Nerve Conduction Study
Also known as: NCS, nerve conduction velocity test, NCV test, peripheral nerve test, nerve function test, nerve electrical study
A nerve conduction study is a diagnostic test that measures how effectively electrical signals travel through your peripheral nerves. This non-invasive procedure helps neurologists identify nerve damage, evaluate muscle weakness, and diagnose many different conditions affecting the nervous system.
What is a nerve conduction study?
A nerve conduction study measures the speed and strength of electrical signals travelling through peripheral nerves that connect your brain and spinal cord to the rest of your body. The test uses surface electrodes placed on your skin to deliver mild electrical pulses and record how your nerves respond to electrical stimulation.
During the procedure, a clinical physiologist or doctor calculates nerve conduction velocity by measuring the time it takes electrical signals to travel between electrode points. This diagnostic test helps determine whether your nerves control muscle movement and sensation properly, or if nerve damage is affecting normal function.
The nerve conduction test is often performed alongside electromyography (EMG) to provide a comprehensive assessment of nerves and muscles. This combination helps distinguish between nerve disorder and muscle disorder, giving your consultant detailed information about what may be causing your symptoms.
Normal nerves conduct electrical impulses at speeds between 50 and 60 metres per second, while damaged nerves show significantly slower conduction velocities. The test evaluates both motor nerves that control muscle movement and sensory nerves that carry signals from your skin back to your spinal cord.
How nerve conduction studies work
A nerve conduction study measures electrical activity naturally produced by your nervous system. Surface electrodes with metal discs are attached to specific points along nerve pathways in your arms and legs, allowing the equipment to record activity from peripheral nerves.
Stimulating electrodes deliver brief, controlled electrical impulses to activate nerves, while recording electrodes capture the nerve signal and any resulting muscle contractions. A computer calculates conduction velocity by dividing the distance between electrodes by the time it takes the electrical signals to travel that distance.
Each small electrical impulse lasts only a few seconds and feels like a mild tingling or a static electricity shock. The electrical stimulation may cause muscles to twitch, but this is entirely normal and indicates that your nerves are responding to the test. How many nerves are tested depends on your symptoms and medical history.
Both motor nerves that control muscle movement and sensory nerves that carry sensation can be evaluated during the same session. The test measures not only nerve conduction velocity but also the strength and shape of electrical signals, providing comprehensive information about nerve function throughout your body.
Conditions diagnosed with nerve conduction studies
Nerve conduction studies (NCS) can diagnose a wide range of peripheral nerve conditions. Carpal tunnel syndrome, one of the most common compression neuropathies, affects nerves at the wrist and causes numbness and muscle weakness in the hand. The test can precisely locate the site of nerve compression and determine its severity.
Diabetic patients often develop peripheral neuropathy due to prolonged high blood sugar levels, affecting nerve function. Diabetes can damage both sensory nerves and motor nerves, leading to symptoms in the feet and legs that progressively worsen without proper management.
Guillain-Barré syndrome, an autoimmune condition in which the body attacks peripheral nerve coverings, can be diagnosed based on distinctive patterns on nerve conduction studies. Similarly, Charcot-Marie-Tooth disease, a hereditary neurological disorder, shows characteristic changes in nerve conduction velocity and electrical activity.
Other conditions diagnosed include:
- Myasthenia gravis affecting the neuromuscular junctions
- Peripheral neuropathy from chemotherapy or vitamin deficiencies
- Herniated disc disease affecting nerve roots from the spinal cord
- Bell’s palsy and facial nerve disorders
- Various compression syndromes affecting nerves at the elbows, knees, and ankles
The test helps differentiate between nerve damage and muscle disorder, ensuring accurate diagnosis and appropriate treatment planning for your specific condition.
When you might need a nerve conduction study
Your doctor may recommend a nerve conduction test if you experience persistent numbness, tingling, or burning sensations in your hands, feet, arms, or legs. These symptoms often indicate that nerves aren’t functioning correctly and require evaluation through diagnostic tests.
Muscle weakness or difficulty controlling specific muscle groups may suggest nerve damage affecting the signals between your brain and muscles. Sharp, shooting pains that follow nerve pathways can also indicate compression or inflammation requiring assessment.
Loss of normal reflexes during physical examination often prompts further investigation with nerve conduction studies. If your consultant suspects nerve compression due to repetitive motions or anatomical abnormalities, this test can confirm the diagnosis and assess severity.
The test is also valuable for monitoring the progression of known nerve disorders and evaluating whether treatment is effective. Before considering surgical intervention for nerve compression, doctors often use nerve conduction studies to establish baseline measurements and confirm the location of problems.
Please call to enquire about the price
Ways to payBefore the test
Proper preparation helps ensure accurate test results and your comfort during the procedure. Avoid applying lotions, creams, or oils to your skin 12-24 hours before the test, as these products can interfere with electrode contact and electrical conductivity.
Wear loose, comfortable clothing that allows easy access to your arms and legs for electrode placement. Loose-fitting clothing makes the procedure more comfortable and allows the clinical physiologist to position electrodes properly on your skin.
Keep your hands and feet warm with gloves and socks before the test, as cold temperatures can impair nerve conduction and yield inaccurate results. If you have a cardiac defibrillator fitted or a pacemaker, inform your healthcare provider, as special precautions may be needed.
Continue taking all regular medications unless specifically instructed otherwise. Very occasionally, for specific specialised tests such as repetitive nerve stimulation, your clinician may ask you to adjust the timing of some medicines. Provide a complete medical history, including any blood-thinning medications or bleeding disorders.
During the test
The nerve conduction study typically takes 45-60 minutes, depending on the number of nerves to be evaluated. The test is performed in an outpatient clinic by a neurologist, physiatrist, or trained technologist who specialises in these diagnostic tests.
You’ll lie comfortably on an examination table while electrodes are positioned on your skin along specific nerve pathways. The procedure involves brief electrical shocks similar to static electricity that may cause slight muscle movements, but these sensations last only briefly.
Each stimulus feels like a small electrical impulse that may be surprising but typically isn’t painful. You might experience mild tingling or see your muscles tested through small contractions, which are entirely typical and expected during the test.
Multiple nerves are usually tested to compare affected and normal areas. You can communicate with the technologist throughout the procedure about your comfort level. If an EMG test is also needed, it may involve inserting a fine needle to record muscle activity directly.
The electrical pulses used are very low voltage and pose no risk of electrical injury. Most patients tolerate the procedure well, though some areas may feel sore afterwards or show minor localised bruising that resolves quickly.
After the test
Once your nerve conduction study is complete, the electrode gel is cleaned from your skin, and you can resume normal activities immediately. There are no driving restrictions or activity limitations following the procedure, and you can return to work or daily activities right away.
If electromyography EMG testing was performed during the same visit using a small needle, you might notice tiny puncture marks on your skin that heal within a day or two. Any minor discomfort at electrode sites typically resolves within a few hours and requires no special treatment.
If you stopped taking pyridostigmine or other medications for the test, resume your regular dosing schedule as directed by your healthcare provider. Contact details for your medical team should be available if you have questions about resuming medications or experience unexpected symptoms.
The electrodes are easily removed after testing, and most patients experience no lasting effects from the electrical stimulation. Other tests, like blood work or imaging studies, may be scheduled as part of your overall evaluation, depending on your symptoms and initial test results.
Risks and safety considerations
Nerve conduction studies are considered very safe procedures with minimal risks for most patients. The main discomfort comes from brief electrical stimulation during testing, but serious complications are rare when qualified professionals perform the test.
The procedure has no long-term side effects or complications, making it suitable for most patients, including elderly individuals and those with chronic conditions. However, patients with a cardiac defibrillator fitted require special precautions to ensure the electrical stimulation doesn’t interfere with their device.
The very low voltage electrical pulses used pose no risk of electrical injury to healthy individuals. Factors such as body temperature, spinal cord damage, or severe pain may affect test accuracy but don’t pose safety concerns.
The procedure is contraindicated in areas with active skin infections or open wounds where electrodes cannot be safely placed. Bleeding risk is minimal as the test uses surface electrodes rather than needles, though some patients may experience minor skin irritation.
A small amount of temporary muscle soreness may occur after testing, but this resolves without treatment.
NCS does not deliver dangerous levels of electricity and cannot cause nerve damage.
Understanding your test results
A neurophysiology consultant or neurologist analyses your test results within 7-14 days of your procedure. The detailed report is sent to your referring doctor, who will discuss findings and potential treatment options during your follow-up appointment.
Typical results show nerve conduction velocities within expected ranges for your age and body type. These measurements confirm that your nerves are transmitting electrical signals properly between your brain and the affected areas of your body.
Abnormal results may indicate nerve damage, inflammation, compression, or demyelination affecting signal transmission. The severity of abnormalities helps determine appropriate treatment approaches, from conservative management to surgical intervention when necessary.
| Result Type | Interpretation | Next Steps |
|---|---|---|
| Normal | Nerve function within the expected range | Consider other diagnostic tests |
| Mild abnormality | Early nerve dysfunction | Conservative treatment, monitoring |
| Moderate abnormality | Significant nerve damage | Targeted therapy, lifestyle changes |
| Severe abnormality | Advanced nerve compromise | Further investigation, specialist referral, or surgical consideration if due to nerve compression |
Your doctor combines these electrical measurements with your clinical symptoms and other tests to arrive at a comprehensive diagnosis. Follow-up testing may be recommended to monitor nerve function over time, especially if you’re receiving treatment for a progressive nerve disorder.
The conduction study results provide objective evidence of nerve function that physical examination alone cannot reveal, making this diagnostic tool invaluable for confirming suspected conditions and guiding treatment decisions for optimal outcomes.
Appointment and Treatment Plan
Before the Test
Your clinician reviews your symptoms and medical history and explains what the test involves. Avoid lotions or oils on the skin and wear loose clothing so electrodes can be placed easily. Tell your clinician if you have a pacemaker or defibrillator.
Preparation
You can continue most regular medicines unless advised otherwise. Keep your hands and feet warm before the test, as cold skin can affect results.
During the Test
Small surface electrodes are placed on the skin. Mild electrical impulses stimulate the nerves to measure speed and strength of nerve signals. You may feel brief tingling or muscle twitching – this is normal.
After the Test
Electrodes are removed and you can return to normal activities straight away. If EMG was also performed, you may notice small temporary marks or mild soreness at the needle sites.
Results & Follow-up
A neurophysiology consultant analyses your results and sends a report to your referring doctor, who will discuss the findings and next steps with you.
Experts
We are proud to provide patients with access to a wide range of clinicians, chosen specifically for their knowledge and reputation in their area of expertise. Our experts align with our values: putting you at the centre of your care and educating you on your options at each step of the journey. We encourage you to learn more about our clinicians and how they can help you below. As always, please contact our patient services team if you require any additional information.
We offer 3 ways to pay for your treatment
We exist to take the stress out of private healthcare.
Our payment options are designed to offer you easy access to our treatments and services. You can choose to pay on the day, spread the cost, or use your private medical insurance.
Our patient services team will guide you through the process, providing clear costs and support throughout your course of treatment so you can focus on the thing that matters most – your health.
Whether you pay in advance, spread the cost, or use your private medical insurance, rest assured you will be receiving exceptional care 365 days a year.
Pay in Advance
Even if you do not have medical insurance, you can still get quick and comprehensive access to private medical care.
We provide transparent pricing from your initial consultation to the completion of your treatment so you know where your stand, every step of the way.
We accept all major debit and credit cards, as well as Apple Pay for UK residents. Please note that we do not accept cash or cheques.
Spread the cost monthly
Paying for your treatment at One Stop Healthcare can be spread monthly from 12 to 60 months, rather than paying in one go.
With an upfront 10% deposit paid, via our Financial partner Chrysalis Finance, we offer various flexible terms to enable you to spread the cost, including 12-months at 0% APR. Click here to find out more.
Monthly payments need to be linked to an One Stop Healthcare treatment over £385 and is subject to a 14-day ‘cooling-off’ period before any treatment can start.
Your on-going payments will be made directly between Chrysalis and yourself. It’s that simple.
Pay using PMI
We are recognised by all major health insurance companies and with our extensive range of services, there are lots of benefits to using your insurance with us. Our patient services team is here to answer any questions you may have about using your private health insurance with us.
Please bring along your policy details including your scheme details, membership or policy number, expiry date and confirmation of eligibility to claim (i.e. your authorisation number). If you do not have these details with you, we will require payment from you on the day. Patients are liable for any amounts not settled by their insurer.