What Symptoms are Associated with Syringomyelia and Chiari 1 Malformations?

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Patient Presentation
An 8-year-old male came to clinic for his health maintenance visit. He was doing well in school and was very active in sports. His parents denied any behavior or physical problems. He was followed by neurosurgery for an incidental finding of a Chiari 1 malformation and syringomyelia of the upper cord after imaging for head trauma when he was 4 years old from a bike accident. He had recently seen them and repeated imaging was unchanged and he had no symptoms.

The family history was positive for migraine and tension headaches on both sides of the family.

The pertinent physical exam showed normal vital signs including blood pressure and growth was 50-75% for age and tracking. His vision screening was 20/20 for both eyes. His examination was normal.

The diagnosis of a healthy male with an incidentally noted Chiari 1 malformation and syringomyelia was made. The family was well-aware of any neurological symptoms that needed to be reported to the pediatrician or neurosurgeon.

Figure 144 – Case Image
Sagittal T2 MRI without contrast of the brain shows peg-like low lying cerebellar tonsils that extend downwards through the foramen magnum and that lie posterior to the upper cervical spinal cord. Within the upper cervical spinal cord are several round areas of bright T2 signal intensity that represents syringomyelia of the spinal cord.

Discussion
Syringomyelia (Syr) is a “…longitudinally oriented fluid-filled cavity of any size in the spinal cord….” Syr is different from the spinal cord central canal dilatation which is called hydromyelia. Syr is accepted to be caused by disruption to the cerebrospinal fluid circulation due to a variety of problems such as arachnoiditiis, cysts, tumors and tethering of the spinal cord. Arnold-Chiari malformation type 1 (CM1) is the most common reason for a Syr. Isolated Syr can occur but it is rare. If a Syr is found on imaging then a reason such as CM1 or the problems above should be sought.

CM1 is usually described as a cerebellar tonsil positioned > 5 mm below the foramen magnum on imaging. The tonsil may be seen to be pegged (e.g. elongated). CM1 with or without Syr is often found on incidental imaging. The actual prevalence and incidence varies with different epidemiological studies which are prone to detection bias. There are few studies of true “control” groups of asymptomatic people who were imaged solely for research purposes; most are imaged for symptoms. CM1 prevalence is estimated at 0.24% – 3.6%, and symptomatic CM1 varies between 32-63%. One study of children estimated a prevalence of symptomatic CM1 at 7:100,000. Syr associated with CM1 was found to be 23% in one pediatric study or overall 0.83% of the study population. Another study estimated the prevalence of a symptomatic Syr at 4.84:100,000. Syr affect the upper spinal cord more often than more caudally. They are also more often associated with pegged cerebellar tonsils and tonsils located more rostrally. Syr are also more often seen in ages < 5 years in the pediatric age groups.

While having a cerebellar tonsil > 5 mm below the foramen magnum is the description of CM1, there are age differences. In a study of tonsil locations by age group, within each 10 year age group studied, there is a gaussian distribution of tonsil locations. However beginning at birth, each age group’s mean tonsil position moves caudally to its lowest position in the 21-30 year age group, and then moves rostrally until at least > 70 years. Females are more likely to have CM1 and a Syr. Older pediatric age groups are more likely to have symptoms but that may also be due to difficulty of diagnosis in young children.

In a 2021 review of the management of CM1 in children found that:

  • Children with CM1 without Syr who were asymptomatic or mildly symptomatic generally had a benign prognosis and did well with conservative management. These children did need to be followed as there was about a 5% risk of needing surgery in the future.
  • Children with CM1 with and without Syr who were significantly symptomatic were small in number and overall if they underwent surgery did well.
  • Syr with an identifiable cause should have that cause addressed. Syr without CM1 was rare but generally these patient seemed to do well overtime without conservative management.

Arnold-Chiari malformations are based on how much brain tissue is affected and are more severe with increasing category:

  • Type 1: The cerebellar tonsils are located below the foramen magnum. This may or may not have clinical problems.
  • Type 2: The cerebellum, medulla, and fourth ventricle are displaced into the cervical spinal canal. This occurs in patients with meningomyelocoele.
  • Type 3: The cerebellum and/or brainstem is displaced into a defect of the head or neck.
  • Type 4: The cerebellum does not develop and may be associated with other malformations. This is the severest form and patients generally do not survive.

Learning Point
Symptoms of CM1 and Syr can vary depending on age.

In infancy and toddlerhood, crying, inconsolability, or sleep problems may indicate pain. Poor feeding, choking, dysphagia, aspiration, stridor, snoring, cough, recurrent respiratory infections and failure to thrive could also be presentations. Children may also have back or neck arching or opisthotonos.

After age 3 years, a history of headache may be easier to elicit. “Classic Chiari headache” is located occipitally that is severe in intensity, short duration ()< 5 min), frequent, and worsened with Valsalva maneuvers (e.g. cough, sneeze, laugh, urination/defecation, crying).

Neck and shoulder pain may also become more common if CM1 is associated with a Syr. Also older age children may be able to demonstrate more potential problems such as loss of muscle strength or coordination including ataxia or gait dysfunction, spasticity, drop attacks and hyperreflexia. Vocal cord problems could present with voice and vocal changes, or patients themselves may be able to describe more specific sensory changes such as paresthesia or temperature changes. Vision problems may accentuate the coordination and movement problems. Other symptoms can include tinnitus, hearing loss, sleep apnea/bradycardia, and scoliosis.

Questions for Further Discussion
1. What are common brain malformations besides Chiari malformations?
2. What causes headaches?
3. What are indications for head imaging with head trauma?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Chiari Malformation and Syringomyelia.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Saletti V, Farinotti M, Peretta P, et al. The management of Chiari malformation type 1 and syringomyelia in children: a review of the literature. Neurol Sci. 2021;42(12):4965-4995. doi:10.1007/s10072-021-05565-9

Holste KG, Muraszko KM, Maher CO. Epidemiology of Chiari I Malformation and Syringomyelia. Neurosurgery Clinics of North America. 2023;34(1):9-15. doi:10.1016/j.nec.2022.08.001

Makoshi Z, Leonard JR. Clinical Manifestations of Chiari I Malformation. Neurosurgery Clinics of North America. 2023;34(1):25-34. doi:10.1016/j.nec.2022.09.003

Chiari Malformation. AANS. Accessed December 17, 2024. https://www.aans.org/patients/conditions-treatments/chiari-malformation/

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Published