A patient with suspected multiple sclerosis undergoes multimodality evoked potentials, EEG, MRI, and CSF testing. Which of the following evoked response patterns is most often abnormal in patients with early MS?
a. Brainstem auditory evoked response (BAER)
b. Far-field somatosensory evoked response (SSER)
c. Visual evoked response (VER)
d. Jolly test
e. Sensory nerve conduction test
the answer is below…
The United States Medical Licensing Examination, or USMLE for short, is a three-part licensing examination that is required in order to receive a license to practice medicine within the United States.
The USMLE assesses a physician’s ability to apply knowledge, concepts, and principles, and to determine fundamental patient-centered skills that are important in health and disease and that constitute the basis of safe and effective patient care.Examination committees composed of medical educators and clinicians from across the United States and its territories prepare the examination materials each year.
This exam is designed by the Federation of State Medical Boards and the National Board of Medical Examiners to determine whether or not an individual understands and can apply the knowledge necessary to practice medicine safely and intelligently.
The USMLE is actually comprised of three different exams that are referred to as steps, which examine the individual’s knowledge of specific topics related to the field of medicine such as basic science, medical knowledge, medical skills, clinical science, and the application of all of these skills and areas of knowledge in the medical field.
All three steps of the USMLE include a series of computerized multiple-choice questions, but the format of the exam and the information covered in each multiple-choice section is different for each step of the USMLE. The USMLE Step II also has a clinical skills portion that examines an individual’s ability to work with real patients and the USMLE Step III has a computerized patient simulation portion in addition to the multiple-choice section of the exam. In order for an individual to receive a license to practice medicine, the individual must pass all three steps of the USMLE.
The correct answer is c; Visual evoked response (VER).
Optic neuritis occurs early and often in many patients with MS. This involves inflammation and demyelination of the optic nerve and slows conduction along the optic nerve. Components of the VER may be slowed or even absent. That an evoked response is disturbed is not proof that the patient has MS, as any problem that produces optic neuritis will disturb the VER. The Jolly test is an evoked response involving muscles. A peripheral nerve is shocked at 5 to 15 times per second, and the pattern of action potentials elicited in the muscle innervated is recorded. Sensory nerve conduction studies also involve an evoked response to a shock, with the resulting signal tracked in the sensory nerve stimulated. Muscle and peripheral nerve function is typically normal in patients with MS, unless they have an unrelated disease of the peripheral nervous system.