Welcome to your Neurophysiology Name Email 1. [All of the following statements regarding EEG changes observed after carotid crossclamping during carotid endarterectomy are true except] EEG changes usually occur within the first 20 seconds in the majority of patients Decrease of anterior alpha and beta activity on the clamped side suggests ischemia Increase of delta amplitude on the clamped side suggests progression of ischemia Bilateral EEG changes always suggest change in anesthesia or blood pressure None . 2. [An epileptiform spike is characterized by all of the following except] Steep upslope and steep downslope Duration less than 70 ms Wider field in Stage 2 sleep compared with REM sleep Horizontal dipole None . 3. [The waveforms shown below were acquired by repetitive nerve stimulation in the same patient at baseline (top) and immediately after exercise (bottom). The results are consistent with which of the following phenomena? (fig)] Facilitation but not repair Repair but not facilitation Both repair and facilitation Neither repair nor facilitation None Comment . 4. [All of the following statements regarding inductors are true except] Their currents are generated by the electrical field surrounding a wire that creates currents in other wires They have a reactance similar to resistors They pose an impediment to current generated by another source The reactance is directly proportional to the inductance None . 5. [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 . 6. [To score an epoch as REM, changes in which of the following are required?] EMG only EMG and EEG EMG or electrooculogram (EOG) EMG, EEG, and EOG None . 7. [In a patient with suspected myasthenia gravis (MG), needle EMG is most likely to reveal] Positive sharp waves and fibrillation potentials Large-amplitude polyphasic motor unit potentials Variation in motor unit amplitude Increased recruitment frequency if the muscle is weak None . 8. [A 45-year-old male with syncope had autonomic testing. His heart rate deep breathingrange was assessed based on the waveform shown below. The likely heart rate deepbreathing range is (fig)] 8 2 18 40 None Comment . 9. [Visual evoked potentials (VEPs) may be successfully recorded in patients with visual field defects and impaired visual acuity by] Dilating the pupils Decreasing the check size Placing the recording electrodes more laterally Asking the patient to fixate at different points around the target None . 10. [Which of the following changes seen during hyperventilation (HV) is considered abnormal?] Diffuse polymorphic delta activity in children Bifrontal delta activity in adults Bitemporal delta activity in adults Unilateral focal slowing in adults None . 11. [A 7-year-old boy, who had normal development, started to have difficulty with language. An EEG showed state-related continuous spike-wave discharges. Which of the following is false regarding this disorder?] It is known as Landau–Kleffner syndrome (LKS) The spike-wave discharges tend to activate in sleep The amount of language regression is related to the duration of the abnormal activity EEG can assist in diagnosis but not in monitoring treatment of the disorder None . 12. [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 . 13. [A sural sensory study was performed in a 56-year-old man. This revealed a latency of 4.9 ms, amplitude of 12 μV, and conduction velocity of 36 m/sec. After the study, the electrodiagnostic technician noticed that the limb temperature was 27°C and repeated the study after rewarming the leg to above 30°C. Which of the following values are likely to be seen on the repeat sural study? Latency (ms) Amplitude (μV) Conduction velocity (m/sec)] 5.0 12 42 5.0 8 36 4.2 14 33 4.2 8 42 None . 14. [Intermittent rhythmic delta activity (IRDA) is] Usually diffuse but predominant in the frontal region in children Activated by hyperventilation (HV) Activated by sleep Not reactive to eye opening None . 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. [Which of the following electrodiagnostic findings in acute inflammatory demyelinating polyradiculoneuropathy (AIDP) is the most reliable predictor of poor prognosis?] Severely prolonged distal latency Severely reduced compound muscle action potential (CMAP) amplitude Severely reduced conduction velocity Positive sharp waves and fibrillation potentials None . 17. [Technical considerations for intraoperative monitoring (IOM) of the 8th nerve using brainstem auditory evoked potential (BAEP) include all of the following except] If Wave I is indistinct, repositioning of the ipsilateral earlobe electrode is helpful Masking of the contralateral ear with white noise is not necessary Shorter epoch length of less than 10 ms is recommended for averaging the signals Stimulation with alternating click polarities is recommended None . 18. [A 58-year-old male presents with new-onset acute weakness in the setting of chronicleft-sided weakness and has the following EEG (filter: 1–70 Hz). Which of the followingscenarios is most likely? (fig)] Mesial temporal sclerosis in the setting of childhood febrile seizures Acute middle cerebral artery (MCA) infarction in the setting of prior infarction Todd’s paralysis after a focal motor seizure Herpes simplex virus (HSV) infection, causing cerebral and spinal cord dysfunction None Comment . 19. [The needle EMG waveforms shown below may be seen in all of the following conditions except (fig)] Motor neuron disease Severe inflammatory polymyositis Severe axonal polyneuropathy Guillain–Barré syndrome (GBS) with demyelinating changes only None Comment . 20. [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 . 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. [The following EEG (filter 1–70 Hz; sensitivity 20 μV/mm; solid vertical lines are 1 secondapart) was obtained from a 19-month-old patient with Landau–Kleffner syndrome (LKS). This EEG is characterized by all of the following ways except (fig)] Association with auditory verbal agnosia Definite association with clinical seizures Clear activation with state change None of the above None Comment . 23. [The resting membrane potential of a neuron is typically] –90 mV –70 mV 0 +55 mV None . 24. [A 61-year-old man is undergoing continuous positive airway pressure (CPAP) titrationstudy for obstructive sleep apnea (OSA). A 30-second epoch of REM sleep during CPAPtitration is shown below. The stage of sleep shown in the epoch is associated with all ofthe following except (fig)] Rapid eye movements Ponto-geniculo-occipital (PGO) waves in animals Dream imagery Regular heart rate None Comment . 25. [A routine median motor study in a 50-year-old secretary with symptoms of hand numbness and weakness is shown below. What does this study reveal? (fig)] Normal median motor study Evidence of median neuropathy in the wrist Evidence of median neuropathy in the forearm Conduction block None Comment .
