Evoked Potential Practice Exam

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• In auditory brainstem response testing, what is the approximate interpeak latency between waves I and V?
• Which retinal structure corresponds to the physiologic blind spot due to lack of photoreceptors?
• What is a typical use of SSEPs in intraoperative monitoring?
• What is the purpose of using alternating polarity stimuli in ABR?
• Which statement about P300 in brain injury is true?
• Absence of all waveforms in a lower extremity somatosensory evoked potential is NOT caused by which of the following?
• In pediatric EP testing, what age-related changes are typically observed in VEP?
• In posterior tibial nerve somatosensory evoked potentials, central conduction time is measured between which two points?
• Which statement about subdermal electrodes is correct?
• Which cranial nerve is purely motor?
• The number of recording channels for full-field VEP should be:
• What is the typical effect of myelopathy on somatosensory evoked potentials (SSEPs)?
• Cup electrodes have lower impedance than needle electrodes because of their size. Which option correctly expresses this?
• What is the recommended sedation plan to minimize EP alterations during prolonged testing?
• Which of the following is a contraindication for transcranial magnetic stimulation–evoked motor evoked potentials (MEP) testing?
• If trials are not reproducible, the recommended action is to perform an additional trial.
• Which practice best addresses myogenic artifact in EP recordings?
• In SSEP recording for median nerve stimulation, where is the recording site typically located?
• With an amplification factor of 500,000, a 1 μV brainstem auditory evoked potential waveform is amplified to how many volts?
• Why might a clinician order pattern reversal VEP vs flash VEP in a patient with cataracts?
• The decussation of the pyramids occurs at which level?
• Which electrode adjustment is implicated first when 60 Hz interference is observed across all channels?
• The N13 component of the median nerve somatosensory evoked potential is generated in which structure?
• In ABR, Wave I originates from which structure, Wave II from which structure, and what is the significance for localization?
• In pattern reversal visual evoked potentials, optic nerve dysfunction prolongs which component?
• Which statement correctly describes the usual polarity convention for recording brainstem auditory evoked potentials?
• Where is the P100 waveform generated in pattern reversal visual evoked potentials?
• Stimulus rates higher than 20 per second may reduce amplitudes of BEAP peaks except for which peak?
• Where is the N13 component of the median nerve somatosensory evoked potential generated?
• Which practice helps reduce artifact and noise besides relaxation?
• How can language impairment or cognitive deficits affect P300 measures?
• In the context of averaging evoked potentials, positive delay refers to averaging starting after stimulus onset.
• Central conduction time in median nerve SSEPs can be measured between N13 and N20, or equivalently between which pair?
• Which EP is also called the cognitive EP or oddball paradigm?
• Which of the following responses can be altered by reversal of click polarity?
• Accuracy of electrode placement is most critical for which type of response?
• Cup electrodes have impedance relative to needle electrodes due to their size. Which option is correct?
• How should inter-eye asymmetry in VEPs be evaluated?
• In which condition is the P100 of the pattern reversal visual evoked potential prolonged?
• If the vertical range on the display is reduced, the data points become spaced closer together.
• Which change would best enhance the resolution of evoked potential waveforms?
• Which cranial nerve is purely sensory?
• Compared to surface electrodes, needle recording electrodes tend to have which characteristic?
• To improve the signal-to-noise ratio, approximately what percentage of total stimulations are rejected as averaging rejection?
• What is a key goal of intraoperative evoked potential monitoring?
• Which statement correctly defines motor threshold?
• If you double the number of epochs averaged, the signal-to-noise ratio increases by approximately which factor?
• Which parameter is commonly emphasized as a safety consideration in somatosensory electrical stimulation?
• Which obligate peak of a MNSEP can vary in latency with level of alertness of the patient?
• Which paradigm is typically used to elicit the P300 component, and what is the typical difference between active and passive task conditions?
• Which parameter is most implicated in safety when adjusting stimulus intensity in somatosensory electrical stimulation?
• What is the approximate amplitude resolution of a 10-bit digitizer with a range of plus or minus 5 μV?
• Which ABR interpeak intervals are most commonly analyzed to assess brainstem conduction?
• How do pattern reversal and flash VEP stimuli differ in cortical activation and clinical utility?
• In somatosensory evoked potentials, N20 is typically recorded from which cortical area, and what pathway does it reflect?
• What causes absent ABR waves despite auditory function being intact?
• When performing motor evoked potentials, what is the role of TMS?
• In ABR, the interpeak latency between waves III and V is typically approximately 1.0-2.0 ms.
• How does the choice of reference electrode affect evoked potential morphology?
• Which structure is involved in the visual system?
• Which symptom is most closely correlated with somatosensory evoked potential abnormalities?
• What is the typical P100 latency range for adults with pattern-reversal VEP, and name a condition that can prolong it?
• In EP testing, which factor best explains why increasing the number of trials can improve data quality?
• Which cognitive potentials are often used to assess attention and decision-making processes?
• Which parameter is most closely tied to safety outcomes in somatosensory stimulation, particularly with regard to pulse shape?
• How is electrode impedance related to evoked potential (EP) signal quality?
• A patient with a left homonymous hemianopsia most likely has a lesion of which structure?
• What does the latency-intensity function imply about neural recruitment when stimulus intensity increases?
• What is the minimum recommended input impedance for the amplifier relative to electrode impedance in evoked potential recordings?
• Why are many trials averaged in evoked potential testing?
• In ABR testing, sensorineural hearing loss typically causes what changes to the waveform?
• A W-shaped pattern reversal visual evoked potential may be resolved with which method?
• Pattern reversal visual evoked potential latencies are most significantly affected by which factor?
• Why is controlling refractive error important in VEP testing?
• In pattern VEP, which component is used clinically to assess visual pathway integrity and its approximate latency?
• EcochG stands for electrocochleography.
• What is the approximate latency of the N20 component in somatosensory evoked potentials?
• Which device is essential for reducing stimulus artifact and for patient safety during stimulation?
• Which parameter is most directly related to safety thresholds in somatosensory electrical stimulation?
• Which disease is characterized by episodes separated in time and space, commonly affecting young adults?
• Pattern reversal visual evoked potentials primarily involve which cortical area?
• Which waveform is elicited by a subject attending to rare stimuli?
• Which of the following is a partial paralysis of the lower extremities?
• Which statement is true about pattern reversal VEP compared with other modalities?
• Which parameter represents the safety risk factor most highlighted in somatosensory stimulation literature?
• In the context of safety considerations for somatosensory stimulation, which parameter is most likely to influence safety outcomes?
• Which of the following describes the normal interocular latency difference of P100?
• The troubleshooting method that best determines the source of a nonphysiologic artifact is to do what?
• Which term describes the long-latency auditory ERP associated with attention and novelty detection?
• Which of the following best reflects typical filter settings to balance signal preservation and noise reduction for ABR, pattern VEP, and long-latency potentials?
• Which structure acts as the primary relay for visual information en route to the cortex?
• What is the difference between pattern VEP and multifocal VEP?
• Which check size in minutes of arc is most appropriate to stimulate the fovea in a pattern reversal visual evoked potential?
• In ABR, how would conductive vs sensorineural hearing loss affect ABR?
• Which setting is the most sensitive for detecting small potentials on the display?
• Which factors can influence VEP P100 latency and amplitude besides pathology?
• Which filter does not produce a phase shift in evoked potential recordings?
• In auditory brainstem responses, what does a prolonged I-V interpeak latency indicate?
• What is the equation for calculating visual angle in minutes of arc?
• Amplitude of an evoked potential depends on which physiological action in a sensory pathway?
• Which state is preferred whenever feasible to minimize EP alterations during prolonged testing?
• What does neural adaptation mean in evoked potentials?
• The maximum leakage current should be limited to which value?
• What role do normative latency and amplitude charts play in EP interpretation?
• Which parameter is a safety concern when considering the electrode grounding in somatosensory stimulation?
• Which statement about ABR wave generators is accurate?
• Pattern reversal visual evoked potential latencies are most significantly affected by which factor?
• What is the role of signal averaging in evoked potential recordings?
• Which structure is the generator for ABR Wave V?
• Long-latency potentials have a typical filter range of?
• If an evoked potential has a voltage of 10 μV and the associated noise is 50 μV, what is the signal-to-noise ratio after 100 averaged responses?
• Smaller surface of stimulating electrodes tends to produce which effect?
• Which factor is most important for maximizing the common mode rejection ratio?
• In ABR testing, which wave is used to assess auditory nerve function and has a latency around 1.5 milliseconds?
• Which of the following is an effect of temperature on somatosensory evoked potentials?
• In pattern VEP, what is the effect of occluding one eye on the recorded waveform?
• Which nerve is primarily targeted by precise CP4 placement in evoked potential testing?
• What stimuli are used to elicit Visual Evoked Potentials, and what is the most clinically used waveform component?
• What are common causes of prolonged VEP P100 latency, aside from optic neuritis?
• Which parameter is most associated with patient safety concerns during somatosensory electrical stimulation?
• What effect on P100 does a decrease in screen luminance have?
• The long latency auditory evoked potential, also called the cognitive EP or oddball paradigm, is the:
• Averaging improves the signal-to-noise ratio by a factor equal to the square root of the number of averages.
• Accurate electrode placement of CP4 is most critical for stimulation of which nerve?
• In AEP, what are the three primary wave peaks used to assess auditory brainstem function, and what are their approximate latencies?
• In what age group do early symptoms of multiple sclerosis usually occur?
• Which factor is most relevant to safety when examining amplitude in somatosensory electrical stimulation?
• What is the minimum input impedance recommended for the amplifier?
• Averaging improves the signal-to-noise ratio by which relation?
• In intraoperative monitoring of somatosensory evoked potentials, which wave is least affected by the anesthetic agents?
• In evoked potentials, which statement best distinguishes latency from amplitude?
• How can P300 be used in coma or brain injury assessment?
• Which statement best describes common sources of EP artifact contamination and how to minimize them?
• What is the latency-intensity function in evoked potentials?
• Which statement about data points on the display is true when the vertical range is changed?
• Which parameter is a safety consideration specifically related to pulse type in somatosensory stimulation?
• In pattern-reversal visual evoked potentials, what is the typical P100 latency range in adults?
• In a median nerve somatosensory evoked potential, Wave V is usually the most prominent peak after approximately which latency?
• Which result occurs from averaging an evoked potential?
• Which parameter among the following is most directly associated with safety risks in somatosensory stimulation?
• Which electrode type is described as having long time constants compared to silver electrodes?
• If the distance between a patient and the pattern generator is halved, what happens to the visual angle subtended by each check?
• Which term describes partial weakness on one side of the body?
• In a brainstem auditory evoked potential, decreasing click intensity will result in which change?
• Which statement is true regarding the brainstem reflection of certain ABR waves?
• What is the primary purpose of evoked potentials in neurophysiology?
• In auditory evoked potentials, which wave is generally believed to reflect the auditory nerve and brainstem conduction earliest?
• In SSEP, what is the difference between N20–P25 and P37 components, and where are they recorded?
• If a signal averager samples every millisecond, what is the theoretical maximum frequency resolution?
• Wave I of the auditory evoked potential cannot appear before:
• What is the typical number of averages used to achieve robust EP signals?
• How does noise level in the recording environment affect EP results?
• A patient has a right homonymous hemianopsia. The lesion is most likely located in which area?
• Which parameter is considered a safety risk factor during somatosensory stimulation?
• When using collodion for electrode adhesion, which statement is correct about its electrical role?
• Which phenomenon refers to fast frequency components of an artifact appearing at slower frequencies?
• Which statement best describes the effect of smaller stimulating electrode surface area?
• What electrode montage is commonly used for VEPs, and what practice is important for impedance?
• In P300 testing, what is the difference between active and passive task conditions?
• Which waveform is the first to appear in the auditory evoked potential and serves as a reference point for brainstem conduction?
• In a spinal cord SSEP, how would a lesion at the thoracic level affect leg SSEPs?
• Which waveform is most commonly used as an early cortical response during intraoperative monitoring of SSEPs?
• In median nerve somatosensory evoked potentials, central conduction time is measured between which two signals?
• Which of the following statements is accurate about ABR wave generators?
• Which statement best describes how sedation or anesthesia affects auditory brainstem response results?
• What is the typical effect of high electrode impedance on EP measurements?
• Paresthesia is best described as which sensation?
• In somatosensory electrical stimulation, which factor is identified as the primary safety concern?
• Where are N20–P25 and P37 components recorded during SSEPs?
• BEAPs are relatively independent of:
• Abnormal interpeak latency I–V in ABR indicates what?
• For SSEP, what is a typical step to ensure robust N20 response?
• If there is 60 Hz interference in all channels during median nerve SSEPs, which electrode should be adjusted first?
• Using the International 10-20 electrode placements, if the measurement from nasion to inion is 30 cm, what is the distance from Fz to Cz?
• What is motor threshold in evoked potentials?
• Masking is recommended to eliminate
• All components of brainstem auditory evoked potential waveforms reach adult configuration by what age?
• What is a typical number of trials to average in SSEP to ensure a robust N20 response?
• During intraoperative monitoring, which changes in N20 and subsequent components are most concerning?
• In median nerve somatosensory evoked potentials, which waveform typically appears around 14 ms after stimulation?
• Which parameter among the following is a principal safety consideration in somatosensory stimulation?
• Which type of evoked potential is least affected by electrode placement accuracy?
• The cochlea generates what EP response?
• Which choice best describes the purpose of the stimulation isolation unit?
• Using the International 10-20 system, if the nasion-inion distance is 40 cm, what is the distance from Fz to Cz?
• Which statement best describes why pattern reversal VEPs are often preferred for assessing the visual pathway when vision is poor?
• Averaging evoked potentials primarily reduces random brain activity noise.
• The recommended somatosensory electrode derivation to best record the N13 response is:
• If the trials are not reproducible, what is the recommended course of action?
• Which factor is a key determinant of the common mode rejection ratio?
• What stimulus type is used for ABR testing in infants, and why?
• Which parameter is most likely to influence safety when using high pulse durations and repetition rates in somatosensory stimulation?
• If the fastest component of a complex waveform is near 100 Hz, which dwell time is most appropriate?
• The appropriate stimulus intensity of stimulating median nerve at the wrist for recording SEP is: