CEREBELLOMEDULLARY COMPRESSION IN RECESSIVE CRANIOMETAPHYSEAL DYSPLASIA

Craniometaphyseal dysplasia (CMD) is a very rare disorder of bone remo delling characterised by sclerosis of the skull base, vault and facial bones and metaphyseal splaying of tubular bones. The recessive form a ppears to be more severe than the dominant. Cranial nerve deficits hav e been reported in infancy and early childhood in a few patients, but the long-term history of recessive CMD is not well documented. We repo rt cerebellomedullary compression in a girl with recessive CMD recogni sed at 14 years because of progressive truncal ataxia. MRI revealed ba ckward angulation of the thickened clivus, narrowing of the foramen ma gnum and upward deviation of the cerebellum by a markedly thickened oc cipital squama, tonsillar herniation and obliteration of the infratent orial cerebrospinal fluid spaces. Posterior cranial fossa decompressio n resulted in marked improvement of the ataxia. Compression of posteri or cranial fossa structures has to be considered in the natural histor y and management of CMD.