Syringohydromyelia is a fluid-filled pocket inside the spinal cord, and many people first meet the word on an MRI report. Some of these pockets are small, cause no symptoms, and stay the same for years. Others grow and slowly damage the cord. What a syrinx means for you depends less on the fact that it’s there than on what caused it and whether it is changing.
What the Term on Your MRI Report Means
The word combines two older terms. The spinal cord has a tiny channel running down its center called the central canal. When that canal widens with fluid, doctors call it hydromyelia. When a fluid cavity, or syrinx, forms in the cord tissue itself, it’s syringomyelia. MRI often can’t separate the two, so reports frequently use “syringohydromyelia” or simply “syrinx” for either. A plainly widened central canal doesn’t share the symptoms or scan features of a true syrinx with an underlying cause.1PubMed. Defining the line between hydromyelia and syringomyelia
The fluid is related to cerebrospinal fluid (CSF), the clear fluid that cushions the brain and spinal cord. Spinal fluid surges with every heartbeat, and when its flow is blocked, those pressure waves can push fluid into the cord.2PubMed Central. Pathophysiology of primary spinal syringomyelia
Your report will usually say where the syrinx sits, using spine levels such as C5 (in the neck) or T4 (in the upper back). It often gives the width in millimeters and how many levels the syrinx spans. A thin, short syrinx is generally less concerning than a wide, long one.
Not everything that looks like a syrinx is one. Some tumors with cysts can mimic it, and so can softened, damaged cord tissue after an injury. Doctors tell them apart by the shape, length and location of the finding, along with your symptoms. Sometimes contrast dye or extra scans are ordered to rule out a tumor.
What Causes a Syrinx
Syringomyelia is most commonly linked to Chiari malformation, spinal trauma and open neural tube defects.3PubMed Central. Syringomyelia in the Tethered Spinal Cords In Chiari malformation, the lowest part of the back of the brain, the cerebellar tonsils, sags down into the opening at the base of the skull. The tonsils partly plug that opening and act like a piston, sending stronger pressure waves down the spine with each heartbeat.4Neurosurgical Focus. Elucidating the pathophysiology of syringomyelia These waves squeeze the cord from outside and push fluid within the syrinx downward, making it grow.5Neurosurgical Focus. Elucidating the pathophysiology of syringomyelia Tonsils sagging more than 12 mm and a small space at the back of the skull have been linked to a higher chance of a syrinx.6PubMed Central. The Pathogenesis of Chiari Malformation and Syringomyelia: A Case Report and Systematic Review of Current Theories
A syrinx can also form after a spinal cord injury, possibly because of scarring or tethering of the cord at the injury site.7Craig Hospital. Post-Traumatic Tethered Spinal Cord and Syringomyelia In one large group of injured patients, about 7 in 100 developed one within 5 years, on average about 3 years after injury.8PubMed Central. Factors associated with early onset post-traumatic syringomyelia Symptoms can begin as early as 3 months or as late as 32 years after the injury.9PubMed Central. Post-traumatic syringomyelia A syrinx wasn’t more likely after more severe injuries, injuries at a particular level, or spinal surgery.10PubMed Central. Factors associated with early onset post-traumatic syringomyelia
Arachnoiditis, scarring of the thin lining around the cord, can block fluid flow and help form a syrinx.11PubMed Central. Syringomyelia and arachnoiditis This scarring can follow bleeding around the brain or past meningitis, sometimes years later.12PubMed Central. Delayed spinal arachnoiditis with syringomyelia following aneurysmal subarachnoid haemorrhage: a case report with patient experience A cord that is abnormally stuck at its lower end, called a tethered cord, is usually behind a syrinx in the bottom third of the cord.13PubMed Central. Syringomyelia in the Tethered Spinal Cords Tumors in the cord can also cause a syrinx.14PubMed Central. Origin of Syrinx Fluid in Syringomyelia: A Physiological Study
In some people no cause is found, which doctors call idiopathic syringomyelia.15PubMed. Idiopathic syringomyelia: phase-contrast MR of cerebrospinal fluid flow dynamics at level of foramen magnum Before using that label, doctors usually review the MRI of the brain, the base of the skull and the whole spine for a subtle Chiari, a tumor, scarring or a tethered cord. Some centers add a flow-sensitive MRI that shows how spinal fluid moves, since a partial blockage can be missed on ordinary pictures.
Idiopathic means no cause has been found with the tests available so far, not that none exists. Because a cause can show up later, a repeat scan or a new symptom is a reason to look again. Finding the cause matters because treatment usually targets the blockage rather than the fluid itself.
Symptoms to Watch For
A syrinx in the middle of the cord damages the nerve fibers that carry pain and temperature as they cross the cord.16PubMed Central. An Atypical Clinical Presentation of Post-traumatic Syringomyelia: A Case Report and Brief Review of the Literature People may lose the ability to feel heat or pain while still feeling light touch, often across the shoulders and arms like a cape. Burns or cuts on the hands that you didn’t notice can be a clue. Over time, weakness and muscle wasting in the hands and arms can follow, along with stiffness in the legs.
Pain is common and varied. Among people with syringomyelia pain, almost all had constant ongoing pain and 7 in 10 had sudden flares.17Journal of Pain. Pain and Somatosensory Abnormalities in Patients With Syringomyelia Ongoing pain is often described as burning, dull, tight or throbbing, and flares as sharp, shooting or tingling.18Journal of Pain. Pain and Somatosensory Abnormalities in Patients With Syringomyelia About 1 in 5 had pain set off by touch or pressure.19Journal of Pain. Pain and Somatosensory Abnormalities in Patients With Syringomyelia Most rated the pain moderate, and about 1 in 10 severe.20Journal of Pain. Pain and Somatosensory Abnormalities in Patients With Syringomyelia
Syrinx pain usually comes with other changes, such as numbness, patchy loss of heat or pain sensation, or odd tingling, whereas a strained muscle hurts without changing how skin feels. Symptoms often affect one side more than the other, or one arm more than the rest of the body. Ordinary muscle pain doesn’t usually cause real weakness or thinning of the hand muscles, so those changes point toward the nerves. Headaches at the back of the head that get worse with coughing, sneezing or straining suggest Chiari, a common companion of a syrinx.
In children, a syrinx can show up as a sideways curve of the spine.21PubMed Central. Detection of syringomyelia in a pediatric patient with mild scoliosis: a case report These curves are more often single and bend to the left more than the usual kind of scoliosis.22PubMed. Scoliosis associated with syringomyelia presenting in children Treating the syrinx in children under 10 with a flexible curve improved or stabilized the curve.23PubMed Central. Scoliosis associated with syringomyelia: analysis of MRI and curve progression Over age 10, spine surgery was often still needed.24PubMed Central. Scoliosis associated with syringomyelia: analysis of MRI and curve progression
A syrinx extending into the brainstem, called syringobulbia, can cause trouble swallowing, slurred speech, double vision, dizziness and breathing problems during sleep.25PubMed Central. Syringobulbia in Patients with Chiari Malformation Type I: A Systematic Review26PubMed Central. Syringohydromyelia, syringobulbia and syringocephaly associated with Chiari – I malformation: A case report
Call your doctor for new weakness or clumsiness in the hands, spreading numbness or unnoticed burns, bladder or bowel changes, or any new swallowing or speech problem.
Watch and Wait or Treat
In people whose syrinx was found by chance with no underlying cause, none worsened neurologically over about 3 years.27PubMed. Clinical course of incidental syringomyelia without predisposing pathologies More than 9 in 10 showed no change on MRI, and all did well without surgery.28PubMed. Clinical course of incidental syringomyelia without predisposing pathologies Close observation, not surgery, is generally recommended in that situation.29PubMed. Clinical course of incidental syringomyelia without predisposing pathologies Even a syrinx that remains after Chiari surgery can be safely watched if it causes no symptoms.30PubMed. Nonoperative management of enlarging syringomyelia in clinically stable patients after decompression of Chiari malformation type I
Surgery is usually considered when symptoms appear or worsen, or the syrinx grows. Treating early, before damage builds, tends to give better results.31PubMed. Long-term outcome and prognostic factors of syringo-subarachnoid shunt for syringomyelia
Monitoring usually includes a neurological exam in which the doctor tests strength, reflexes and feeling to heat, pain and light touch, so changes are caught early. Repeat MRI scans are typically done at set intervals, such as every 6 to 12 months at first, to check whether the syrinx is growing. If both exam and scans stay stable, the gaps between scans are usually lengthened.
At your appointment, it helps to ask whether there is an underlying cause like Chiari or a tumor, and whether the cord is expanded or the syrinx is growing. You can also ask whether your symptoms match the syrinx’s location, when your next scan is, and what would change the plan.
How Surgery Works and How Well It Helps
Decompression surgery removes a small piece of bone at the base of the skull to make room and restore fluid flow. In one large group of patients, the syrinx shrank meaningfully in 85 in 100.32Neurospine. Relationship Between Syrinx Resolution and Cervical Sagittal Realignment Following Decompression Surgery for Chiari I Malformation Related Syringomyelia Based on Configuration Phenotypes Syrinxes usually start narrowing within about 4 months and can keep shrinking for years.33PubMed Central. Time course of syringomyelia resolution following decompression of Chiari malformation Type I Symptoms often improve before the syrinx visibly shrinks.34PubMed Central. Time course of syringomyelia resolution following decompression of Chiari malformation Type I Patching the brain covering to widen the space may shrink the syrinx more, though not clearly with better recovery.35Journal of Neurosciences in Rural Practice. Response of Syrinx Associated with Chiari I Malformation to Posterior Fossa Decompression with or without Duraplasty and Correlation with Functional Outcome: A Prospective Study of 22 Patients
Recovery takes some patience. A hospital stay of a few days is typical, and neck pain and stiffness are common for weeks as the area heals. A follow-up MRI is usually done some months later rather than right away. The first scan shouldn’t be the measure of success, since the syrinx narrows slowly and symptoms may improve first.
Recovery is often partial. After surgery, 94 in 100 patients had better symptoms.36PubMed Central. Time course of syringomyelia resolution following decompression of Chiari malformation Type I Quality of life scores improved after decompression surgery in adults, especially for pain.37PubMed Central. Syringomyelia Associated with Chiari 1 Malformation in Adults: Positive Outcome Predictors after Posterior Fossa Decompression with Duraplasty Still, about two-thirds had some lingering symptoms, and about half kept abnormal sensations or numbness.38PubMed Central. Time course of syringomyelia resolution following decompression of Chiari malformation Type I Surgery mainly stops damage from worsening; nerves already harmed may not fully recover. Ongoing nerve pain may stay even after the syrinx disappears.39PubMed Central. Investigation of the Neuropathic Pain Caused by Syringomyelia Associated with Chiari I Malformation
A shunt is a thin tube that drains fluid from the syrinx to the space around the cord, the chest lining, or the belly. Shunts are often a second-line or last-resort option.40PubMed. Long-term outcome and prognostic factors of syringo-subarachnoid shunt for syringomyelia In one group, the syrinx collapsed in almost all patients, yet function worsened over time in about 6 in 10.41PubMed. Long-term outcome and prognostic factors of syringo-subarachnoid shunt for syringomyelia Shunts often need repeat surgery, and lasting improvement was rare in one hospital’s patients.42PubMed. Comparative outcomes of syringopleural, syringosubarachnoid, and syringoperitoneal shunts for syringomyelia: a single-center retrospective cohort study
Other causes get their own fixes. Freeing a tethered cord or scarring can restore flow, and tumor-related syrinxes improve when the tumor is removed.
A syrinx that persists or returns may mean the original decompression wasn’t enough or another cause exists.43PubMed Central. Neurological deterioration after posterior fossa decompression for adult syringomyelia: Proposal for a summarized treatment algorithm Ask for a cause to be looked for before deciding on more surgery.
Living With a Syrinx Day to Day
Syrinx pain is nerve pain, which usually responds better to nerve-pain medicines than to ordinary painkillers. If your hands can’t feel heat, check bath water with a thermometer, since the arms and elbows may have lost heat sensation too.
If you have Chiari, many doctors advise caution with heavy straining or lifting, since these raise pressure in the spine and head. Contact sports are usually decided case by case, depending on the Chiari, the syrinx and your symptoms. Physical therapy can help with strength and balance, and a therapist can be told about the syrinx so exercises are chosen safely.
Tell other doctors about your syrinx, especially before any procedure involving spinal anesthesia. Bring past MRI reports so changes can be compared, and mention it during pregnancy planning so labor care is discussed.
Chronic pain can affect mood and sleep, and both can be treated. Patient groups for Chiari and syringomyelia offer support.