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Syringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. Often, syringomyelia is used as a generic term before an etiology is determined. (2025). 9781451100129, Lippincott Williams & Wilkins. ISBN 9781451100129 This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in loss of feeling, paralysis, weakness, and stiffness in the back, shoulders, and extremities.
Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. It may also lead to a cape-like bilateral loss of pain and temperature sensation along the upper chest and arms. The combination of symptoms varies from one patient to another depending on the location of the syrinx within the spinal cord, as well as its extent.
Syringomyelia has a prevalence estimated at 8.4 cases per 100,000 people, with symptoms usually beginning in young adulthood. Signs of the disorder tend to develop slowly, although sudden onset may occur with coughing, straining, or myelopathy.
The primary symptom of post-traumatic syringomyelia (often referred to using the abbreviation of PTS) is pain, which may spread upward from the site of injury. Symptoms, such as pain, numbness, weakness, and disruption in temperature sensation, may be limited to one side of the body. Syringomyelia can also adversely affect sweating, sexual function, and, later, bladder and bowel control. A typical cause of PTS would be a car accident or similar trauma involving a whiplash injury.
What can make PTS difficult to diagnose is the fact that symptoms can often first appear long after the actual cause of the syrinx occurred (e.g., a car accident occurring and then the patient first experiencing PTS symptoms such as pain, loss of sensation, and reduced ability on the skin to feel varying degrees of hot and cold a number of months after the car accident).
It has been observed that obstruction of the cerebrospinal fluid spaces in the subarachnoid space can result in syrinx formation, and alleviation of the obstruction may improve symptoms. A number of pathological conditions can cause an obstruction of the normal cerebrospinal fluid spaces. These include Chiari malformation, spinal arachnoiditis, scoliosis, spinal vertebrae misalignment, spinal tumors, spina bifida, and others. The reasons that blockage of the cerebrospinal fluid space within the subarachnoid space can result in syrinx formation are not fully understood although a small posterior fossa is one known cause. It is unclear if syrinx fluid originates from bulk movement of cerebrospinal fluid into the spinal cord, from bulk transmural movement of blood fluids through the spinal vasculature into the syrinx, or from a combination of both. Recent work suggests that central nervous system compliance is the underlying problem for the central nervous system, and also that hydrocephalus and syringomyelia have related causes.
The physician may order additional tests to help confirm the diagnosis. One of these is called electromyography (EMG), which show possible lower motor neuron damage. Note this test isn't used diagnostically for injuries to the spine but to nerves and muscles. This would be part of a patient's rehab routine. In addition, computed axial tomography (CT) scans of a patient's head may reveal the presence of tumors and other abnormalities such as hydrocephalus.
Like MRI and CT scans, another test, called a myelogram, uses radiographs and requires a contrast medium to be injected into the subarachnoid space. Since the introduction of MRI, this test is rarely necessary to diagnose syringomyelia.
The possible causes are trauma, tumors, and congenital defects. It is most usually observed in the part of the spinal cord corresponding to the neck area. Symptoms are due to spinal cord damage and include pain, decreased sensation of touch, weakness, and loss of muscle tissue. The diagnosis is confirmed with a spinal CT, myelogram or MRI of the spinal cord. The cavity may be reduced by surgical decompression.
Furthermore, evidence also suggests that impact injuries to the thorax area highly correlate with the occurrence of a cervical-located syrinx.
The main goal of surgical intervention is to correct the condition which led to the formation of the syrinx. Draining the syrinx can also help, by preventing it from becoming worse, but the symptoms the syrinx has already caused may not go away.
In cases involving an Arnold–Chiari malformation, the main goal of surgery is to provide more space for the cerebellum at the base of the skull and upper cervical spine, without entering the brain or spinal cord. This often causes the syrinx to shrink or disappear over time, as the normal flow of cerebrospinal fluid is restored. If syringomyelia is caused by a tumor, removing the tumor – if possible – is the treatment of choice.
Most patients' symptoms stabilize or have a modest improvement following surgery. Syringomyelia can come back, however, requiring additional surgeries which may be less effective.
In some cases, including both communicating and non-communicating forms of the condition, a syrinx may require ongoing drainage. This is done with a shunt, which uses tubes and valves to let cerebrospinal fluid (CSF) drain from the syrinx into another cavity within the body (usually the abdomen). This type of shunt, called a ventriculoperitoneal shunt, is particularly useful in cases involving hydrocephalus. By continually draining the syrinx, a shunt can arrest the progression of symptoms and relieve pain, headache, and tightness.
Many factors affect the decision to use a shunt. There are risks of injury to the spinal cord, infection, drainage becoming blocked, and bleeding, and they do not always achieve the intended results. Draining the fluid more quickly does not produce better outcomes, but for some syrinxes, a shunt is the only drainage option.
In the case of trauma-related syringomyelia, the surgeon operates at the level of the initial injury. The syrinx collapses at surgery, but a tube or shunt is usually necessary to prevent it from returning.
Radiation is rare, but may be used if a tumor is involved. In these cases, it can halt the extension of a cavity and may help to alleviate pain.
Treatment is usually reserved for cases which are causing symptoms. Treatment may not provide enough benefits to be recommended for elderly patients, or when symptoms are stable instead of worsening. Whether treated or not, many patients are advised to avoid activities that involve straining.
A conservative approach may be recommended, as the natural history of syringomyelia is not yet well understood. When surgery is not currently advised, patients are monitored with regular physical evaluations and MRI's.
Surgical techniques are also being refined by the neurosurgical research community. Successful procedures expand the area around the cerebellum and spinal cord, improving the flow of cerebrospinal fluid and thereby reducing the syrinx.
It is also important to understand the role of birth defects in the development of hindbrain malformations that can lead to syringomyelia, as syringomyelia is a feature of intrauterine life and is also associated with spina bifida. Learning when these defects occur during the development of the fetus can help with the understanding of this and similar disorders, and may lead to preventive treatment that can stop the formation of some birth abnormalities.
Diagnostic technology is another area for continued research. MRI has enabled scientists to see the situation within the spine, including syringomyelia, before any symptoms appear. A new technology, known as dynamic MRI, allows investigators to view spinal fluid flow within the syrinx. CT scans allow physicians to see abnormalities in the brain, and other diagnostic tests have also improved greatly with the availability of new, non-toxic, contrast dyes.
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