Types of Spinal Cord Injuries
The spinal cord contains the large bundle of nerves that communicate information between the brain and the body. There are four sections of the spinal cord: cervical, thoracic, lumbar, and sacral. Each section of the spine protects different groups of nerves. The type of spinal cord injuries depends on the place of the injury along your spinal cord and the severity of the injury.
Cervical Spinal Cord Injuries
The Cervical Spine, or “C-Spine”, includes the first seven vertebrae of the spinal column, C1 to C7, in the neck. Being closer to the brain and affecting a larger portion of the body, cervical spinal cord injuries are typically the most severe type of spinal cord injury. If there is an injury in the cervical area, it may result in tetraplegia or quadriplegia, whereby there is limited or lack of feeling or movement below the shoulders and neck. Injuries located higher on the spine will be more severe, with high cervical spinal cord injury often being fatal.
Thoracic Spinal Cord Injuries
The thoracic spine is located in the upper and middle of the back. The thoracic spine is important for stability – it helps keep the body upright. It also connects the cervical spine, which is located in the neck, and the lumbar spine, which is located in the lower back. Twelve vertebrae are located in the thoracic spine, T1 to T12, and each number corresponds with the nerves in that section of the spinal cord.
Injuries to the nerves in the T1 to T5 section of the spine affect the upper chest, mid-back and abdominal muscles. These nerves and muscles help control the rib cage, lungs, diaphragm and the muscles that help you breathe.
Injuries to the nerves in the T6 to T12 section of the spine affect the abdominal and back muscles. These nerves and muscles are important for balance and posture. They also help you cough or expel foreign matter from your airway.
Thoracic spinal cord injuries typically result in paraplegia, whereby arm and hand function is usually normal.
Lumbar Spinal Cord Injuries
The lumbar region of the spine, commonly referred to as the lower back, consists of five vertebrae, L1 to L5, and comprises the lowest major portion of the spinal cord. These lumbar vertebrae contain spinal cord tissue and nerves that control communication between the brain and the legs. Damage to the lumbar spinal cord subsequently affects the hips and groin area, and may impact the lower abdominal muscles and thigh flexion.
Lumbar spinal cord injuries may be complete or incomplete and may affect one or both sides of the body. Injuries to the lumbar nerves generally result in some loss of function in the hips and legs. People with injuries to the lumbar spinal cord usually have little or no voluntary control of their bowel or bladder, but can manage on their own with special equipment and may need a wheelchair or (depending on the strength of their legs) braces in order to walk.
Sacral Spinal Cord Injuries
The sacral spine (sacrum) is located below the lumbar spine and above the tailbone (coccyx), which is the lowest segment of the vertebral column. The hips, back of the thighs, buttocks, and pelvic organs are affected by injuries to the sacral spinal cord. Pelvic organs include the bladder, bowel and sex organs.
There are five sacral vertebral bones, S1 to S5. Each number corresponds with the nerves in that section of the spinal cord:
- S1 nerves affect the hips and the groin area
- S2 nerves affect the backs of the thighs
- S3 nerves affect the medial buttock area
- S4 nerves affect the perineal area
Sacral spinal cord injuries generally result in some loss of function in the hips and legs. There may be little or no voluntary control of bowel or bladder organs, but people with this injury can manage on their own with special equipment. People with a sacral spinal cord injury will most likely be able to walk.
Complete Spinal Cord Injury Versus Incomplete Spinal Cord Injury
Spinal cord injuries are generally divided into two types of injury – complete and incomplete. A complete spinal cord injury causes permanent damage to the area of the spinal cord that is injured and affects the associated nerves. Paraplegia or tetraplegia result from complete spinal cord injuries.
An incomplete spinal cord injury refers to partial damage to the spinal cord. The ability to move and the amount of feeling retained depends on the area of the spine injured and the severity of the injury.
Outcomes vary from patient to patient and many variables may affect prognosis, including overall health and medical history, existing medical conditions and other injuries that may have occurred at the time of the spinal cord injury.
A significant proportion (estimates range from 16–74%) of patients with spinal cord injury have concomitant traumatic brain injury.