25.8 million Americans have diabetes – 8.3 percent of the U.S. population. Of these, 7 million do not know they have the disease.
Statistics show that about 60% of diabetic patients probably have some degree of peripheral neuropathy. Early detection of this problem is essential, particularly in patients who are over age 30, but younger than 65. Devastating complications can be prevented in these younger patients and their outcomes significantly improved when they receive specific preventative care and adequate treatment.
The American Diabetes Association recommends that diabetics be tested annually to help determine the specific degree of neuropathy, both in the extremities and generally. By setting up a NCV study the severity of the disease can be evaluated and serious autonomic complications recognized. Annual retesting will help in determining any progress or degradation in the patient.
Electrodiagnostic (EDX) tests are a series of electrical tests that examine various aspects of the neurological system. The most common of these tests are: Nerve Conduction Velocity Studies and Evoked Potentials.
The complete testing profile consists of multiple tests designed to evaluate different portions of the nerves of the arms and legs. The tests in the upper and lower extremities subject nerves to an electrical impulse to assess how they conduct signals. Recording electrodes are placed on the skin to acquire information such as the speed the signal travels and the amplitude of the signal. These evaluations can determine whether the nerve is normal or shows signs of damage.
The end result of EDX testing is a comprehensive profile that will be read by a qualified neurologist. The neurologist will develop a written report that will state whether nerve impairment is demonstrated by the testing and the diagnostic conclusions that may be drawn from the testing.
Nerve Conduction Velocity Studies (NCV) can provide invaluable information to assist in the diagnosis of problems related to the nervous and muscular systems. They measure the speed and intensity of electrical signals that travel through the nerves and calculate the time and velocity in which muscles respond to these impulses.
Nerve Conduction Velocity (NCV)
A nerve conduction velocity test, also called a nerve conduction study, measures how quickly electrical impulses move along a nerve
A healthy nerve conducts signals with greater speed and strength than a damaged nerve. The speed of nerve conduction is influenced by the myelin sheath – the insulating coating that surrounds the nerve.
Most neuropathies are caused by damage to the nerve’s axon rather than damage to the myelin sheath surrounding the nerve. The nerve conduction velocity test is used to distinguish between true nerve disorders (such as Charcot-Marie-Tooth disease) and conditions where muscles are affected by nerve injury (such as carpal tunnel syndrome).
This test is used to diagnose nerve damage or dysfunction and confirm a particular diagnosis. It can usually differentiate injury to the nerve fiber (axon) from injury to the myelin sheath surrounding the nerve, which is useful in diagnostic and therapeutic strategies.
During the test, flat electrodes are placed on the skin at intervals over the nerve that is being examined. A low intensity electric current is introduced to stimulate the nerves.
The velocity at which the resulting electric impulses are transmitted through the nerves is determined when images of the impulses are projected on a computer screen. If a response is much slower than normal, damage to the myelin sheath is implied. If the nerve’s response to stimulation by the current is decreased but with a relatively normal speed of conduction, damage to the nerve axon is implied.
There is generally minimal discomfort with the test because the electrical stimulus is small and usually is minimally felt by the patient.
Conditions that NCV testing helps diagnose include:
- Carpal Tunnel Syndrome
- Pinched Nerve
- Muscle Disease
- Muscular Dystrophy
- Lou Gehrig’s Disease
- Myasthenia Gravis
Evoked potentials are used to measure the electrical activity in certain areas of the brain and spinal cord. Electrical activity is produced by stimulation of specific sensory nerve pathways. These tests are used in combination with other diagnostic tests to assist in the diagnosis of multiple sclerosis (MS) and other disorders.
Evoked potentials test and record how quickly and completely the nerve signals reach the brain. Evoked potentials are used because they can indicate problems along nerve pathways that are too subtle to show up during a neurologic examination or to be noticed by the person. The disruption may not even be visible on MRI exam.
NeuroRad Diagnostic Centers also provides musculoskeletal and soft-tissue ultrasound testing for the cervical, thoracic, and lumbar areas, along with extremities of shoulders, elbows, wrists, knees, and ankles.