11-25 Pedi Neurosurg

Question 1

3 general types of spina bifidia (wiki)

Answer 1

[IMAGE]

Question 2

Myelomeningocele

Answer 2

both spinal cord/cauda equina AND dura are outside the body

—caused by Incomplete closure of neural tube

Question 3

, meningocele

Answer 3

only the dura is in the cyst

Question 4

, myelocystocele

Answer 4

—error in secondary neurulation

Question 5

, lipomyelomeningocele

Answer 5

—fat grows into spine cord area

—caused by early disjunction in secondary neurulation

Question 6

, split cord malformation

Answer 6

look up

Question 7

, dermal sinus

Answer 7

—Incomplete disjunction of ectoderm

—can present on exam as deep dimple within gluteal fold

Question 8

, tethered spinal cord

Answer 8

several causes including: Tight filum terminale, Lipomeningomyelocele, Split cord malformations, Dermal sinus tracts, others
—all involve the pulling of the spinal cord at the base of the spinal canal

Question 9

spina bifida occulta

Answer 9

the outer part of some of the vertebrae is not completely closed splits are so small that cord doesn’t protrude
—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
—10-20% of population have it!
—usually benign

Question 10

symptoms of tethering

Answer 10

—bowel/bladder dysfunction
—orthopedic deformity (e.g. high arches, hammertoes)
—weakness
—progressive scoliosis
—back pain (rare in kids, so investigate)

Question 11

neurulation time marks (just get the gist)

Answer 11

POD* 16 - neural plate induced
POD 17 – neural groove forms
POD 24 - ant neuropore closes
POD 26 – caudal neuropore closes
POD 27 – secondary neurulation – starts 
*post ovulation day

Question 12

dimples on babies backs

Answer 12

be worried if ABOVE the gluteal fold (ass crack)

—below gluteal fold common and likely benign (though could be communication called “dermal sinus”)

Question 13

primary neurulation

Answer 13

cells surrounding the neural plate direct the neural plate cells to proliferate, invaginate, and pinch off from the surface to form a hollow tube

Question 14

secondary neurulation

Answer 14

the neural tube arises from a solid cord of cells that sinks into the embryo and subsequently hollows out (cavitates) to form a hollow tube.

Question 15

folic acid recommendations

Answer 15

—400 mcg/day in all women of child-bearing age

—4000 mcg/day in women w/ previous child w/ neural tube defect (may be enzymatic abnormality in the folic acid pathway)

Question 16

normal level of the end of the conus medularis

Answer 16

~L1

Question 17

Why do 80% of kids w/ spina bifida need a shunt?

Answer 17

—spina bifida causes obstruction (e.g. deformity tugs downward on cord) of CSF outflow
—hydrocephalus develops —> resp failure if bad

Question 18

Where is CSF made?

Answer 18

Choroid plexus makes about 70% of spinal fluid; rest is transudate from ependyma

Question 19

Chemistry ∆s between CSF & plasma?

Answer 19

CSF has 2/3 serum glucose

—similar sodium and chloride content

Question 20

Functions of CSF

Answer 20

—Cleansing - wash away potentially noxious byproducts of metabolism
—Communication - proteins may play a role in cellular communication. Variation in proteins (such as APP) correlate with ventricular size
—Protection - protects and cushions the brain
—Cushioning - pressure dampening of the pulse wave from blood vessels (if not there to do so, syrinx can develop)

Question 21

causes of hydrocephalus outside the head?

Answer 21

hepatitis—drainage of CSF thru choroid plexus is PASSIVE, therefore incr CVP decr gradient between CSF and venous system decr’ing the amount of CSF that can passively drain into venous system

Question 22

categories of hydrocephalus

Answer 22

• Obstructive (Blockage of CSF flow)
• Communicating (Poor reabsorption of CSF)
• Overproduction of CSF (Rare, e.g. Choroid plexus papilloma)

Question 23

s/sx of hydrocephalus

Answer 23

Headache, lethargy, blurry vision, emesis, obtundation, lack of upward gaze

Question 24

ETV tx for hydrocephalus

Answer 24

endoscopic third ventriculostomy;

—better outcomes than shunt (fewer need of repeat surg to fix occluded catheter)

Question 25

dystonia vs. spasticity

Answer 25

spasticity = resistance to passive mov't
dystonia = random, uncontrolled mov'ts

Question 26

surgical tx options for spasticity

Answer 26

Selective Dorsal Rhizotomy, baclofen pump, deep brain stimulation in globus pallidus interna

Question 27

Chiari malformation - general definition

Answer 27

cerebellar tonsils below the foramen magnum

Question 28

Chiari I vs. Chiari II malformation

Answer 28

Chiari I = Cerebellar tonsils > 5mm below foramen magnum
Chiari II = Descent of cerebellar vermis; Brainstem herniates through foramen magnum; Only in patients with myelomeningocele

Question 29

S/Sx Chiari I

Answer 29

—Occipital, valsalva (i.e. exercise) induced headache
—Cranial neuropathy
—Cord dysfunction
—Syrinx

Question 30

S/Sx Chiari II

Answer 30

Respiratory distress in an infant

—Headache or brainstem dysfunction in older kid

Question 31

When do to Chiari surg?

Answer 31

Many do not need surgery (often incidental finding on head imaging for other reason)
—Surgical can help if patient has sx

Question 32

Surg options for epilepsy

Answer 32

Grid placement with tailored cortical resection and brain mapping
—Functional hemispherectomy, corpus callosotomy
—Vagal nerve stimulator