Why does paralysis occur when someone injures their spinal cord?

Answer 1

The spinal cord is the main line that brings all nerve signals back to the brain so when this is damaged it interrupts the line. When the line is damaged bad enough the signal cannot pass and therefore cannot communicate with the brain. When for example the legs can no longer communicate with the brain they can no longer receive the "orders" to move, meaning paralysis.

Answer 2

Spinal cord paralysis is damage to the spinal cord that causes a partial or total loss of muscle and sensory functions. The spinal cord does not need to be severed for paralysis to occur. The location of the spinal cord injury dictates what muscle and sensory functions are affected and the degree of injury (complete or incomplete) dictates how much (if any) function remains.

Answer 3

There can be injuries to peripheral nerves--in the arms and legs. Injuries to peripheral nerves rarely result in paralysis, but can cause symptoms such as numbness, or neuropathy--a complex type of pain that ranges from numbness to extreme burning. Otherwise, most functioning after peripheral nerve injury remains intact, though there may be limited mobility and intentional guarding and limited range of motion of the affected limb due to pain.

With spinal cord injuries, the injury can result in an Incomplete Spinal Cord Injury. This means nerve signals still get through the spinal cord, but there are problems with the way the signals come through the spinal cord. The person can still move the body parts controlled from specific levels of the spine, but nerve transmission can be intermittently interrupted due to inflammation and consequences from the injury itself. There may be one sided Foot Drop. The person may have intense neuropathy pain in the legs (or arms if the injury is high spine). The person typically has had a low back injury, with resulting low Back pain. So mobility is present but often limited due to pain and nerve symptoms like Foot Drop.

If a very high cervical spinal cord injury, the higher mortality. However, a person can suffer a spinal fracture at C-1 or C-2 and not only survive but never be aware they were injured. For example, about 40% of people with odontoid fracture (C1-C2) never know of the injury until it shows on an MRI, while the other 60% die immediately. It depends on if the fracture severely affected the spinal cord. Those who live, though, often have chronic neck pain and even shoulder pain.

In order to result in paralysis from a spinal injury, it must be an injury to the cervical spine or thoracic spine, e.g. cervical is neck, while thoracic is chest level. The higher the injury in these levels, the higher chance of being a quadriplegic-- with all 4 limbs and breathing paralyzed. Full quads lose all sensation also in the upper body. Some quads retain some limited sensory feelings.

If a thoracic injury, the person often becomes a paraplegic--with continued breathing and use of their arms, but cannot use or feel their legs. They still feel sensations in the upper body.

However, not all cervical, thoracic, or lumbar spinal injuries result in any type of paralysis. It depends on the severity of the injury. But most people who've had any spinal injury have chronic pain or other strange symptoms for the rest of their lives. A minor or incomplete spinal cord injury can also progress throughout life, with degeneration of both the bones (vertebral bodies) around the cord, degeneration in the cord itself, and diminshed nerve signals trying to travel down from the brain to the peripheral nerves OR up from the peripheral nerves to the brain. One example of this is Intermittent Foot Drop in which the person chooses to walk, but the brain cannot get the toes and front of the foot to lift normally. Humans must lift the toes and front of the foot FIRST to be able to take a step. When the nerve signal to the leg-foot is disrupted, it results in the person lifting the hip on the problem side, as they struggle to lift the front of the foot. In the most severe cases, which mean a person cannot stand or walk at all, the Foot Drop causes an inability to pull (lift) the toes toward the leg---the foot/toes stay permanently in a front-downward position. In Intermittent Foot Drop, the person is at risk of falling or breaking toes and the forefoot because the toes won't lift (they curl under when trying to walk).

So--

1. Not all spinal cord injuries cause paralysis.

2. Peripheral Nerve Injury alone can cause a localized paralysis---for example, one finger--but peripheral nerve injury does not include a spinal injury.

3. An incomplete Spinal Cord Injury can result in lifelong nerve symptoms, impairments, and pain---without paralysis.

4. A chest (thoracic) spinal cord injury usually results in paraplegic status.

5. A neck (cervical) spinal cord injury usually results in quadriplegic status.

6. The highest cervical fracture with spinal cord involvement typically means instantaneous death. But 40% of people can have an odontoid fracture at C1-C2 without major spinal cord injury, and the persons may not know they broke their necks until an MRI coincidentally finds the fracture.

Answer 4

The nervous system would not have a path through which to send messages to the brain.

Answer 5

Yes, muscle paralysis can occur due to a spinal cord injury.

Answer 6

The chain of nerves is broken, disrupting the signals between the brain and all body parts below the injury. This causes paralysis when the brain can't send signals for the body to move.

Answer 7

Yes, it very often does.