Sacral agenesis

Abstract

The neurologic deficits in sacral agenesis involved motor function much more than sensory function, in a lumbosacral distribution; autonomic involvement, with neurogenic bladder, was variable. Relative sensory sparing may be due to the derivation of sensory nerves from neural crest tissue, which was uninvolved. An occult sacral meningomyelocele with ectopic neural tissue was found at necropsy in one of the patients. Primary amyoplasia may account for small but histologically normal muscles derived from the same somites as the aplastic vertebrae.