“This patient needs an EMG.”

It’s something I say to my nurses all the time, but from a patient’s perspective, it might be a little confusing. Let’s take a closer look at EMG testing, starting with the why.

This article continues my series on diagnostic testing in neurology, which applies to both conventional neurology, functional, and regenerative medicine. Last time we focused on lumbar punctures and what you can expect from a spinal fluid examination and the conclusions we can draw.

Now, nerve conduction testing and EMGs are under the spotlight. Let’s get started.

Understanding the nervous system

Nerve conduction and EMG (which stands for electromyography) testing are used in neurology to evaluate the peripheral nervous system. 

As a neurologist, I focus on what we broadly call the nervous system. The nervous system can be divided into two parts:

• The central nervous system, which includes the brain, brain stem, and spinal cord, and
• The peripheral nervous system, which is everything outside of the spinal cord

The peripheral nervous system encompasses the roots that flow off your spinal cord and form a web of nerves in the pelvis and the lower neck/shoulder area. This web of nerves is called a plexus. These plexuses fuse and divide, creating the individual nerves that run down the arms and legs.

Some of these nerves control muscles and are called motor nerves or efferent nerves.

Sensory nerves, which send information to the central nervous system, are called afferent nerves. These nerves transmit their signals to the brain and spinal cord, and sometimes just to the spinal cord. 

Back to motor nerves. These activate the muscles, but they don’t actually connect directly to the muscles. They come very close, though, in an area called a neuromuscular junction. The nerve endings secrete a neurotransmitter chemical signal called acetylcholine. A receptor on the muscle picks up the acetylcholine, which leads to a chain of chemical reactions that causes the muscle to contract.

The limitations of nerve conduction and EMG testing

As I mentioned, nerve conduction and EMG testing evaluate the peripheral nervous system. If you have weaknesses or numbness, or some other symptom, these tests are only helpful if a peripheral nervous system problem is to blame.

The value of nerve conduction and EMG testing is also dependent on the quality of the information I have beforehand.

Let’s use an example to illustrate. Say you have a broken leg – I hope you don’t have a broken leg, but let’s suppose you do. Your doctor sends you off to the radiology department for an X-ray with a referral that basically says you hurt somewhere. Not very descriptive, right?

So, with limited information, the radiologist gives you a chest X-ray, thinking maybe you hurt in your chest. That’s not going to tell your doctor much about your broken leg, is it?

The same logic applies to nerve conduction and EMG testing. The more specific information I have, the better quality the test, and the more useful the results.

What can nerve conduction and EMG testing tell us?

I use nerve conduction and EMG testing to look for muscle diseases (myopathy), neuromuscular junction diseases, and peripheral nerve diseases. There are different types of each, so let’s take a closer look.

Mononeuropathy

Single nerve disease, or what we call mononeuropathy, involves one nerve, as the name suggests. A classic example is carpal tunnel syndrome, which affects the median nerve that comes in and out through a tissue tunnel in the wrist called the carpal tunnel.

Another common nerve disease is ulnar neuropathy, which often impacts the area around the elbow.

Multiple mononeuropathies

In contrast to mononeuropathy, multiple mononeuropathies – also known as mononeuropathy multiplex – are nerve diseases in which several nerves are involved, but they’re kind of random. So, the disease affects one nerve here, one nerve there, and so on.

I don’t see these conditions in my clinic very often. Typically, they show up in immune-compromised patients, like AIDS, conditions in which blood vessels are inflamed, called vasculitis, and alongside certain cancers. 

Polyneuropathy

Like carpal tunnel syndrome, ulnar neuropathy, and other mononeuropathies, polyneuropathies are pretty common. Polyneuropathy means many nerves, but in contrast to multiple mononeuropathies, polyneuropathies affect the nerves symmetrically.

Polyneuropathy impacts the longest nerves first, which means it generally starts in the toes and feet, then works its way up the legs. As this neuropathy progresses it affects the fingers and hands, too. This is why neurologists say polyneuropathies follow a stocking-and-glove distribution.

The most common reason someone has polyneuropathy is diabetes. This is so common that I often have people come in after their test, and I say, “Well, are you diabetic?”

They say, “No. When my blood sugar gets tested, it’s normal.”

They haven’t been diagnosed yet, but they come in with neuropathy or polyneuropathy I work backward, checking their blood sugar, insulin level, and what’s called their hemoglobin A1C, which gives me an idea of what their average blood sugar is over about three months. What I often find is that they either have diabetes, and they didn’t know it, or they are pre-diabetic and working their way, unfortunately, toward diabetes.

But there is a silver lining. My clinic is a functional medicine clinic, so we can help reverse diabetes. It’s a 100 percent reversible disease.

Radiculopathy and Plexopathy 

I can also use nerve conduction and EMG testing to look for radiculopathy and plexopathy, a pinched nerve in or near your back or neck. This condition happens for a variety of reasons, the most frequent being degenerative changes in the spine, auto-immunity, and trauma. Sometimes tumors are involved, too.

 

Neuromuscular Junction Diseases

Generally, these are one of two diseases, the first is an autoimmune condition called myasthenia gravis and the second is a cancer-related condition called Lambert Eaton Syndrome. In both of these conditions, repeated stimulation of a nerve leads to recognizable changes in the ability of the nerve to transmit its signal to the muscle. 

Identifying the cause so that you can regain control of your health

At my clinic, I follow a unique Five-Pillar system that goes deeper and further than the conventional medicine approaches you’ve likely experienced in the past. Identify is the very first pillar, and I use all the traditional and cutting-edge diagnostic tools – including nerve conduction and EMG testing – to uncover the root causes of your symptoms.

If you are ready to redefine the trajectory of your health and start living life on your terms, schedule your initial consultation today.