30. Pediatric Neurosurgery

Question 1

define myelomeningocele

Answer 1

incomplete closure of neural tube. most significant/common form of spina bifida. problem of PRIMARY neurulation

Question 2

define spinal bifida

Answer 2

incomplete closing of the embryonic neural tube. some vertebrae are incompletely formed, and spinal cord protrudes through the opening in the bones.

Question 3

define meningocele. vertebrae? meninges? prognosis?

Answer 3

aka meningeal cyst. least common form of spina bifida. Vertebrae develop normally, but the meninges are forced into the gaps between the vertebrae. Nervous system remains undamaged so individuals with meningocele are unlikely to suffer long-term health problems, although cases of tethered cord have been reported.

Question 4

define myelocystocele

Answer 4

Problem with SECONDARY neurulation. spinal bifida where some of the spinal cord and meninges protrudes through the opening. Fluid collection.

Question 5

define tethered cord

Answer 5

Involves the pulling of the spinal cord at the base of the spinal canal, literally a tethered cord. The spinal cord normally hangs loose in the canal, free to move up and down with growth, and with bending and stretching. A tethered cord is held taut at the end, or some point in the spinal canal. In children, a tethered cord can force the spinal cord to stretch as they grow.

Question 6

define lipomyelomeningocele

Answer 6

a fatty mass covered in skin that is attached to the spinal cord. early disjunction of cutaneous and neural ectoderm.

Question 7

Define split cord malformation

Answer 7

spinal bifida with longitudinal split in cord

Question 8

define dermal sinus

Answer 8

incomplete disjunction of ectoderm.

connection from skin into spinal cord. risk for meningitis.

Question 9

define spinabifida occulta

Answer 9

Mildest form of spina bifida. The outer part of some of the vertebrae is not completely closed. The splits in the vertebrae are so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, or a birthmark. Usually asx.

Question 10

symptoms of tethered spinal cord?

Answer 10

bowel/bladder dysfunction, orthopedic deformity (hammertoes, high arch), weakness, progressive scoliosis, back pain (back pain in a child is rare, should be looked at)

Question 11

how much CSF does an adult have?

Answer 11

150 cc

Question 12

how much CSF does an adult make daily?

Answer 12

450cc because the 150 cc turns over 3x/day

Question 13

where is CSF made?

Answer 13

70% choroid plexus, rest is a transudate from ependyma (lining of ventricles and spinal cord)

Question 14

primary neurulation creates what

Answer 14

develops brain and spinal cord to S2

Question 15

what day does secondary neurulation start?

Answer 15

post-ovulation day 27

Question 16

what is the timing of primary neurulation? (on what PODs do things happen?)

Answer 16

POD 16: neural plate induced
POD 17: neural groove forms above notochord
POD 24: anterior neuropore closes
POD 26: caudal neuropores
POD 27: secondary neurulation starts

Question 17

defects caused by defects in secondary neurulation?

Answer 17

• abnormal filum terminale
• terminal lipoma
• myelocystocele

Question 18

folic acid: how much recommended per day for child-bearing aged women?

Answer 18

400 microgram/day

Question 19

folic acid: how much recommended per day for child-bearing aged women with prior child having neural tube defect?

Answer 19

4000 microgram/day. there may be an enzymatic abnormality in the folic acid pathway.

Question 20

MOMS trial: what were they comparing?

Answer 20

prenatal surgery vs postnatal repair of myelomeningocele.

Question 21

MOMs trial: results?

Answer 21

improved mental dev and motor function at 30 months in PREnatal group
no difference in cognitive scores between groups
but prenatal group had more complications, born preterm.

Question 22

80% of kids with spina bifida also have what? therefore need what?

Answer 22

also have hydrocephalus. mech: spinal cord slightly lower, may cause brainstem/cerebellum to herneate, closing flow of CSF.
therefore need a shunt.

Question 23

Three types of hydrocephalus?

Answer 23

• obstruction
• communicating
• overproduction

Question 24

define obstructive hydrocephalus

Answer 24

blockage of CSF flow

Question 25

define communicating hydrocephalus

Answer 25

poor reabsorption of CSF

Question 26

define overproduction hydrocephalus

Answer 26

rare, choroid plexus papilloma

Question 27

how does CSF content compare with serum levels for glucose, sodium, chloride?

Answer 27

CSF has 2/3 serum glucose

same sodium, same chloride

Question 28

generally, circulation of CSF?

Answer 28

lateral ventricles –> third ventricles –> fourth ventricle –> behind cerebellum -> arachnoid granules between arachnoid and dura

Question 29

biggest signs of hydrocephalus in children?

Answer 29

incr head circumference, bulging fontanelle, delayed development, loss of upward gaze, lethargy, papilledema

Question 30

symptoms of hydrocephalus in children?

Answer 30

irritability, n/v, headache, lethargy

Question 31

three treatments for hydrocephalus?

Answer 31

• ventriculoperitoneal shunt
• endoscopic third ventriculostomy
• choroid plexus cauterization

Question 32

endoscopic third ventriculostomy: what is it?

Answer 32

endoscope into lateral ventricle, scope drive through foramen of monroe and floor of third ventricle is punctured.

Question 33

endoscopic third ventriculostomy: outcomes

Answer 33

96% success for aqueductal stenosis. better if also do choroid plexus cauterization

Question 34

shunt: outcomes

Answer 34

infection rate 5-12%. shunt will eventually get clogged up with debris, will have to replace.
use ETV first to avoid these problems.

Question 35

define Chiari I malformation

Answer 35

cerebellar tonsils > 5mm below foramen magnum

Question 36

define Chiari II malformation

Answer 36

Spina bifida only: pts with myelomeningocele. brainstem herniates through foramen magnum

Question 37

symptoms for Chiari I malformation?

Answer 37

occipital, exercise induced headache
cranial neuropathy
cord dysfunction
syrinx (collection of CSF into cyst)

Question 38

Symptoms for Chiari II malformation?

Answer 38

resp distress in infant

headache or brainstem dysfunction in older kid

Question 39

treatment for Chiari malformations?

Answer 39

many do not need treatment; surgery if sx need to be treated

Question 40

definition of spasticity

Answer 40

resistance to passive movement. can get contractures if get stuck in certain postures.

Question 41

definition of dystonia

Answer 41

neuro movement disorder, sustained contractions cause twisting or repetitive movements or abnl postures

Question 42

define rhizotomy

Answer 42

selective destruction of problematic nerve roots. can reduce hypersensitivity, which decr spasticity.