Crouzon and Apert syndromes: intracranial volume measurements before and after cranio-orbital reshaping in childhood.

This study applied a proven method for obtaining intracranial volume (ICV) measurements using computed tomographic scans to document ICVs in children with Crouzon and Apert syndrome before and after cranio-orbital reshaping procedures. Their ICV also was compared with those of an age- and gender-matched cohort and reviewed their rate of cranial expansion. The study included 21 children who presented sequentially with Crouzon (n = 13) or Apert (n = 8) syndrome between 1987 and 1991 and who subsequently underwent a standard first-stage cranio-orbital reconstruction by the senior author (J.C.P.) in conjunction with a pediatric neurosurgeon. The primary method of osteotomy and bone graft fixation varied (i.e., wires, microplates, miniplates, and screws). The series included 16 females and 5 males with an average age at the time of operation of 13 months (range, 6 to 46 months). The postoperative clinical follow-up ranged from 12 to 60 months at the time of the study's completion. Comparison of the IVCs of the Apert patients preoperatively and postoperative with age and gender control volumes showed that six of eight had volumes at least 2 SD above the mean. Postoperatively, the trend continued with all eight patients followed longitudinally; all maintained volumes in excess of 2 standard deviations above the mean. Preoperatively, for the Crouzon children evaluated, 12 of 13 had ICV values greater than the mean. When comparing the patients' postoperative volumes to the normative data, all 13 maintained values at or greater than the mean at the time of their postoperative determination. Ten of the 13 achieved ICVs at or greater than 2 SD above the mean. When reviewing each Crouzon patient's cranial capacity over time, 5 of the 13 approximated the normal growth curve whereas 6 of the 13 exceeded it. This study confirms that Apert patients are macrocephalic before and after standard cranio-orbital procedures carried out in childhood. For the majority of children born with Crouzon syndrome, the cranial capacity will exceed the mean early in life and expand at a rapid rate after cranio-orbital decompression. The biologic explanation for these findings remain unclear.