What is Post-Traumatic Syringomyelia (cyst/syrinx)?

Post-traumatic syringomyelia is a condition that can occur following spinal cord injury and can result in progressive deterioration of the spinal cord. Post-traumatic syringomyelia involves development of a fluid-filled cavity (called a cyst or syrinx) within the spinal cord following a spinal cord injury. Tethering or scarring of the spinal cord has been suggested as a pathophysiological cause for the formation of a syrinx or cyst in the spinal cord.

A post-traumatic tethered cord can occur without evidence of syringomyelia; however, in our experience, post-traumatic syrinx or cystic formation will not occur without some degree of tethering of the spinal cord. Post-traumatic syringomyelia is treated surgically when a complex of symptoms occurs.

Signs and Symptoms

The clinical symptoms for syringomyelia may include:

• Progressive loss of sensation or strength
• Hyperhidrosis (profuse sweating)
• Spasticity, pain, autonomic dysreflexia (labile blood pressure)
• Horner’s syndrome (dilated pupil)

Deterioration of the spinal cord related to these myelopathies can occur above and/or below the level of injury. Sensory and motor symptoms are a result of changes occurring in the spinal cord, and are directly related to the specific location of these changes in the spinal cord. In other words, if changes occur above the level of injury preserved function is affected. Patients may experience a slow and progressive loss of the ability to feel hot or cold water on their skin or develop hypersensitivity, so that touching the skin causes pain. This change in sensation occurs in areas where the patient previously had normal or impaired sensation. Loss of strength can be described by patients as the inability to use certain muscles that were previously present and/or the development of fatiguing muscle groups which interferes with function. For instance, patients often say they have difficulty wheeling their chair the same distances or performing repetitive motions for the same amount of time.

Hyperhidrosis or profuse sweating can occur anywhere on the body and occurs without a specific cause. Patients can develop the new onset of spasticity, or spasticity can worsen, unrelated to other issues such as a plugged catheter, skin breakdown, or bowel program.

The onset of new pains or the worsening of pains that were present at the time of injury may occur. Secondary to these pains, patients report various types of symptoms, including burning, stinging, stabbing, sharp, shooting, electrical, crushing, squeezing, tight, vise-like cramping pains. These pains generally occur in areas where patients have lost sensation or where sensation sense is not normal.

Surgical Treatment for Post-Traumatic Syringomyelia

Surgical intervention for syringomyelia is an option when patients are experiencing progressive loss of sensory and/or motor function. If medical management of pain, spasticity, autonomic dysreflexia, and/or hyperhidrosis has been unsuccessful, surgical intervention may be considered. The surgery involves removing bone in the back of the spine to get to the dura- the covering around the spinal cord. We use ultrasound to evaluate the extent and size of the syrinx. As in the spinal cord untethering surgery, we release the scar tissue from the surrounding dura to restore spinal fluid flow and motion. We again ultrasound to evaluate the syrinx. In our experience, 80% of the time the syrinx collapses with the untethering; 20% of the time a small tube called a shunt is placed within the syrinx cavity to drain the fluid. Like the untethering surgery, the dura is then closed using an expansion duraplasty- a graft placed to enhance the dural space and decrease the risk of re-scarring.

The Take Home Message:

People with SCI need to be aware of changes in sensation, function, pain, and strength. With any change, speak with your doctor and report changes early. Be proactive in your health – losing function or sensation can lead to other problems.

Craig Hospital’s Neurosurgical Program for Syringomyelia and Tethered Spinal Cords.

References:

1. Falci, S. P., Indeck, C., & Lammertse, D. P. (2009). Post-traumatic spinal cord tethering and syringomyelia: surgical treatment and long-term outcome. Journal of Neurosurgery: Spine, 11(4), 445-460.