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 57:370-377, 1982.

• Another 38% have ‘borderline’ ICP

Thompson DN, Malcolm GP, Jones BM, Harkness WJ, Hayward RD: Intracranial pressure in single-suture craniosynostosis. Pediatr Neurosurg 22:235-240, 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 215-226.

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 46:112-122, 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 (1987-2000)

• 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%)

3 + 4=7

Study Design

48 Children

BCA Groupn=20

Non-BCA Groupn=28

BCA scoreSymptoms of ICP

Serial HC

BCA scoreSymptoms 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 4 - 156 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=0.00684)

BCA Score• In 18/20 (90%) children the BCA was ‘diffuse’

with five (25%) children having the maximum possible score of 8.

• 28.6% (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

21 6 (28.6) 5 (23.8) 4 (19.0)

18-48 months

15 4 (26.6) 4 (26.6) 1 (6.7)

> 48 months

12 10 (83.3) 9 (75) 6 (50)

16 months postop 30 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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