Significance of Beaten Copper Appearance on Skull Radiographs in Children with Isolated Sagittal Synostosis Deepak Agrawal, Paul Steinbok, D Cochrane Division of Neurosurgery, UBC and BC Children’s Hospital, Vancouver, Canada

Raised ICP in Single suture Synostosis Noted in 14% - 24% of the children Renier D, Sainte-Rose C, Marchac D, Hirsch JF: Intracranial pressure in craniostenosis. J Neurosurg 57: , Another 38% have ‘borderline’ ICP Thompson DN, Malcolm GP, Jones BM, Harkness WJ, Hayward RD: Intracranial pressure in single-suture craniosynostosis. Pediatr Neurosurg 22: , 1995.

Measuring ICP problematic Absence of normative values Ethical considerations Increase in ICP in children with single suture craniosynostosis is low-grade and chronic Camfield PR, Camfield CS: Neurological aspects of craniosynostosis, in Cohen MM (ed) Craniosynostosis: diagnosis, evaluation, and management. New York, Raven Press, 1986, pp

In absence of ICP monitoring… Indirect E/O raised ICP Symptoms of ↑ICP Beaten Copper Appearance (BCA) on skull radiographs

Symptoms of chronic ↑ICP Headache-Classical symptom Head banging, episodic screaming

Beaten Copper Appearance (BCA) Thought to correspond to the gyral pattern of the underlying brain Significance has been debated, but is generally felt to be a ‘normal’ finding in children Du Boulay G: The significance of digital impressions in children's skulls. Acta Radiol 46: , 1956.

Although the authors concluded BCA to be normal in children with craniosynostosis However, in children <18 months, BCA highly specific for ↑ICP

Also…. Raised ICP was defined as >15mmHg even in infants (normal <5mmHg) No attempt made to correlate with symptoms of ↑ICP

OBJECTIVE Look for any correlation between BCA and symptoms suggestive of intracranial hypertension in children operated for isolated sagittal synostosis

Materials & Methods Retrospective study ( ) Children operated for isolated sagittal synostosis Postoperative skull radiographs available

COHORTS BCA Group Children who had beaten-copper appearance on skull radiographs at follow up Non-BCA Group Children who did not have this finding

BCA SCORE Depth (0 = none, 1 = mild to moderate, 2 = severe) Extent (0 = none, 1 = ≤ 50%, 2 = >50%) =7

Study Design 48 Children BCA Group n=20 BCA score Symptoms of ICP Serial HC Non-BCA Group n=28 BCA score Symptoms of ICP Serial HC

Operative procedure 39 children - vertex craniectomy plus parietal osteotomies and/or craniectomies. 9 children operated in a delayed fashion (after eight months of age)

Operative procedure N=4 replacement of the strip of bone over the sagittal suture N=5 cranial vault remodeling

RESULTS Median age at surgery: 4.8 months -BCA group 4 months -Non-BCA group Radiological follow up months (mean of 36.2 months)

Results 40/48 had preoperative skull X-rays & none had BCA preoperatively 9/20 (45%) symptomatic in BCA group 3/28 (10.7 %) symptomatic in the non- BCA group (p= )

BCA Score In 18/20 (90%) children the BCA was ‘diffuse’ with five (25%) children having the maximum possible score of % (n=6) of the children with follow up radiographs done at ≤ 18 months of age had BCA No difference was found between the mean BCA score in the symptomatic (score of 5.77) and non-symptomatic (score of 5.90) children (p=0.722)

BCA in various age groups Number of children with skull radiographs available Number of children with BCA (%) Number of children with diffuse BCA (%) Number of children with BCA & Symptoms (%) ≤ 18 months 216 (28.6)5 (23.8)4 (19.0) months 154 (26.6) 1 (6.7) > 48 months 1210 (83.3)9 (75)6 (50)

16 months postop30 months postop

Head Growth Curve 5/48 (10.41%) children had deceleration in head growth in the follow up period, of which only one child was symptomatic for raised ICP and that child had BCA as well. Deceleration on the head growth curve was not predictive of possible raised ICP (symptoms + BCA) in our patients.

CONCLUSIONS Significant number of children with BCA on radiographs develop symptoms suggestive of raised ICP following surgical treatment for sagittal synostosis in infancy 28.6% of the children ≤ 18 months of age in our study had BCA Prolonged follow up may be warranted in this group of patients.

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