Tetraplegia

Tetraplegia (from Greek tetra — four and plegia — paralysis, strike) is a severe neurological condition characterized by the complete loss of voluntary movements and all types of sensation in both arms, both legs, and the torso.

This pathology is a direct consequence of catastrophic damage to the spinal cord at the cervical level.

Etiology and pathophysiology

The critical substrate of the injury is the transverse destruction or profound ischemia of the spinal cord at the level from the first cervical (C1) to the first thoracic (T1) segments. Such damage most often occurs with complicated fractures of the cervical vertebrae as a result of traffic accidents, falls from a height, or careless diving into shallow water.

The mechanism of developing total paralysis is linked to the complete anatomical interruption of descending motor pathways (corticospinal tracts), through which commands from the brain’s cortex are transmitted to the skeletal muscles. Simultaneously, all ascending sensory tracts that transmit signals from the body to the brain are interrupted.

Clinical significance

Tetraplegia represents one of the most disabling injuries in medicine. The clinical severity of the patient’s condition depends on the exact level of spinal cord injury. An injury above the level of the fourth cervical vertebra (C4) leads to paralysis of the phrenic nerve, making independent breathing impossible and requiring lifelong artificial lung ventilation.

In addition to total immobilization of the limbs, patients suffer from profound autonomic nervous system dysfunction. This manifests as a lack of control over urination and defecation, disturbances in thermoregulation, and life-threatening episodes of autonomic dysreflexia (uncontrolled spikes in blood pressure).