Overview
This lecture reviews key spinal cord syndromes, their clinical presentations, causes, and anatomical distinctions, focusing on trauma and somatotopic organization.
Major Spinal Cord Syndromes
- Anterior cord syndrome is rare, typically from anterior spinal artery infarction, causing loss of motor/sensory but preserved dorsal columns.
- Central cord syndrome is most common; presents with hand weakness > arm/leg, usually from hyperextension injury in elderly with cervical stenosis.
- Brown-Séquard syndrome results from hemisection (often penetrating injury), causing ipsilateral motor and dorsal column loss, contralateral pain/temperature loss.
- Bell’s cruciate paralysis mimics central cord syndrome but is due to upper cervical injury, leading to weak hands and strong legs.
- Conus medullaris syndrome (spinal cord conus injury) causes severe autonomic dysfunction and mixed upper/lower motor neuron signs.
- Cauda equina syndrome (below L1/L2) is a peripheral nerve injury, with hyporeflexia, asymmetric symptoms, and prominent autonomic dysfunction.
Central Cord Syndrome Details
- Predominantly affects elderly after neck hyperextension with buckling ligamentum flavum in pre-existing stenosis.
- Characterized by severe hand weakness, mild or no leg weakness, and incomplete sensory loss.
- Patients generally improve over time.
Somatotopic Organization Reappraisal
- Traditional view: corticospinal tract organized so arm fibers are more affected in central cord syndrome.
- Recent research disputes this; concludes corticospinal tract lacks somatotopic organization for limbs.
- Weak hand function is due to unique human corticospinal tract role, not anatomical fiber arrangement.
Key Terms & Definitions
- Anterior Cord Syndrome — Loss of motor and pain/temperature sensation below injury; dorsal column (touch/proprioception) spared.
- Central Cord Syndrome — Greater weakness in hands/arms than legs, often after neck hyperextension.
- Brown-Séquard Syndrome — Ipsilateral motor/proprioception loss, contralateral pain/temperature loss after cord hemisection.
- Conus Medullaris Syndrome — Mixed upper/lower motor neuron signs with bowel and bladder dysfunction.
- Cauda Equina Syndrome — Peripheral nerve injury below spinal cord, causing hyporeflexia and asymmetric symptoms.
- Somatotopic Organization — The spatial arrangement of nerve fibers in the spinal cord for specific body parts.
Action Items / Next Steps
- Review new research on corticospinal tract organization in journal Neurosurgery, April issue.
- Understand distinguishing clinical features of each spinal cord syndrome for exams.