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CRANIOSYNOSTOSIS
DEFINITION:
A congential anomaly of the CNS characterized by premature closing of one or more cranial sutures due to abnormalities of skull development.
EPIDEMIOLOGY:
 incidence: ½,000 live births
 age of onset:
 most cases evident at birth
 risk factors:
 familial - autosomal dominant and autosomal recessive
 chrom.#: 7p21.3-p21.2
 gene: ?
 M = F (except in sagittal type where M > F (4:1))
 genetic syndromes account for 10-20% of cases:
 Apert Syndrome
 Chotzen Syndrome
 Pfeiffer Syndrome
 Carpenter Syndrome
 Crouzon Syndrome
CLASSIFICATION:
1. Primary
 etiology unknown but may involve abnormal cranial suture development which leads to inactive cranial suture growth re-sulting in the failure of adjacent cranial bones to increase in size perpendicular to the affected suture -> lack of growth of skull perpendicular to affected suture and overgrowth of skull parallel to the affected suture
2. Secondary
 results from failure of brain growth and expansion
TYPES:
Suture % Skull Shape
Sagittal 40 scaphocephaly
Bicoronal 20 brachycephaly
Unicoronal 15 plagiocephaly (frontal)
Coronal + Sagittal 10 acrocephaly
Total 10 microcephaly
Metopic 4 trigonocephaly
Lambdoid + Sagittal 1 plagiocephaly (occipital)
CLINICAL FEATURES:
1. Craniosynostosis
 abnormally-shaped head
 prominent bony ridge over affected suture
2. Complications
 hydrocephalus
 increased intracranial pressure (ICP)
 developmental delay
3. Sagittal Craniosynostosis
 head shape: scaphocephaly
 long and narrow skull (increased A-P diameter)
 prominent occiput and broad forehead
 small or absent anterior fontanelle
 usually not associated with other congenital malformations, a family history, or complications
 normal neurologic examination
4. Bicoronal Craniosynostosis
 head shape: brachycephaly
 wide and short skull (decreased A-P diameter)
 characteristic deformity of orbits:
 shallow with poorly formed orbital ridges & frontal bone leads to a decreased orbital volume and results in:
 proptosis -> corneal damage
 orbital hypertelorism
 nasolacrimal duct narrowing -> conjunctivitis
 decreased visual acuity (optic nerve damage)
 complications:
 hydrocephalus +/- increased ICP
 associated anomalies:
 choanal atresia and high-arched palate
 hypoplasia of maxilla with prominent lower jaw and poor dental occulsion
 associated syndromes:
 Acrocephalosyndactyly Syndromes
5. Unicoronal Craniosynostosis
 head shape: plagiocephaly (frontal)
 marked craniofacial asymmetry
 unilateral flattening of the forehead
 elevation of ipsilateral orbit and eyebrow
 prominence of ipsilateral ear
 ipsilateral orbital ridge poorly formed -> proptosis and malalignment of eyes
6. Coronal + Saggital Craniosynostosis
 head shape: acrocephaly
 cone-shaped head
 anterior fontanelle may remain widely opened
 may be associated with increased ICP
 associated syndromes:
 Pfeiffer Syndrome
7. Total Craniosynostosis
 head shape: microcephaly
 skull has a normal shape but small
 may be associated with increased ICP and developmental delay
8. Metopic Craniosynostosis
 head shape: trigonocephaly
 keel-shaped forehead (prominent frontal ridge visible externally) -> triangular-shaped
 thickened frontal bones
 deformity of orbits:
 hypotelorism
 flattened orbital ridges
 may be associated with developmental abnormalities of the fore-brain
9. Lambdoid + Sagittal Craniosynostosis
 head shape: plagiocephaly (occipital)
 flattened occipital bone
 bulging of frontal bone
 may be unilateral
INVESTIGATIONS:
1. Imaging Studies
1. Skull X-Ray/CT
 fused sutures
MANAGEMENT:
1. Team Approach
 multidisciplinary pre-op evaluation
 Paediatrics, Surgery, Neurology, Psychology, Genetics,
 Ophthalmology
 to investigate for other malformations or complications, i.e., hydrocephalus or increased ICP
2. Craniotomy
 directed to correct the skull to prevent intracranial and oph-thalmologic complications
 should be corrected within the 1st year of life
 elevation and contouring of bones easier
 reossification and remodelling occur rapidly
 facial involvement still minimal
3. Supportive
 genetic counselling
 recurrence risk
 rule out syndrome
 multidisciplinary Craniofacial Team
 follow for
 disorders of speech and hearing
 respiratory or feeding problems due to deviated nasal septum or choanal atresia
 long term ophthalmologic problems
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