Welcome to your Neurophysiology Name Email 1. [A 25-year-old woman noticed numbness in her left hand after she started wearing a new, tight-fitting bracelet. On examination, she has sensory loss over the dorsum of the left hand. There was no clear weakness on examination and deep tendon reflexes were normal. A nerve conduction study was requested. Apart from routine testing, which nerves should be tested to localize her neuropathy?] Bilateral lateral antebrachial cutaneous sensory studies Bilateral median palmar sensory studies Bilateral radial motor studies Bilateral radial sensory studies None . 2. [A neuromuscular fellow notices the findings shown below while performing an EMG ofa weak muscle. What is the source of the waveforms shown? (fig)] Anterior horn cells Muscle fibers Motor nerve axons Ephaptic transmission in muscle fibers None Comment . 3. [Decreased limb temperature may cause the following electrodiagnostic changes on motor nerve conduction studies:] Increased motor amplitudes Prolonged distal latencies Slowed nerve conduction velocities All of the above None . 4. [In a resistor–capacitor (RC) circuit, impedance is equal to] Resistance only Capacitive reactance and inductive reactance Resistance and capacitive reactance Resistance, capacitive reactance, and inductive reactance None . 5. [A 50-year-old male had intractable back pain and the diagnostic workup was significant for L3–L5 disc bulges. He underwent surgical decompression with intraoperative monitoring (IOM). All the baseline potentials were within normal limits. During the procedure, the N34 and P37/38 potentials disappeared with preservation of the N22 potential. What is the most appropriate localization?] Peripheral nerve Cauda equina Lumbar anterior horn cells Cortex None . 6. [Ictal patterns at the onset of generalized tonic–clonic seizures include all of the following except] Voltage attenuation Paroxysmal beta activity Generalized polyspike-wave discharges Rhythmic 3 Hz sinusoidal activity None . 7. [All of the following statements are true regarding the effect of age on visual evoked potential (VEP) except] P100 latencies reach adult values by age 1 year for larger check sizes P100 latencies reach adult values by age 1 year for smaller check sizes P100 latency may decrease during adolescence P100 latency increases after age 60 years None . 8. [When requesting muscle biopsy in a patient with suspected myopathy, which of the following should be considered to increase the yield of the biopsy?] Biopsy a muscle with normal strength (5/5 on MRC scale) Biopsy a muscle with mild weakness (4/5 on MRC scale) Biopsy a muscle with severe weakness (2–3/5 on MRC scale) Obtain an MRI of the muscle before biopsy None . 9. [Which of the following statements regarding the relationship between age and the sleep stages is false?] Sleep latency tends to increase with age N1 decreases with age N3 decreases with age REM tends to decrease with age None . 10. [A tibial motor study with abductor hallucis recording from a 45-year-old man withdifficulty walking is shown below. A1 represents stimulation at the ankle and A2represents stimulation at the popliteal fossa. The distance between the ankle andpopliteal fossa stimulation is 40 cm. Sweep speed is 5 ms per division and gain isset at 5 mV. Which combination of the following latency, amplitude, and conductionvelocity measurements is correct? (f ig)] None Comment . 11. [Which of the following changes are seen during hyperventilation (HV)?] Both PaCO2 and PaO2 decrease Both PaCO2 and PaO2 increase PaCO2 decreases but PaO2 increases PaCO2 decreases but PaO2 increases only after cessation of HV None . 12. [A 35-year-old male was admitted to the neurological ICU after a severe traumatic brain injury. He was found to have fluctuating mental status in the setting of a subarachnoid hemorrhage (SAH). Continuous video-EEG (cEEG) monitoring was ordered. The EEG technician, a recent graduate, called the neurophysiology fellow to learn more about the various pros and cons regarding EEG electrode choice. Which of the following statements is true?] Metal electrodes lead to a “star-burst” effect on CT images due to the absorption of x-rays All metal electrodes cause susceptibility artifact on MRI Long leads and ferrous metals can lead to skin heating and burning during acquisition of MRI Short-lead, silver, subdermal wire electrodes lead to significant artifact on both MRI and CT images None . 13. [P100 waveform is characterized by all of the following except] It can be preceded and followed by negative waveforms It can be “W-shaped” because of an active mid-frontal reference It can be “W-shaped” because of projections from different parts of the calcarine cortex It is predominantly generated in the visual association areas None . 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. [A 50-year-old man developed double vision and difficulty walking over 3 days. Initial examination in the emergency department revealed decreased eye movements. Strength in limbs was relatively preserved, all reflexes were absent, and he was noted to be ataxic. What would the motor nerve conduction study in this patient likely show?] Normal motor amplitude and conduction velocity Conduction block Severely reduced motor amplitudes Normal motor amplitudes but severely reduced conduction velocity None . 16. [Small sharp spikes (SSS) can be differentiated from epileptiform discharges by all of the following except] SSS appear in light sleep and disappear during deeper stages of sleep SSS tend to have a steep descending limb SSS are not associated with aftergoing slow waves SSS may have transverse oblique dipoles on transverse montages None . 17. [All of the following enzyme defects leading to a glycogen storage disorder (GSD) are associated with neuromuscular manifestations except] Acid alpha glucosidase deficiency Beta enolase deficiency Glucose 6-phosphate deficiency Aldolase deficiency None . 18. [A 20-year-old was stabbed with a long blade knife in the neck during a fight. He noticed weakness and numbness in his right hand after the injury. Which of the following findings will differentiate brachial plexopathy from cervical root injury?] Ulnar sensory amplitude Median H-reflex with flexor carpi radialis recording Median somatosensory evoked potential study Ulnar motor amplitude None . 19. [Which of the following EEG abnormalities is associated with a risk for seizures?] Frontal phantom spike-wave discharges Occipital phantom spike-wave discharges Rudimentary spike-wave discharges (pseudo petit mal discharges) Needlelike occipital spikes None . 20. [The EEG signal is characterized by all of the following except] The action potential is unlikely to contribute to the signal because the spike amplitude decays quickly away from the dendritic tree The action potential is unlikely to contribute to the signal because the spike duration is too long (10–250 ms) The signal recorded at the cortex tends to be of shorter duration than the signal recorded simultaneously at the scalp The signal is influenced by the characteristics of the moving dipole None . 21. [All of the following statements regarding infant audiologic screening are true except] Initial infant screening should be done within 3 months of birth Transient-evoked otoacoustic emissions (EOAE) test can be used instead of brainstem auditory evoked potentials (BAEPs) Infants failing the screening should be retested within 3 months False positive tests can occur because of middle ear infection None . 22. [A tumor in the medulla can be expected to reduce or abolish all of the following waveforms except] N13 P14 N18 P31 None . 23. [Which of the following statements is true regarding the homeostatic and circadian sleep drives?] The homeostatic drive decreases with sleep The circadian drive is controlled by the suprachiasmatic nucleus of the hypothalamus The ventrolateral preoptic nucleus of the hypothalamus promotes sleep All of the above None . 24. [Calculation of the negative peak duration and area on the proximal and distal compound muscle action potential (CMAP) are most useful in assessing which of the following electrodiagnostic measures on motor nerve conduction studies?] Conduction velocity Latency Temporal dispersion Stimulus intensity and duration None . 25. [In a patient with suspected median mononeuropathy, a thorough EMG was performed after nerve conduction studies. The EMG findings are summarized below. What is the most likely diagnosis? (fig)] Median mononeuropathy at the wrist Median mononeuropathy proximal to the nerve supply to pronator teres Median mononeuropathy distal to the nerve supply to pronator teres Lower trunk brachial plexopathy None Comment .
