Sciatica is pain is caused by irritation of the sciatic nerve. It starts from nerve roots in the lumbar spinal cord in the low back and passes through the buttock area to send nerve endings down the lower limb.
- The most common cause of sciatica is disc herniation directly pressing on the nerve.
- Irritation or inflammation of this nerve can mimic the symptoms of sciatica. Irritation of the nerve can be caused from bony irregularities (eg, osteoarthritic osteophytes, spondylolisthesis), tumors, muscle, internal bleeding, infections, injury, and other causes.
Pain is the major symptom of sciatica. Sciatica pain typically occurs in the low back to behind the thigh and radiates down below the knee. The pain often starts gradually and slowly worsens.
The pain can vary widely in character from a mild tingling, dull ache, or a burning sensation radiating from the lower back and upper buttock down the back of the thigh and to the back of the leg. Severe pain can make walking difficult if not impossible.
In some people symptoms of sciatica are worsened by walking or bending at the waist and eased by lying down. Sciatica pain may be aggravated by
- Prolonged standing or sitting
- During night
- By sneezing, coughing, or laughing
- On bending backwards or walking more than a few steps, especially if caused by spinal stenosis
Tests and diagnosis
- Clinical evaluation: Sciatica can be diagnosed clinically based on the characteristic pain. If it is suspected a complete neurological evaluation to assess strength, reflexes, and sensation is done. If you have neurologic deficits or if your symptoms persist for > 6 wk, your doctor may advise imaging and electrodiagnostic studies.
- Magnetic resonance imaging (MRI) scan, computed tomography (CT) scan, can confirm structural abnormalities causing sciatica (including spinal stenosis)
- Electrodiagnostic studies can establish the presence and extent of nerve root compression and exclude conditions that may imitate sciatica, such as polyneuropathy. Abnormalities are evident on electrodiagnostic studies a few weeks after the symptoms begin.
Treatment of sciatica depends on the cause and severity of the pain. In some people sciatica will improve and go away with time. In acute pain 24 to 48 h of bed rest with the head of the bed elevated about 30° can help to relive pain. Heat or cold therapy and physical therapy may be useful to relieve muscle spasm and pain.
- NSAIDs: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, diclofenac. mefenamic acid can be used to relieve pain for upto 6 weeks. NSAIDs in high dose to relieve pain can cause side-effects such as GI bleeding, hence these medications should be avoided in patients with stomach ulcers.
- Muscle Relaxants: Muscle relaxing medications (such as baclofen, carisoprodol, chlorzoxazone, methocarbamol, diazepam) ease muscle spasm, and pain. But these medications can make you drowsy.
- Drugs that decrease neuropathic pain like pregabalin and gabapentin can ease pain in some patients. These drugs should be taken with caution in the elderly, patients at risk of falls, and those with arrhythmias.
- Narcotic analgesics like morphine and codeine may be used in cases of severe pain. But as these can cause tolerance and dependence, they must be used under close supervision, for a limited period of time only as prolonged use of narcotic medication can be dangerous.