Randevu 0216 449 09 41
Prof. Dr. Cengiz BAHADIR


MEP:Motor Evoked Potentials

Motor Evoked Potentials test, MEP in short, is a diagnosis and monitoring method used for the treatment of disorders effecting central nervous system (brain-spinal cord). Many disorders can impact central nervous system.Hemiplegia (stroke) resulting from cerebral infarction or hemorrhage, Parkinson’s, multiple sclerosis, ALS, degenerative brain disorders, malignant and benign tumors, herniation putting pressure on the spinal cord are among the most common nervous system disorders. Brain disorders cause dysfunction by damaging nerve cells (neurons). This damage results in many symptoms in human body. Stroke, muscle weakness, speech disorders, balance disorders and movement disorders are common symptoms. Spinal cord damage may also lead to paralysis and sensory loss in some body parts.

MEP test is a novel test that can measure the impact of these disorders on nervous system. With this test, the responses of the muscles on the arms or legs are recorded upon the magnetic stimuli to the part of the brain controlling movement orders and the time between stimulation and evoked movement is determined. The movement responses on the same muscles via stimulation of lumbar or neck nerve roots are also recorded. The time between stimulation starting from the movement center of the brain to getting out on the spinal cord at lumbar or neck area is detected. This parameter called central conduction time provides the most objective data on the capacity of the brain and spinal cord to produce movement. For example, if we can get a timely response on hand or foot muscles of a patient suffering from stroke secondary to blockage of an artery on the brain upon magnetic stimulation, it means that the patient can recover to a large extent. If there are no or extremely late muscle response via magnetic stimulation, this means that there is a low possibility of recovery. MEP test can sometimes provide important data on the progress rate of especially progressive brain-spinal cord disorders (ALS etc.). The patient can be followed up by checking MEP values in periodical tests. MEP test is also used for spinal stenosis. It provides significant results especially during the surgery decisions for spinal cord compressions on the neck secondary to cervical disc hernia or osteoarthritis and it can reveal an early stage spinal cord damage which cannot be detected in MRI images.

It is a pain-free test lasting for 20-30minutes. It has no outstanding side effects. It can be carried out on the arms and legs or both, based on the disorder. Since it provides objective values, it is increasingly used for the recent years.