A Prospective Natural History Study of Patients With Syringomyelia

OBJECTIVE

The natural history of patients who have syringomyelia has not been addressed in a prospective study. Present surgical treatment of patients with syringomyelia and neurologic deficit results in disease stabilization in many but not all patients, although objective improvement is less common. Delayed deterioration is not uncommon. The natural history of patients with syringomyelia and without a neurologic deficit or an associated lesion is also uncertain. By identifying factors that influence syringomyelia progression and that affect the response to surgical treatment, we can acquire knowledge that will enable us to provide more accurate recommendations to future patients with syringomyelia regarding optimal surgical or non-surgical treatment of their condition.

STUDY POPULATION

This study will enroll patients with syringomyelia and patients who are at risk of developing syringomyelia, including patients with Chiari I malformation and patients with presyringomyelia.

DESIGN

Prospective radiological and clinical data will be collected over a 5-year period from patients with syringomyelia and patients at risk of developing syringomyelia. Patients with syringomyelia and a neurological deficit will be considered to be surgical candidates. In this group, neurologic and radiographic outcomes in patients that undergo surgery will be compared to those in patients that refuse surgical treatment. Patients with syringomyelia but without neurological deficit will not be considered to be surgical candidates. In this group, initial neurologic and radiographic findings will be compared to those found one year after entrance into the study. Any patient with syringomyelia that develops progressive neurological deficit will be offered surgical treatment for his/her condition. In this study we will also prospectively collect information on processes that may influence the development and progression of syringomyelia, such as trauma and inflammatory diseases.

OUTCOME MEASURES

The primary outcome measure will be the change in motor strength, as measured by the American Spinal Injury (ASIA) Grading Scale, over 1 year. The secondary outcome measure will be the change in maximal syrinx diameter over 1 year in surgical candidates (surgically-treated vs. surgically untreated) and in non-surgical candidates.

• INCLUSION CRITERIA:

To be eligible to participate in this research study, the subject must:

• Be 18 years of age or older.
• Have syringomyelia, presyringomyelia, or Chiari I malformation without syringomyelia.
• Be able to give informed consent.

ADDITIONAL CRITERIA FOR PATIENTS THAT MAY UNDERGO SURGERY (not required for study inclusion)

• new or increased impairment in sensation, strength, or walking within the previous 2 years; and
• an MRI-scan showing a syrinx or the presence of abnormal fluid and swelling in the spinal cord; the abnormality in the spinal cord must be located in a part of the spinal cord that could produce the patient s symptoms; and
• evidence of abnormalities at the base of the skull or within the spine that are often associated with syringomyelia, or abnormalities in CSF circulation that increase the pressure of the cerebrospinal fluid; and
• medical health that is sufficient to allow the subject to withstand a major surgical procedure and to remain active during the recovery period after surgery.

Exclusion criteria

The subject will not be eligible to participate in this research study if the subject:

• Is pregnant (because multiple MRI scans might injure a fetus).
• Cannot have an MRI scan as determined by the radiologist (see the risks below).
• Has a problem with bleeding that cannot be corrected.

Note: Prior surgery for syringomyelia does not result in exclusion from the study if there is radiographic evidence of recurrent or persistent syringomyelia after surgery for this condition (failed previous surgery).