Spinal intradural arachnoid cysts

Overview

Spinal intradural arachnoid cysts: A rare disorder involving a fluid-filled cysts on the arachnoid membrane which is one of the thin layers of tissue that form a membrane which covers the spinal cord. The type and severity of symptoms is determined by the size and location of the cyst.

Symptoms

Progressive back pain Progressive leg pain Tingling in legs Leg numbness Tingling in arms

Causes

Normally, about 20 days after conception, the embryo develops a neural groove in the dorsal ectoderm. This groove rapidly deepens, and the two edges fuse to form the neural tube. By about day 23, this tube is completely closed except for an opening at each end. Theoretically, if the posterior portion of this neural tube fails to close by the 4th week of gestation, or if it closes but then splits open from a cause such as an abnormal increase in CSF later in the first trimester, a spinal defect results. Viruses, radiation, and other environmental factors may be responsible for such defects. However, spinal cord defects occur more often in offspring of women who have previously had children with similar defects, so genetic factors may also be responsible.