Craniosynostosis and Positional Skull Deformities

https://en.wikipedia.org/wiki/Craniosynostosis

Introduction

The incidence of posterior flattening of the skull has become more common with the Back to Life program to help prevent SIDS. Positioning the infant in the supine position has increased the number of infants presenting to the pediatrician to evaluate unusual skull shapes. Other causes of a flattened occipital area include growth restrictions in-utero and torticollis. It is imperative to differentiate true synostosis of a suture from positional deformities.

Fontanelles and sutures as seen from above https://en.wikipedia.org/wiki/Craniosynostosis

Craniosynostosis

Defined as premature closure of the cranial sutures. 

1. Primary synostosis is defined as closure of one or more suture secondary to abnormality of skull development.
   1. Usually recognized at birth 
   2. If only one suture is affected, skull and brain growth will be normal and will result in cosmetic deformity
   3. If two or more sutures are closed, brain growth will be impaired and there will be neurologic deficits.
2. The closure of a suture will cause a bony prominence ridge along the suture line. 
3. Compensatory growth is in the direction of or parallel to the closed suture. For example, premature closure of the sagital suture will result in an elongated head (scaphalocephaly).

Recognizable syndromes associated with craniosynostosis

1. Apert's syndrome-usually both coronal sutures, cleft palate, hand, feet, and facial anomalies. Autosomal dominant
2. Crouzon's syndrome-coronal and sagital sutures, hypertelorism, exophthalmos, mid-face anomalies. Autosomal dominant with half the cases new mutations. 
3. Pfieffer's syndrome- digital anomalies.
4. Secondary synostosis- altered forces working on the developing skull
   1. Microcephaly- premature closure of the sutures without evidence of increased intracranial pressure. 
   2. Sagittal synostosis after shunting for hydrocephalus
5. Surgical Treatment
   1. Older children (>6 months) can undergo cranial vault remodeling, involving moving and reshaping the skull.
   2. Younger children (<3 months) can undergo less invasive endoscopic alteration to the skull and fixed sutures.

Deformational Abnormalities

Secondary to positional influences on skull growth. 

1. Supine position resulting in posterior plagiocephaly
   1. Sutures remain open
   2. No bony ridge or prominence along lamboidal suture line
   3. Prominence of frontal and temporal areas on the same side of occipital flattening and flattening of the frontal area on the opposite side. Ear is forward and lower placed.
   4. Evaluation- plain skull radiograph. If suture is open, no further evaluation is necessary. If closed or unclear, CT of the skull should be performed.
   5. Treatment
      1. Emphasize changing the infants position. May need to rearrange the room and use pillows to alter the child's position.
      2. the child is awake, place in the prone position as much as possible
      3. If associated with torticollis (asymmetric or abnormal head/neck position), introduce physical therapy to stretch sternocleidomastoid muscle
      4. If the above measures are not effective, a molded orthoplastic helmet worn all the time may be helpful. 
      5. Surgery rarely necessary
      6. Reassure parents

References

1. Liptak GS and Serletti JM. Consultation with the Specialist: Pediatric Approach to Craniosynostosis. Pediatrics in Review 1998
2. Rohan AJ, Golombek SG, Rosenthal AD.Infants with Misshapen Skulls: When to worry. Contemporary Pediatrics February 1999.
3. Maugans TA. The Misshapen Head. Pediatrics 2002
4. Pershing J. Positional Skull Deformities in Infants.  Pediatirics Jully 2003
5. Hutchinson L. Determinants of Nonsynostotic Plagiocephaly: A case control study.  Pediatrics October 2003
6. Hutchinson L. et al. Plagiocephaly and Brachycephaly in the First Two Years of Life:A Prospective Cohort Study. Pediatrics October 2004
7. Van Vlimmeren et al. Risk Factors for Deformational Plagiocephaly at Birth and at 7 Weeks of Age: A Prospective Study.  Pediatrics Jan 2007
8. Speltz M. Case Control Study of Neurodevelopment in Deformational Plagiocepohaly.  Pediatrics 2010 
9. Prevention and Management of Positional Skull Deformities in Infants.  Pediatrics 2012

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