Leg weakness is often caused by nerve damage in the spinal cord.
Leg weakness indicates serious medical conditions, yet many people ignore it. It is more than just being tired or overworked. Leg weakness refers to someone's inability to move the leg muscles in certain ways that are normal. It can inhibit a person's ability to work and lead to other problems, such as paralysis and foot drop, which is the inability to lift the foot up to walk. Nerve damage plays a large role in leg weakness.
Function of Nerves
The nerves along the spinal cord and the lower back supply the legs with sensations and movement. Without these nerves, it would be impossible for a person to walk or do other activities involving the legs and feet. There are diseases, however, which can negatively affect these nerves, such as slip disc (cartilage inter-vertebral disc compresses nerves of spinal cord), sciatica (compression of nerve bundle in hip joint), and leprosy (damage to nerves near the skin). Any of these diseases can cause nerve damage which leads to leg weakness.
Significance
Any type of nerve damage is a medical emergency because nerve tissue does not normally grow back. Therefore, when someone loses nerve tissue, it is permanent. Permanent loss of nerves in the spine can result in a person not being able to properly use her legs. The first sign of leg weakness should be taken seriously and treated right away to avoid any type of permanent nerve damage. The window of opportunity to get tested and treated for nerve damage is small, perhaps only a few days.
Identification
Nerve compression in the lower back is the most common cause of leg weakness. This condition is called sciatica, and a person will most likely feel shooting pains from the lower back to the knee or ankle. A doctor will identify this nerve disruption by having a patient perform several movements to test the strength of the leg muscles and testing sensory loss with a cotton wisp or pin. X-rays, MRIs and nerve conduction studies are also performed to investigate the causes of leg weakness.
Diagnosis
Following a doctor's tests, the cause of leg weakness can be determined as spinal cord compression, spinal nerve compression or a local nerve disease. Spinal cord compression and spinal nerve compression are usually related to an inter-vertebral disc protrusion; however, they can also be caused by a tumor, sciatica, spondylolisthesis, a fractured vertebra or spinal stenosis. Leprosy, syphilis, a nerve cut injury and neurofibroma are examples of local nerve diseases that can cause leg weakness.
Treatment
If leg weakness is due to a local nerve disease, it is treated based on that disease. For example, if a person has syphilis that causes leg weakness, the doctor will treat the syphilis, and in turn treat the leg weakness. Spinal cord and nerve compression require surgery for treatment. Surgery is then followed by months of bed rest, painkillers and physical therapy. Muscle relaxants and neurovitamins are also prescribed to reduce pain after surgery.
