A spinal cord injury (SCI) may happen due to blunt force on the nerves themselves or if a violent accident (such as a significant fall or a car accident) damages the vertebrae around them. In turn, the cracks or dislodged pieces of bone can press on the spinal cord, damaging its neurons.
The nerves alongside the spinal cord act as the main connector between the brain and the entire body including hands and feet. As a result, any injury to the spinal cord is likely to cause long-term, severe damage to sensation, mobility, and muscle function including control of urination, defecation and the function of the sexual organs.
Types of Spinal Cord Injury
Spinal cord injury is usually classified depending on the onset and severity of the damage:
- Primary cord injury. This is when the spinal cord is severed during the initial accident, dividing it into two or more sections with a visible interval between them. When this happens, patients will usually lose mobility and sensation below the point of the injury, and the damage remains permanent.
- Secondary cord injury. Also known as secondary injury cascade. This is when the spinal cord is crushed and not entirely disconnected. Such an injury can result in permanent or progressive loss of loss function depending on the severity of the local damage.
Symptoms of Spinal Cord Injury
A spinal cord injury will cause:
- Complete or partial loss of muscle strength
- Loss of voluntary movement of the affected areas
- Loss of sensation in the affected areas
- Loss of involuntary movement of the affected areas.
The body regions affected by a spinal cord injury will depend on the injury’s location. Typically, all sensation and movement below a certain point are lost.
- Cervical spinal cord injuries are the most severe and may result in immediate death or tetraplegia (loss of function of all four limbs).
- Thoracic spinal cord injuries may affect the chest, back and legs. However, arm and hand function may be left intact.
- Lumbar spinal cord injuries may affect the hips and legs but leave arms, hands, and trunk intact.
- Sacral spinal cord injuries will damage mobility and sensation on the hips, back of the tights, and sexual organs. However, the patient may be able to walk.
Management of Spinal Cord Injuries
Immediately after a spinal cord injury, the priority is to stabilize the patient’s general condition, ensure they can continue breathing, and prevent any further or secondary damages by stabilization of the vertebrae to prevent additional damage caused by instability and pressure to the spinal cord. Depending on the location and severity of the injury, long-term management may include:
- Physical or occupational therapy
- Preventing pressure ulcers
- Controlling bowel and bladder function
- Preventing blood clots due to immobilization
In cases of partial paralysis (following a lumbar or sacral injury), physical therapy and rehabilitation will focus on helping the patient regain as much independence as possible. Furthermore, for damages to the thoracic spine, it will also be necessary to maintain muscle strength in the upper limbs and prevent deconditioning.
Treatment of Spinal Cord Injuries
The prognosis is usually very poor for primary cord injuries, and the damage is usually treated as irreversible.
On the other hand, for secondary spinal injuries, early treatment will make it possible to prevent continuous damage and allow regeneration of damaged nerves. In some cases, following intensive physical therapy, patients may be able to regain mobility and sensation.
Mesenchymal Stromal Cells for Spinal Cord Injuries
Damaged nerves once considered irreversible can sometimes regenerate and repair function. Unfortunately, spinal cord injury that resulted in complete cut results in permanent loss of function below the damaged area. However, new treatments offer hope for patients who retain some continuity between both sides of the damaged spinal cord thanks to the use of multipotent mesenchymal stromal cells (MSCs). Multipotent MSCs can be differentiated into neural cells and be differentiated into different neuronal cell types under laboratory conditions, leaving hopes that similar differentiation may also occur in vivo. MSCs can home actively to the sites of damage that needs to be repaired. Furthermore, one of the problems that impairs neuronal repair is the scar formation (fibrosis) in the damaged area. Interestingly, MSCs can also prevent development of fibrosis and facilitate continuity of neuronal growth, including differentiation into oligodendrocytes (the cells responsible for myelin production that isolates and protects the neurons). The therapeutic effects ascribed to MSCs may also be partly mediated by exosomes, excretory nanoparticles that can also induce regeneration by locally residing patient’s own MSCs. Taken together, the use of MSCs for treatment of SCI provides great hope for treatment of patients considered until recently untreatable, especially if treatment can be provided as early as possible following the accident.