New Quiz 03 Jan Welcome to your Neurophysiology Name Email 1. [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 . 2. [While performing the tibial H reflex, the H wave amplitude decreases with increasing stimulus intensity because] At higher stimulus intensity, Ia afferent fibers are not activated At higher stimulus intensity, there is increased collision between antidromic motor stimulus and orthodromic H reflex potentials At higher stimulus intensity, the M response suppresses H waves D. At higher stimulus intensity, there is synergy between antidromic motor stimulus and orthodromic H reflex potentials None . 3. [Which of the following statements regarding analog-to-digital conversion is true?] Analog EEG measures the data at discrete time points Digital EEG is made up of continuous nondiscrete data The higher the sampling rate, the closer the digital signal resembles the analog signal The less number of bits an analog-to-digital converter (ADC) has, the more the digital sample resembles the analog signal None . 4. [A 45-year-old man has a few month history of weight loss and low appetite. Extensive evaluation found an enlarged supraclavicular lymph node. He underwent biopsy of the lymph node. After the biopsy, he developed pain and weakness in his left shoulder area. EMG of which of the following muscles is going to be abnormal?] Deltoid Trapezius Serratus anterior Supraspinatus and infraspinatus None . 5. [EEG reactivity to auditory or tactile stimulation in a term infant is characterized by all of the following except] Diffuse flattening Burst of generalized theta activity Burst of generalized delta activity Occipital delta activity None . 6. [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 . 7. [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 . 8. [Assume an EEG acquisition system that has a 10-bit analog-to-digital converter (ADC) with a voltage range of –2 mV to +2 mV. What will happen to the voltage resolution if the voltage range of the EEG system is reduced to the –1 mV to +1 mV range?] It will remain the same because the number of bins has not changed It will decrease by a factor of 2 It will increase by a factor of 2 It will increase by a factor of 4 None . 9. [A 45-year-old man presents with weakness for more than 20 years. On examination, he has predominantly symmetrical, proximal more than distal, weakness with diminished reflexes and intact sensation. He was previously told that he had a form of muscular dystrophy. Needle EMG revealed few positive sharp waves and fibrillation potentials along with long-duration and large-amplitude motor unit potentials with severely reduced recruitment. If a muscle biopsy is performed in this patient, it will most likely reveal] Rimmed vacuoles Perifascicular atrophy Fiber type grouping Glycogen positive vacuoles None . 10. [A 56-year-old female presented with difficulty walking. On examination, she was found to have spastic paraplegia with a mid-thoracic sensory level. The cranial nerve and upper extremity exams were normal. Which of the following sets of somatosensory evoked potential (SSEP) patterns could be expected in this patient?] Normal N22 latency, normal N22–P37 latency, normal N9–N20 latency Normal N22 latency, abnormal N22–P37 latency, abnormal N9–N20 latency Abnormal N22 latency, normal N22–P37 latency, abnormal N9–N20 latency Abnormal N22 latency, abnormal N22–P37 latency, normal N9–N20 latency None . 11. [Serial EEGs in a patient with progressively worsening encephalopathy can be characterized by all of the following except] A 6 Hz, medium voltage, reactive posterior dominant rhythm (PDR) A 9 Hz, low-voltage, reactive PDR Frontal intermittent rhythmic delta activity (FIRDA) Continuous generalized asynchronous delta activity None . 12. [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 . 13. [Which of the following does not facilitate a faster conduction velocity?] Larger nerve cross section Longer nerve length Low transmembrane capacitance High transmembrane resistance None . 14. [The blink reflex study shown below was performed in a patient with facial symptoms.Ipsilateral stimulation is shown in the left panel; contralateral stimulation is shown in the right panel; the top four traces are obtained after right-sided stimulation; the bottom four traces are obtained after left-sided stimulation. What does it suggest? (fig)] Right trigeminal neuropathy Right facial neuropathy Left trigeminal neuropathy None Comment . 15. [Which of the following is true regarding the nomenclature of EEG activity?] Sigma rhythm refers to 15–20 Hz activity Rho waves refer to positive occipital sharp transients of sleep (POSTS) Phi rhythm refers to temporal rhythmic delta activity in children Ripples refers to 50–80 Hz activity None . 16. [A 55-year-old woman presented with progressive weakness over 4 months. Initially, she noticed increasing difficulty with climbing steps and getting up from the floor. She recently noticed difficulty lifting her arms when reaching above her head or brushing her hair. She reports a mild dull ache in her muscles. She does not have any skin rash. On examination, she has moderate proximal weakness in the upper and lower limbs with preserved distal limb strength. Deep tendon reflexes and sensory examination were normal. Cranial nerve examination revealed mild facial weakness.The rest of the neurological examination is normal.The above patient underwent a routine nerve conduction study as shown below. Whatdoes it reveal? (fig )] Axonal neuropathy Demyelinating neuropathy Normal study Decreased motor amplitude, but cause is unclear None Comment . 17. [Which of the following is an absolute contraindication to proximal stimulation with nerve conduction studies?] Regular on-demand pacemaker External pacer wires Increased bleeding tendency Mechanically ventilated patient None . 18. [A 20-year-old college student presents with difficulty walking for 5 years but recently developed an increased tendency to trip and fall along with mild weakness in her hands. She also reports mild numbness in her feet. She denies any pain. Her birth and initial development were normal, but as a child she did not perform well in sports. On examination, cranial nerves are normal. Proximal limb strength is normal. She has distal weakness with bilateral foot drop and moderate finger extension and abduction weakness. She also has high-arched feet and atrophy of foot intrinsic muscles. Deep tendon reflexes are absent and there is lengthdependent sensory loss. What is the next best diagnostic step for this patient?] Nerve conduction studies Repetitive nerve stimulation Brain and spine MRI Genetic testing None . 19. [A 39-year-old male presents with a 2-week history of intermittent right index fingertwitching. What is the most likely interpretation of his EEG (filter: 1–70 Hz) shownbelow? (fig)] Psychogenic nonepileptic event Scalp-negative epileptic seizure discharge Slow alpha variant Occipital intermittent rhythmic delta activity (OIRDA) None Comment . 20. [Which of the following sleep disorders is known to predominantly manifest in the sleepstage as depicted in the 30-second epoch below? (fig)] Bruxism Sleep-related rhythmic movement disorder (head banging) Sleep terror Hypnic jerks None Comment . 21. [Which of the following EMG responses is generated from the motor unit?] Complex repetitive discharges Fibrillation potentials Myokymic discharges Myotonic discharges None . 22. [A new clinical neurophysiology fellow was assisting the technologist during a brainstem auditory evoked response procedure. He noted that there was a fairly sudden increase in all of the absolute latencies. Which of the following could the fellow have noted in addition to the above change?] Decrease in all the interpeak latencies (IPL) Increase in the amplitude of all waveforms The knob for the click intensity was inadvertently decreased The patient had fallen asleep None . 23. [Which of the following anticonvulsants decreases both slow-wave sleep and REM?] Carbamazepine Gabapentin Phenytoin Barbiturates None . 24. [All of the following statements about occipital sharp transients are true except] They can be seen in blind individuals without seizures They can disappear with eye closure They can disappear with eye opening If seen in young children, they almost always indicate intractable epilepsy None . 25. [Which of the following statements best describes the paroxysmal depolarization shifts (PDSs)?] They refer to fluctuations of postsynaptic potentials They are characterized by a depolarization–repolarization sequence lasting less than 40 ms They correlate with surface negative direct current (DC) fluctuations at the beginning of a seizure They reflect the resting activity of the normal hippocampal neurons None .
