Syrinx

A syrinx is a fluid-filled cavity that develops in the spinal cord (called a syringomyelia), in the brain stem (called a syringobulbia), or in both.

Syrinxes are rare. In about half of the people who have a syrinx, it is present at birth, and then for poorly understood reasons, it enlarges during the teen or young adult years. Often, children who have a syrinx at birth also have other abnormalities. Usually, syrinxes that develop later in life are due to injury or tumors. About 30% of spinal cord tumors eventually result in a syrinx.

Symptoms

Syrinxes that grow in the spinal cord press on it from within. Although most common in the neck, a syrinx can occur anywhere along the length of the spinal cord and often extends to affect a long segment of the cord. Usually, the nerves that detect pain and temperature changes are most affected. Cuts and burns are common, because people with this type of nerve damage cannot feel pain or heat. As a syrinx extends further, it can cause spasms and weakness, usually beginning in the arms. Eventually, the muscles supplied by the affected nerves may begin to waste away.

Syrinxes in the brain stem can produce vertigo, nystagmus (rapid movement of the eyes in one direction followed by a slower drift back to the original position), unusual sensations (such as pins-and-needles) in the face, loss of taste, difficulty speaking, difficulty swallowing, and weakness and wasting away (atrophy) of the tongue.

Diagnosis and Treatment

Doctors may suspect a syrinx in a young child or teenager on the basis of symptoms. Magnetic resonance imaging (MRI) with a paramagnetic contrast agent, such as gadolinium, can outline the syrinx (and a tumor if present).

A neurosurgeon may make a hole in a syrinx to drain it and prevent it from expanding, but surgery does not always correct the problem. Even if the surgery successfully drains the syrinx, the nervous system may already be damaged irreversibly. Symptoms may not be relieved, or the syrinx may recur.