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)