5. Paediatrics (Neuro)

Question 1

Choanal atresia (5)

Answer 1

Results from oronasal membrane that separates the nasal cavity from the oral cavity.
Can be unilateral or bilateral.
Classic Hx is can’t pass NG tube
Most important finding is thickening of the vomer.
Associated with CHARGE syndrome.

Question 2

Congenital piriform aperture stenosis (5)

Answer 2

Due to abnormal development of the medial nasal eminences, and subsequent failure of formation of the primary plate.
Piriform aperture of the nasal cavity is stenotic, and the palate is narrow.
Classically associated central maxillary MEGA-incisor.
Midline defects of the brain (corpus callosal agenesis and holoprosencephaly) are associated.
Needs brain imaging

Question 3

Branchial cleft cyst (5)

Answer 3

Several types, commonest is 2nd branchial cleft cyst (95%).
Angle of the mandible is classic location.
Can get infection but often asymtomatic.
Extension of the cyst between the ICA and ECA (notch sign) just above the carotid bifurcation is pathognomonic.

Question 4

Lateral cyst in the neck =

Answer 4

Branchial cleft cyst

Question 5

Midline cyst in the neck =

Answer 5

Thyroglossal duct cyst.

Question 6

Fibromatosis coli (4)

Answer 6

Benign mass in the sternocleidomastoid in neonates, presents with torticollis (chin points to opposite side).
US can look scary, but is just enlarged SCM.
Sometimes looks like 2 of them, because SCM has two heads.
Self limiting, but some need passive physical therapy

Question 7

Retinoblastoma (4)

Answer 7

Calcifications present in 90%.
Can have bilateral (or trilateral involving the pineal gland with pineoblastoma).
Unilateral ones are sporadic, and the bilateral and trilateral ones are autosomal dominant, related to chromosome 13.
RB suppressor on 13 links up with lots of other tumours (melanoma, fibrosarcoma, osteosarcoma)

Question 8

Orbital calcifications DDx (5)

Answer 8

Under 3
- Retinoblastoma
- CMV
- Colobomatous
Older than 3
- Toxoplasmosis
- Retinal astrocytoma

Question 9

Low lying cord/tethered cord. (5)

Answer 9

Canal grows faster than the cord, so a fixed attachment “tethering” results in cord stretching and subsequent ischaemia.
Can be primary (isolated) or secondary (associated with meningocele, filum terminale lipoma, or trauma).
Secondary types on MRI will show associated mass or fluid collection.
Primary on US will show low conus (below L2) and thickened filum terminale (>2mm).
Meningomyelocele is associated with Chairi malformations, lipomyelomeningocele isn’t.

Question 10

Tethered cord trivia (4)

Answer 10

Anal atresia = high risk for occult cord problems, including tethering. should get screened.
Low lying/tethered cords linked closely with spina bifida.
Low dimples (below gluteal crease) do NOT need screening.
High dimples (above gluteal crease) need screening.

Question 11

Periventricular leukomalacia (5)

Answer 11

Due to ischaemic/haemorrhagic injury, typically from hypoxic insult during birth.
Risk factors
- Premature, low birth weight
Favours watershed areas (classically white matter dorsal and lateral to lateral ventricles).
Eventually cavitates into periventricular cystic changes, occuring 1-3 weeks post injury. Difficult to see on imaging before this point.
50% will develop cerebral palsy

Question 12

Germinal matrix haemorrhage (6)

Answer 12

Seen in premature infants.
By 32 weeks, germinal matrix is only present at the caudothalamic groove.
By 36 weeks, no germinal matrix left (no GM = no GM haemorrhage).
Earlier they’re born, the more common these are.
Up to 40% occur in the first 5hrs. 90% occur by day 4.
Will always be in a premature infant, usually earlier than 30 weeks.

Question 13

Premature suture closing buzzwords (5)

Answer 13

Sagittal: Dolichocephaly (long and skinny)
Metopic: Trigonocephaly (pointed forehead)
Coronal: Brachycephaly (also gets orbit issues)
Unilateral lambdoid: Phagiocephaly
Bilateral lambdoid: Turricephaly