In an older adult with pre‑existing cervical spondylosis who sustains a hyper‑extension neck injury, what are the rapid bedside assessment findings and the underlying pathology of central cord syndrome?

Central Cord Syndrome: Rapid Bedside Assessment and Pathology

Central cord syndrome presents with disproportionately greater upper extremity weakness compared to lower extremity weakness (the hallmark feature), accompanied by bladder dysfunction and variable sensory loss in the hands. 1, 2, 3

Clinical Assessment Findings

Motor Pattern

• Upper extremity weakness is markedly more severe than lower extremity weakness (e.g., 2/5 strength in arms versus 3/5 in legs), constituting the defining clinical feature 1, 3, 4
• Hand and finger weakness with loss of manual dexterity is particularly prominent, reflecting corticospinal tract injury 2, 5
• Lower extremities show relatively preserved strength 3, 4

Bladder Dysfunction

• Urinary retention or incontinence frequently accompanies the motor deficit pattern 1, 2
• This represents a key component of the clinical syndrome 3

Sensory Findings

• Variable sensory loss, particularly prominent in the hands 3, 4
• Sensory function is typically less severely impaired than motor function 3
• May demonstrate sacral sparing in more severe cases 3

Patient Demographics

• Most commonly affects older adults (around 70 years of age) with pre-existing cervical spondylosis 1, 4
• Now represents the most common acute traumatic spinal cord injury in the elderly population 1
• Can also occur in younger individuals from high-energy trauma 4, 6

Underlying Pathology

Mechanism of Injury

• Hyperextension force acting on a cervical spine with pre-existing stenosis (degenerative or congenital) is the typical mechanism 1, 2, 7
• The injury follows low-energy mechanisms such as falls in older adults 1, 4
• Nearly 50% of patients have congenital or degenerative spinal stenosis 2

Anatomic Pathology

• The injury primarily affects the lateral white matter columns (corticospinal tracts), NOT the central gray matter as historically believed 5
• MRI-pathological correlation studies demonstrate diffuse axonal disruption in the lateral funiculi where corticospinal tracts are located 5
• Intramedullary hemorrhage is NOT a necessary or common feature—the predominant finding is axonal injury 5

Compression Mechanism

• Direct compression of the cervical spinal cord occurs from buckling of the ligamentum flavum into an already narrowed cervical canal during hyperextension 5
• Pre-existing posterior osteophytes at C4/C5 or C5/C6 contribute to cord compression 7
• Fragmented and fissured intervertebral discs from degeneration allow excessive motion 7

Critical Imaging Considerations

Urgent MRI is essential to detect ongoing spinal cord compression, epidural hematoma, disc herniation, or ligamentous injury requiring operative intervention 1

• MRI provides superior sensitivity compared to CT for identifying these pathologies and guides surgical decision-making 1
• Hyperintense signal within the cervical spinal cord on T2-weighted or gradient echo sequences is characteristic 5
• Cervical spine radiographs often show only degenerative changes without obvious acute trauma, making the diagnosis easily overlooked 7

Common Pitfalls

• The diagnosis is frequently missed in elderly patients because neurologic deficits are complex and radiographs may show only spondylotic changes without obvious acute injury 7
• The historical concept that central cord syndrome involves hemorrhagic injury to the central gray matter is incorrect—the pathology is predominantly white matter axonal injury in the lateral columns 5
• Delayed onset of paralysis can occur, making early recognition challenging 7