
Abnormal membranous cochlear duct
AR
SNHL
Amplification
What is Enlarged Vestibular Aqueduct?
- Vestibular aqueduct is bony structure that houses the endolymphatic duct
- Both structures are enlarged
Seen on CT scans
EVA is frequently associated with syndromes or other malformations like:
____________
____________
Or occurs isolated
________________________________________
EVA is frequently associated with syndromes or other malformations like:
Mondini
Pendred
Or occurs isolated
Enlarged vestibular aqueduct syndrome
