spinal cord injury

Spinal cord injury occurs when trauma, disease, or congenital conditions damage the spinal cord, disrupting communication between the brain and body below the injury level. Primary injury involves direct mechanical damage (contusion, compression, laceration), while secondary injury results from ischemia, inflammation, and cellular death cascades. Classification includes complete (no motor/sensory function below injury) vs incomplete (some preservation), and level of injury (cervical C1-C8, thoracic T1-T12, lumbar L1-L5, sacral S1-S5). Cervical injuries above C4 affect diaphragmatic breathing and may require mechanical ventilation. Incomplete injury syndromes include central cord syndrome (upper extremity weakness > lower), anterior cord syndrome (loss of motor/pain/temperature with preserved vibration/proprioception), Brown-Séquard syndrome (ipsilateral motor/proprioception loss with contralateral pain/temperature loss), and cauda equina syndrome (lower motor neuron signs). Complications include neurogenic shock (hypotension, bradycardia from sympathetic disruption), autonomic dysreflexia (hypertensive crisis from noxious stimuli below T6 injuries), spasticity, bladder/bowel dysfunction, and pressure ulcers. Management involves methylprednisolone within 8 hours (controversial), surgical stabilization, and comprehensive rehabilitation.