What would an MRI of the cervical spine show in a patient with Ehlers-Danlos syndrome (EDS)?

MRI Findings in Ehlers-Danlos Syndrome Cervical Spine

In patients with Ehlers-Danlos syndrome (EDS), cervical spine MRI may show ligamentous laxity, craniocervical instability, and associated soft-tissue abnormalities, though standard recumbent MRI often fails to capture the dynamic instability that characterizes this condition. 1, 2

Key MRI Findings in EDS

Craniocervical Junction Abnormalities

• Ligamentous laxity and hypermobility are the hallmark findings, though these may not be apparent on standard supine MRI 1, 3
• Craniocervical instability (CCI) can manifest with abnormal measurements including altered clivo-axial angle, basion-axial interval, and pB-C2 measurements 1, 3
• Cervical cord compression may be present when instability is severe enough to cause neurological symptoms 2

Soft-Tissue Changes

• MRI demonstrates high sensitivity for soft-tissue injuries including ligamentous abnormalities, though specificity is limited (64-77% for various structures) 4
• Paraspinal muscle changes and disc abnormalities may be visible 4
• Associated findings can include tethered cord syndrome in some hEDS patients, which may be radiographically occult on standard imaging 2

Critical Diagnostic Limitations

Standard MRI Inadequacy

• Conventional recumbent MRI frequently misses dynamic instability that only manifests in upright, weight-bearing positions 5
• The static nature of traditional MRI fails to capture the positional symptoms characteristic of EDS-related cervical instability 5, 1
• No high-quality evidence exists supporting the diagnostic utility of standard MRI for detecting clinically significant spinal abnormalities in EDS patients 5

Interpretation Challenges

• There are no widely accepted MRI criteria for grading the severity of cervical soft-tissue injury, making interpretation subjective 4
• MRI has a false-positive rate of 25-40% for ligamentous injuries, frequently identifying abnormalities of unclear clinical significance 4, 6
• Distinguishing pathological instability from inherent hypermobility in EDS remains a major diagnostic challenge 1, 3

Recommended Diagnostic Approach

When to Order MRI

• Order MRI when neurological symptoms are present, including headaches, vertigo, tinnitus, vision changes, syncope, radiculopathy, pain, or dysphagia 2
• MRI is indicated for evaluating suspected spinal cord compression or myelopathy 4
• Consider MRI when CT shows no fracture but clinical suspicion for instability remains high 4

Complementary Imaging

• Dynamic imaging (flexion-extension views) on CT or radiography should complement MRI, though these have significant limitations in the acute setting 4
• Four key radiographic parameters should be evaluated: clivo-axial angle, Harris measurement, Grabb-Mapstone-Oakes measurement, and angular displacement of C1 to C2 3
• CT remains the gold standard for identifying osseous abnormalities with >98% sensitivity 4, 6

Important Clinical Caveats

Avoid Common Pitfalls

• Do not rely solely on MRI findings to make surgical decisions in EDS patients, as radiographic abnormalities may not correlate with clinical instability 1, 3
• Avoid unnecessary MRI in asymptomatic patients given the high false-positive rate and lack of established diagnostic criteria 6
• Do not assume normal MRI excludes instability in EDS, as dynamic instability may only be apparent with positional imaging 5, 1

Management Implications

• Surgical fixation should only be considered when there is clear radiographic evidence of instability AND concordant neurological symptoms 3
• The presence of MRI abnormalities alone, without clinical correlation, does not warrant surgical intervention 1, 3
• Multidisciplinary evaluation is essential given the complexity of distinguishing pathological instability from constitutional hypermobility in this population 1, 2