Types (Minimal Spinal Dysraphism)

Drawings of the pathoanatomical types of minimal spinal dysraphism. Top left: Subcutaneous lipoma which continues like a sand-glass through an opening in the fascia and dura to the conus and cauda equina. Both isolated intraspinal and subcutaneous lipoma occur; a protrusion of the arachnoid may proceed into the lipoma. A fluid transition to a lipomyelomeningocele may be present. Top right: The terminal filum is tight and during growth leads to a tethering of the conus. Bottom left: Also, tight adhesions between the conus and the dura may lead to a tethering. Bottom right: A fistula communicates between the skin surface and the spinal channel with or without a dermoid cyst.