E. R. Flotte
MD, 2009
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send comments and corrections to admin@flotte2.com
·
Head
Circumference: Neonate: 1cm/wk; 1-3m: 2cm/mo; 4-6mo:
1cm/mo; 6-12mo: 0.5cm/mo
·
Estimate of pediatric blood volume: 90-100ml/kg for
premature infant, 80mg/kg for term infant, 75ml/kg for 1-12mos, 70ml/kg for
>1 year
Craniosynostosis
·
Types
o Sagittal:
scaphocephaly (most common)
o Coronal:
causes “harlequin eye”
o Lambdoid
o Metopic (frontal): trigonocephaly.
o Oxycephaly,
turricephaly, acrocephaly: lambdoid and coronal (cone head, oxycepaly
= pointed, turricephaly = flat forehead).
o Klebblattschadel
(Clover-Leaf): all sutures except squamosal. Image: 3D CT reconstruction – Reynolds MR JN:P9/08
o Nonsynostotic
scaphocephaly: “sticky sagittal suture” (JN:P 8/04)
·
Causes increased ICP in 11%.
·
Ridge often forms over synostosis
·
Diagnosis:
·
Treatment: Surgery – for cosmesis
& brain development. Craniectomy with reconstruction (often with plastic
surgeon).
o
Generally done 3-12 months old.
o
Metopic/coronal:
craniotomy and orbital bar advancement
o
Saggital:
“strip” craniectomy (some do “endoscopic” thru 2
transverse incisions), 3-12 mos
·
Deformational
Plagiocephaly (“Lazy Lambdoid”): positional occipital flattening,
mimics synostosis.
o
Treated by repositioning (eg prone) or molding helmets
o
Review: Robinson S JN:P4/09
Macrocephaly
·
>60cm.
Usually due to untreated hydrocephalus
·
Vault
reduction cranioplasty: Mathews MS JN:P10/07
·
May present in children or adults
·
Locations:
o
Occipital: more common in caucasians
o
Frontal (sincipital, frontoethmoidal): more common in asians.
o
Sinonasal: associated with “nasal
gliomas” - benign intranasal heterotopias of glial tissue
o
Sphenoidal / temporal: thru
greater wing of sphenoid
o
Spontaneous
temporal encephalocoeles: Wind JJ NF 12/08
o
Parietal
o
Acquired
meningoencephalocoele: post-surgical or
post-traumatic
·
Meckel’s syndrome: encephalocoele + dysplastic kidneys, cardiac probs, facial clefts.
·
50% develop hydrocephalus within 1 month
·
May
cause CSF rhinorrhea
·
Treatment:
surgical excision & dural closure.
o
Sinonasal: combined bifrontal
transcranial and transnasal
approach. See CSF Leak for
intracranial technique.
Sinus
pericranii
·
Large subcutaneous venous sinus connecting
with dural venous sinus.
·
Presents as blue, reducible scalp
mass.
·
Injury may cause hemorrhage, air
embolism
·
Treatment: Surgical removal (or
endovascular obliteration of communication)
Dermoid cyst:
Inion is most likely site for intracranial extension
Growing
skull fracture: 75% of patients are <1yo. Rare >3yo. Requires >3mm diastasis
to occur.
Cephalohematoma: subperiosteal, does not cross sutures, Caput succedaneum in subcutaneous fat, crosses sutures; Subgaleal hematoma; all may cause significant
blood loss, check Hct.
Arachnoid Cyst
·
Can occur anywhere. Most common in middle fossa (seizures), suprasellar (visual loss, precocious puberty, bobble-headed
doll).
·
May present at any age
·
Symptoms: seizures, deficits,
headache, visual deficits, developmental delay, endocrinopathies.
Can rupture, cause hyperostosis or hydrocephalus.
·
Associated with intracystic
and subdural hemorrhage.
·
Natural history is variable: may
enlarge, regress, or remain static
Treatment
·
Most recommend treating only if symptomatic
(intractable headaches, seizures, focal deficits) or increasing size
·
Surgical Options:
- Needle/burrhole drainage: most
recur (not recommended)
- Craniotomy
& fenestration: most effective if fenestrated
into basilar cisterns.
- Improves
seizure control and focal deficits; visual disturbances, developmental
delay, and endocrinopathies persist
- Cystoperitoneal
shunt: usually if fenestration fails. Shunt
dependency may develop.
- Endoscopic
fenestration
- Suprasellar:
Transcallosal ventriculocystostomy
(endoscopic).
HCP may increase after treatment. Concomitant hydrocephalus usually
requires VP shunt. Subfrontal fenestration not
recommended
o
All cases presenting with
hydrocephalus required VP shunting regardless whether fenestration was
performed.
·
Outcome: Improvement (keyhole crani): Hemiparesis & CN6
palsy 100%, headaches 66%, seizures 50%.
Chiari I
Malformation
·
3-5mm
tonsillar herniation. Controversial whether degree of
herniation correlates with symptoms or postop improvement.
·
Headaches:
classically occipital, worsen w/Valsalva.
o Also cranial nerve, brainstem &
spinal cord syndromes. Downbeat
nystagmus.
·
Syringomyelia occurs in 60% (may
be thoracic or lumbar)
·
25% have hydrocephalus
(HCP); 25% craniocervical junction abnormalities; 20% scoliosis; 5% Klippel-Fiel, 5% GH deficency.
Not associated with other developmental brain abnormalities.
·
No recommendation
for participating in athletics.
·
Diagnosis:
MRI (brain, craniocervical junction).
o
“Peg-shaped”
tonsils are more likely to be symptomatic than normal, rounded tonsils. Also
obliteration of CSF in FM around brainstem.
o
Obtain preop flexion/extension c-spine x-rays to r/o
instability before decompression.
o
Check for hydrocephalus on MRI.
o
Cine-MRI may demonstrated
decreased CSF flow in the foramen magnum but predictive value is controversial.
·
Treatment
o
Asymptomatic: Most favor observation only if asymptomatic, (Schijman E
CNS04); although some advocate prophylactic surgery (Navarro R CNS04)
o
Both Chiari
malformation and syrinx may spontaneously improve; many patients remain
asymptomatic (Novengo F JN:P9/08)
o
Symptomatic:
o
Chiari
decompression for significant symptoms (below)
o
If
concomitant hydrocephalus is present, consider VP shunting first
o
Decompress for symptomatic syrinx.
§ Debatable whether to treat syrinx if asymptomatic.
Favored for progression on MRI
·
Nishizawa N9/01: 8 of 9 patients with syrinx remained
asymptomatic; syrinx size did not correlate with symptoms
§ Persistent syrinx: repeat decompression or shunt syrinx (Aghakhani N N2/09
)o
Anterior compression (VBSC): transoral odontoidectomy
BEFORE decompression.
o
Scoliosis: improves with decompression; perform
spinal fusion only for Cobb angle >50º. (JN8/03)
o
3x3cm suboccipital craniectomy, C1 (or lower) laminectomy,
duraplasty, (some cauterize tonsils).
o
If extensive scarring can use ultrasound to find 4th
ventricle.
o
Postop: watch for sleep apnea. 50-85% success.
o
SE: “cerebellar sag”:
requires cranioplasty. Recurrent CSF leak – think
hydrocephalus
§ CSF leak:
skin closure. R/O hydrocephalus. Lumbar drain. Reclose graft in OR.
·
Videos: CNS
University of Neurosurgery
·
100% associated with myelomeningocoele.
90% have hydrocephalus.
·
Treat hydrocephalus with shunt 1st
o
4th ventricular shunt (low pressure valve)
§ Lateral
ventricles communicate with the cyst in 50% - requires iohexol
CT to identify.
·
Source: Neonate = germinal matrix; full-term =
choroid plexus.
·
Hydrocephalus ex
vacuo: not true hydrocephalus, due to cerebral atrophy
·
Aqueductal
stenosis: some are X-linked. Consider endoscopic 3rd ventriculostomy
·
Imaging: Ventriculomegaly, ballooned frontal horns, enlarged
temporal horns, transependymal edema
o
Ventriculoperitoneal (VP) Shunt
§ Common shunt
valves: PS Medical, Cordis (Hakim), Holter valve (with Rickham
reservoir)
o
Ventriculoatrial (VA) Shunt: Causes SBE, shunt nephritis
(immune).
§ Confirm
placement with flouro and/or EKG. Use atrial tubing.
§ Obtain CXR q
year. Revise when tip
@ T4.
§ Always make
sure system has valve to avoid blood reflux into head (before doing distal revision)
§ Over 6yo can
use Seldinger technique (vs
cut-down – facial v.) in jugular or subclavian
o
Ventriculopleural Shunt: Place b/t 2nd
& 3rd ribs
o
Ventriculo-sagittal sinus Shunt: Infants, thru anterior fontanelle
o
Torkilsden shunt: to cisternal space
o
Endoscopic 3rd
ventriculostomy:
§ Venrticulostomy left in place postop.
§ Consider
placement of Ommaya reservoir for emergency (N7/03)
§
Videos: CNS
University of Neurosurgery
§
AANS Course: Selecting
Patients For Endoscopic Third Ventriculostomy (ETV) (Rekate HL)
§ Use
prophylactic antibiotics before dental procedures, bladder instrumentation
§ Most
recommend removing shunt, placing ventriculostomy,
and replacing shunt when CSF in clear.
§ Limited data
for leaving shunt in place and treating with antibiotics only.
§ Antimicrobial-impregnated
shunts used (Bactiseal; Codman)
§ Antimicrobial-impregnated
suture in shunt surgery: Rozzelle CR JN:P8/08
o
Shunt Malfunction: common
causes include occlusion (e.g. choroid plexus), catheter fracture
§ AANS
Course: EVALUATION
OF SHUNT MALFUNCTION
·
Patients with shunts should not be restricted from
playing sports (N5/04)
·
Videos: Drake
JM N2/08S (pediatric), Bergsneider M N2/08S (adult)
·
Audio: Hydrocephalus:
History and Current Perspectives – Madsden JR
§ Drain at preset
minimum/maximum pressures – available in low, medium, high
o
Flow-limiting: Orbis Sigma
(Integra), Delta (with anti-siphon device)
(Medtronic)
·
Antibiotic-Impregnated catheters
o
Manufacturers: Bactiseal (Codman), Ventriclear
(Cook)
·
Reviews: Drake JM N2/08S (pediatric), Bergsneider M N2/08S (adult)
·
Occurs due to shunting for communicating
hydrocephalus (IVH, meningitis)
·
Causes headaches, ataxia, quadriparesis,
apnea, bradycardia.
Subgaleal/subperiosteal hematoma: avoid aspirating, follow Hct
·
Type II: Midbrain or
thalamic AVM that drains into VOG. Presents in adults as SAH, ICH, dementia.
·
Treatment: Transarterial or
transvenous (transtorcular)
embolization.
o
Some which partially thrombose
will go on to completely thrombose
·
Due to defect in primary neurulation
(3-4 weeks). Covered by thin membrane.
·
Almost all patients have associated Chiari II malformation
·
Myeloschisis: Placode is ventral
·
Risk factors: Maternal low
folate, valproate, Tegretol. 3% risk on subsequent births.
o
Check for hydrocephalus preop (CT/US)
o
Repair may be planned electively if diagnosed
prenatally.
o Delivery via C-section is preferred if leg motion is detected (Perry VL N9/02)
·
Complications: Tethered cord, Chiari II,
syrinx, hydrocephalus.
o
Urology, orthopedic consults needed. Bladder
catheterization.
o
With neurologic deterioration always check for shunt
malfunction first.
·
Causes of neurologic decline in patients with history
of myelomeningocoele:
o
Cover defect with saline-moistened dressing
o
Close MM within 24hrs whether open or not. Decreases infection, doesn’t change function.
o
Intrauterine myelomeningocoele
repair has been performed
o
Avoid contacting placode
with betadine or other solutions (general belief)
o
Oval incision around junction of placode
and intermediate zone (abnormal epidermis).
o
Avoid including epidermis with placode
– may for epidermoid, etc
o
Laminectomy of last normal level to identify normal dura.
o
Dissect dura around placode. Preserve nerve roots
·
Review: Perry VL (Albright) N9/02 (Operative
Nuances)
Occult spinal
dysraphisms (OSD)
·
Cutaneous abnormality: “Fawn’s tail”, lipoma,
dermal sinus tract, dimple, etc.
o
May not correspond to level of dysraphism.
o
Fawn’s tail very suggestive of diastematomyelia.
o
Capillary hemangiomas are
normal near occiput, 10% OSD if thoracolumbar.
·
In general not associated with brain abnormalities.
·
Maternal AFP not elevated. Dx:
MRI +- xrays.
·
Usually neurologically normal, no associated
abnormalities. Rule out hydrocephalus.
·
May contain aberrant nerve roots/ gliotic
tissue. May occur off-midline.
·
Treatment: elective
repair. Usually ends in narrow neck.
·
AKA spinal lipoma of the
conus (SLC).
·
Usually have cutaneous stigmata. Not associated with
Chiari II.
·
May be off midline (ipsilateral LE more affected),
contain CSF.
·
Dorsal insertion
(type I): Nerve roots lie ventral. Usually contiguous with subcutaneous fat.
o
Some include transitional (type II): inserts on
conus, no normal tissue below defect
o
Type I occur during primary neurulation,
III during secondary neurulation.
·
Can contain teratomas (i.e. bowel).
·
Symptoms: Usually
normal in infancy. Causes tethered cord - leg pain, LE neurologic
deficit.
·
Diagnosis: MRI. Check for hydrocephalus
o
Surgery if symptomatic, scoliosis etc.
o
Dorsal: Can use laser to remove fat, close pia.
o
Use SSEP, nerve root stimulation
o
Keeping the patient prone postop may reduce CSF leak
and retethering(?)
o
Neurogenic bladder is
most common complication (Drake JM NF8/07)
·
Cutaneous abnormality (75%) may not correspond to diastem. Fawn’s tail most common.
·
May consist of 1 or 2 dural tubes; may have
duplication of spinal cord (diplomyelia).
o
Diastem may
incompletely span canal, may be dorsal or ventral; may not have bony diastem.
o
May have lipomatamous filum - Remove septum before detethering.
o
May be aberrant nerve roots in midline near septum,
can sacrifice.
Butterfly vertebrae/ Hemivertebrae: may mimic
fracture
·
Asymptomatic may be followed if not enlarging, no
chance of pregnancy.
·
May end extradually or
extend intradurally.
·
In cervical or thoracic spine it can end in central
canal.
·
Lumbar can terminate in filum
or intradural dermoid cyst (may be in filum or intramedullary).
·
May be associated with a lipoma.
·
May have purulent drainage. Can cause recurrent
meningitis.
·
Sacral or coccygeal sinuses
don’t need to be explored, lumbar do.
·
Probing and contrast injection may cause meningitis.
·
If extends to dura, open dura. Can require
laminectomies to T12.
·
Attempt total removal initially – will recur with
significant scarring
Myelocystocoele: see Muthukumar JN:P
8/07.
·
Excise dilated cystic tissue, preserving anterior
nerve roots
Other
Pediatric Spinal Disorders
Spinal tumors in infants: neuroblastoma, Wilm’s (biopsy first)
Intramedullary Spinal Cord
Tumors: astrocytoma, ependymoma
Atlantoaxial rotary subluxation
·
May be traumatic or spontaneous – common after upper
respiratory infection (Grisel’s syndrome)
·
Secondary spasm in sternocleidomastoid on opposite
side of head tilt (“cock robin”)
·
Xray, thin cut CT
with reconstructions
·
Most resolve spontaneously. If mild may treat with
soft collar and activity restriction
Adolescent
idiopathic scoliosis:
·
Generally curve is convex to the right (to the left
is indication for MRI)
·
Treatment: observation (<20°), orthoses,
operation (>40° that progress despite bracing)
o
Anterior vertebrectomy with
removal of pedicle and posterior decompression and stabilization
Neuromuscular
Spinal Deformities
Spondylolysis (Isthmic Spondylolisthesis)
Congenital Cervical Spinal Abnormalities
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