Idiopathic localized hydromyelia: dilatation of the central canal of the spinal cord of probable congenital origin.

Three adult patients are reported with asymptomatic localized widening of the central canal of the spinal cord. These patients were followed for a period of 24 years by imaging and/or clinical history and physical examination without evidence of signs or symptoms related to the spinal cord. This condition probably represents persistence into adult life of a fetal configuration of the central canal of the spinal cord. This process may be termed "idiopathic localized hydromyelia" to distinguish it from syringomyelia secondary to such causes as Chiari malformation, trauma, infection, or neoplasm.