Overview of Electrodiagnostic Evaluation of Peripheral Neuropathy

Peripheral neuropathy, also known as peripheral polyneuropathy, is a term that covers a variety of disorders that lead to damage or dysfunction of the nerves outside the brain and spinal cord. These nerves make up what we call the peripheral nervous system and can be affected in several different ways.

One way of identifying and assessing these nerve disorders is through a process known as electrodiagnostic testing (EDX). This testing not only helps confirm the presence of peripheral neuropathy, but also provides details about the problem’s severity, cause and long-term outlook. To evaluate and treat patients with symptoms of peripheral neuropathy, doctors need to take a thorough medical history, perform a physical examination, and conduct EDX tests.

Peripheral neuropathies are commonly seen in patients with diabetes or those who drink alcohol excessively. However, they can also be associated with a range of medical conditions. Some are acquired – they may result from conditions like diabetes, HIV, amyloidosis (a disease where an abnormal protein, amyloid, accumulates in organs), or treatments like cis-platinum chemotherapy. Others are inherited, such as Charcot-Marie-Tooth disease.

Symptoms often involve a tingling sensation, numbness, or pain in the extremities, like the feet or hands. These symptoms can occur suddenly or develop gradually over time. Patients might have trouble with tasks like buttoning clothes or report tripping over their feet. These may be signs of increasing weakness and disease progression. Some inherited neuropathies present with unsteadiness (ataxia) and muscle cramps, while acquired neuropathies often feel like burning or tingling.

An essential part of investigating these symptoms is a detailed history, which includes understanding the patient’s medication use, diet, work and social situation, and family history. Exposure to heavy metals or certain drugs (like vincristine or amiodarone), or conditions like hypothyroidism or vitamin B12 deficiency could increase the risk of developing peripheral neuropathies. A family history of certain hereditary diseases, like Charcot-Marie-Tooth Type 1 disease or Refsum’s disease, could also provide clues to a genetic cause.

The physical examination can assist in recognising the cause and characteristics of peripheral neuropathy. For example, patients with diabetic peripheral neuropathy often describe a type of numbness in their hands and feet that feels like wearing a stocking or glove. Hearing loss, eye problems like cataracts, or certain physical deformities might suggest a genetic cause. Reduced sensitivity to light touch or vibration can be signs of a sensory neuropathy, while muscle weakness in the feet and hands and reduced reflexes might indicate a motor neuropathy. Specific treatments such as dapsone or cis-platinum therapy can also have characteristic physical findings.

Anatomy and Physiology of Electrodiagnostic Evaluation of Peripheral Neuropathy

The reason peripheral neuropathies, conditions that cause weakness, numbness, and pain, develop can vary greatly. For instance, peripheral neuropathy related to excessive alcohol use may be due to direct damage to the nerves or lack of proper nutrition. Multifocal motor neuropathy, a form of nerve disease, is linked to an irregular response of the immune system, resulting in nerve damage and repair.

Different forms of peripheral neuropathies can exist in people with HIV, and their symptoms may fluctuate depending on the nerves affected. For instance, ‘mononeuropathy multiplex’ can occur at any stage of HIV infection and is often caused by blood clots in tiny blood vessels that supply the nerves. This can create multiple damaged areas in numerous nerves, primarily causing the loss of nerve fibers without much damage to the protective layer around the nerves.

Autonomic neuropathy, which affects the nerves controlling automatic body functions like heart rate, blood pressure, and bowel and bladder control, can also occur in those with HIV.

It’s also important to note that Electromyography (EDX), a diagnostic procedure to assess the health of muscles and the nerve cells that control them, is only able to test one specific type of nerve fiber and cannot detect ‘small fiber neuropathies’ (diseases related to thin, small nerve fibers). If a person has common symptoms of peripheral neuropathy, but their EDX results are normal, additional tests like a skin biopsy or reflex tests might be necessary for a concrete diagnosis. Diseases like diabetes, amyloidosis (a condition where an abnormal protein called amyloid builds up in your organs) and HIV often result in small fiber neuropathies.

Why do People Need Electrodiagnostic Evaluation of Peripheral Neuropathy

If a person experiences strange sensations, pain, or weakness in more than one limb, and it can’t be explained by a known condition affecting a single nerve (like nerve entrapment neuropathy), doctors might use a tool called EDX (electrodiagnostic testing) to check if there’s a nerve disorder called peripheral neuropathy. This condition occurs when nerves outside the brain and spinal cord are damaged. It can arise due to harmful substances, metabolic problems, genetic causes, small blood vessel disease, or immune system disorders.

A detailed personal health history and physical examination can usually reveal a specific risk factor for peripheral nerve damage. Using EDX, doctors may further narrow down the possible causes based on the common features seen in the nerve responses during the test.

When a Person Should Avoid Electrodiagnostic Evaluation of Peripheral Neuropathy

Nerve conduction studies (NCS) and electromyography (EMG) needle tests, used to understand the state of nerves, have very few reasons for doctors not to do them. One reason these tests might not be done is if a patient has a heart pacemaker or defibrillator implanted, as it was formerly thought that this could interfere with the device. However, research has shown that pacemakers with bipolar sensing, a type of pacemaker that’s common today, are not usually affected by such tests. Although for pacemakers with unipolar sensing, there was some evidence suggesting interference during repetitive nerve stimulation studies.

Generally, modern implantable pacemakers with bipolar sensing are not put in danger by NCS. However, doctors still take a cautious approach and avoid testing too close to the pacemaker. They also follow the device makers’ instructions carefully and consult the patient’s heart doctor for advice, especially if the patient has a defibrillator or a pacemaker with unipolar sensing. An additional safety measure is monitoring the patient’s heart through telemetry while the device is deactivated for the test. If a patient has an external cardiac pacemaker, NCS is usually avoided because these wires are usually more sensitive to electricity. Also, tests should not be carried out over a central line, as it could potentially affect the heart.

Another reason to avoid needle EMG tests is if the patient has severe bleeding disorders. If a patient is on medications that prevent blood clots, the test can still be considered but has to be overseen carefully to ensure no uncontrollable bleeding occurs. Generally, it is not required to stop taking these medications for the test. However, doctors need to be very careful if patients have low platelet counts (a part of your blood that helps form clots to stop bleeding) or a high INR indicating their blood is too thin. Needles should never be inserted into infected areas since it could potentially spread the infection.

Equipment used for Electrodiagnostic Evaluation of Peripheral Neuropathy

The text below provides a basic idea of the tools required, although it doesn’t cover everything:

* Electrodiagnostic machine with a stimulator: a device used to evaluate and assess nerve and muscle function
* Surface electrodes (wire ring, disposable or standard bar): these are used to pick up electric signals from your nerves or muscles
* Ultrasound gel: a thick liquid applied to the skin to help with ultrasound tests
* Needle electrodes: small needles that are inserted into the muscle to pick up electric signals
* Alcohol prep pads: used to clean the skin before the procedure
* 4×4 gauze: a piece of cloth used to stop bleeding or soak up any fluids during the procedure
* Adhesive bandages: also known as plasters, these are used to cover and protect small wounds [15]

Who is needed to perform Electrodiagnostic Evaluation of Peripheral Neuropathy?

A doctor who specializes in physical medicine (physiatrist) or brain-related issues (neurologist) may be brought in for a test called EDX (Electrodiagnostic studies). This test helps to understand if there are any nerve-related issues in the body. Sometimes, a specifically trained technician might help gather the test results, which consist of nerve conduction studies and electromyography (a test to diagnose muscle and nerve functions).

Even though a technician can record all the data, it’s usually preferred that a specialized doctor is present during the test itself. This is because, based on how you, as a patient, are doing during the test or what the results are showing, the doctor might need to adjust the test right there and then. This ensures that the most accurate diagnosis can be reached based on your unique situation.

Preparing for Electrodiagnostic Evaluation of Peripheral Neuropathy

Before the medical test, it’s important for patients to know what it involves. On the day of the test, patients should take their medicine and eat as usual. Doctors also recommend that patients clean their bodies but avoid using any lotions or creams on their arms or legs that could interfere with the test results.
On the day of the exam, you may wear loose clothing for comfort or might be asked to put on a hospital gown. This makes it easier for doctors to reach the muscles needed for the test.
The temperature in the room and of your arms or legs can affect the test. If your hands or feet are cold, it could change the test results and lead to a wrong diagnosis. This is because a drop in temperature can temporarily change the way certain proteins in your body work, which causes a change in test results. It can artificially amplify the results and slow down the recording of the results.
If you feel cold, the doctor may change the room temperature or warm your arms or legs with heat packs. Then, the test might be performed again to ensure accurate results.

How is Electrodiagnostic Evaluation of Peripheral Neuropathy performed

An electrodiagnostic study is a type of test your doctor might use to check if you have peripheral neuropathy. This condition is damage to your nerves, often in your hands and feet, which can cause symptoms like numbness, tingling, and pain. The study aims to confirm the presence of this nerve damage and evaluate how severe it is.

This test involves two parts: Nerve Conduction Studies (NCS) and Electromyography (EMG). NCS measures the speed and strength of signals travelling through your nerves, while EMG looks at how well your nerves and muscles are working together. To plan these tests, the doctor will consider your symptoms and medical history. They will choose the best approach based on your unique situation, rather than following a standard plan. For instance, if you have certain types of nerve damage, such as from diabetes or inflammation, your tests might focus more on your arms than your legs.

Usually, doctors start these studies by examining one of your legs, looking specifically at how well the nerves in your leg (Peroneal and Tibial nerves) are functioning. If the nerves aren’t performing well, they might also check the muscles in your leg. After that, they compare the results in both legs to see any significant differences.

Next, they perform a similar test on your arms. They might focus on your non-dominant hand (the one you don’t use to write) because it’s less likely to have other nerve issues. They may also test both your arms for comparison if they couldn’t get enough data from your legs.

Finally, they perform the EMG part of the test. This involves checking muscles in both your arms and legs at rest and while they are active. The doctor might continue testing different muscles until they find one that doesn’t show any problems.

The goal of these tests is to help your doctor understand how your nerves are functioning and plan the best course of treatment. They might seem complex, but they are crucial tools in diagnosing and managing nerve-related conditions.

Possible Complications of Electrodiagnostic Evaluation of Peripheral Neuropathy

Tests like nerve conduction studies and EMG needle examinations are mostly safe. The electrical stimulation used in these tests usually doesn’t harm the nerves hardly at all, if anything it’s very temporary. However, like all procedures involving needles, there is a very small chance of infection or bleeding when the needle is inserted during the EMG test. Doctors minimize this risk by keeping the area clean and putting pressure on the site after the needle is removed.

Most people find nerve conduction studies a little uncomfortable, but generally, they can handle it. Sometimes, the ‘shock’ sensation, needle exam, or, very occasionally, a bout of lightheadedness or faintness (known as a vasovagal episode) might be too much for the patient to bear. In these cases, they can take breaks during the test or even reschedule it for a different day.

Normally, letting patients know what the test entails and advising them to eat and drink beforehand can help prevent these issues from happening.

What Else Should I Know About Electrodiagnostic Evaluation of Peripheral Neuropathy?

EDX, or Electrodiagnostic medicine, is a way for doctors to understand more about peripheral neuropathy. Peripheral neuropathy is a condition where the nerves outside your brain and spinal cord get damaged and might cause weakness, numbness or pain. Usually this affects your hands and feet. Using EDX, doctors can identify what type of neuropathy it is – like whether it damages the protective coating of your nerves, if it affects sensory or motor nerves, or how widely spread the problem is. Some overlaps may occur too.

When there’s an injury that strips off the protective layer of the nerves, it results in slow communication between your nerves. This can be seen in tests as delayed responses or blocked communication. These are common in single nerve injury conditions like Carpal Tunnel Syndrome or Peroneal Neuropathy at the knee. In peripheral neuropathies, there can be similar findings even in areas not affected by an injury. But remember, slow communication can also happen for harmless reasons that don’t damage nerve protection.

Tests usually show injury findings like blocked communication and delayed responses when there’s a loss in the protective layer of nerves. However, these are more often seen in conditions that damage nerve protection later in life, rather than ones present from birth. For example, Charcot-Marie-Tooth type 1, which is a nerve disorder, doesn’t have much difference in muscle response regardless of the stimulation site since the changes in the nerve are slow and uniform. However, in conditions like Guillain-Barre syndrome, which results in weakness due to an attack on nerve cells usually after an infection, early testing might not appear abnormal. Later on though, the tests could show indications of nerve damage mainly affecting motor nerves more than sensory ones. This kind of recognition can help doctors start treatment promptly.

In axonal injuries, which refers to damage to the main part of the nerve, tests usually show reduced muscle activity with near-normal response times and communication speeds. As peripheral neuropathy becomes worse, mild damage might occur to the main part of the nerve, which can be either motor (movement) or sensory (feeling) predominant, or a mixed pattern. These conditions can be identified using EMG (Electromyography), which is a test to evaluate the health of muscles and the nerves controlling them. This testing should include checking for unwanted activity during rest and during voluntary activity. Findings like waves indicating nerve loss would not be present in injuries that degrade nerve protection.

In slowly progressive conditions, usually of the inherited type, the recruitment pattern of muscle units can be evaluated with EMG. An observation of several muscle units discharging at high frequency rates suggest loss of muscle units. Such muscle units can also be inspected for increased amplitude (or size) as well. For ongoing loss of axons, the recruitment and size of muscle units is moderately reduced, and they become more complex.

Other important aspects to keep in mind are whether the disease is spread out uniformly or is segmental (focussed in an area). Some nerve disorders can affect most nerves in a length-dependent manner; that means they usually affect the longest nerves first (those reaching out to your hands and feet). Others can occur in one or more areas all over the body. Conditions like Charcot-Marie-Tooth Type I or Guillain-Barre syndrome usually present as widespread nerve disorders. Diabetic neuropathy is also quite common; here, patients usually experience painful sensations and numbness mainly in the lower limbs. In such cases, the disorder usually starts from the furthest point (the feet) and gradually moves upwards. Similar observations are seen in patients with chronic kidney disease requiring dialysis.

Frequently asked questions

1. What specific tests will be included in my electrodiagnostic evaluation for peripheral neuropathy? 2. How will the results of the electrodiagnostic tests help determine the severity and cause of my peripheral neuropathy? 3. Are there any risks or potential complications associated with the electrodiagnostic evaluation? 4. How will the results of the evaluation guide my treatment plan for peripheral neuropathy? 5. Are there any additional tests or procedures that may be necessary to confirm the diagnosis or gather more information about my condition?

Electrodiagnostic Evaluation of Peripheral Neuropathy, specifically Electromyography (EDX), is a diagnostic procedure that assesses the health of muscles and the nerve cells that control them. However, it can only test one specific type of nerve fiber and cannot detect small fiber neuropathies. If a person has common symptoms of peripheral neuropathy but their EDX results are normal, additional tests like a skin biopsy or reflex tests might be necessary for a concrete diagnosis.

You may need Electrodiagnostic Evaluation of Peripheral Neuropathy to understand the state of your nerves. This evaluation involves nerve conduction studies (NCS) and electromyography (EMG) needle tests, which can help diagnose and assess the severity of peripheral neuropathy. These tests can provide valuable information about the functioning of your nerves and muscles, helping your doctor determine the underlying cause of your symptoms and develop an appropriate treatment plan. However, there are certain situations where these tests may not be recommended, such as if you have a heart pacemaker or defibrillator implanted, or if you have severe bleeding disorders. In such cases, your doctor will take precautions or consider alternative testing methods.

You should not get an Electrodiagnostic Evaluation of Peripheral Neuropathy if you have a heart pacemaker or defibrillator implanted, as there is a potential risk of interference with the device. Additionally, if you have severe bleeding disorders or infections, it is advisable to avoid this procedure.

The text does not provide information about the recovery time for Electrodiagnostic Evaluation of Peripheral Neuropathy.

To prepare for an Electrodiagnostic Evaluation of Peripheral Neuropathy, the patient should take their medication and eat as usual on the day of the test. They should clean their body but avoid using lotions or creams on their arms or legs that could interfere with the test results. The patient may wear loose clothing or a hospital gown for comfort, and the temperature in the room and of their arms or legs should be regulated to ensure accurate test results.

The complications of Electrodiagnostic Evaluation of Peripheral Neuropathy include a small chance of infection or bleeding when the needle is inserted during the EMG test. There is also a possibility of discomfort during nerve conduction studies, including a "shock" sensation, needle exam, or lightheadedness or faintness (known as a vasovagal episode). However, these complications can be minimized by keeping the area clean, applying pressure after needle removal, taking breaks during the test, and advising patients to eat and drink beforehand.

Symptoms that require Electrodiagnostic Evaluation of Peripheral Neuropathy include strange sensations, pain, or weakness in more than one limb that cannot be explained by a known condition affecting a single nerve.

Based on the provided text, there is no specific information regarding the safety of Electrodiagnostic Evaluation of Peripheral Neuropathy during pregnancy. It is recommended to consult with a healthcare professional to assess the potential risks and benefits of the procedure in the context of pregnancy.

Join our newsletter

Stay up to date with the latest news and promotions!

"*" indicates required fields

This field is for validation purposes and should be left unchanged.

We care about your data in our privacy policy.