Is a patient who develops quadriplegia with preserved consciousness after a traumatic injury, such as a fall from a trampoline, considered to have locked-in syndrome?

Locked-In Syndrome After Traumatic Injury

A patient who develops quadriplegia with preserved consciousness after a traumatic injury such as a fall from a trampoline is not considered to have locked-in syndrome, but rather likely has a cervical spinal cord injury.

Differentiating Locked-In Syndrome from Cervical Spinal Cord Injury

Locked-In Syndrome (LIS)

• Definition: Characterized by quadriplegia, anarthria (inability to speak), and preserved consciousness with ability to communicate only through vertical eye movements and blinking 1
• Primary cause: Ventral pontine lesion in the brainstem, most commonly due to basilar artery occlusion (86.4% of cases) 2
• Traumatic etiology: Traumatic brain injury accounts for only 13.6% of LIS cases 2
• Anatomical basis: Damage to specific structures in the pons, mesencephalon, or thalamus 1

Cervical Spinal Cord Injury

• Definition: Damage to the spinal cord in the cervical region resulting in quadriplegia with preserved consciousness
• Mechanism: Typically from traumatic injury causing vertebral fracture, dislocation, or compression of the spinal cord
• Traumatic etiology: Common causes include falls, motor vehicle accidents, and sports injuries 3

Key Diagnostic Features

Scenario Analysis

The described scenario of a trampoline fall resulting in quadriplegia with preserved consciousness is most consistent with a cervical spinal cord injury rather than locked-in syndrome for the following reasons:

1. Mechanism of injury: Traumatic falls typically cause cervical spine injuries rather than pontine lesions 3
2. Anatomical considerations: Trampoline falls often cause axial loading to the cervical spine, resulting in compression fractures or dislocations 3
3. Epidemiology: Cervical spine injury complicates 2-12% of blunt polytrauma cases, while LIS is rare and predominantly caused by vascular events 3, 2

Management Considerations

Immediate Management for Suspected Cervical Spine Injury

• Immobilization: Maintain spinal motion restriction by manually stabilizing the head to minimize movement of the head, neck, and spine 3, 4
• Caution: First aid providers should not use immobilization devices unless properly trained 3

Risk Factors for Cervical Spine Injury

Suspect spinal injury if an injured victim has any of the following:

• Fall from greater than standing height (as in this trampoline scenario)
• Tingling in extremities
• Pain or tenderness in neck or back
• Sensory deficit or muscle weakness involving torso or upper extremities
• Not fully alert or intoxicated
• Other painful injuries, especially of head and neck 3

Potential Complications

• Missed or delayed diagnosis of cervical spine injury may produce 10 times the rates of secondary neurological injury (10.5% vs. 1.4%) 3
• Up to 4.3% of cervical fractures may be missed, with 67% of these patients suffering neurological deterioration as a result 3

Diagnostic Approach

• Imaging: MRI is recommended 6-8 weeks post-injury to assess for corpus callosal lesions, dorsolateral upper brainstem injury, or corona radiata injury 3
• Serial neurological assessments: Monitor for changes in neurological status that might indicate deterioration 3

Prognosis and Quality of Life

• Cervical spine and associated spinal cord injury significantly affect functional capacity and quality of life 3
• A 27-year-old rendered tetraparetic would consume approximately US$1 million for lifetime care 3
• Early rehabilitation is essential to optimize outcomes in both conditions 4, 5

Key Pitfalls to Avoid

1. Misdiagnosis: Failing to distinguish between locked-in syndrome and cervical spinal cord injury can lead to inappropriate management
2. Delayed treatment: Secondary neurological injury can occur if appropriate immobilization and treatment are not provided promptly
3. Underestimation of quality of life: Medical providers often underestimate quality of life in patients with severe neurological conditions, potentially leading to less aggressive care 6

In summary, the scenario described is consistent with a cervical spinal cord injury rather than locked-in syndrome, requiring immediate spinal stabilization and appropriate trauma management to prevent secondary neurological injury.