A syrinx is a fluid-filled cyst that forms within the spinal cord. This condition, known as syringomyelia, can also extend into the brainstem, a related condition called syringobulbia. While some individuals with a syrinx may not experience any symptoms, many can find the condition quite serious. Its seriousness stems from its potential to expand over time, which can compress and damage the delicate nerve tissue of the spinal cord or brainstem.
Understanding a Syrinx
A syrinx is a fluid-filled cavity that develops within the spinal cord or, less commonly, the brainstem. The fluid filling this cavity is cerebrospinal fluid (CSF), which normally surrounds and cushions the brain and spinal cord. When the normal flow of CSF around these structures is disrupted, the fluid can accumulate within the spinal cord tissue, leading to the formation of a syrinx.
There are two primary classifications of a syrinx within the spinal cord: syringomyelia and hydromyelia. Syrinxes most frequently develop in the cervical (neck) or thoracic (upper back) regions of the spinal cord, but they can occur anywhere along its length.
Why a Syrinx Can Be Serious
A syrinx can lead to serious health issues because its expansion directly compresses or damages the surrounding nerve fibers within the spinal cord. This compression interferes with the transmission of nerve impulses between the brain and the body. The extent of the neurological deficits depends on the syrinx’s size, its specific location within the spinal cord, and its rate of growth.
Damage to nerve tracts can result in various symptoms. For instance, the spinothalamic tract, which carries information about pain and temperature, is often affected early, leading to a loss of sensitivity to hot and cold or pain, sometimes in a “cape-like” distribution over the shoulders and back. As the syrinx expands, it can also impair motor pathways, causing muscle weakness, atrophy (wasting), stiffness, or spasticity in the arms and legs. Individuals may also experience chronic pain, headaches, difficulty with balance, and in advanced cases, problems with bowel and bladder control. In severe situations, extensive damage can result in paralysis.
Identifying and Managing a Syrinx
Identifying a syrinx often begins when individuals experience symptoms that prompt a medical evaluation. Common symptoms include pain, numbness, weakness, a diminished ability to feel temperature changes, or alterations in bowel and bladder function. The presentation of symptoms can vary significantly among individuals, depending on where the syrinx is located and how large it has grown.
Diagnosis primarily relies on imaging techniques, with magnetic resonance imaging (MRI) of the spine and brain being the most reliable method. An MRI provides detailed images that can clearly visualize the syrinx and any associated abnormalities. A dynamic MRI may also be performed to assess the flow of cerebrospinal fluid around the spinal cord and within the syrinx. A comprehensive neurological examination, assessing motor and sensory functions, also forms a part of the diagnostic process.
Management strategies for a syrinx vary widely based on its characteristics and the presence of symptoms. For syrinxes that are small, stable, and not causing symptoms, a “watchful waiting” approach may be adopted, involving periodic monitoring with MRI scans.
If the syrinx is progressive or causing significant symptoms, surgical intervention is often considered. Surgical goals typically involve addressing the underlying cause of the syrinx, such as decompressing a Chiari malformation by removing bone from the skull to create more space, or removing spinal cord tumors that obstruct CSF flow. In some cases, a shunt may be inserted to drain the syrinx fluid into another body cavity, such as the abdomen, where it can be absorbed. Medications are also used to manage specific symptoms like pain.
Prognosis and Living with a Syrinx
The prognosis for individuals with a syrinx can be quite variable. Some syrinxes may remain stable for many years, never causing significant problems, while others can progress, leading to worsening neurological symptoms over time. Even after successful treatment, some neurological deficits, particularly those present before intervention, may persist.
Living with a syrinx often involves ongoing management and adaptation. Regular follow-up appointments with neurologists or neurosurgeons are important to monitor the condition and address any new or worsening symptoms. Physical therapy can help maintain and improve muscle strength, flexibility, and balance, while occupational therapy can assist with adapting daily activities. Pain management strategies are frequently used to improve comfort and quality of life. Individuals may also find it beneficial to avoid activities that involve straining or heavy lifting, as these can sometimes exacerbate symptoms.