Welcome to your Neurophysiology Name Email 1. [Amplitude of somatosensory evoked potential (SSEP) waveforms can be increased in all of the following conditions except] Nitrous oxide Benzodiazepines Etomidate Certain focal and generalized epilepsy syndromes None . 2. [A 25-day-old infant was noted to have severely reduced tone. Her pediatrician would like to exclude an underlying neuromuscular cause for her decreased tone and requested an electrodiagnostic evaluation. Nerve conduction velocities of median and peroneal motor nerves were in the range of 25–26 m/sec. This finding suggests that the infant has] Demyelinating polyneuropathy Axonal polyneuropathy Normal conduction velocity for age Myopathy None . 3. [Which of the following studies provides information regarding cardiovagal function?] Phase IV part of the Valsalva waveform Phase II Late part of the Valsalva waveform Sudomotor testing Heart rate deep breathing range None . 4. [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 . 5. [Submaximal stimulation is used in which of the following nerve conduction studies?] Motor nerve conduction and F-wave responses All sensory studies H-reflex study All nerve conduction studies are always performed with supramaximal stimulation and submaximal stimulation should never be used None . 6. [The interface between the EEG electrode and the electrolyte paste can be considered as] An electrical double layer that presents capacitance impeding current flow Potentially unstable with new electrodes causing “pop” artifacts A source of half-cell potential that remains stable despite movement of the electrode Highly polarized when a silver–silver chloride interface is used None . 7. [The accepted nomenclature of EEG electrodes includes all of the following except] Even numbers over the right hemisphere Odd numbers over the left hemisphere The letter “z” refers to midline electrode M1 and M2 refer to the earlobe electrodes None . 8. [A 33-year-old female with meningoencephalitis had a stroke with left facial droop. She presents with new episodes of dizziness and right facial twitching. She had 2 witnessed seizures described as “shaking all over.” She is back to baseline with proper mentation and no appreciable twitching. An EEG was then done. What is the most prominent finding seen on the EEG (filter: 1–70 Hz)? (fig)] Periodic lateralized discharges (PLDs) Intermittent rhythmic delta activity (IRDA) Sharply contoured polymorphic delta slowing Seizure discharge None Comment . 9. [A 25-year-old man was admitted to the intensive care unit after a motor vehicle accident. He has a significant head injury and is not able to follow commands. His orthopedic surgeon would like to exclude radial neuropathy from a humerus fracture. A bedside radial nerve conduction study performed within 24 hours of the accident showed normal amplitude with stimulation at the elbow. What is the most appropriate conclusion?] Radial nerve is not injured It is not possible to rule out radial nerve injury with the above information Radial nerve is not injured below the elbow Radial sensory response is needed to answer this question None . 10. [Which of the following is true regarding the sodium–potassium pump?] It helps to neutralize the membrane potential It involves passive transport of sodium and potassium ions It actively transports 3 sodium ions into the cell and 2 potassium ions out of the cell It allows for secondary active transporters to function via the use of the sodium gradient None . 11. [An obese 30-year-old male with excessive daytime sleepiness was evaluated. An overnight polysomnogram (PSG) showed sleep-onset latency of 20 minutes, sleep efficiency of 90%, periodic limb movement of sleep (PLMS) index of 10, and an apnea hypopnea index (AHI) of 4. A multiple sleep latency test (MSLT) performed the following morning was not diagnostic for narcolepsy. What is the likely cause of his excessive daytime sleepiness?] Apnea Periodic limb movements of sleep Respiratory effort-related arousals (RERAs) Insomnia None . 12. [In a resistor–capacitor (RC) circuit, a larger resistor will cause the time constant to be] Longer Shorter Unchanged More dependent on the capacitor size None . 13. [Which of the following potentials is considered a standing wave?] The motor response seen when stimulating the peroneal nerve above the knee with the patient standing The sensory response in standard bipolar digit sensory nerve conduction The P37 potential seen when stimulating the posterior tibial nerve The P9 potential seen when stimulating the median nerve None . 14. [All of the following physiological changes occur in REM sleep except] Atonia Impaired thermoregulation Reduction in ventilatory chemosensitivity Decreased cerebral blood flow None . 15. [All of the following statements regarding somatosensory evoked potentials (SSEPs) are true except] Up to 40% of patients with multiple sclerosis (MS) without sensory symptoms may have abnormal SSEPs The N20 waveform may be abolished by anesthesia Intravenous etomidate decreases the amplitude of cortical potentials Amplitude of cortical potentials may be increased in progressive myoclonus epilepsy syndromes None . 16. [In the following EEG showing a left temporal discharge, what are the relative polaritiesof electrodes Fp1 relative to F7, and electrode P7 relative to T7? (fig)] Negative; Negative Negative; Positive Positive; Negative Positive; Positive None Comment . 17. [A 25-year-old man was involved in a motor vehicle accident 3 weeks ago. He suffered a crush injury to his forearm and was noted to have diffuse weakness in his hand. A few days after recovery from extensive surgery to his forearm, he continued to have weakness. An EMG of a distal weak muscle might reveal which of the following patterns? Choices Spontaneous activity Motor unit Motor unit Recruitment pattern duration amplitude ] None . 18. [Which of the following is NOT considered a normal feature in the EEG of a 15-year-old child?] 10 Hz posterior dominant rhythm (PDR) Gradual dropout of posterior alpha at the onset of drowsiness Rhythmic midline frontal sharply contoured activity upon arousal Occasional photoconvulsive response None . 19. [Which of the following statements is true regarding the electrodiagnostic changes in patients with botulism?] Low compound muscle action potential (CMAP) amplitude and decrement on fast repetitive stimulation Low CMAP amplitude and increment in slow repetitive stimulation Low CMAP amplitude and normal findings on needle EMG Low CMAP amplitude, increment in fast repetitive stimulation, and active denervation potentials in weak muscles None . 20. [Which of the following features of the motor unit potential should be taken into consideration before analyzing individual motor units?] Duration of motor unit potential Rise time Number of phases or turns Amplitude of motor unit potential None . 21. [All of the following can occur with decreasing click intensity during brainstem auditory evoked potential (BAEP) recording except] Prolongation of interpeak latencies (IPLs) Prolongation of absolute latencies Decrease in amplitude Change in Wave I shape None . 22. [Where is the maximal negativity in the following EEG (filter: 1–70 Hz)? Note that the 2frames display the same 3-second EEG in 2 separate montages. (fig)] F3 C3 F7 T7 None Comment . 23. [Needle EMG in a patient with severe deltoid weakness revealed the following motor unit firing pattern on full activation. What does this finding suggest? (fig 3)] An underlying myopathy An underlying neuromuscular junction dysfunction An underlying neurogenic process This is a normal interference pattern None Comment . 24. [How many leg movements can be scored as periodic limb movements of sleep (PLMS) in the 2 consecutive 30-second epochs of a polysomnogram (PSG) shown below? Note that the thick vertical line separates the two epochs. (f ig)] 2 3 4 5 None Comment . 25. [The following EEG (filter: 1–70 Hz; sensitivity: 10 μV/mm; solid vertical lines are 1second apart) is from a 9-year-old boy with intractable epilepsy with psychiatric comorbidities. What medication is likely causing the diffuse changes? (fig)] Antidepressant Anxiolytic Antipsychotic Analgesic None Comment .
