Congenital Hearing Impairment- Aetiology and Risk Factors. Flashcards Preview

Audiology and ENT Yr2 > Congenital Hearing Impairment- Aetiology and Risk Factors. > Flashcards

Flashcards in Congenital Hearing Impairment- Aetiology and Risk Factors. Deck (28)
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1
Q

Deafness may be as a result of _________ or _____ loss.

A

Conductive

Sensorineural

2
Q

What structures does conductive hearing loss involve?

A
  • Canal

- Middle ear

3
Q

What structures does sensorineural hearing loss involve?

A
  • Cochlea
  • Cochlear Nerve
  • Brain.
4
Q

What does congenital mean?

A

You are born with it.

5
Q

Name the features of conductive hearing impairment.

A
  • Involves mostly the middle ear
  • Most commonly Otitis Media with Effusion
  • Mild
  • Self-limiting
6
Q

Name the features of sensorineural hearing impairment.

A
  • Involves mostly the cochlea (& auditory nerve)
  • Congenital (or acquired early)
  • Permanent
7
Q

Describe the clinical picture if congenital hearing impairment.

A
  • Varies in severity (mild, moderate, severe and profound).
  • Is Unilateral or Bilateral
  • Can be static or progressive (gets worse)
  • Various aetiologies.
8
Q

What has an incidence of 1.3 per 1000 live births?

A

Bilateral Hearing Impairment of 40 dB.

9
Q

Why is hearing important?

A
  • to develop speech and language
  • for behaviour- don’t react to sound so pathways won’t develop
  • for education eg. classroom environment
  • Employment- can’t hear= poorer opportunities.
10
Q

Explain what is meant by the window of opportunity.

A

It’s thought that by age 2, it’s too late to have sound input.

11
Q

What are the 2 types of cause of congenital hearing impairment?

A

1/3 Acquired

2/3 Hereditary (Genetic )

12
Q

When can acquired cases of congenital hearing impairment occur?

A
  • Prenatal (before birth)
  • Perinatal (during birth)
  • Postnatal (shortly after birth)
13
Q

What are the prenatal causes of congenital hearing impairment?

A

Infection eg. rubella, syphilis, toxoplama, CMV

14
Q

What are the perinatal causes of congenital hearing impairment?

A
  • Premature baby- in SCBU (special care baby unit)

- Perinatal probelms eg. hypoxia, antibiotics, jaundice

15
Q

What are the postnatal causes of congenital hearing impairment?

A

Meningitis
Mumps
Measles
Head Injury

16
Q

What does meningitis do to affect hearing?

A

It blocks up the cochlea (6-8 weeks or no chance of cochlear implant).

17
Q

How is congenital hearing loss identified?

A

Babies are screened in the hospital.

18
Q

2/3 of congenital Hearing Impairment is down to _______ causes.

A

Genetic.

19
Q

In genetic cases, 25% are ________ and 75% are _____________.

A

Syndromal (associated w/ syndromes)

Non-Syndromal (no warning, random, fam have normal hearing).

20
Q

Name the syndromic genetic causes of congenital hearing impairment.

A
  • usher
  • pendred (thyroid symptoms, mild bump to head=lose ehearing)
  • Stickler (no chin)
  • Waardenberg (white patch, wide apart eyes)
  • Jervell and Lange-Nielsen (heart problems too).
21
Q

What are the Non-Syndromal genetic causes of congenital hearing impairment?

A
  • Autosomal recessive inheritance (80% of cases)- parents normal, past generations passed down- connexin 26 mutation
  • Autosomal dominant inheritance (15% of cases)- family history
  • Sex-linked inheritance eg. missing X chromosome- turner’s syndrome.
  • Mitochondrial Inheritance- can’t process gentomyosin= hearing loss.
22
Q

What should we ask in the clinic?

A
  • Family History
  • Normal Pregnancy?
  • Normal Delivery?
  • SCBU (special care baby unit)?
  • Jaundice?- enough to need phototherapy?
  • Head Injury?
  • Severe illnedd in hospital?- otoxic drugs?
23
Q

What should be looked for in clinic?

A
  • Syndromes eg. dysmorphic appearance
  • Abnormalities around the ear, head and neck
  • Otoscopy
  • Audiometry
  • If bit older- developmental delay? problems with speech?
24
Q

What is the most common congenital anomaly?

A

Deafness.

25
Q

The implications for congenital hearing impairment are ______________.

A

Serious.

26
Q

There’s __________ and ____________ causes of congenital hearing impairment.

A

Genetic, Environmental

27
Q

_________ is more important for treatment than the underlying cause.

A

Severity.

28
Q

What may children need if they have congenital hearing impairment?

A

A Cochlear Implant.