Information about Syringomyelia & Arnold Chiari Malformation (ACM)

What is Syringomyelia?

Syringomyelia is a disorder affecting the nervous system where fluid-filled cavities develop inside the spinal cord. The spinal cord is normally a solid structure which passes down the back, inside the spinal canal. It connects the brain to the rest of the body, passing signals to and fro, enabling an individual to move his or her limbs at will, to feel objects and to control various bodily functions.

Within the spinal canal, the spinal cord is bathed with a clear, watery fluid, known as cerebrospinal fluid - a term usually abbreviated to CSF. The fluid from which Syringomyelia cavities are formed is identical to CSF.

What causes Syringomyelia?

Hindbrain Hernia also known as Arnold Chiari Malformation (ACM)

A variety of different conditions lead to the formation of Syringomyelia cavities. The common factor in most cases is obstruction to the normal flow of CSF, up and down the spinal canal, on the outside of the spinal cord. Perhaps the most common cause of such obstruction is a disorder known as Hindbrain Hernia, also commonly referred to as Arnold Chiari Malformation. In this condition the lower-most part of the brain has descended through an opening in the base of the skull (named the Foramen Magnum) and this causes a blockage of the CSF channels, at the top of the spinal canal. Normally CSF flowing in the spinal canal communicates freely with CSF circulating inside the head but when CSF is trapped inside the spinal canal some of it begins to accumulate within the substance of the spinal cord.

MRI showing Hindbrain Hernia Next to ACM, the most common cause of Syringomyelia is spinal injury. A minority of victims of severe spinal cord trauma, who are already severely disabled as a result of their original injury, go on to develop additional problems as a result of Syringomyelia. Scar tissue within the spinal canal, developing as a consequence of the initial injury, obstructs CSF movement causing, once again, fluid to accumulate within the substance of the spinal cord.

There are other causes of Syringomyelia beyond the scope of this brochure.

How is Syringomyelia diagnosed?

MRS showing Hindbrain Hernia and Syrinx Patients who have Syringomyelia present with a variety of symptoms ranging from neck and arm pain through to fairly severe disability, with muscle weakness and paralysis. Fortunately nowadays, most cases of Syringomyelia are detected at an early stage before major disability develops.

Any of the symptoms of Syringomyelia can have other causes. Indeed, it is much more likely that somebody presenting with, say, neck and arm pain, will have a more common disorder and not syringomyelia. It is only when more common diseases are excluded that Syringomyelia may be considered as a diagnosis. In most cases the diagnosis of Syringomyelia is made by a specialist, usually a Neurologist.

Once the diagnosis of Syringomyelia is suspected, it is readily confirmed by an MRI scan.

How is Syringomyelia treated?

How Syringomyelia is treated In many cases of Syringomyelia all that is required by a sufferer is an explanation and reassurance, together with periodic review by a specialist. The symptoms arising from Syringomyelia can then be treated with drugs or other measures - or simply tolerated. In some instances, however, if the cavity in the spinal cord is enlarging and threatens to cause significant disability, there may be a place for surgical intervention. In these circumstances the services of a neurosurgeon may be required. Before any surgery is undertaken, detailed discussions need to take place between the patient and the neurosurgeon, as to the potential benefits of surgery as well as the inconveniences, discomforts and risks that go with an operation on the brain or spinal cord.