Spinal Arachnoid Web

An arachnoid web is a rare but treatable cause of spinal cord compression. The “web” consists of an abnormally thickened band of otherwise normal tissue known as an arachnoid membrane. Symptoms may include pain, sensory loss, or temperature changes in the torso or legs, leg weakness or incoordination, and bowel or bladder dysfunction, among others. Spinal arachnoid webs are rare, and the cause is uncertain. They occur most commonly in the thoracic spine.

Spinal arachnoid webs are diagnosed after a careful history and physical exam and an MRI scan of the spine (see example images below). The MRI scan usually shows that the spinal cord appears to be kinked or displaced, and there is often an accompanying syrinx - an abnormal collection of fluid within the spinal cord.

For patients with symptoms from an arachnoid web, the recommended treatment is surgery to remove the web. Surgery involves a laminectomy to access the spinal canal followed by microsurgical removal of the web and decompression of the spinal cord. Patients typically spend 1-3 days in the hospital. Timing and degree of symptom relief depend on the severity and duration of cord compression.

If you live near Denver and have a spinal arachnoid web, please consider scheduling a consultation to learn more about treatment options.