Welcome to your Neurophysiology Name Email 1. [Giant somatosensory evoked potential (SSEP) can be seen in all of the following conditions except] Lafora body disease Conditions causing focal motor seizures Juvenile myoclonic epilepsy Hemispheric hemorrhagic stroke None . 2. [A 56-year-old female presented with difficulty walking. On examination, she was found to have spastic paraplegia with a mid-thoracic sensory level. The cranial nerve and upper extremity exams were normal. Which of the following sets of somatosensory evoked potential (SSEP) patterns could be expected in this patient?] Normal N22 latency, normal N22–P37 latency, normal N9–N20 latency Normal N22 latency, abnormal N22–P37 latency, abnormal N9–N20 latency Abnormal N22 latency, normal N22–P37 latency, abnormal N9–N20 latency Abnormal N22 latency, abnormal N22–P37 latency, normal N9–N20 latency None . 3. [A 9-year-old girl with staring spells had an EEG that showed high-amplitude, 3–4 Hz sharply contoured delta activity. In which of the following scenarios would this finding always be pathological?] Hyperventilation (HV) Drowsiness Photic stimulation Slow wave sleep None . 4. [In a normal subject, the activity seen at Point 2 can be appreciated in all of the following channels except(fig)] Temporal Parietal Occipital Frontal None Comment . 5. [All of the following are features of a normal EEG in a 6-year-old child except] Posterior dominant rhythm (PDR) of 8 Hz or higher Absence of hypnagogic hypersynchrony Sleep spindles with duration of about 1 second Low-voltage record None . 6. [A 35-year-old neurology resident noticed numbness over the dorsum of his left foot and weakness of the foot dorsiflexion for 6 months. Because his symptoms did not improve with rest, he ultimately had a nerve conduction study and needle EMG of the left leg muscles. EMG findings are tabulated below. What is the most likely localization for his weakness? (fig)] Peroneal nerve at fibular head Peroneal nerve above the fibular head L5 radiculopathy Sciatic nerve None Comment . 7. [Diagnosis of brain death by median somatosensory evoked potential (SSEPs) is based on all of the following except] N9, N13, and P14 should be preserved N18 should be absent N20 should be absent A cervicomedullary lesion should be excluded None . 8. [A 50-year-old man is admitted to the ICU with an unclear neurological disorder. He is sedated with propofol for severe agitation and is on ventilatory support. Electrodiagnostic study showed normal motor and sensory responses but absent F-wave responses. Which of the following is the most appropriate conclusion based on the available information?] He has Guillain–Barré syndrome (GBS) with agitation and needs spinal fluid analysis Absent F-wave responses can be due to sedation with propofol He will need somatosensory evoked potential (SSEP) studies to rule out peripheral processes Without repetitive nerve stimulation, it is not possible to come to a definitive conclusion None . 9. [All of the following statements regarding clamp-related EEG abnormalities during carotid endarterectomy are true except] They occur in less than 30% of patients They are associated with a high false positive rate for predicting postoperative stroke risk They are associated with a high false negative rate for predicting postoperative stroke risk They persist despite shunting in the majority of patients None . 10. [Which of the following sleep disorders is known to predominantly manifest in the sleepstage as depicted in the 30-second epoch below? (fig)] Bruxism Sleep-related rhythmic movement disorder (head banging) Sleep terror Hypnic jerks None Comment . 11. [A technologist was performing an EEG on a 9-year-old and noted that hyperventilation (HV) led to altered awareness. All of the following clinical observations by the technologist can be consistent with HV-induced high-amplitude rhythmic slowing (HIHARS) except] Fidgeting Yawning Staring Eyelid flutter None . 12. [Which of the following waveforms encountered in the median somatosensory evoked potential (SSEP) is a far-field potential?] N9 N13 P14 N20 None . 13. [What is the best interpretation of the hypnogram shown below? (fig)] Poor sleep efficiency REM rebound after continuous positive airway pressure (CPAP) therapy Narcolepsy REM sleep behavior disorder (RBD) None Comment . 14. [The time required for the appearance of fibrillation potentials or positive sharp waves after a nerve injury depends upon which of the following?] Distance between the site of the nerve injury and the muscle Distance between the spinal cord and muscle Extent of demyelination in the nerve Distance between the spinal cord and the site of the nerve injury None . 15. [All of the following statements are true about generation of EEG waveforms except] A negative field potential develops at the surface with activation of a superficial excitatory synapse A positive field potential develops at the surface with activation of a deep inhibitory synapse Individual excitatory postsynaptic potentials (EPSPs) in the upper dendrites of the neurons summate to produce depolarization Thalamocortical feedback loops modulate the amplitude of EEG waveforms None . 16. [Which of the following statements best describes the normal evolution of the frequency of the posterior dominant rhythm (PDR)?] It is 3 Hz by age 3 months It is 4 Hz by age 12 months It is 6 Hz by 3 years It is 10 Hz by 8 years None . 17. [The standard paper speed for EEG recording in the United States is] 15 mm/sec 30 mm/sec 45 mm/sec 60 mm/sec None . 18. [When multiple capacitors are placed in a circuit, they exhibit the behavior opposite to that of] Inductors Resistors Invertors Operative amplifiers None . 19. [What would the sensitivity be if there is 2 mm deflection in the FP1–F3 channel where FP1 is −60 μV and F3 is −50 μV?] 5 μV/mm –5 μV/mm 75 μV/mm 7.5 μV/mm None . 20. [Which of the following is true regarding electrode impedance when performing an EEG?] It should be more than 5 kΩ for scalp electrodes It is not critical because the electrode–electrolyte interface does not resemble a resistor– capacitor (RC) circuit Large electrode impedances can lead to large artifacts It is increased by removing the scalp oil None . 21. [All of the following statements regarding the direct current (DC) shifts seen at seizure onset are true except] DC shifts can only be recorded using dedicated DC-coupled amplifiers DC shifts can be recorded using an amplifier with a long-time constant DC shifts are better seen by decreasing the low-frequency filter DC shifts at seizure onset are useful in localizing the seizure onset zone None . 22. [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 . 23. [Giant somatosensory evoked potentials (SSEPs) are characterized by all of the following except] Their peak-to-peak amplitude is usually more than 15 μV They have normal amplitude and latency of the N20 potential They reflect cortical hyperexcitability in area 3b They are always preceded by an abnormal cortical spike, which is best seen with jerklocked back-averaging of EEG None . 24. [Prolongation of central conduction time (CCT; ie, N22–P37 interpeak latency [IPL]) after tibial nerve stimulation can be seen in all of the following conditions except] Barbiturate-induced anesthesia Brainstem multiple sclerosis Neuromyelitis optica Adrenomyeloneuropathy None . 25. [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 .
