The most important part of a patient visit is the history and physical exam, which allows the physician to become familiar with the patient and his/her problems. No diagnostic modality can compare to a through history and physical examination. However, there are some tests that can provide better understanding of nerve function.
Pressure Specified Sensory Device (PSSD) was developed by Dr. Dellon and an Aerospace engineer. It is a computer-based device which painlessly measures how hard the skin has to be pressed before it can be sensed by the patient. It is the most accurate method of measuring for sensory deficits. This test offers a way to stage the degree of neuropathy you are experiencing, and to determine if your nerves are regenerating or continuing to degenerate. The test tends to indentify small fiber neuropathy.
Nerve Conduction Velocity (NCV) is a test commonly used to evaluate nerves, more commonly identifying large fiber neuropathy. An electrical current is used to stimulate the nerve. Since the nerve is in effect an electrical conduit, the time for the electrical impulse to travel to a site further along the nerve is measured. Normal values have been established, and comparison of your test to these values helps to indicate if there is damage to your nerves.
Electromyography (EMG) is typically an invasive technique, in which needles are inserted into your muscles. This test helps to identify disorders in the activation of muscles and their stimulating nerves, or neuromuscular diseases. Normal muscles at rest fall into certain ranges of electrical activity. Abnormal electrical activity might indicate some nerve and/or muscle damage.
Epidermal Nerve Fiber Density Testing (ENFD) In short, epidermal nerve fiber density testing involves taking a small "punch" of skin from the calf to visually count the number of nerve fibers. This allows a physician to identify small fiber peripheral neuropathy. Additionally, it also establishes an objective baseline so a physician can determine if treatments are effective.