Distinguishing Spinal Cord Compression from General Cord Compromise

Definitions and Scope

The American College of Radiology defines spinal cord compression as extrinsic mechanical compression of the cord by structures located outside the neural tissue 1, 2, 3.
The American College of Radiology describes spinal cord compromise as an umbrella term that includes any pathological process—extrinsic or intrinsic—that impairs spinal cord function 1, 4.

Degenerative disease (disc herniation, osteophyte formation, spondylotic narrowing) is a common cause of extrinsic mechanical compression 1, 2.
Epidural pathology such as abscesses or hematomas can produce external pressure on the cord 2, 3.
Neoplastic lesions (both extradural and intradural‑extramedullary tumors) are recognized sources of compressive cord injury 4, 2.
Post‑surgical complications (e.g., seromas, pseudomeningoceles) may create new external compressive forces 1, 4.

In addition to extrinsic compression, vascular compromise (ischemia, infarction, arteriovenous malformations) can impair cord function 2, 3.
Inflammatory/demyelinating diseases (multiple sclerosis, neuromyelitis optica, acute disseminated encephalomyelitis) are included under cord compromise 4, 5.
Intrinsic cord pathology (myelomalacia, gliosis, primary spinal cord tumors) also falls within this umbrella 5, 6.
Metabolic derangements (vitamin B12 or copper deficiency) can lead to functional cord impairment 4, 5.
Infectious processes (myelitis, epidural or intramedullary abscess) are part of the broader compromise spectrum 4, 5.

The American College of Radiology recommends that all patients with acute or chronic myelopathy be first evaluated for extrinsic compression, as it is the most frequent and surgically treatable cause 1, 2, 3.
MRI of the spine, performed with and without gadolinium contrast, is the gold‑standard imaging modality for assessing both external compression and intrinsic cord pathology 1, 4, 5.
Presence of intramedullary T2‑weighted signal abnormalities (e.g., myelomalacia, gliosis) indicates cord compromise beyond simple mechanical compression 5, 6.
Dynamic (flexion/extension) MRI can uncover positional cord compromise that may be missed on neutral‑position studies 6.
Static compression is visualized on standard neutral‑position MRI as canal narrowing and cord deformation 1, 6.

The American College of Radiology notes that intramedullary cord signal changes on MRI are critical prognostic factors for surgical outcomes 5, 6.
T2 hyperintensity reflects edema or early myelomalacia and may be reversible with timely intervention 5, 6.
T1 hypointensity signifies severe myelomalacia and is associated with a poorer prognosis 5.
Gadolinium enhancement patterns localized to the level of stenosis are characteristic of spondylotic myelopathy and help differentiate it from inflammatory myelitis 5, 6.