New Quiz 10 Dec Welcome to your Neurophysiology Name Email 1. [A 25-year-old male with intractable epilepsy had seizure onset at age 15 years withgrand mal seizures. He also has a history of bipolar disorder and prior suicide attempt.All of the following findings are seen in his EEG (filter: 1–70 Hz) except (fig)] Generalized spike-wave discharges Generalized theta slowing Generalized polymorphic delta slowing Posterior background slowing None Comment . 2. [All of the following statements regarding EEG activity during sleep are true except] K-complex represents a depolarizing–hyperpolarizing sequence within an oscillatory cycle Spindles are generated by the dorsal nucleus of the thalamus Gamma-aminobutyric acid (GABA)ergic neurons underlie generation of sleep spindles Sleep spindles serve to block incoming stimuli to the cortex None . 3. [An 80-year-old man has difficulty walking from an unclear neurodegenerative disease.Needle EMG recording from a distal upper limb muscle is shown below. What is theapproximate firing frequency of the grouped motor unit activity below? (fig)] 9–12 Hz 4–5 Hz 1–2 Hz 16–18 Hz None Comment . 4. [All of the following statements regarding the EEG during conceptional age 32–34 weeks are true except] The interburst intervals during QS are typically less than 10 seconds Delta brushes are seen in active sleep (AS) and wakefulness over the centro-occipital regions Temporal theta evolves into alpha frequencies Background reactivity is absent None . 5. [All of the following statements are true about brainstem auditory evoked potentials (BAEPs) except] Wave I is seen only ipsilateral to the stimulated ear Wave III has lower amplitude contralateral to the stimulated ear Wave V is generated by structures located in the lower pons Waveforms are not significantly affected by most anesthetic agents None . 6. [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 . 7. [Which of the following patterns of electrodiagnostic abnormalities is likely in a patient with subacute nerve injury?] None . 8. [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 . 9. [Significant decrement may be seen on slow repetitive stimulation in which of the following conditions?] Lambert–Eaton myasthenic syndrome (LEMS) Myasthenia gravis Botulism All of the above None . 10. [Bifid sensory nerve action potentials in children are seen because of which of the following?] Poor technique Normal variant in children because of different degrees of myelination Axonal neuropathy Demyelinating neuropathy None . 11. [Which of the following statements is true about electrical shock?] A current of 100 mA or higher applied to the skin can cause ventricular fibrillation in a patient Using 3-hole electrical receptacles eliminates risk of electrical shock to the patient Human susceptibility to electrical shock is maximal at 70 Hz Indwelling catheters do not pose additional risk for electrical shock None . 12. [A 10-year-old boy was undergoing hyperventilation (HV) during EEG recording asshown below (filter: 1–70 Hz; sensitivity: 15 μV/mm; solid vertical lines are 1 secondapart). What does it show? (fig )] Seizure Frontal intermittent rhythmic delta activity (FIRDA) Normal response Irregular generalized spike-wave discharges None Comment . 13. [In evaluating a spinal cord lesion with somatosensory evoked potential (SSEP)] SSEP has no prognostic value regarding sensory recovery compared to clinical examination after acute spinal cord injury SSEP has no value in evaluation of cervical intramedullary tumors since SSEP abnormalities are always accompanied by clinical symptoms Prolonged central conduction time (CCT) with normal potentials suggests extramedullary tumor rather than an intramedullary tumor Cervical syrinx is most commonly associated with absence of N13, P14, and N20 potentials None . 14. [A 9-year-old girl with staring spells had an EEG that showed high-amplitude, 3–4 Hz sharply contoured delta activity. In which of the following scenarios would this finding always be pathological?] Hyperventilation (HV) Drowsiness Photic stimulation Slow wave sleep None . 15. [All of the following statements regarding the evolution of photic driving response are true except] The initial photic driving appears at 1 year of age Best driving response in preschool children occurs at lower flash frequencies (less than 8 Hz) Best driving response in older children occurs at medium flash frequencies (6–12 Hz) Best driving response in adolescents occurs at wider flash frequencies (6–20 Hz) None . 16. [All of the following statements about shut-eye waves are true except] They have an occipital distribution They are triggered by eye blinking They are typically seen in adolescents over the age of 12 years They tend to be high-amplitude, broad, diphasic waveforms None . 17. [All of the following statements regarding the tibial somatosensory evoked potential (SSEP) are true except] N7 potential reflects the afferent volley in the cauda equina N22 potential reflects activity in the lumbar cord P31 potential reflects activity in the brainstem P37 potential reflects activity in the parietal cortex None . 18. [A 45-year-old man presents with a 5-year history of slowly progressive speech andswallowing difficulty. He recently noticed some limb weakness and this prompted areferral to a neuromuscular physician. On examination, he has dysarthria, flaccid limbweakness, decreased reflexes, and occasional fasciculations. Findings on sensory nerveconduction studies are shown below. Which of the following conditions does the patient most likely have? (fig)] Sporadic amyotrophic lateral sclerosis (ALS) Primary lateral sclerosis (PLS) Spinobulbar muscular atrophy Spinal muscular atrophy (SMA) None Comment . 19. [In terms of neuropsychiatric effects, repetitive transcranial magnetic stimulation (rTMS)] Does not alter mood in nondepressed subjects Worsens mood in depressed patients Improves mania Improves or worsens neuropsychological function None . 20. [How often is REM sleep thought to occur in adults?] Every 30 minutes Every 60 minutes Every 90 minutes Every 120 minutes None . 21. [A 25-year-old male had an EEG (filter: 1–70 Hz; sensitivity: 5 μV/mm; the solid verticallines are 1 second apart) as part of the workup for syncope. During the recording asshown below, the technologist noted focal rhythmic activity in the left central region,which went away when the patient wiped his nose with his right hand. Which of thefollowing statements is true regarding this activity? (fig)] Its frequency is in the theta range Nose wiping with the right hand has no relation to the activity It represents the resting rhythm of the Rolandic cortex It represents a brief ictal discharge that may have originated in the temporal region None Comment . 22. [A neonate of 36 weeks conceptional age (CA) was found to have respiratory arrestshortly after birth. Shortly thereafter, the patient was extubated and clinically stable.An EEG was done for suspected seizures as shown below (filter: 1–70 Hz; sensitivity: 15μV/mm; the solid vertical lines are 1 second apart). The patient was noted to be restingquietly at time of recording. What is the best interpretation of the findings seen?(fig)] Epileptiform activity Artifact Encephalopathy Normal finding None Comment . 23. [In the figure below, what is the firing rate of the most prominent motor unit potential? (fig)] 20 Hz 5 Hz 50 Hz 15 Hz None Comment . 24. [All of the following statements regarding the generators of median somatosensory evoked potential (SSEP) waveforms are true except] N9 is a near-field potential reflecting the afferent volley in the brachial plexus N13 is a far-field potential reflecting activity in the dorsal columns of cervical cord P14 is a far-field potential reflecting activity in the caudal medial lemniscus in the CPi–EPc derivation N20 is a near-field potential reflecting activity in the parietal cortex None . 25. [An 8-year-old boy was undergoing lumbar spine surgery for an injury sustained after a fall. Which of the following statements is true regarding the use of EMG monitoring during the placement of the pedicle screws?] A loss of EMG activity correlates with the screw broaching the vertebral cortex If more than 30 V of stimulation cannot elicit EMG, then the screws have not broached the vertebral cortex Properly placed screws within the bone will have high impedance resulting in EMG activity EMG activity can normally be elicited with less than 20 V None .
