Sciatic Nerve Dysfunction
Sciatic nerve dysfunction is a condition in which the sciatic nerve conducts impulses abnormally. The sciatic nerve is the main nerve of the leg. Abnormalities of this nerve can impair movement and/or sensation. Sciatica is a term that describes pain along the sciatic nerve.
What is going on in the body?
The sciatic nerve runs through the leg and is the largest nerve in the body. It conducts nerve impulses to and from the following areas:
- the hip joints
- some of the thigh muscles
- the knee and ankle joints
- all the muscles of the lower leg
- joints and muscles in the feet
Sciatic nerve dysfunction may affect any of these areas of the body. Most often, the nerve damage occurs when a disk in the spine ruptures. The vertebrae of the spinal column are separated by vertebral disks that act like shock absorbers. A disk is made up of two parts. The outer ring or annulus is a tough, fibrous material. The inner part or nucleus is a soft, jelly-like material. A ruptured disk occurs when the outer ring tears or breaks, allowing the jelly-like material to poke through the crack. The disk may press on the sciatic nerve.
What are the causes and risks of the condition?
Trauma is the usual cause. Injury to the sciatic nerve can occur because of:
pelvic or hip joint fractures
gunshot or knife wounds to the leg
injection into the buttock
- compression of the nerve from prolonged sitting or lying
Unusual causes include:
- hematoma (blood clot in the pelvis or leg)
What can be done to prevent the condition?
Proper lifting techniques are important to avoid a ruptured disk. These techniques can be enhanced by the use of an abdominal support belt. Other preventive measures include the following:
- regular physical activity
- rest breaks to interrupt long periods of vibration, such as when driving a car
- smoking cessation
for individuals who smoke
- weight management
for people who are obese
A person with diabetes
can prevent some nerve problems by controlling his or her blood glucose levels.
How is the condition diagnosed?
Diagnosis of sciatic nerve dysfunction begins with a medical history and physical exam. Depending on the suspected cause of the problem, the provider may order diagnostic tests, such as:
- blood and urine tests
- a nerve conduction velocity test, or NCV, which measures transmission along the nerve
- an electromyogram, or EMG, which measures muscle response to nerve stimulation
- a bone scan
- a myelogram,
which uses a contrast agent and X-rays to detect abnormalities along the spine
Long Term Effects
What are the long-term effects of the condition?
Sciatic nerve dysfunction may result in permanent muscle weakness and long-term abnormal sensations. Chronic or constant pain is also a possible long-term effect. Other long-term effects depend on the underlying cause.
What are the risks to others?
Sciatic nerve dysfunction is not contagious and poses no risk to others.
What are the treatments for the condition?
A ruptured disk is generally treated conservatively at first. Initial treatments include:
- activity limitations
- anti-inflammatory pain medicine, such as ibuprofen, ketoprofen, flurbiprofen, or naproxen
- application of heat
- muscle relaxants, such as carisoprodol
- a specialized exercise program
If conservative treatment is not successful, the healthcare provider may recommend surgery. The following operations may be helpful for people with a ruptured disk:
- diskectomy or laminectomy,
which allows the surgeon to remove the ruptured disk and relieve nerve pressure
- injection of chymopapain, an enzyme, into the disk to dissolve it
- spinal fusion, which involves the joining of two or more vertebrae
Medicines may be prescribed to improve blood glucose control and help treat the nerve dysfunction if diabetes
is the cause. In some cases, such as toxin exposure, nerve function cannot be restored.
What are the side effects of the treatments?
Side effects of medicines include allergic reactions
and stomach upset. Surgery is associated with a risk of infection, bleeding, and allergic reaction
What happens after treatment for the condition?
If the cause is reversible and is treated, no further treatment may be required. A person can often return to normal activities. Treatment may be prolonged if the underlying cause cannot be fixed. Such a cause would be diabetes.
After conservative treatment of a ruptured disk, a person can usually resume activity as tolerated. Symptoms may recur every now and then, requiring repeated treatment. After surgery, the signs and symptoms usually disappear, and a person will slowly resume normal activity after proper recovery. Physical therapy
can be helpful to teach appropriate body mechanics and lifting techniques.
How is the condition monitored?
An individual with sciatic neuropathy will need routine follow up with his/her healthcare professional at first, to monitor for improvement or worsening, so as to direct physical therapy and/or further investigation or treatment for the condition.