PATIENT INFORMATION
Sciatica
Pain radiating from the lower back or buttock down the leg, usually from a nerve root in the lower spine.
What is sciatica?
Sciatica describes pain radiating from the lower back or buttock down the leg. It is usually caused by irritation or compression of one of the nerve roots in the lower spine (radiculopathy), most commonly due to a slipped (herniated) disc or age-related wear and tear.
Symptoms may include:
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Sharp, burning, or shooting pain down the leg
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Numbness or tingling in the leg or foot
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Muscle weakness
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Pain that is worse when coughing, sneezing, or sitting
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Difficulty walking or standing for prolonged periods
Symptoms typically affect one side, although both legs can occasionally be involved.
Why have I been referred for NCS and EMG?
These tests confirm whether your symptoms are due to a pinched nerve in the lower back, identify which nerve root is affected, assess whether there is evidence of nerve damage, and exclude other conditions such as peripheral neuropathy or peroneal nerve palsy.
Although MRI shows the structure of the spine, it does not always indicate whether a nerve is functioning normally — EMG provides that additional functional information.
What to Expect During the Test
Nerve conduction studies: small electrodes on the leg and foot assess how well the nerves conduct signals. These are often normal in sciatica, but are important in excluding other nerve disorders.
EMG is usually the most informative part of the assessment: a very fine needle samples selected leg muscles, and occasionally the lower back, for signs of nerve root irritation or injury. Read more about NCS/EMG.
Summary
Sciatica is a common condition caused by irritation or compression of a nerve root in the lower back. NCS and EMG help confirm the diagnosis, identify the affected nerve root, and exclude other causes. The results assist in determining the most appropriate treatment, which may include physiotherapy, medication, injections, or surgery.