Hereditary spinal arachnoid cysts, distichiasis, and lymphedema.

Familial congenital spinal arachnoid cysts causing progressive paraplegia are reported in two adolescent siblings as part of a hereditary syndrome. The other features of this unusual dominantly inherited disorder include double rows of eyelashes, partial ectropion of the lower eyelids, and acquired late-onset lymphedema of the lower extremities. The siblings' mother, who had roentgenographic evidence of a similar intraspinal lesion, was free of neurological symptoms but had the other characteristic features. Surgical treatment of the arachnoid cysts improves the progressive paraplegia.