New Quiz 10 Dec Welcome to your Neurophysiology Name Email 1. [A polysomnogram (PSG) is being scored. The technologist labeled an epoch as Stage N2 when he noticed a K-complex. During the next 2-minute period, there are no spindles or K-complexes, but the EEG background consists of low-voltage mixed-frequencies. At the end of the 2 minutes, there is an arousal; after the arousal, the background continues to show low-voltage mixed-frequencies.] 2 3 4 5 None . 2. [Which of the following is the best interpretation of this EEG in a neonate who is 38-week conceptional age? (fig)] Dysmature EEG Normal for gestational age Severe encephalopathy Increased risk for epileptic seizures None Comment . 3. [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 . 4. [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 . 5. [All of the following physiological changes occur in NREM sleep except] Secretion of thyroid stimulating hormone (TSH) Decreased blood pressure Decreased cardiac output Decreased heart rate None . 6. [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 . 7. [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 . 8. [What percentage of the input amplitude will pass at the cutoff frequency of a filter?] 0% 50% 70% 100% None . 9. [Which of the following is false regarding frontal intermittent rhythmic delta activity (FIRDA)?] It can be a normal finding after hyperventilation (HV) It can be a normal finding in the elderly It tends to have an interval between consecutive waveforms It tends to have a monomorphic morphology None . 10. [A 27” computer screen has a resolution of 1920 (horizontal) by 1080 (vertical) pixels with vertical borders of 250 pixels each. An EEG sampled at 1000 Hz is displayed at 15 seconds per page. What is the maximum frequency of the EEG activity that can be displayed based on the specified parameters?] 47 Hz 95 Hz 500 Hz 1000 Hz None . 11. [Absence seizures are characterized by all of the following features except] Rhythmic eye blinking Repetitive oral automatisms Loss of postural control Impairment of working memory None . 12. [Which of the following statements regarding action potential transmission along a myelinated nerve is true?] It is termed salvatory conduction If the internodal distance is too great, transmission could fail Transmission may fail if the internodal myelin thickness is increased It relies on opening of both sodium and potassium channels in the intermodal Membrane None . 13. [A 55-year-old man presents with severe fatigue and weakness for over 4 months and recent onset of dry mouth. He does not report any obvious diplopia. He is a chronic smoker. On examination, he has mild facial weakness, ptosis, mild to moderate weakness of neck flexion, and proximal limb weakness. Deep tendon reflexes are absent. Sensory examination is normal. The most likely neuroanatomical localization for his symptoms is] Peripheral nerve Neuromuscular junction (NMJ) Muscle Anterior horn cells None . 14. [Which of the following studies can help differentiate a cervical root avulsion from brachial plexopathy?] Motor nerve conduction studies in upper limb F-wave reflex testing in upper limb Somatosensory evoked potential (SSEP) testing from the upper limb Sensory nerve conduction study None . 15. [Decreasing the time constant will cause the waveform to appear] Sharper Smoother Phase shifted to the right Larger None . 16. [The activity seen at Point 2 can be altered by all of the following factors except(fig)] Opening eyes Increasing age Follicular phase of the menstrual cycle Ambient light None Comment . 17. [What is the chance that the first routine EEG will be nondiagnostic for epilepsy?] 10% 20% 50% 90% None . 18. [Ctenoids are] Rhythmic sinusoidal waveforms Surface positive waveforms Frontal in distribution with shifting predominance Seen in 58% of healthy adults None . 19. [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 . 20. [A 51-year-old male undergoes brainstem auditory evoked potential (BAEP) monitoring during resection of a right vestibular schwannoma. All of the following changes suggest an adverse postoperative outcome except] Loss of Waves I, III, and V suggests damage to the internal auditory artery Ninety percent attenuation of Wave I with intact Waves III and V during bone drilling suggests permanent damage to the cochlea Delay of Waves III and V but not Wave I suggests 8th nerve damage Loss of Waves III and V with preservation of Wave I suggests damage to the lower pons None . 21. [While performing a sural sensory nerve conduction study, the examiner notices that the leg feels cold to the touch. Which of the following is the most appropriate step before continuing with the study?] Measure the temperature and proceed with nerve conduction study testing Compare the response to motor studies in the lower limb Measure the temperature and warm the lower limb Measure the temperature and use formulas to correct latency and velocity None . 22. [From term to 3 months of age, drowsiness typically consists of all of the following characteristics except] Eyes may be open Decrease in movement Decrease in muscle tone Temporal slowing None . 23. [The commonly evaluated interpeak latencies (IPLs) of brainstem auditory evoked potentials (BAEPs) include all of the following except] I – III III–V V–VII I–V None . 24. [The leakage current from a medical instrument should be] Less than 1 μA Less than 10 μA Less than 100 μA Less than 1 mA None . 25. [A blink study was performed in a 58-year-old man with facial symptoms. The results are summarized in the following table. What does this study suggest? (fig)] Right trigeminal neuropathy Left trigeminal neuropathy Right facial neuropathy Left facial neuropathy None Comment .
