Neurologic Testing and Procedures
As part of your evaluation and treatment at Bernstein & McCasland, M.D., P.C., it may be necessary for you to undergo one or more tests or procedures. Some of our most common tests and procedures are described below.
EMG and Nerve Conduction Test
This test is designed to evaluate the function of the nerves and muscles, and actually consists of two parts. The Nerve Conduction Test, performed first, involves a device that delivers a mild shock to a nerve and small electrodes that record the shock over other parts of the nerve or muscle. The speed with which the nerve carries electrical current, and the amount it is able to carry, provide useful information about whether the nerve is functioning up to par or not. The second part of the test, the EMG or electromyogram, evaluates the function of parts of the nerve that cannot be shocked (because they are not close to the skin) and evaluates the muscles as well. In this part of the test, a fine needle electrode is inserted into selected muscles, and the electrical currents generated by the muscle are recorded during rest and during a contraction. The results can be seen on a screen and heard on a speaker. While the test involves some unavoidable discomfort, nearly all patients are able to complete the test successfully. This test may be conducted as part of an evaluation for pinched nerves in the neck or back, numbness or weakness of an extremity, muscle pain, and a number of other reasons. The only preparation needed is to present for the test with clean dry skin, free from lotions or oils. These can, of course, be applied once the test is complete.EEG
An EEG or electroencephalogram is a test designed to display and evaluate brainwaves, electrical impulses generated by the brain that can be recorded outside the head. In this test, wire electrodes are applied to the head using a paste or gel and plugged into a machine. Recordings are made under a variety of circumstances including eyes open, eyes closed, while taking deep breaths, and with a flashing strobe light. There is no pain or discomfort, and the recording lasts only about 20 minutes. This test is conducted in our office by a technician and the results are interpreted by the doctors. Under certain circumstances, an extended recording (24 hours, 48 hours, or more) may be necessary. If this is the case, referral is made to a company that routinely conducts extended EEGs. For one of these recordings, the electrodes are left in place and attached to a small recorder worn on the waist so that the individual having the test may undergo the recording at home. An EEG may be needed if the doctor suspects seizures or a number of other conditions.Evoked Potentials
An evoked potential test is really a battery of three tests that evaluates various parts of the central nervous system. The first component of the battery, the VER or visual evoked response test, evaluates the function of the visual pathways in the eye and the brain. Electrodes are placed over the back of the head, the area associated with vision, and brain waves are recorded while the patient watches a monitor screen showing a black and white checkerboard pattern. The second component, the BAER or brainstem auditory evoked response test, similarly evaluates pathways in the brain and brainstem associated with hearing. Electrodes are placed over the sides of the head and record brainwaves while the patient is listening to a series of clicks on headphones. The third component of the battery, the SSEP or somatosensory evoked response test, evaluates the function of various sensory pathways in the spinal cord and brain. Once again, electrodes are placed over the skull, but also over the spine. Recordings are made while a small shock is delivered to a nerve in the arm or leg. Evoked potential testing may be used to evaluate conditions of the white matter of the brain and spinal cord, among others.Imaging Studies
Some type of imaging study is often required as part of a neurologic evaluation, though not always. Examples of imaging studies include MRI, CT scan, arteriogram, myelogram, and others. These tests may be performed on various regions of the body depending on the clinical situation. If one of these tests is needed, the staff at Bernstein & McCasland, M.D., P.C. can arrange it with a top-notch, local provider at a convenient time.Lumbar Puncture
At times, it may be necessary for patients to undergo a lumbar puncture, known commonly as a spinal tap. During a lumbar puncture, the patient is draped as in a minor surgical procedure and the skin is cleansed and numbed with lidocaine. A needle is passed between the bones of the spine into the sac containing spinal fluid, the same fluid that circulates around the brain. Fluid is collected and sent to a laboratory for analysis. The procedure is only minimally uncomfortable and is performed in our office. The results can yield information about infections, inflammatory and cancerous diseases of the brain and spine.