The practice of electroneurodiagnostic (END) technology involves the use of devices such as an electroencephalograph (EEG) unit to evaluate the function of a
END technologists use various devices to aid in the evaluation and examination of the nervous system. These devices receive and record the electrical impulses produced by the brain or other parts of the nervous system. Characteristic changes in the nerve impulses can determine whether a patient has an organic basis for a mental or behavioral problem, such as a tumor or Alzheimer's disease. The devices can also diagnose particular diseases such as neuropathies (disease of the nerves), myopathies (diseases of the muscles), epilepsy, or stroke. These tests can evaluate the condition of critically ill patients, to determine the presence of cerebral death, and help assess the probability of a patient recovering from a coma.
One test commonly performed by END technologists is electroencephalography. This test monitors the electrical output of the brain, displays it on a monitor, and records it on a strip of paper for review by a neurologist or other physician. The technologist is often responsible for taking the patient's medical history, helping the patient relax by explaining the procedure of the test, and applying the electrodes to the designated sites on the person's head. To get medically useful results, the technologist must use the appropriate machine settings and correct for interference coming from sources other than the patient's brain.
EEG studies can be done within the hospital or clinic, or on an ambulatory basis (typically over a 24-hour period) while the patient continues everyday activities. For ambulatory monitoring, the technologist is responsible for patient education and answering questions, correctly attaching the electrodes, and upon completion of the monitoring, removing the recorder and obtaining a read-out. Technologists review the entire read-out and select specific areas for examination by the neurologist.
Another specialized form of EEG is long term monitoring for epilepsy (LTME). This procedure is used to accurately diagnose the type of seizure occurring in patients who are not responding to medication. In many cases, the patient is admitted to the hospital for 24-hour-a-day monitoring so that seizures can be captured on videotape and EEG recording. Monitoring is performed to diagnose seizure type or to localize seizure onset within the brain for possible epilepsy surgery. Technologists place electrodes on the patient's head, as in a standard EEG, and behavior is recorded by closed circuit camera onto videotape. Additional wire electrodes are sometimes inserted near the ear by the neurologist; these electrodes provide better information about temporal lobe seizures than scalp electrodes alone. Antiepileptic drugs are generally reduced or tapered off before or during the admission, which can last from one to several days. Often a family member is asked to stay with the patient, so that a seizure alarm can be triggered.
A second group of procedures commonly performed by END technologists are evoked potential tests. These tests separate the response of the patient's nervous system to various specific stimuli from background activity and record the results. The technologist is responsible for attaching electrodes to the patient and setting the machine to deliver the desired type and intensity of stimulus. Often the technologist performs a step-wise increase in the intensity of the stimulus and records the response of the patient's brain, spinal nerves, or sensory receptors to the input. Commonly, the stimulus is magnetic or electrical in origin, although visual and auditory stimuli are also used.
Technologists also perform nerve conduction studies (NCS), in which an electrode is placed over a peripheral nerve and a muscle, and a record is made of the response of the muscle to stimulation of the nerve. Various nerve and muscular problems have characteristic responses to repeated or increased intensity of stimuli, and the results from these tests can aid in differential diagnosis. NCS is often performed in conjunction with an electromyogram. That test is performed by a physician, although the END technologist can help with the process.
Another test often performed by END technologists is electronystagmography (ENG). ENG records the electrical potentials of the eyes. This test is used to document induced or spontaneous nystagmus, involuntary rapid movements of the eyeballs. An ENG can differentiate between inner ear and central nervous system causation for complaints of dizziness.
A subset of END technologists specialize in administering sleep disorder studies and are called polysomnographic technologists. During these testing procedures, called polysomnography, technologists monitor brain waves, respiration, and heart activity. They must understand the usual effect upon each of these systems with the different stages of sleep. Often a detailed report of each evening's readings is required for review by the supervising physician, separating the recorded results into the various sleep stages. As the primary medical personnel present for overnight monitoring, they may also have additional responsibilities in overseeing the well-being of patients staying at the sleep center.
Electroencephalography—The recording of changes in electric output in various areas of the brain using electrodes commonly placed on the scalp.
Electronystagmography—The electronic recording of eye movements that can document induced or spontaneous nystagmus.
Evoked potential testing—The electronic measurement of sensory and physical responses to specific stimuli.
Nerve conduction studies—The electronic measurement of the muscular response to the stimulation of a particular nerve.
Technologists' duties may also include clerical and technical work such as scheduling appointments, ordering supplies, and maintaining equipment. More senior END technologists may have administrative duties such as supervising and training less experienced technicians, managing the END laboratory, arranging work schedules, and keeping records. Additionally, some more senior personnel can perform research or have teaching duties.
END technology is practiced in general hospitals, psychiatric hospitals, health maintenance organizations (HMOs), and in private clinic or office practice settings. In the hospital, technologists may work within a dedicated room in the neurology department, may push portable equipment to the patient's bedside, or may do both kinds of monitoring. One area of rapid growth is the performance of intraoperative neurodiagnostic tests by END technologists. These tests require an understanding of the effects of anesthesia on brain activity and involve working in the operating room with general and neurosurgeons.
Education and training
Although many current END technologists were trained on the job, employers are now favoring candidates who have completed formal training in the area. Some hospitals require applicants for trainee positions to have postsecondary training, whereas others only expect a high school diploma. Employers will look for courses taken in health, biology, anatomy, and mathematics in applicants for training positions. Often those who do not have formal training are transfers from other allied health professions, such as licensed practical nurses.
The formal postsecondary school training in this area is offered by hospitals and two-year community colleges. As of 2001, there were 12 formal programs approved by the Joint Review Committee on Education in Electroneurodiagnostic Technology of the Commission on Accreditation of Allied Health Programs (CAAHP). The programs usually last from one to two years with laboratory training, and often include the following classroom courses:
- human anatomy and physiology
- neurology and neuroanatomy
- medical terminology
- computer technology and instrumentation
Training to perform polysonograms may require a full year of additional study.
Advanced education and training
The American Board of Registration of Electroencephalographic and Evoked Potential Technologists awards the credentials of Registered EEG Technologist, Registered Evoked Potential Technologist, and Certification in Neurophysiologic Intraoperative Monitoring (CNIM). These certifications are based on the successful completion of both an oral and a written exam. On-the-job training is required to sit for the exam. Continuing education hours are required every two years for certificate renewal and the certificates are good for 10 years. The Board of Registered Polysomnographic Technologists certifies polysomnographic technologists as Registered Polysomnographic Technologists, which involves on-the-job training and a passing score on a written examination.
Continuing education opportunities are available through various organizations including the American Society of Electroneuordiagnostic Technologists and the American Association of Electrodiagnostic Medicine.
The 2000-01 Occupational Outlook Handbook of the U.S. Department of Labor states that demand for this occupation will grow more slowly than average through the year 2008. Reasons for the slower growth include more sophisticated equipment and cross-training of other
U.S. Department of Labor, Bureau of Labor Statistics. "Electroneurodiagnostic Technologist." In Occupational Outlook Handbook 2000-01 Edition. Washington, D.C.: The Bureau. 2000.
American Board of Registration of Electroencephalographic and Evoked Potential Technologists, P.O. Box 916633, Longwood, FL 32791-6633. (407) 788-6308. <http://www.abret.org>.
The American Society of Electroneurodiagnostic Technologists, 204 West 7th Street, Carroll, IA 51401-2317. (712) 792-2978. <http://www.aset.org>.
American Society of Neurophysical Monitoring, 7510 Clairemont Mesa Blvd., Suite 100, San Diego, CA, 92111. (800) 479-7979. <http://www.asnm.org>.
Association of Polysomnographic Technologists, c/o Applied Measurement Professionals, P.O. Box 14861, Lenexa, KS, 66285-4861. (913) 541-1991 ext. 474, <http://www.aptweb.org>.
Board of Registered Polysomnographic Technologists, 475n Riverside Drive, Seventh Floor, New York, NY, 10115.(212) 367-4370. <http://www.brpt.org>.
Michelle L. Johnson, M.S., J.D.