Welcome to your Neurophysiology Name Email 1. [Motor evoked potentials (MEPs) during scalp transcranial electrical stimulation (TES) are generated by] Action potentials that are initiated at the axon hillocks of the cortical pyramidal neurons Action potentials that are initiated in the cell bodies of the cortical pyramidal neurons The outward transmembrane current under the anode The inward transmembrane current under the cathode None . 2. [The use of traditional EEG filter settings in polysomnogram (PSG) studies would result in which of the following?] Underscoring of N3 sleep Overscoring of N3 sleep Underscoring of the posterior dominant rhythm None of the above None . 3. [Which of the following is true regarding the current lines generated by a depolarizing wave front?] The associated current lines along a depolarized nerve will fan into the current sink There is asymmetry between the depolarizing and repolarizing regions of the nerve Current lines traveling opposite to the direction of electrode movement will lead to an upward deflection The closer an electrode is to the generator, the wider the waveform None . 4. [The figure below shows a waveform obtained after a normal Valsalva testing in a patient. Which phase of Valsalva does the arrow point to? (fig)] Phase III Phase II Late Phase IV Phase II Early None Comment . 5. [Which of the following correctly lists the order in which the analog signals are converted to digital signals?] Analog signal is sensed, amplified, filtered, and sampled at discrete time intervals Analog signal is sensed, filtered, amplified, and sampled at discrete time intervals Analog signal is sensed, sampled at discrete time intervals, filtered, and amplified Analog signal is sampled at discrete time intervals, amplified, and filtered None . 6. [A 45-year-old man presents with weakness for more than 20 years. On examination, he has predominantly symmetrical, proximal more than distal, weakness with diminished reflexes and intact sensation. He was previously told that he had a form of muscular dystrophy. Needle EMG revealed few positive sharp waves and fibrillation potentials along with long-duration and large-amplitude motor unit potentials with severely reduced recruitment. If a muscle biopsy is performed in this patient, it will most likely reveal] Rimmed vacuoles Perifascicular atrophy Fiber type grouping Glycogen positive vacuoles None . 7. [Bifid sensory nerve action potentials in children are seen because of which of the following?] Poor technique Normal variant in children because of different degrees of myelination Axonal neuropathy Demyelinating neuropathy None . 8. [Magnetoencephalography (MEG) is a measure of] Magnetic fields caused by tangential current dipoles Magnetic fields caused by radial current dipoles Cortical current dipoles on the convexity of gyri Summated volume currents None . 9. [Which of the following technical considerations is applicable for motor evoked potential (MEP) recording by transcranial electrical stimulation (TES) during intraoperative monitoring (IOM)?] Signal averaging should be used for recording myogenic MEPs (M-waves) Stimulus intensity should be kept low enough to produce the MEP waveforms in only 1 limb A train of 3–7 pulses is used to obtain D-waves Limb movement is more likely while recording D-waves None . 10. [Which sleep state is least likely to show epileptiform abnormalities?] N1 N2 N3 REM None . 11. [Which of the following statements is true regarding sphenoidal electrodes?] They are positioned medial to the foramen ovale They may pick up posterior–temporal potentials better than surface electrodes They are felt to pick up similar potentials as FT9 and FT10 They require placement under fluoroscopic guidance None . 12. [All of the following statements are true regarding the multiple sleep latency test (MSLT) except] It can distinguish between narcolepsy and idiopathic hypersomnia without the need for a preceding full-night polysomnogram Occipital scalp EEG electrodes are used during the test The patient has 5 opportunities to nap at 2-hour intervals Medications affecting sleep need to be stopped prior to the study spanning an interval of at least 5 half-lives of the longest active metabolite None . 13. [A 55-year-old man presents with severe fatigue and weakness for over 4 months and recent onset of dry mouth. He does not report any obvious diplopia. He is a chronic smoker. On examination, he has mild facial weakness, ptosis, mild to moderate weakness of neck flexion, and proximal limb weakness. Deep tendon reflexes are absent. Sensory examination is normal.Ulnar motor study done in this patient is shown below. Top trace is at baseline and thebottom trace is after 10 seconds of exercise. What does it reveal? (fig )] Normal test after 10 seconds of exercise Decreased motor amplitude on repeat stimulation, suggestive of postsynaptic neuromuscular junction (NMJ) disorder Increased motor amplitude on repeat stimulation, suggestive of presynaptic NMJ disorder Technically limited study None Comment . 14. [Needle EMG of the tibialis anterior muscle revealed the following motor unit potentials. What type of neuromuscular process does this suggest? (fig)] Acute neurogenic process Acute myopathic process Chronic reinnervation process Acute neuromuscular dysfunction None Comment . 15. [Impedances from the adjacent electrodes should be similar in order to] Prevent “salt bridging” effects Prevent aliasing Ensure a pathway for current to flow from one electrode to another Maintain signal fidelity in the differential amplifier None . 16. [A 45-year-old man has a few month history of weight loss and low appetite. Extensive evaluation found an enlarged supraclavicular lymph node. He underwent biopsy of the lymph node. After the biopsy, he developed pain and weakness in his left shoulder area. EMG of which of the following muscles is going to be abnormal?] Deltoid Trapezius Serratus anterior Supraspinatus and infraspinatus None . 17. [Glial cells are characterized by] Lower intracellular potential than neurons Postsynaptic potentials similar to neurons Depolarization with increase in extracellular potassium concentration Activity that serves to dampen extracellular field potentials None . 18. [Twitching of which of the following muscles is most associated with the photomyogenic effect seen on EEG?] Orbicularis oris muscle Temporalis muscle Frontalis muscle Mentalis muscle None . 19. [A 78-year-old man with chronic mild back pain presents with difficulty walking. On examination, he has sensory loss and mild weakness. Ankle reflexes are absent. Electrodiagnostic findings are shown below. What is the most appropriate interpretation? (fig)] He has polyneuropathy because sural sensory responses are absent He has polyneuropathy because peroneal motor conduction velocity is decreased He has lumbosacral radiculopathy because peroneal motor amplitudes are decreased He has either polyneuropathy or lumbosacral radiculopathy; further differentiation is not possible based on the given data None Comment . 20. [A 55-year-old man noticed right leg weakness for a few weeks. On examination, he hasweakness of his right toe extension and sensory loss on the dorsum of the foot. A peroneal motor study with recording from tibialis anterior is shown below. Which of the following is most likely to be the underlying etiology? (fig)] Recent significant weight loss Traumatic ankle fracture Recent lumbosacral spine injury Recent fracture of tibia None Comment . 21. [Which of the following criteria is considered as significant to cause an “alarm” during intraoperative monitoring (IOM) of brainstem auditory evoked potential (BAEP)?] Amplitude drop of 50% or higher of a waveform measured from the peak to the following trough Amplitude drop of 50% or higher of a waveform measured from the preceding trough to the peak Increase in peak latency by 0.5 ms Increase in Waves I–V interpeak latency (IPL) by 2 ms None . 22. [The N13 component of the median somatosensory evoked potential (SSEP) is characterized by all of the following except] It is generated by stimulation of large myelinated fibers in the dorsal horn It is best seen as a negative potential over the C5–C7 spinous processes It is preserved in brain death It is abolished in cervicomedullary lesions None . 23. [Transcranial magnetic stimulation (TMS) is not suitable for intraoperative monitoring of motor evoked potentials (MEPs) because of all of the following except] It does not effectively activate the motor cortex It does not produce D-waves It produces different MEPs with different orientation of the stimulating coil It can interfere with the functioning of other operating room equipment None . 24. [During a routine EEG, the technologist asks the patient to spell the word “gladiolus” (the first National Spelling Bee winning word in 1925). Which of the following EEG activities can be expected to appear or enhance?] Alpha rhythm Mu rhythm Theta rhythm Lambda waves None . 25. [The activity seen at Point 2 was noted to have an amplitude asymmetry with the amplitude being 80–110 μV on the left side and 100–130 μV on the right. Which of the following statements is true about the amplitude of the depicted activity? (fig)] It is always asymmetric, being higher on the left side Amplitude asymmetry of more than 25% between the 2 sides is considered abnormal It tends to diminish with age It can be increased by doing simple math None Comment .
