Syringomyelia (sear-IN-go-my-EEL-ya) is a disorder in which a cyst forms. This cyst, called a syrinx, expands and elongates over time, destroying the centre of the spinal cord.
If not treated surgically, syringomyelia often leads to progressive weakness in the arms and legs, loss of hand sensation and chronic, severe pain.
In most cases, the disorder is related to a congenital abnormality of the brain called the Arnold-Chiari malformation. This malformation occurs during the development of the foetus and causes the lower part of the cerebellum to protrude from its normal location in the back of the head into the cervical or neck portion of the spinal canal.
Some cases of syringomyelia are familial, although this is rare.
Since the spinal cord connects the brain to nerves in the extremities, this damage results in pain, weakness and stiffness in the back, shoulders, arms or legs. Other symptoms may include headaches and a loss of the ability to feel extremes of hot or cold, especially in the hands.
Each patient experiences a different combination of symptoms. Magnetic resonance imaging (MRI) has significantly increased the number of syringomyelia cases diagnosed in the beginning stages of the disorder. Signs of the disorder tend to develop slowly, although sudden onset may occur with coughing or straining.
Syringomyelia may occur as a complication of trauma, meningitis, haemorrhage, a tumour, or arachnoiditis. Symptoms may appear months or even years after the initial injury, starting with pain, weakness and sensory impairment originating at the site of trauma.
Symptoms usually begin between the ages of 25 and 40 and may worsen with straining or any activity that causes cerebrospinal fluid pressure to fluctuate. Some patients, however, may have long periods of stability.
Surgery results in stabilisation or modest improvement in symptoms for most patients. Delay in treatment may result in irreversible spinal cord injury.
Surgery is usually recommended for syringomyelia patients. Recurrence of syringomyelia after surgery may make additional operations necessary; these may not be completely successful over the long term.
In some patients it may be necessary to drain the syrinx, which can be accomplished using a catheter, drainage tubes and valves. In the absence of symptoms, syringomyelia is usually not treated.
In addition, a physician may recommend not treating the condition in patients of advanced age or in cases where there is no progression of symptoms.
Whether treated or not, many patients will be told to avoid activities that involve straining.
(Reviewed by Dr Andrew Rose-Innes, Department of Neurology, Yale University School of Medicine)