New Quiz 10 Dec Welcome to your Neurophysiology Name Email 1. [Which antidromic median sensory configuration would result in an initial positivity?] Recording from digit 3 with the reference electrode over digit 5 Recording from digit 3 with the reference electrode over digit 3 Recording from digit 5 with the reference electrode over digit 3 Any of the above configurations would result in an initial positivity if the stimulating anode and cathode were reversed with stimulation at the wrist None . 2. [The following quantitative EEG (qEEG) fast Fourier transform (FFT) spectrograms show0–20 Hz activity from the left and right hemispheres (top 2 panels), amplitude-integrated EEG, and peak envelope; the color bar indicates the power, black being the lowest and white being the highest. Note that the red vertical lines represent 2-minute intervals; for illustrative purposes, 3 different time periods are spliced together. What is the best explanation of what occurred after the blue vertical line indicator? (fig)] The patient had a seizure with postictal slowing afterwards The patient had diffuse cerebral ischemia due to cardiac arrest with subsequent infarction The patient was disconnected from continuous video-EEG (cEEG) monitoring temporarily to be taken to CT scan without any significant interim clinical event The patient transitioned from a wakeful state to deeper stages of normal sleep None Comment . 3. [All of the following statements about Rolandic spikes are true except] They can be seen in healthy siblings of patients with benign Rolandic epilepsy (BRE) They typically resolve by age 16 years They exhibit horizontal dipole with central negativity and temporal positivity They can occur in trains during sleep None . 4. [A 55-year-old man noticed right leg weakness for a few weeks. On examination, he hasweakness of his right toe extension and sensory loss on the dorsum of the foot. A peroneal motor study with recording from tibialis anterior is shown below. Which of the following is most likely to be the underlying etiology? (fig)] Recent significant weight loss Traumatic ankle fracture Recent lumbosacral spine injury Recent fracture of tibia None Comment . 5. [A 48-year-old male with a history of seizures has an EEG as shown below. During therecording, the patient is noted to be drowsy by the technologist. What is the best interpretation of his EEG (filter: 1–70 Hz)? (fig)] Psychomotor seizures Mild encephalopathy Temporal lobe seizures No known disease process None Comment . 6. [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 . 7. [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 . 8. [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 . 9. [What is the gold standard for measuring airflow?] Pneumotachograph Thermistor Nasal pressure transducer Respiratory inductance plethysmograph None . 10. [A 50-year-old man developed double vision and difficulty walking over 3 days. Initial examination in the emergency department revealed decreased eye movements. Strength in limbs was relatively preserved, all reflexes were absent, and he was noted to be ataxic. What would the motor nerve conduction study in this patient likely show?] Normal motor amplitude and conduction velocity Conduction block Severely reduced motor amplitudes Normal motor amplitudes but severely reduced conduction velocity None . 11. [A 60-year-old man developed Bell’s palsy. He was treated with oral corticosteroids andantiviral agents but continued to have facial weakness. He was seen by an ear–nose–throat physician for possible surgical intervention for the facial weakness, and facial electrodiagnostic studies were requested. EMG from the frontalis muscle during maximum activation is shown below. What does it reveal? (fig)] Early recruitment Severely reduced recruitment Normal recruitment for frontalis muscle Synkinesis None Comment . 12. [The following waveforms show ulnar slow repetitive stimulation in a patient withsuspected myasthenia gravis at baseline and after 1 minute of exercise. What is theinterpretation? (fig)] Repair of decrement Both repair and facilitation Only facilitation This is a normal study None Comment . 13. [Which of the following waveforms encountered in the median somatosensory evoked potential (SSEP) is a far-field potential?] N9 N13 P14 N20 None . 14. [Repetitive nerve stimulation was performed in a man with proximal limb weakness asshown below. Which of the following statements is correct? (fig)] This is slow repetitive stimulation which reveals significant decrement This is fast repetitive stimulation which reveals significant decrement This is slow repetitive stimulation which reveals significant increment This is fast repetitive stimulation which reveals significant increment None Comment . 15. [A 50-year-old presents with a 25-year history of bilateral ptosis and double vision. In addition, she has a history of cardiac arrhythmia for which she eventually needed a cardiac pacemaker. On examination, she has bilateral ptosis, limitation of the extraocular movement, and mild proximal weakness. Which of the following findings is likely to be seen on electrodiagnostic testing?] Greater than 10% decrement on slow repetitive stimulation Greater than 100% on increment on fast repetitive stimulation Short duration motor unit potentials on needle EMG Long duration motor unit potentials on needle EMG None . 16. [All of the following statements regarding the maintenance of wakefulness test (MWT) are true except] It assesses the ability of a subject to remain awake A preceding full-night polysomnogram (PSG) is required Four trials lasting 40 minutes each are performed at 2-hour intervals The room should be lit with low light None . 17. [A 55-year-old man is referred to the electrodiagnostic lab to find a neuromuscular cause for increasing shortness of breath. His routine nerve conduction study is normal. Needle EMG of the proximal and distal muscles, as well as the thoracic paraspinal muscles, is also normal. The patient requests you to perform a diaphragmatic EMG even though you are not trained in diaphragmatic EMG. The patient really would like to have the study performed right away as he does not want to come back on another day for the study. The best action is] Perform the study since this is convenient for the patient Request a colleague who is experienced in diaphragmatic EMG to perform the study Obtain an ultrasound machine to guide you with needle EMG even though you have not used the ultrasound machine before Perform phrenic motor studies and explain to the patient that this will provide as much information as needle EMG of the diaphragm muscle None . 18. [Which of the following statements best describes the utility of somatosensory evoked potentials (SSEPs) in the evaluation of peripheral nervous system disorders?] Intact N9 and absence of subsequent potentials suggest brachial plexus trunk lesion Absent popliteal fossa potential but intact lumbar potential (LP) is characteristically seen in Guillain–Barré syndrome SSEPs obtained by dermatomal stimulation are useful in the evaluation of radiculopathy SSEPs are always normal in Friedreich’s ataxia despite abnormal nerve conduction studies None . 19. [Which of the following disorders is considered to be present or worsen during REM sleep?] Sleepwalking Epileptic seizures Obstructive sleep apnea Periodic limb movement disorder None . 20. [A 50-year-old male had intractable back pain and the diagnostic workup was significant for L3–L5 disc bulges. He underwent surgical decompression with intraoperative monitoring (IOM). All the baseline potentials were within normal limits. During the procedure, the N34 and P37/38 potentials disappeared with preservation of the N22 potential. What is the most appropriate localization?] Peripheral nerve Cauda equina Lumbar anterior horn cells Cortex None . 21. [A 30-second epoch of polysomnogram (PSG) in a patient with a history of excessive daytime sleepiness is shown below. The most significant finding noted in the figure can be seen in all of the following conditions except (fig)] Postarousal Stroke Acetazolamide treatment High altitude None Comment . 22. [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 . 23. [A 64-year-old man with a history of hypertension, seizures, dementia, and resection of a brain tumor 35 years ago was admitted for bizarre behavior noted at the nursing home. His wife stated that his last seizure, described as a staring spell, was 7 years ago. His MRI brain showed a left posterior–temporal lobe meningioma along with evidence of a prior right temporal lobe resection. Twelve hours into the monitoring session (filter 1–70 Hz), a dramatic decrease in EEG amplitude was seen as shown below. What is the most likely cause of the change? (fig)] Cessation of a generalized seizure discharge Suctioning the patient Cerebral hypoperfusion Starting propofol infusion without a bolus None Comment . 24. [Many types of artifacts exist in the ICU setting of physiological and nonphysiological origin. Which of the following is NOT a typical description of the EEG pattern associated with the listed artifact?] Extracorporeal membrane oxygenation (ECMO) is associated with a 1–3 Hz square wave artifact Ventilators can cause artifact that varies widely in morphology, amplitude, and polarity, but can be associated with a faster frequency artifact due to charged water molecules in the ventilator tubing that can be improved by suctioning Mechanical chest percussion device can cause rhythmic 5–6 Hz activity in 1 electrode Cardiopulmonary resuscitation (CPR) can lead to high-amplitude, rhythmic 1–2 Hz activity that is due to movement artifact and is not cerebral activity None . 25. [Which of the following is true regarding the relative intracellular and extracellular potential difference across the membrane?] Intracellular polarity is negative during maximal sodium influx Extracellular polarity is positive during hyperpolarization Extracellular polarity is negative during the resting state The intracellular and extracellular potentials are isoelectric during the resting state None .
