Spinal cord injury (SCI) occurs when a traumatic event results in damage to cells within the spinal cord or severs the nerve tracts that relay signals up and down the spinal cord. The most common types of SCI include contusion (bruising of the spinal cord) and compression (caused by pressure on the spinal cord). Other types of injuries include lacerations (severing or tearing of some nerve fibers, such as damage caused by a gun shot wound), and central cord syndrome (specific damage to the corticospinal tracts of the cervical region of the spinal cord). Severe SCI often causes paralysis (loss of control over voluntary movement and muscles of the body) and loss of sensation and reflex function below the point of injury, including autonomic activity such as breathing and other activities such as bowel and bladder control. Other symptoms such as pain or sensitivity to stimuli, muscle spasms, and sexual dysfunction may develop over time. SCI patients are also prone to develop secondary medical problems, such as bladder infections, lung infections, and bed sores.

Brain The brain's primary role is to function as the body's control center. This organ receives and interprets nerve signals from every part of the body and initiates the appropriate response. These responses include adjustments in internal bodily functions (eg, heart rate and temperature), movement, speech, and emotions and consciousness

Cervical spinal nerves (C1 to C8)

These nerves (eight pairs) supply the back of the head, the neck and shoulders, the arms and hands, and the diaphragm.

Thoracic spinal nerves (T1 to T12)

These nerves (12 pairs) supply the chest, some muscles of the back, and parts of the abdomen.

Lumbar spinal nerves (L1 to L5)

These nerves (five pairs) supply the lower parts of the abdomen and the back, the buttocks, some parts of the external genital organs, and parts of the legs.

Sacral spinal nerves (S1 to S5)

These nerves (five pairs) supply the thighs and lower parts of the legs, the feet, most of the external genital organs, and the area around the anus.