EMG-NCV Electomyography Nerve conduction Velocity study: Do you need one?

Your physician might recommend you undergo EMG-NCV study and you are wondering what it is. The simplest but not that accurate way of explaining it to my patients is by doing an analogy of this test with ECG or electocardiogram. ECG is the placement of electrodes on the chest which gets the electrical activity of the heart. It then helps the physician diagnose problems related to the electrical function of the heart. As for EMG-NCV it also tests the electrical function of either the nerve, the muscle or the junction between nerve-muscle. But the analogy actually ends there.

EMG-NCV is generally broken down into 2 parts.

1. The NCV test wherein electrodes or wires are placed on specific parts of the body depending on what nerve to test. Then a small probe that stimulates the nerve is initiated in order to see how fast or how slow the nerve traveled from the point of stimulation up to the point where the wires are placed. Usually more than one nerve is tested and may require comparison with the other side.

2. The EMG test is using a hairlike size needle that is attached to a computer. The needle is then inserted into the particular muscle that needs to be tested. Sort of an injection needle being inserted into your skin. The needle is then left there to see the electrical activity or any abnormalities that can be seen during the procedure. A youtube video by dsbgd011 shows this procedure found here.

Pictures as reference are taken from monarch diagnostic website.
The website link also explain this test.

Do you need one?
Usually this could be recommended if the nerve affected is the one coming out from the spine(back) and goes to the periphery (either to the hands or feet) called the peripheral nerve. If the nerve being tested is the spinal cord itself or the brain which is medically the central nervous system, then this test might not be beneficial.

So what specific conditions can EMG-NCV be recommended?

Back or neck pains that consider an impingement of the nerves, weakness of muscles of the upper and lower limbs that suspects a compromised peripheral nerve. Some of this are carpal tunnel syndromes, brachial plexus injuries or lumbar/cervical radiculopathies. EMG-NCV can also be recommended on some systemic conditions such as diabetic neuropathies or Guillane Barre syndromes. Facial nerve problems or trigeminal neuralgias are some conditions also that EMG-NCV can be used.

If an MRI or an imaging study is already done, would you still need this test? What is the difference?

Imaging studies usually will show the picture of the area where the suspected problem is but that is all it will tell the physician. EMG-NCV supplements that by telling the physician the function or electrical physiology of the suspected nerve/muscle. It can help the physician know if the problem is recent, an old one and how severe it is.

So if you need one, I hope this helps out in explaining the procedure.

What is a Physiatrist?

Since, Physical Medicine and Rehabilitation is a specialty that was created during the near end of world war 2 era, not all are familiar with it. Unlike a cardiologist or dermatologist, a layman automatically knows what the doctor is specializing.

So as a way to give clarity as to what a Physical Medicine and Rehabilitation (PM&R) specialist or Physiatrist treats, I have placed links that will help out in explaining it.

The Association of Academic Physiatrists have a particular segment in explaining well on "What is a Physiatrist?" For those who like to view it in Flash player click here. The first few slides show the scope of the specialty. However, the later slides are more for medical students in the USA who are interested in taking this specialty. So you may skip that.

For those of you who has an ailment that is giving you some form of physical disability, Physical Rehabilitation assessment and management can help out. This is then the blog for you.

Painful, Inflamed or Both? What medications to use.

Are pain medications the same with anti-inflammatory medications? Should one be used instead of the other? Can they be used interchangeably? Can they be used at the same time?

First off, pain medications get a bad publicity both in the media and in the movies. You usually see stars or news on patients getting addicted to it. This is a sad faith for such useful medications. In reality, there are many types of pain medications, it is generally classified as “Analgesics” but from it stems various subtypes with each specific effect. This will range from the very basic such as acetaminophen or what we call paracetamol to the more advanced medications such as opiods. The opiods are the “addicting” medications portrayed in the media. If used accordingly and through a physician’s guidance, its medical importance is undeniable.

However, in most cases patients get pain medications mixed up with another subtype or kind, the anti-inflammatory medications or NSAID (non-steroidal anti-inflammatory drugs). From the term itself, anti-inflammatory medications are used on a condition that warrants control and abating inflammatory processes. In my previous article, acute inflammation is “usually” obvious to the naked eye. This is not the case if the inflammatory process is found deep within. Muscle, nerves or even ligaments or bone that are found in the inner layers of the limb may still be inflamed even if there is no warmth nor swelling outside. The patient only notices pain on certain positions or movements. One added benefit of anti-inflammatory medications is that it has a pain reliever effect too.

When patients tell their medication history, it is often only pain relievers. The pain goes away but after the effect of the medication subsides, they complain again. So they usually state that the medication is not working or useless. It is actually working but the cause of the pain is not addressed. Anti-inflammatory medications should then be used instead.

These are the common generic “Over the Counter” (OTC) pain medications in the Philippine drugstore:
1. paracetamol or acetaminophen
2. Mefenamic acid.
Brands such as Tylenol or Biogesic are Paracetamol base while Ponstan is mefenamic acid.

The anti-inflammatory medications that are over the counter are Ibuprofen found in Advil, or in the US, it is Motrin. Another one that recently became OTC is Flanax or Naproxen its generic name.

Some combine the two (Ibuprofen+paracetamol) such as Alaxan and Restolax. Its purpose is to combine the effect of removing the inflammation at the same time further relieve the pain while minimizing the usual side effect of gastric (stomach) irritation peculiar for anti-inflammatory medications.

So can your physician combine the two? Generally yes especially if the pain is too much. However, if your physician feels it can be taken care off by only one, then that would be 1 less medication to take.

Unfortunately, here in the Philippines, most of us like to take the advice given by a “friend” or “neighbor” who used this certain medication for his painful joint. Please be careful on such recommendations. This might not be the best drug for you and might end up making it worse. Consult your physician please.

Conclusion:

Pain medications address only the pain and not the cause. If it is inflamed then,
anti-inflammatory medication should be used.

If over the counter (OTC) drugs such as those mentioned above do not work after a day or two, consult your nearest physical medicine and rehabilitation specialist.

Do NOT self medicate based on the advise of a non-physician.

Combining both (pain and anti-inflammatory) medications can be done especially if the pain is too much to handle by the patient.

Cold or Hot? What should I use after a soft tissue injury?

This past week in the clinics, I was surprised to see patients in succession who attained sports injuries while playing. From an ankle sprain to muscle strains. What strike me the most, is that their first aid during the acute stage or within 24 to 48 hours after the injury is the application of heat on that area. The result is a more swollen and painful injured limb.

The rule of thumb for first aid in sports injuries or injuries sustained from a hard bump is to apply the RICE principle. RICE is the acronym for (R)est, (I)ce, (C)ompression, (E)levation on the affected area. Our body automatically reacts to the trauma it sustained (i.e. ankle landed unevenly on the floor causing an inversion injury) by making the area more swollen, reddish and warm or hot to touch. In worse cases, you see hematoma formation or blood clotting.

Now why (I)ce? Its effect upon application is that cold causes the blood vessels to constrict (become smaller). This then limits the amount of fluid to go out to the area and cause further swelling or hematoma formation.
If warm compress is applied instead the blood flow on that area increases and will further provide increased fluids that will aggravate the situation. Cold should be applied for 15 to 20 minutes every hour for at least 3 to 4 times or until it is seen by a physician when the patient is rushed to one.
As for the other components, (R)est or immobilization is needed in order not to further aggravate whatever is already injured. (C)ompression or bandaging snugly and (E)levating the area is done in order to prevent further swelling or direct the fluid back to the heart. If the patient feels increase in pain or further bluish discoloration of the distal part, the bandaging may be too tight. Remove and reapply it.

When does one shift to warm compress?
Definitely before doing so, consult your physical medicine and rehabilitation specialist as soon as you can on acquiring the injury. This is to further assess if the injury needs further evaluation (i.e. an xray, CTscan or MRI) and to provide medications that will help in the recovery. Physical Therapy may be recommended in order to prevent further complications of nearby or adjacent soft tissue.
The general guideline as to when to shift can be based on time or on signs or symptoms of the injured part. If time is used, it is usually 48 to 72 hours after the injury. If based on sign or symptoms, the element to consider is the characteristics of the swollen part. If it is still warm to touch or reddish, then cold should still be used.

Conclusion:
So if you have an injured limb, joint or muscle from playing or an accident RICE is your ally. HOT is NOT.