Syringomyelia
Syringomyelia is a condition in which a fluid-filled cavity, called a syrinx, develops within the spinal cord. Over time, the syrinx may enlarge and place pressure on surrounding nerve fibers, leading to progressive neurological symptoms. Syringomyelia is most commonly associated with Chiari malformation, but it can also occur after trauma, infection, inflammation, tumors, or other conditions that disrupt the normal flow of cerebrospinal fluid. MRI is the primary imaging test used to diagnose and monitor the condition.
What is it?
Syringomyelia refers to the formation of a syrinx, a fluid-filled cavity that develops within the spinal cord itself.
The fluid inside the syrinx resembles cerebrospinal fluid (CSF), the protective fluid that normally circulates around the brain and spinal cord.
As the syrinx enlarges, it can stretch and damage nearby spinal cord tissue, particularly the nerve fibers responsible for transmitting pain and temperature sensation.
This often produces characteristic neurological symptoms while leaving other types of sensation relatively preserved in the early stages.
The most common condition associated with syringomyelia is Chiari malformation, in which part of the cerebellum extends downward through the opening at the base of the skull and disrupts normal CSF flow.
Other causes include prior spinal cord injury, spinal cord tumors, arachnoiditis, meningitis, inflammation, congenital abnormalities, and scar tissue that interferes with CSF circulation.
In some patients, no clear cause can be identified.
Symptoms usually develop gradually and depend on the size and location of the syrinx.
The cervical spinal cord is most commonly affected, leading to symptoms involving the neck, shoulders, arms, and hands.
Common symptoms include burning pain, numbness, weakness, loss of pain or temperature sensation, muscle wasting, stiffness, and balance difficulty.
As the syrinx enlarges, symptoms may extend into the legs or affect autonomic functions such as bowel, bladder, or sexual function.
Some patients notice worsening symptoms with coughing, straining, sneezing, or certain neck positions because these activities temporarily alter CSF pressure dynamics.
MRI of the spine is the preferred imaging test for evaluating syringomyelia because it clearly shows the size, location, and extent of the syrinx within the spinal cord.
MRI also helps identify associated conditions such as Chiari malformation, spinal cord tumors, tethered cord, inflammation, or prior injury.
Brain MRI is typically performed to evaluate the craniovertebral junction and assess for Chiari malformation or other intracranial causes affecting CSF flow.
In select cases, cine MRI may be used to evaluate real-time cerebrospinal fluid movement around the spinal cord and brainstem.
CT myelography may occasionally be used when MRI cannot be performed.
Important to Know
Treatment of syringomyelia is highly individualized and depends on the underlying cause, the severity of symptoms, and whether the syrinx is stable or progressing.
Small asymptomatic syrinxes are often monitored with periodic MRI examinations rather than treated immediately.
When symptoms are present or the syrinx is enlarging, treatment is usually directed at correcting the underlying cause.
For patients with Chiari malformation, surgical decompression at the base of the skull may improve CSF flow and reduce progression of the syrinx.
Other treatments may involve removal of a spinal cord tumor, treatment of scar tissue blocking CSF flow, or, less commonly, placement of a shunt to drain fluid from the syrinx.
Because surgery involves operating near the spinal cord and brainstem, treatment decisions are carefully individualized.
Early recognition is important because prolonged spinal cord compression can lead to permanent neurological injury.
Imaging findings are always interpreted together with symptoms, neurological examination findings, and the overall clinical picture.
Red flag symptoms include rapidly worsening weakness or numbness, progressive gait or balance difficulty, bowel or bladder dysfunction, severe new neck or back pain, swallowing or breathing difficulty, or sudden neurological decline. These symptoms require prompt medical evaluation because they may indicate progression of the syrinx or significant spinal cord compression.