At its most basic level, Syringomyelia symptoms are characterised by the formation of a cyst (a fluid filled sac) in the spinal canal. Although the cyst may initially have little or no impact on neurological function, as it increases in size it puts pressure on the nerves which are present in the spine, resulting in the nerve fibres failing to work effectively. Compromised nerve tissue can result in a wide range of symptoms, depending on the location of the cyst, which in turn determines which nerves are affected. Without appropriate diagnosis and treatment, the cyst can cause irreversible nerve damage, as well as continuing to grow, affecting a greater number of nerves as it does so.
A variant of Syringomyelia, Arnold-Chiari Syndrome, occurs when part of the lower rear portion of the brain (the cerebellum), develops abnormally so that it extends out of the skull and into the upper part of the cervical spinal cord (at the very top of the neck). This malformation can cause a cyst, also known as a syrinx in this context, to develop in the cervical region of the spinal canal. This is potentially a particularly serious form of the disorder, as the higher up the spinal cord compression occurs, the greater the number of nerves which are affected.
Arnold-Chiari Syndrome and Syringomyelia can both be quite difficult to diagnose, as the presentation of symptoms can be very varied. Many people remain asymptomatic for long periods of time. Onset can be gradual or rapid, depending on cyst progression. The location of the cyst determines the exact set of symptoms, as the nerves which it presses against will each affect a particular function or body part. For example, a syrinx in the lumber or sacral (lower area) of the spine might result in leg pain, difficulties walking or incontinence whilst the upper part of the body remains symptom free.
A cyst may form after an injury to the spinal cord, or can occur due to the growth of a tumour. Symptoms can include muscle weakness, numbness and tingling, difficulties in detecting temperature, incontinence and abnormal sweating. Because the symptoms are generic in nature and can be confused with a number of other conditions, magnetic resonance imaging (an MRI scan) is usually indicated as a diagnostic tool. This gives a clear view of the spinal cord, enabling clinicians to identify the presence of a syrinx, tumour or other spinal blockage. Once the cause of the symptoms has been found, an appropriate treatment can be developed.
Treatment depends on the location of the syrinx and the severity of the symptoms it causes. Surgical removal or draining of a syrinx is never undertaken lightly, due to the incredibly delicate nature of the spinal cord and the serious consequences if further nerve damage occurs as a result of intervention. This is particularly the case where Arnold-Chiari Syndrome has been identified as the cyst is located so high in the spinal column, where any damage during treatment will have maximal ill effect. Draining the cyst is the less risky option, but may require repetition periodically as it can refill over time. Provided permanent nerve damage has not occurred, relieving the pressure caused by the syrinx normally results in the partial or complete alleviation of symptoms, providing considerable relief to patients.