Syringomyelia is a chronic disorder affecting the spinal cord. Its name is derived from the Greek words syrinx, meaning “pipe” or “tube,” and myelia, meaning “spinal cord.” It literally describes the formation of a fluid-filled, tube-like cavity within the spinal cord.

To understand how this happens, it is helpful to first picture the normal flow of cerebrospinal fluid (CSF). The brain and spinal cord are bathed in this clear, protective fluid, which circulates in the space around them and also through a very tiny, thread-like central canal within the core of the spinal cord. The CSF provides cushioning and transports nutrients and waste products.

In syringomyelia, the normal, free circulation of CSF is obstructed somewhere along its path. This blockage causes the fluid to back up and, under pressure, it is forced to enter the spinal cord tissue itself. Over time, this constant pressure dissects the delicate nerve fibers and forms a distinct, fluid-filled pocket or cyst, the syrinx.

A helpful analogy is to think of the spinal cord as a tightly woven rope made of billions of delicate fibers. This rope is meant to be bathed in a gently flowing stream of CSF. In syringomyelia, a “dam” (an obstruction) blocks the normal flow of this stream. The pressure builds up behind the dam, forcing water to seep into the very core of the rope, creating a “water-logged” pocket. As this pocket of fluid slowly expands and elongates over months and years, it stretches and tears the delicate fibers of the rope from the inside, disrupting the messages they are designed to carry.

Clinically, I’ve seen that many patients are surprised by the diagnosis, they often seek help for vague symptoms like hand numbness or shoulder pain, only to discover it’s linked to a structural spinal issue they never knew they had.

Syringomyelia is caused by the disruption of normal cerebrospinal fluid (CSF) flow, leading to the formation of a syrinx. The underlying causes are the conditions that create the blockage in the first place. These are generally classified into two main types.

1. Communicating Syringomyelia (Associated with Chiari I Malformation)

This is the most common cause of syringomyelia.

• A Chiari I malformation is a congenital condition where the lower part of the brain, specifically the cerebellar tonsils, is misshapen and extends down through the base of the skull into the upper spinal canal.
• This creates a “cork-in-a-bottle” effect at the foramen magnum (the opening at the base of the skull), obstructing the normal, pulsatile flow of CSF between the brain and the spinal canal.
• This obstruction causes pressure waves that force CSF down into the central canal of the spinal cord, leading to the formation of a syrinx, typically in the cervical (neck) or thoracic (upper back) region.

2. Non-communicating Syringomyelia

In this type, the syrinx is not directly connected to the main CSF pathways from the brain and is caused by other forms of spinal cord damage or obstruction.

• Spinal Cord Trauma: This is the second most common cause of syringomyelia. A syrinx can develop months or even years after an initial spinal cord injury. The injury can lead to inflammation and the formation of scar tissue (arachnoiditis) that tethers the spinal cord and blocks the local flow of CSF, causing a cyst to form at the site of the injury.
• Spinal Tumors: A tumor growing within or next to the spinal cord can compress it and obstruct CSF flow.
• Meningitis or Arachnoiditis: Inflammation of the membranes surrounding the spinal cord, either from an infection (like tuberculosis) or other causes, can lead to scarring and adhesions that block the CSF pathways.
• Hemorrhage: Bleeding into the space around the spinal cord.

In some cases, despite a thorough evaluation, a specific cause for the syrinx cannot be found. This is known as idiopathic syringomyelia.

In my experience, Chiari malformation-related cases are more likely to be diagnosed earlier, especially as brain MRIs become more common even incidental findings can lead to timely intervention before severe symptoms begin.

Syringomyelia is not contagious. In most cases, it is an acquired condition that develops as a long-term consequence of a spinal cord injury, tumor, or infection.

In the case of Chiari-related syringomyelia, a person is born with the underlying Chiari malformation, but the syrinx itself and its associated symptoms often do not develop until adolescence or early adulthood. While most Chiari malformations are sporadic, some can be inherited, meaning there may be a familial component to this type of syringomyelia.

I’ve often seen patients who sustained spinal trauma in the past, believing they fully recovered, only to develop syringomyelia years later proving how crucial long-term monitoring is after serious spinal injuries.

The specific symptoms of syringomyelia a person experiences depend entirely on the location, shape, and size of the syrinx within the spinal cord.

The most characteristic and classic presentation is caused by a syrinx that starts in the center of the cervical (neck) spine.

• The Hallmark Symptom: “Cape-like” Sensory Loss. As the syrinx expands from the center of the cord, it first damages the nerve fibers that cross over in the middle. These are the fibers that carry pain and temperature information. This leads to a “dissociated sensory loss,” where a person loses the ability to feel pain and hot/cold, but their sense of light touch, vibration, and position is preserved. This loss often occurs in a distribution across the back of the shoulders, the upper back, and down the arms, resembling the pattern of a cape or shawl. This can be dangerous, as a person may not feel a burn or a cut in these areas.

Other common signs and symptoms that develop as the syrinx grows and affects more nerve tracts include:

• Chronic Pain: This can be a deep, aching pain or a burning, tingling neuropathic pain in the neck, shoulders, and arms.
• Progressive Muscle Weakness and Atrophy: Weakness and wasting of the muscles, particularly in the hands and arms.
• Stiffness: A feeling of tightness or stiffness in the back, shoulders, and limbs.
• Scoliosis: A sideways curvature of the spine, especially if the syrinx develops in childhood or adolescence.
• Headaches and Neck Pain: These are particularly common in patients whose syringomyelia is caused by a Chiari malformation.
• Loss of Reflexes in the upper limbs.

If the syrinx extends lower down the spinal cord, it can cause weakness and spasticity in the legs, and bladder and bowel control problems.

Patients often tell me they first noticed odd symptoms like accidentally burning themselves without realizing it. This loss of pain perception is a classic red flag in syringomyelia.

A diagnosis of syringomyelia is often delayed because the symptoms begin so gradually and can be unusual. A doctor, usually a neurologist or neurosurgeon, will suspect the condition based on the patient’s unique pattern of symptoms, especially the dissociated sensory loss.

• Magnetic Resonance Imaging (MRI): This is the gold standard and definitive tool for diagnosing syringomyelia. An MRI of the spine can clearly visualize the fluid-filled syrinx cavity within the spinal cord, showing its exact size and location. An MRI of the brain is also always performed at the same time to look for a Chiari malformation or other potential causes.
• Computed Tomography (CT) Myelogram: This is an alternative imaging test that may be used if an MRI cannot be performed. It involves injecting contrast dye into the cerebrospinal fluid space and then taking a CT scan.

Clinically, I’ve found that early MRI imaging is key especially in patients with unexplained upper limb weakness, chronic burning sensations, or signs of nerve compression without a clear orthopedic cause.

There is no medication that can make a syrinx go away. The goals of treatment are to stop the progression of the spinal cord damage by addressing the underlying cause and, if necessary, to drain the syrinx itself. The decision to treat, and how to treat, depends on the severity of the symptoms and whether the syrinx is growing.

1. Observation

For individuals with a small syrinx that was found incidentally and is not causing any symptoms, a neurosurgeon may recommend a “watch and wait” approach. This involves regular follow-up appointments and periodic MRI scans to monitor the syrinx for any signs of expansion.

2. Neurosurgery

For patients with a symptomatic or enlarging syrinx, neurosurgery is the mainstay of treatment.

• Treating the Underlying Cause: The primary surgical goal is to fix the problem that is causing the CSF blockage in the first place.
  • For a Chiari Malformation: The most common surgery is a posterior fossa decompression. In this procedure, a neurosurgeon removes a small piece of bone from the back of the skull (the foramen magnum) and sometimes the top vertebra. This creates more space for the brainstem and cerebellum and restores normal CSF flow. In many cases, this is enough to cause the syrinx to gradually collapse over time.
  • For a Spinal Tumor: Surgery will be aimed at removing the tumor.
  • For Scar Tissue: A delicate surgery may be performed to release any scar tissue that is tethering the spinal cord.
• Draining the Syrinx (Shunting): If the syrinx continues to cause problems despite treating the underlying cause, or if there is no identifiable cause, a surgeon may place a shunt.
  • A shunt (a small, flexible tube with a one-way valve) is surgically placed directly into the syrinx to drain the fluid away to another body cavity, such as the chest (syringopleural shunt) or the abdomen (syringoperitoneal shunt), where the excess fluid can be safely drained and reabsorbed.

3. Supportive and Symptomatic Care

Because surgery aims to halt progression but may not reverse existing nerve damage, supportive care is vital.

• Pain Management: Medications used for neuropathic pain can help control chronic pain symptoms.
• Physical and Occupational Therapy: Rehabilitation is crucial for maximizing function, improving muscle strength, managing spasticity, and learning to adapt to any permanent neurological deficits.

In my experience, timely decompression surgery in Chiari patients with a syrinx can dramatically halt progression and even reverse symptoms in some cases, especially if done before permanent nerve damage sets in.

Syringomyelia is a chronic and progressive disorder caused by the formation of a fluid-filled cyst, or syrinx, within the spinal cord, most often due to a Chiari malformation or a past spinal cord injury. While its symptoms, such as the classic “cape-like” loss of pain and temperature sensation, can be perplexing, a diagnosis can be made definitively with an MRI. While existing nerve damage may not be reversible, the progression of syringomyelia can often be halted. Neurosurgery to correct the underlying cause of the CSF blockage is the most effective treatment. A proactive approach with a neurosurgeon and a rehabilitation team is key to managing symptoms and preserving neurological function for as long as possible.

National Institute of Neurological Disorders and Stroke (NINDS). (2023). Syringomyelia Fact Sheet. Retrieved from https://www.ninds.nih.gov/health-information/disorders/syringomyelia

American Association of Neurological Surgeons (AANS). (n.d.). Syringomyelia. Retrieved from https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Syringomyelia

American Syringomyelia & Chiari Alliance Project (ASAP). (n.d.). Syringomyelia. Retrieved from https://asap.org/syringomyelia/