- Etiology
- Large, central lumbar disc herniation (m/c)
- Epidural tumor, abscess, or inflammation in the region
- Clinical manifestations
- Severe, radicular lower back pain
- Impaired motor/sensory/reflex activity in the lower extremities, bowel/bladder/sexual dysfunction, and/or saddle anesthesia.
- Management
- Immediate MRI to evaluate for a surgical lesion.
- Surgical decompression within 24-48 hours is generally required to prevent irreversible neurologic sequelae.
| Spinal cord compression | Conus medullaris syndrome | Cauda equina syndrome | |
| Etiology | Damage to or compression of the spinal cord at any level | Damage to or compression of the spinal cord at the vertebral level T12–L2, resulting in injury to the conus medullaris Common causes: spondylolisthesis, tumors, trauma | Damage to or compression of the cauda equina (nerve fibers L3–S5) located below L2 Common causes: large posteromedial disc herniation, trauma, and tumors. |
|---|---|---|---|
| Onset | Variable, bilateral | Sudden, bilateral | Gradual, typically unilateral |
| Pain | Localized neck or back pain | Lower back pain Less severe radicular pain | Lower back pain Severe radicular pain |
| Motor symptoms | Bilateral paralysis below the affected level of the spinal cord Hyperreflexia Positive Babinski sign, Ataxia | Symmetric, hyperreflexic distal paresis of lower limbs, possibly fasciculations Achilles reflex may be absent. | Asymmetric, areflexic, flaccid paresis of the legs Muscle atrophy |
| Sensory symptoms | Loss or reduction of all sensation below the affected level of the spinal cord | Symmetric bilateral perianal numbness Sensory dissociation | Saddle anesthesia: lack of sensitivity in the dermatomes S3–S5, affecting the areas around the anus, genitalia, and inner thighs (may be asymmetric) Asymmetric unilateral numbness and/or paresthesia in lower limb dermatomes |
| Urogenital and rectal symptoms | Sphincter dysfunction with urinary or bowel urgency, retention, or incontinence | Early onset of bladder and fecal incontinence Erectile dysfunction | Late onset of urinary retention Change in bowel habits due to loss of anal sphincter control Decreased rectal tone or bulbocavernosus reflex Erectile dysfunction |
Saddle anesthesia.