Post-traumatic syringomyelia (PTS) is a condition that can emerge following a spinal cord injury (SCI). It involves the formation of a syrinx, which is a fluid-filled cavity, within the spinal cord. This development is considered a delayed complication, often appearing months or even years after the initial trauma. The presence of this cyst can lead to a gradual worsening of neurological function.
Formation and Progression
The development of post-traumatic syringomyelia stems from a disruption in the normal circulation of cerebrospinal fluid (CSF), the clear liquid that surrounds and cushions the brain and spinal cord. Following a spinal cord injury, the body’s natural healing process can lead to inflammation and the formation of dense scar tissue. This scarring, sometimes called arachnoiditis or adhesions, can create blockages in the subarachnoid space.
This obstruction alters the fluid dynamics within the spinal canal. Much like a dam blocking a river, the scar tissue can impede the steady, low-pressure flow of CSF. The continuous production of this fluid can cause pressure to build up, potentially forcing it into the spinal cord’s central canal or the surrounding tissue. This process leads to the initial formation of a fluid-filled cavity.
Once a syrinx forms, it can expand over time, which explains the delayed onset of symptoms. The expansion may be due to a one-way valve effect, where CSF can enter the cavity but cannot easily exit. This enlargement puts increasing pressure on the delicate nerve fibers within the spinal cord, leading to progressive neurological symptoms. The entire process from injury to symptomatic syrinx can take anywhere from a few months to several decades.
Recognizing the Symptoms
The symptoms of post-traumatic syringomyelia can worsen over time. Because the syrinx is a physical structure expanding within the spinal cord, the specific symptoms a person experiences are directly related to the syrinx’s size and precise location along the spine. A common presentation involves a “central cord syndrome,” which affects the center of the cord first.
Sensory changes are frequently reported. Individuals may experience a loss of sensation, particularly to pain and temperature, while the ability to feel touch is preserved. This pattern of sensory loss is sometimes described as having a “cape-like” distribution, affecting the neck, shoulders, and upper back. Numbness, tingling, and chronic pain, which can be burning or aching in nature, are also common.
Motor impairments typically involve progressive weakness and the wasting away of muscle tissue, known as atrophy. Patients might also develop increased muscle stiffness and rigidity, a condition called spasticity, which is highly correlated with the presence of a syrinx. These motor deficits can lead to functional losses, such as difficulty with mobility or performing daily activities that were previously manageable. In some cases, autonomic functions like bowel, bladder, or sweating control can also be affected.
Diagnostic Process
Diagnosing post-traumatic syringomyelia begins with a thorough clinical evaluation. The first step is typically a detailed neurological examination to assess reflexes, muscle strength, sensory function, and gait. This physical assessment helps to pinpoint the location and extent of the neurological changes.
The patient’s medical history, with the previous spinal cord trauma being the primary indicator, is important. The physician will inquire about the timeline of symptoms, noting that they often appear long after the initial injury has stabilized. This delayed presentation is a hallmark of the condition.
Imaging studies are necessary to confirm the diagnosis. Magnetic Resonance Imaging (MRI) is the preferred method because it provides detailed pictures of the spinal cord and can clearly visualize the fluid-filled syrinx. In situations where an MRI cannot be performed, a CT myelogram may be used as an alternative. This procedure involves injecting a contrast dye to highlight the spinal cord and can help identify blockages in CSF flow.
Management and Treatment Approaches
The approach to managing post-traumatic syringomyelia depends on several factors, including the size of the syrinx, the severity of the symptoms, and whether the condition is progressing. For individuals with a small syrinx that is not causing symptoms or is not growing, a conservative “watch and wait” strategy may be recommended. This involves regular monitoring with MRI scans to track any changes over time.
When symptoms are progressive, particularly motor weakness, surgical intervention is often considered. The primary goals of surgery are to drain the fluid from the syrinx and to correct the underlying cause of the fluid buildup. One common surgical technique involves placing a shunt, which is a small tube that drains the fluid from the syrinx into another body cavity. Another approach is decompression surgery, where the surgeon removes the scar tissue or other obstruction that is blocking the normal flow of cerebrospinal fluid.
Non-surgical treatments are focused on managing symptoms and improving quality of life. Physical therapy can help maintain muscle strength and function, while occupational therapy can assist with adapting to any functional limitations for daily activities. Pain can be managed with various medications. These supportive therapies can be used alone for mild cases or in conjunction with surgery to optimize outcomes.