A test evaluating the function of muscles and peripheral nerves through a fine needle electrode and surface skin recordings. Used in the diagnosis of nerve entrapments and muscle disorders.
Indication
- Complaints of numbness, tingling, and weakness in the hands, arms, or legs
- Suspected carpal tunnel syndrome (nerve compression at the wrist)
- Evaluation of nerve root compression (radiculopathy) due to lumbar or cervical disc herniation
- Diagnosis and follow-up of polyneuropathy (widespread nerve damage from causes such as diabetes)
- Muscle disorders (myopathy) and neuromuscular junction diseases such as myasthenia gravis
- Assessment of advanced neurological diseases such as ALS (motor neuron disease)
- Recovery and post-surgical follow-up after nerve injury
Preparation
- Do not apply cream, lotion, or oil to the skin before the procedure
- Inform your physician about all your medications, especially blood thinners
- Be sure to mention if you have a pacemaker, deep brain stimulator, or any other implant
- Fasting is not required; choose comfortable, easily removable clothing
- For children and those with severe needle phobia, pre-procedure assessment with the physician may be performed
How it's performed
- The procedure has two parts: nerve conduction study and needle EMG; only one may be performed if needed
- Adhesive electrodes are placed on the skin surface; brief, mild electrical stimuli are applied
- In the needle EMG part, a thin, single-use needle electrode is inserted into the relevant muscles
- The physician first records the muscle's resting activity, then signals during mild and strong contraction
- The procedure lasts approximately 30-60 minutes depending on the number of muscles tested
- At the end, the needle is removed; brief pressure may be applied to the area if needed
Post-procedure
- The result report is usually prepared on the same day or shortly afterwards
- Results are forwarded to the neurology, orthopedics, or neurosurgery physician planning the treatment
- You can return to your daily activities immediately after the procedure
- Mild soreness or tenderness in the tested muscles may occur for 1-2 days; simple pain relievers are sufficient
- Follow-up EMG may be requested when symptoms change or to measure treatment response
Risks
- Brief needle prick, mild discomfort, and transient pain are common during and after needle electrode application
- Small bruising (hematoma) may occur at the skin entry site; resolves in a few days
- Skin infection is very rare; the risk is low with single-use needles
- Bruising risk may be higher in patients on blood thinners; inform the physician beforehand
- Very rare risk of pneumothorax (lung collapse) in muscles near the lung; minimized with an experienced physician
FAQ
Is EMG very painful?
During needle EMG, you may feel discomfort during the needle insertion and muscle activation, but most patients find it brief and tolerable. Severe pain is not expected; the level of discomfort varies depending on the muscle being tested.
Can I drive or return to work after EMG?
Yes, since EMG does not require sedation, you can drive and return to your daily activities afterwards. Mild stiffness in the tested muscles may occur for 1-2 days.
Can I have an EMG if I have a pacemaker?
EMG is performed carefully in patients with a pacemaker or implanted device; the stimulation site and technique are chosen accordingly. Inform your physician about your device before the procedure.
If my EMG is normal, does that mean my symptoms are 'in my head'?
No. EMG only evaluates peripheral nerves and muscles; pain, central nervous system disorders, or early-stage diseases may exist even with a normal EMG. Your physician will interpret the result together with your symptoms.
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