Author(s): Kate Delaney, MD, Daniel Nguyen, MD
Originally published: September 20, 2013 Last updated: April 10, 2025
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Disease/Disorder

Definition

Syringomyelia is an abnormal cystic collection of fluid, or syrinx, that forms within the parenchyma of the spinal cord. 

Etiology

There are two major types of syringomyelia: congenital or acquired. Most cases of congenital syringomyelia (see Pediatric Syringomyelia) are associated with neurologic conditions, such as Chiari malformations, myelomeningocele, or tethered cord; however, idiopathic and rare familial cases are described. Acquired syringomyelia can be secondary to spinal cord injury, arachnoiditis, inflammatory or infectious conditions, or neoplasms.1,2

Other terms used to describe syringomyelia further include communicating or non-communicating syringomyelia. Communicating syringomyelia refers to a central canal syrinx that is in continuity with the 4th ventricle; this is often associated with hydrocephalus. Noncommunicating syringomyelia refers to cavities without communication with the fourth ventricle and is often associated with trauma. However, magnetic resonance imaging (MRI) studies have shown that most collections are not in continuity with the 4th ventricle, and therefore the terms communicating and noncommunicating are falling out of favor.3 Post-traumatic syringomyelia that occurs as a complication of spinal cord injury (SCI) is covered as a separate topic in KnowledgeNow, and therefore will not be covered here.

Epidemiology including risk factors and primary prevention

Children and young adults are most commonly affected by syringomyelia. Historical studies showed an overall prevalence of 9 per 100,000; however, the widespread use of MRI has increased detection. The majority of cases occur between the ages of 20 to 50, with mean age of onset at 30 years. All cause syringomyelia occurs more often in men than women, reflecting the higher incidence of traumatic SCI in men. Syringomyelia in adults is associated with a Chiari I malformation in approximately 50% of cases, and is post-traumatic SCI or associated with arachnoiditis in an additional 25% of cases.3 Syringomyelia associated with Chiari malformations is most commonly cervical, whereas idiopathic cases may have a higher prevalence of thoracic lesions in children.4 Other, less common associations with syringomyelia include spinal cord tumors, transverse myelitis, and meningitis.5

Patho-anatomy/physiology

The pathophysiology of syringomyelia is not entirely understood. The majority of pathophysiological theories are described using Chiari I malformation as a cause of syringomyelia.6 It was historically believed that syrinx formation was the result of cerebrospinal fluid (CSF) being driven into the parenchyma of the spinal cord through persistent connections with the 4th ventricle or perivascular channels. Chiari I malformations affect the flow of CSF through the foramen magnum, resulting in altered fluid dynamics.7,8 Recent studies and theories, however, support the idea that the accumulations are at least partially due to impaired venous compliance, leading to a build-up of extracellular fluid.8 Asymmetric syringomyelias result in differential growth in both the adjacent hemicord, paraspinal musculature, and vertebrae, resulting in scoliosis.9

There is limited research on the pathophysiology of syringomyelia unrelated to Chiari I malformation.5

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

Symptomatic syringomyelia presents with progressive neurologic deterioration over months to years, though rapid deterioration has been described. Initial symptoms from Chiari I malformations typically become clinically evident in young adulthood, and it can take several years from symptom onset until diagnosis.2-4 Symptoms of syringomyelia can vary between patients and some may be asymptomatic. The general symptoms of syringomyelia include pain, altered sensation, motor deficits, and autonomic dysfunction. Clinical examination findings often reveal extremity weakness, altered light touch and/or pain/temperature sensation in an irregular distribution, muscle wasting, scoliosis, ataxia, spasticity, and hyper- or hyporeflexia, depending on the level of the syrinx.3,8 With earlier diagnosis made by MRI, the syrinx may be detected before classical symptoms are evident, or with milder, or even absent, symptomatology.6,8

Specific secondary or associated conditions and complications

In children with syringomyelia associated with Chiari I malformations, about 30% will have progressive scoliosis. With increased access to advanced imaging, Syringomyelia or Chiari I malformations are more commonly found during a workup of scoliosis. A left-sided curve, persistent back pain, or other atypical neurological symptoms associated with scoliosis should prompt the practitioner to have a higher level of suspicion for nonidiopathic causes of scoliosis. Hydrocephalus may also be associated with syringomyelia in children. Complications of syringomyelia include scoliosis, chronic pain, and symptoms associated with progressive myelopathy.10

Essentials of Assessment

History

Syringomyelia is complex and initial presentation is often affected by etiology, location, and pathology. Symptoms from the syrinx itself can include weakness, clumsiness, paresthesias, and dysesthesias. Symptoms do not necessarily follow an expected anatomical pattern and may be unilateral. Neuropathic and chronic pain are sequelae that often present during ages thirties to forties, although the classical description of a cape-like loss of pain and temperature sensation but preservation of light touch is rare.Unsteady gait, muscle atrophy, spasticity, urinary or fecal incontinence, or male impotence may also be described.2,3,8 Patients with concomitant Chiari I malformations often present with symptoms due to the malformation before symptoms of the syrinx itself. Chiari malformation anomalies often manifest at two time points: around 8-9 years of age or around 41-46 years of age.10 Symptoms associated with Chiari I malformations include headaches, clumsiness, inner ear dysfunction, altered facial sensations, ocular changes, dysarthria, and dysphagia. In children, one of the most prominent associations between Chiari malformation and syringomyelia is early onset scoliosis.2,10

Physical examination

Physical exam should include a thorough neurologic and musculoskeletal exam including evaluation of reflexes, tone, sensory, and motor function. A Cobb Angle should be used to assess scoliotic curve.11 Non-myotomal or nondermatomal motor and sensory defects are often asymmetric, as are altered reflexes.3 Atrophy of intrinsic hand muscles or fasciculations may also be an early finding when anterior horn cells are affected. For syrinx associated with a Chiari malformation, headache or neck pain can by exacerbated by maneuvers that increase CSF pressures, such as a Valsalva maneuver.12 Signs of myelopathy in the lower extremities, such as spasticity or hyperreflexia, can become evident as the disease progresses. Dysesthesias may be elicited during the sensory examination.13

Functional assessment

Patients with motor and sensory deficits should be assessed for strength, balance, bed mobility, transfer status, ambulatory or wheelchair mobility status, as well as their ability to perform activities of daily living, such as bathing, dressing, and grooming. Patients with concurrent hydrocephalus or Chiari malformation should have a cognitive assessment, including assessment of school or work performance, driving skills, memory, safety awareness, attention, medication management, and finance management. This may also be useful to consider for patients who require medications to manage pain or tone. Coughing, hypoxia, or wet dysphonia are frank indicators for swallowing evaluation; patients with Chiari malformation or bulbo syringomyelia should be evaluated for silent aspiration.

Laboratory studies

The diagnosis of syringomyelia is confirmed with MRI imaging. However, laboratory serum or CSF testing may be used in the workup of a syrinx of unknown etiology, particularly if there is a suspicion of spinal infection or inflammatory conditions.

Imaging

MRI is the gold standard for diagnosis of syringomyelia. Specifically, T1-, T2-, FLAIR-, T2*, and enhanced T1 sequences are used to evaluate the syrinx. Dynamic MRI with a study of CSF flow may confirm the diagnosis. Cine phase contrast MRI yields detailed information on both anatomy and CSF flow. Impairment of cerebrospinal fluid flow across the foramen magnum can be used to select patients for surgical decompression of the foramen. This can also be predictive of symptom recurrence after surgery. To identify the site of cerebral spinal fluid obstruction, a 3D constructive interference sequence in steady state or phase contrast MR can be used.13 CT myelography can be used when MRI is unavailable or unsafe.

Supplemental assessment tools

Electromyographic (EMG) studies may be used early in the work-up of extremity pain, weakness, or sensory changes to determine their etiology. SSEP/MEP differences can sometimes be detected before clinical changes.13 They may also be used to measure disease progression over time for patients being treated conservatively or postoperatively. More detailed imaging of the spinal column with plain radiographs or CT may help evaluate coexisting scoliosis.3

Early predictions of outcomes

Increased age and duration of symptoms at the time of surgical decompression have been shown to predict worse clinical outcomes for patients with a syrinx and Chiari malformation.10,12 Early decompression of Chiari I malformations may halt the progression or improve associated spinal deformities. While symptoms may stabilize for some patients, progressive symptoms should be treated aggressively, because they can lead to increased morbidity and mortality.Surgical outcomes including syrinx size and complication rate did not differ with decompression between an extra arachnoid technique and arachnoid dissection.14

Environmental

Syringomyelia is most often associated with Chiari I malformations and posttraumatic causes. Less common etiologies include postinfectious and postinflammatory causes. Case reports of familial causes exist, but there are no clear environmental links to syringomyelia at this time.

Social role and social support system

Patients may require assistance with redefining their social roles as impairments worsen and if adaptive equipment is needed. This may include developing a support network of family, friends, clergy, social work, peer support, vocational rehabilitation, coordination with school and work staff, and respite programs.

Professional issues

Parents (or legal guardians) should be intimately involved in the decision-making process for pediatric patients. Delay in treatment once neurologic symptoms develop could result in poor outcomes.15,16 Management of syringomyelia often requires an interdisciplinary treatment team, as described below.

Rehabilitation Management and Treatments   

Available or current treatment guidelines

There are no formal published treatment guidelines for nontraumatic syringomyelia. In general, current management is individualized to the patient’s symptoms, and may include surgical, pharmacologic, or non-pharmacologic strategies.

At different disease stages

The natural history of Chiari malformations and associated syringomyelia is unpredictable.

Nonoperative management may be considered for patients with small 2 level syrinxes and who are asymptomatic or have relatively mild symptoms; however, they must be monitored regularly with MRI.5,10,11,17-20

Patients with new neurologic symptoms, mass lesions, worsening pain, expanding syrinxes, or increasing scoliosis should be referred for neurosurgical evaluation. Neurosurgical evaluation should occur before scoliosis surgery because of the increased risk of neurologic deterioration.15 Hydrocephalus should be shunted before considering surgery for syringomyelia.10

The goal of surgical treatment is to restore CSF flow. Neurosurgical approaches may include suboccipital decompression, duroplasty, laminectomy, tonsillar resection, removal of subarachnoid adhesions, shunting, cord untethering, syrinx fenestration, removal of tumor, infection, or arteriovenous malformation.15,17-19 Medical postoperative complications include aseptic or bacterial meningitis, deep venous thrombosis, urinary tract infection, and pneumonia.6 Therefore, standards of care should include infection prevention, venous thromboembolism prophylaxis, early removal of indwelling catheters, and bladder assessment and adequate pulmonary hygiene. Other surgical complications can include peri-operative hematomas, cerebrospinal fluid leakage, shunt obstruction and scar formation.2

Stable postoperative patients should receive physical therapy, occupational therapy, and speech therapy. Goals are to relieve pain, preserve range of motion, normalize tone, and improve balance, strength, swallow, phonation, respiration, fine and gross motor coordination, activities of daily living, and sitting balance. Psychosocial counseling may help with coping. Pain may be treated with nonsteroidal anti-inflammatory drugs, muscle relaxants, anticonvulsants, antidepressants, topical agents, or narcotics.13 No drugs have been evaluated specifically for neuropathic pain in syringomyelia in humans. Tricyclic antidepressants such as amitriptyline have been shown useful in other conditions, but anticholinergic side effects must be considered Gabapentin and pregabalin have been shown to be effective in neuropathic pain in spinal cord injury with no difference in efficacy between the two. Lamotrigine and Carbamazepine have been moved to second line due to their side effect profiles. Strong opioids are the last line of treatment.13 There is no evidence that spinal infusions or modalities (electric stimulation, heat, massage) are helpful.17 A few case reports have suggested that spinal cord stimulation may be effective for patients with syringomyelia related neuropathic pain.21-23 Long-term complications can include shunt failure, catheter tip migration, and syrinx recurrence. If neurologic decline occurs, the patient should be referred back to neurosurgery.

Coordination of care

Care should be coordinated between the primary care physician or pediatrician, physiatrist, rehabilitation nurses, neurosurgeon, orthopedic surgeon, pain specialist, psychiatrist or psychologist, social worker, physical therapist, occupational therapist, speech-language pathologist, dietician, and third-party payers. Community resources may include, but are not limited to, vocational rehabilitation, driver rehabilitation, support groups, sports programs, school programs, and legal and financial aid groups.

Patient & family education

Information for patients and families can be obtained from the Chiari & Syringomyelia Foundation or the American Syringomyelia & Chiari Alliance Project. Chiari Malformation and Syringomyelia–A Handbook for Patients and Their Families is available.24

Emerging/unique interventions

EMG and somatosensory evoked potentials may be used for monitoring postsurgical outcomes. A case report from 2022 described a case in which a patient received a transplant of mesenchymal stem cells which led to improved pain and decrease in syrinx size.25

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

The presence of syringomyelia requires life-long management. Delay in treatment once neurologic symptoms appear may result in poorer outcomes.15,16

Cutting Edge/Emerging and Unique Concepts and Practice:

Dynamic contrast-enhanced MRI technology enables viewing of spinal fluid pulsating within the syrinx, even before symptoms appear in syringomyelia.26

Exploration of the factors and their role in the development and progression of syringomyelia is researched in the following areas27

  • Role of genetic factors related to a Chiari I malformation.
  • Learning the role of birth defects in the development of hindbrain malformations.
  • Abnormal CSF flow that may contribute to the progression.
  • Developing preventive treatment to stop the formation of birth defects.
  • Role for the cardiovascular system, as evidenced by forceful downward movement of the CSF with heartbeat.
  • Improvement in surgical techniques.

Gaps in the Evidence-Based Knowledge

There are no evidence-based guidelines.

Rehabilitation is focused on ameliorating symptoms and not on a scientific evidence base. The exact mechanism of syrinx development remains unknown and no prevention or cure exists. Surgery for the treatment of syringomyelia may not be successful over the long term in relieving symptoms. The role of shunting procedures is questioned, and more recently their placement is regarded as a last resort.27 Although the diagnosis is easily done today with the relatively common availability of MRI scanning, it is difficult to decide what the optimal treatment strategy is for the individual patient. Considerable controversy still surrounds the management of hindbrain hernia and syringomyelia, and this debate is largely because of the uncharted natural history of the condition. Inevitably, any discussion of the management of syringomyelia involves intimately the management of Chiari I malformation.15 The unanswered questions are when do hindbrain hernia/Chiari I malformation and syringomyelia or recurrent syringomyelia or associated hydrocephalus need treatment and what are the best surgical procedures?15

References

  1. Roy Chaudhary B, Fehlings MG, Di Lorenzo N, Cacciola F. Adult-onset syringomyelia: From theory to practice and beyond. *J Neurosurg Sci.* 2005;49(3):65-72. doi:10.1007/s10334-005-0216-8. PMID: 16288188.
  2. Vandertop WP. Syringomyelia. Neuropediatrics. 2014;45(1):3-9. doi:10.1055/s-0033-1361921. PMID: 24272770.
  3. Roguski M, Groves ML. Adult syringomyelia. In: Youmans and Winn Neurological Surgery. 6th ed. Philadelphia, PA: Elsevier; 2011:2601-2606.e2.
  4. Magge SN, Smyth MD, Governale LS, et al. Idiopathic syrinx in the pediatric population: a combined center experience. J Neurosurg Pediatr. 2011;7:30-36. doi:10.3171/2010.11.PEDS10294.
  5. Giner J, Pérez López C, Hernández B, Gómez de la Riva Á, Isla A, Roda JM. Update on the pathophysiology and management of syringomyelia unrelated to Chiari malformation. Neurologia. 2019;34(5):318-325. doi:10.1016/j.nrl.2016.09.010. PMID: 27939111.
  6. Heiss JD, Snyder K, Peterson MM, et al. Pathophysiology of primary spinal syringomyelia. J Neurosurg Spine. 2012;17(5):367-380. doi:10.3171/2012.8.SPINE111059.
  7. Koyanagi I, Houkin K. Pathogenesis of syringomyelia associated with Chiari type 1 malformation: review of evidences and proposal of a new hypothesis. Neurosurg Rev. 2010;33:271-285. doi:10.1007/s10143-010-0266-3
  8. Flint G. Pract Neurol. 2021;21:403-411. doi:10.1136/practneurol-2021-002994.
  9. Shenoy VS, Munakomi S, Sampath R. Syringomyelia. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2024 Jan-.
  10. Holly LT, Batzdorf U. Chiari malformation and syringomyelia. J Neurosurg Spine. 2019 Nov 1;31(5):619-628. doi:10.3171/2019.7.SPINE181139. PMID:31675698.
  11. Noureldine MHA, Shimony N, Jallo GI, Groves ML. Scoliosis in patients with Chiari malformation type I. Childs Nerv Syst. 2019;35(10):1853-1862. doi:10.1007/s00381-019-04309-7. PMID: 31342150.
  12. Alfieri A, Giampietro P. Long-term results after posterior fossa decompression in syringomyelia with adult Chiari type 1 malformation. J Neurosurg Spine. 2012;17(5):381-387. doi:10.3171/2012.7.SPINE12105. PMID: 22998480.
  13. Leclerc A, Matveeff L, Emery E. Syringomyelia and hydromyelia: Current understanding and neurosurgical management. Rev Neurol (Paris). 2020 Aug 18:S0035-3787(20)30633-0. doi: 10.1016/j.neurol.2020.07.004. Epub ahead of print. PMID: 32826067. PMID: 32826067.
  14. Perrini P, Anania Y, Cagnazzo F, Benedetto N, Morganti R, Di Carlo DT. Radiological outcome after surgical treatment of syringomyelia-Chiari I complex in adults: a systematic review and meta-analysis. Neurosurg Rev. 2021 Feb;44(1):177-187. doi: 10.1007/s10143-020-01239-w. Epub 2020 Jan 17. PMID: 31953784.
  15. Akhtar OH, Rowe DE. Syringomyelia-associated scoliosis with and without the Chiari I malformation. J Am Acad Orthop Surg. 2008;16(7):407-414. doi:10.5435/00124635-200807000-00006. PMID: 18611995.
  16. Aghakhani N, Parker F, David P, et al. Long-term follow-up of Chiari-related syringomyelia in adults: analysis of 157 surgically treated cases. Neurosurgery. 2009;64(2):308-315. doi:10.1227/01.NEU.0000337574.00353.A7. PMID: 19240538.
  17. Fernandez AA, Guerrero AI, Martinez MI, et al. Malformations of the craniocervical junction (Chiari type I and syringomyelia: classification, diagnosis, and treatment). BMC Musculoskelet Disord. 2009;10(Suppl 1):S1. doi:10.1186/1471-2474-10-S1-S1. PMID: 19284653.
  18. Sharma M, Coppa N, Sandhu FA. Syringomyelia: a review. Semin Spine Surg. 2006;18:180-184.
  19. Roy AK, Slimack NP, Ganju A. Idiopathic syringomyelia: retrospective case series, comprehensive review, and update on management. Neurosurg Focus. 2011;31(6):E15. doi:10.3171/2011.9.FOCUS11198. PMID:22133183.
  20. Langridge B, Phillips E, Choi D. Chiari Malformation Type 1: A systematic review of natural history and conservative management. World Neurosurg. 2017;104:213-219. doi:10.1016/j.wneu.2017.04.082. PMID:28435116.
  21. Beyaz SG, Bal N. Spinal cord stimulation for a patient with neuropathic pain related to congenital syringomyelia. Korean J Pain. 2017;30(3):229-230. doi:10.3344/kjp.2017.30.3.229. PMID:28757924.
  22. Yamana S, Oiwa A, Nogami R, et al. Successful spinal cord stimulation using fast-acting sub-perception therapy for postoperative neuropathic pain of syringomyelia with Chiari malformation type 1: a case report and literature review. BMC Neurol. 2024;24(1):284. Published 2024 Aug 13. doi:10.1186/s12883-024-03789-8. PMID:39138444.
  23. Lu Z, Fu L, Fan X. Spinal cord stimulation for the treatment of neuropathic pain associated with syringomyelia. Asian J Surg. 2022;45(12):2936-2937. doi:10.1016/j.asjsur.2022.06.111. PMID:35773104.
  24. American Syringomyelia & Chiari Alliance Project Web site. Available at: www.asap.org. Accessed December 2024.
  25. Ahn H, Lee SY, Jung WJ, Lee KH. Treatment of syringomyelia using uncultured umbilical cord mesenchymal stem cells: A case report and review of literature. World J Stem Cells. 2022;14(4):303-309. doi:10.4252/wjsc.v14.i4.303. PMID:35662863.
  26. Mauer UM, Gottschalk A, Mueller C, et al. Standard and cardiac-gated phase-contrast magnetic resonance imaging in the clinical course of patients with Chiari malformation type I. Neurosurg Focus. 2011;31(6):E5. doi: 10.3171/2011.9.FOCUS11275. PMID: 22186535.
  27. Klekamp J. Treatment of syringomyelia related to nontraumatic arachnoid pathologies of the spinal canal. Neurosurgery. 2013;72(3):376-389; discussion 389. doi: 10.1227/NEU.0b013e31827e1b19. PMID: 23361386.

Original Version of the Topic

Jean L. Nickels, MD, K. Rao Poduri, MD. Syringomyelia. 9/20/2013

Previous Revision(s) of the Topic

Jean L. Nickels, MD, K. Rao Poduri, MD. Syringomyelia. 5/5/2016

Andriana Tompary, DO, Jean L. Nickels, MD, Susan Belcher, MD, K. Rao Poduri, MD. Syringomyelia. 6/8/2021

Author Disclosure

Kate Delaney, MD
Nothing to Disclose

Daniel Nguyen, MD
Nothing to Disclose