A RABBIT MODEL OF HUMAN FAMILIAL, NONSYNDROMIC UNICORONAL SUTURE SYNOSTOSIS - II - INTRACRANIAL CONTENTS, INTRACRANIAL VOLUME, AND INTRACRANIAL-PRESSURE

This two-part study reviews data from a recently developed colony of N ew Zealand white rabbits with familial, nonsyndromic unilateral corona l suture synostosis, and this second pare presents neuropathological f indings and age-related changes in intracranial volume (ICV) and intra cranial pressure (ICP) in 106 normal rabbits and 56 craniosynostotic r abbits from this colony. Brain morphology and anteroposterior length w ere described in 44 rabbit fetuses and perinates (27 normal; 17 synost osed). Middle meningeal artery patterns were qualitatively assessed fr om 2-D PCC MRI VENC scans and endocranial tracings from 15, 126-day-ol d rabbits (8 normal, 7 rabbits with unicoronal synostosis). Brain meta bolism was evaluated by assessing 18F-FDG uptake with high-resolution PET scanning in 7, 25-day-old rabbits (3 normal, 4 with unicoronal or bicoronal synostosis). Intracranial contents and ICV were assessed usi ng 3-D CT scanning of the skulls of 30 rabbits (20 normal,10 with unic oronal synostosis) at 42 and 126 days of age. Serial ICP data were col lected from 66 rabbits (49 normal; 17 with unicoronal synostosis) at 2 5 and 42 days of age. ICP was assessed in the epidural space using a C odman NeuroMonitor microsensor transducer. Results revealed that cereb ral cortex morphology was similar between normal and synostosed fetuse s around the time of synostosis. Significantly (P<0.05) decreased A-P cerebral hemisphere growth rates and asymmetrical cortical remodeling were noted with increasing age in synostotic rabbits. In addition, rab bits with unicoronal suture synostosis exhibited asymmetrical middle m eningeal artery patterns, decreased and asymmetrical brain metabolism, a ''beaten-copper'' intracranial appearance, significantly (P<0.05) d ecreased ICV, and significantly (P<0.01) elevated ICP compared with no rmal control rabbits. The advantages and disadvantages of these rabbit s as a model for human familial, nonsyndromic unicoronal suture synost osis are discussed, especially in light of recent clinical neuropathol ogical, ICV, and ICP findings recorded in human craniosynostotic studi es.