Normal EMG but still nerve pain? Why that happens

You had the test. You sat through the needles, and then someone told you it was normal. But your foot still burns, tingles or aches. It is a frustrating place to be, and it is more common than most people realize. Here is why it happens and what to do next.

What the tests can and can’t show

Nerve conduction studies and EMG are electrical tests. They can show whether a nerve is affected, where along its path the trouble is, how severe it is and, in some cases, how likely the nerve is to recover.^[4] They are useful, but they are not perfect. Our guide to what to expect from an EMG explains how they work.

Here is what the research says about their limits:

• They can miss an entrapment. An evidence-based review of tarsal tunnel syndrome found that nerve conduction studies were abnormal in some people with the condition, that sensory studies were more likely to be abnormal than motor studies, and that the actual sensitivity and specificity could not be determined.^[1]
• A normal result doesn’t predict a poor outcome. A study of 53 people who had tarsal tunnel release noted that the sensitivity of electrodiagnostic testing is just over 50%. People with positive and negative studies both improved significantly, with no significant difference in outcomes or recovery time.^[2]
• Guidelines are limited. Guidelines for electrodiagnostic testing of entrapment neuropathies are generally sparse, and more research is needed.^[5]

When the small fibers are the problem

Patients with lower-extremity sensory symptoms and pain, but without abnormalities on the clinical examination or on standard neurophysiological testing, may have a small fiber neuropathy.^[3] A skin biopsy was abnormal in 88.1% of 67 patients who had symptoms suggestive of sensory neuropathy but normal nerve conduction studies, compared with 10% of healthy controls.^[3] A joint European guideline gave skin biopsy a strong recommendation for diagnosing neuropathic pain.^[6] See small fiber neuropathy: burning feet with normal tests.

Other possibilities

• The pain may not be coming from a nerve at all. Pain in the foot can also come from tendons, joints, bones or circulation, which is why the examination keeps the whole list of possibilities in view. See heel pain: plantar fasciitis or a pinched nerve? for one example.
• Sometimes, the cause is never found. In up to 27% of adults with neuropathy, no cause is identified after diagnostic testing.^[7]

What to do next

1. Bring the report, not just the result. The details matter, including which nerves were tested and whether a needle study was done. Reports can save you a repeat test.
2. Get a careful examination. For many foot nerve problems the examination is the most informative step: mapping numb areas, tapping along the nerve, checking strength and reflexes, foot alignment and footwear.
3. Consider imaging. Ultrasound and MRI show what may be pressing on a nerve, such as a cyst, scar tissue or a swollen tendon sheath.^[8] See ultrasound or MRI for nerve pain in the foot.
4. Look at the whole pathway. Symptoms that persist after treatment at one site may be due to a problem at another, which is the idea behind double crush syndrome. It is debated, but it is one reason to look again at the back, the leg and the foot together.^[9] See back or foot? finding the source of nerve pain.
5. Treat the symptoms while you look. Nerve pain can be treated even when the cause is not yet proven.

Read more in nerve testing for foot pain.

When to see a specialist

Consider an evaluation if burning, tingling or numbness in your foot lasts more than a few weeks, or if you’ve had tests that were normal but your symptoms haven’t gone away.