Ruling Out Spinal Cord Compression in Neurological Patients
MRI of the entire spine is the gold standard for ruling out spinal cord compression in neurological patients due to its superior soft-tissue resolution and ability to detect both compressive and non-compressive myelopathies. 1, 2
Initial Assessment and Imaging Selection
MRI without and with IV contrast has a sensitivity of 96% and specificity of 94% for evaluating suspected spinal cord compression, providing optimal depiction of the intraspinal contents including the epidural space and spinal cord 1
CT is excellent for identifying fractures and bony abnormalities but is significantly inferior to MRI in identifying soft-tissue pathologies that can cause neurologic deficits and require surgical intervention 1
Plain radiographs are insensitive for evaluation of the epidural space and spinal cord compression, making them inadequate as the initial imaging examination in patients presenting with neurologic compromise 1
MRI Protocol Considerations
MRI should include T2-weighted images and gradient-echo sequences to best display compression of the cord by disc herniation, bone fragments, and hematomas 1
When IV contrast is utilized, comparing pre-contrast and post-contrast MRI sequences is essential to identify abnormal enhancement patterns that may indicate infection, inflammation, or neoplasm 1
Whole spine MRI is indicated in most patients with suspected malignant spinal cord compression because multiple levels of compression are found in 39% of cases, often involving more than one region of the spine 3, 4
Common Causes of Spinal Cord Compression
Degenerative disease, particularly in the cervical spine, is the most common cause of extrinsic compression in the acute setting 2, 5
Other causes include:
- Epidural hematoma (especially in anticoagulated patients) 2
- Vertebral fractures with retropulsion 2
- Traumatic spinal injuries 1, 2
- Postoperative complications (seromas, hematomas, abscesses) 2
- Neoplastic compression from primary or metastatic tumors 2, 6
- Epidural abscess 1, 2
- Vascular causes (ischemia, hematomyelia, AVMs) 2
- Inflammatory/demyelinating diseases (MS, NMO, ADEM) 2
Clinical Pitfalls to Avoid
Relying solely on sensory level to localize the lesion - in 26% of cases, the sensory level is four or more segments below or three or more segments above the actual lesion 3
Missing multiple levels of compression - present in up to 39% of patients with malignant spinal cord compression 3, 4
Delaying diagnosis - ED misdiagnosis of spinal cord compression in non-trauma patients occurs in approximately 29% of cases, resulting in significant delays to treatment 7
Overlooking subtle presentations - 24% of patients with spinal cord compression may have no motor or sensory deficit, and 23% may present with only unilateral findings 7
Failing to assess gait - impaired gait may be present even in patients without associated motor or sensory deficits 7
Special Considerations
In trauma settings, CT is the preferred initial modality for detecting fractures, subluxation, and dislocations requiring immediate stabilization, but MRI should follow if there is clinical concern for cord compression 1
When MRI is contraindicated or unavailable, CT myelography can be performed to assess for traumatic spinal canal narrowing due to disc herniation or epidural hematoma 1
For suspected spinal infections with neurologic compromise, MRI without and with IV contrast should be performed on an emergent basis, especially in patients with risk factors and elevated inflammatory markers 1