New Quiz 10 Dec Welcome to your Neurophysiology Name Email 1. [Which of the following is true regarding cathode?] It is the positively charged terminal of a galvanic cell It is the negatively charged terminal of a galvanic cell It repels electrons It represents the terminal into which the current flows None . 2. [A 37-year-old woman has had multiple visits to the emergency department (ED) withgeneralized convulsions, incontinence, and tongue biting. She had a typical event duringphotic stimulation lasting 7 minutes, characterized by motionless staring noted by theEEG technologist. The video file was corrupted and could not be reviewed. What is theinterpretation of the captured episode considering the EEG (filter: 1–70 Hz) below whichdepicts the activity 4 minutes into the spell? (fig)] Recorded event Psychogenic nonepileptic event Scalp EEG negative epileptic seizure Frontal lobe seizure None Comment . 3. [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 . 4. [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 . 5. [How far along in a patient’s course with Creutzfeldt–Jakob disease (CJD) would the following EEG pattern be expected to be seen? (fig)] As the first EEG pattern prior to symptom onset In the middle of the disease course Only in the very late stages Throughout the entire disease course None Comment . 6. [All of the following statements about neuronal postsynaptic potentials (PSPs) are true except] Intracellular potential of a neuron is about –60 mV Action potentials as opposed to postsynaptic potentials contribute to the generation of the extracellular field potentials There is net influx of cations into the neuron with an excitatory PSP There is net outflow of cations from the nerve cell with an inhibitory PSP None . 7. [Continued insertional activity after moving a concentric EMG needle is considered normal if it lasts less than how many milliseconds?] 100 ms 200 ms 300 ms 400 ms None . 8. [Which of the following statements is true of photoparoxysmal response (PPR)?] It is never seen in focal seizures Its presence is always considered as abnormal It is most likely to be elicited by a flash frequency of 15–18 Hz in photosensitive epilepsy It is more likely to occur upon eye opening None . 9. [How does the number of bits in the analog-to-digital converter (ADC) affect the sampling rate?] It reduces it It increases it It depends on the bit rate It does not affect the sample rate None . 10. [Which of the following combination of deep tendon reflex abnormalities is seen in an upper trunk brachial plexopathy?] Absent triceps reflex Absent biceps reflex but preserved triceps and brachioradialis reflexes Absent brachioradialis reflex but preserved biceps and triceps reflexes Absent biceps and brachioradialis reflexes with preserved triceps reflex None . 11. [Low-voltage EEG records are characterized by all the following except] They are common in children They are seen in 5% of adolescents They are seen in 12% of adults They are dominated by beta range activity None . 12. [A 2-month-old term infant who had a normal doctor’s visit last week was seen by herparents to have an episode of arm stiffening lasting 2–5 seconds. What does her EEG (filter: 1–70 Hz; sensitivity: 10 μV/mm; solid vertical lines are 1 second apart) show? (fig)] Seizure discharge Normal sleep Patting artifact Electrode artifact None Comment . 13. [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 . 14. [A 45-year-old man is referred to the electrodiagnostic laboratory for evaluation of brachial plexopathy. On examination, he is noted to have severe atrophy in the first dorsal interosseus muscle. This most likely localizes to which part of the brachial plexus?] Lateral cord Posterior cord Upper trunk Lower trunk None . 15. [A 10-year-old, developmentally normal boy has a 4-year history of seizures. Which ofthe following is true based on the EEG (filter 1–70 Hz)? (fig)] The epilepsy syndrome is typically associated with myoclonic jerks There is a high chance of the epilepsy syndrome going into remission The seizure associated with the above EEG pattern does not present with automatisms This is a normal hyperventilation (HV) response not associated with epilepsy None Comment . 16. [Ideally, where should the reference electrode be located in reference to the recording electrode in order to get the most robust waveform?] On top of Next to Far from Depends on the electrode type used None . 17. [A 35-year-old man presents with right arm weakness. On examination, he has weakness of the right elbow flexion but other muscle groups are strong. He also has sensory loss over the lateral forearm. Which of the following is the most likely cause for his clinical presentation?] C5–C6 radiculopathy Medial cord brachial plexopathy Lateral cord brachial plexopathy Musculocutaneous neuropathy None . 18. [Which of the following statements best describes the predictive value of multimodality evoked potentials (visual evoked potential [VEP], brainstem auditory evoked potentials [BAEPs], and somatosensory evoked potential [SSEP]) in multiple sclerosis (MS)?] In patients with suspected MS and an evoked potential abnormality, one-third eventually develop definite MS In patients with suspected MS and normal evoked potentials, less than 0.1% eventually develop definite MS In patients with suspected MS, VEP abnormalities are more likely to be seen in those who eventually develop definite MS In patients with suspected MS, SSEP abnormalities are more likely to be seen in those who eventually develop definite MS None . 19. [Compared to concentric EMG needles, monopolar needles have which of the following features?] Smaller motor unit potential amplitude Increased pain Increased variability of motor unit potentials Recording smaller area of muscle None . 20. [Which of the following agents is not commonly known to cause necrotizing myopathy?] Cyclosporine 3-Hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitors Amiodarone Propofol None . 21. [Which of the following is false regarding myelinated nerves?] Sodium channels and potassium channels are not evenly distributed in myelinated nerves Increased potassium conductance leads to repolarization in myelinated nerves Myelin reduces membrane capacitance and increases transmembrane resistance The junction of Schwann cells is called node of Ranvier None . 22. [A 61-year-old African American man presented with recent onset eyelid droopiness and weakness over 4 weeks. He used to lift heavy weights but recently noticed difficulty lifting small objects above his head. A few days before coming to the hospital, he noticed a mild right eye droop. Initial examination was significant for right eye ptosis, facial weakness, mild weakness of neck flexion, and proximal limb weakness. The rest of the strength examination, reflexes, and sensation were normal. Which of the following tests in the above patient is most likely to provide a quick confirmation of the diagnosis?] Creatine phosphokinase (CPK) level Routine nerve conduction study to look for neuropathy Repetitive nerve stimulation Acetylcholine receptor (AChR) antibody testing None . 23. [All of the following findings on a brainstem auditory evoked potential (BAEP) can be interpreted as normal except] Wave I is absent contralaterally Wave III has higher amplitude contralaterally Waves II, VI, and VII are often absent Wave IV is often buried within and indistinguishable from Wave V None . 24. [All of the following statements regarding sleep spindles in infants are true except] They are clearly seen by age 3 months They become synchronous by age 1 year Early on they typically occur in runs lasting seconds They are comb-shaped rather than sinusoidal None . 25. [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 .
