New Quiz 10 Dec Welcome to your Neurophysiology Name Email 1. [Which of the following promotes sleep?] Ingesting an adenosine antagonist A lesion in the ventrolateral preoptic nucleus of the hypothalamus Low levels of orexin All of the above None . 2. [All of the following statements regarding the stimulating parameters used for transcranial electrical stimulation (TES) are true except] Fz/Cz electrode pair stimulates corticospinal tracts to the legs C3/C4 electrode pair stimulates corticospinal tracts to the arms C1/C2 electrode pair stimulates corticospinal tracts to both arms and legs Laterally placed electrode pair selectively stimulates the corticospinal tracts to both arm and leg contralateral to the anode None . 3. [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 . 4. [The needle EMG waveforms shown below may be seen in all of the following conditions except (fig)] Motor neuron disease Severe inflammatory polymyositis Severe axonal polyneuropathy Guillain–Barré syndrome (GBS) with demyelinating changes only None Comment . 5. [A 30-year-old is suspected to have brachial plexus injury after trauma. He has weakness and sensory loss in the hands. Routine nerve conduction studies revealed mildly decreased median and ulnar motor amplitudes. The resident doing the procedure is unsure if F-wave studies of the median and ulnar nerve would be helpful. What is the correct response?] Median and ulnar F-wave responses will not help with localization in this case F-wave responses should be done routinely but will not help in this case F-wave responses may help with localization in this case F-wave responses are not useful because the amplitudes were mildly decreased None . 6. [All of the following statements are true about the excitatory postsynaptic potentials (EPSPs) except] The current is carried by positive ions at the synapse The current is directed toward the intracellular medium, causing an active sink at the synapse The extracellular potential at the synapse is positive Along the cell (away from the synapse), there is a distributed passive source None . 7. [Which of the following statements is true about the alpha rhythm?] It reaches its mean adult frequency of 10 Hz around age 10 years Its frequency remains unchanged even in the elderly Its frequency has no relationship to eye closure or opening It has higher amplitude over the left hemisphere in right-handed subjects None . 8. [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 . 9. [Age-related EEG slowing in the elderly is characterized by] 4–5 Hz activity Greater predominance over the right temporal region Occurrence in trains of 7–10 theta waves lasting 1–2 seconds Disappearance with light sleep None . 10. [In a patient with weakness, a muscle biopsy was completed. Muscle tissue was stained with adenosine triphosphatase at different pH values. On these stains, the patient was noted to have fiber-type grouping and loss of the usual checkerboard pattern of type 1 and type 2 fibers. Among the following, which type of EMG finding best correlates with fiber-type grouping on muscle biopsy?] Positive sharp waves and normal motor unit potentials Motor unit potentials with large amplitude and long duration Motor unit potentials with small amplitude and short duration Fasciculation potential None . 11. [The time required for the appearance of fibrillation potentials or positive sharp waves after a nerve injury depends upon which of the following?] Distance between the site of the nerve injury and the muscle Distance between the spinal cord and muscle Extent of demyelination in the nerve Distance between the spinal cord and the site of the nerve injury None . 12. [While performing needle EMG and analyzing the motor unit potentials, all of the following factors directly affect the motor unit morphology except] Age of the patient Distance between the needle and the core of the muscle Specific muscle being studied Temperature None . 13. [All of the following statements are true about frontal arousal rhythm (FAR) except] It may be associated with cerebral dysfunction It consists of trains of delta waves It appears during sleep-to-wake transitions It is mainly seen in children None . 14. [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 . 15. [What EEG pattern is expected in neonates starting at 29 weeks of conceptional age?] Tracé discontinu Tracé alternant Burst suppression Isoelectric None . 16. [Low compound muscle action potential (CMAP) amplitudes are seen in all of the following conditions except] Adult-onset acid maltase deficiency Severe critical illness myopathy Lambert–Eaton myasthenic syndrome (LEMS) During an episode of periodic paralysis None . 17. [The generalized periodic discharges (GPDs) in Creutzfeldt–Jakob disease (CJD) are characterized by all of the following except] They tend to disappear during sleep They can be confined to the occipital region They can be unilateral They have a 95% sensitivity None . 18. [Which of the following is false regarding the neuronal membrane potential?] It is dependent on the differential ionic concentrations across the membrane It is dependent on the permeability of ions across the membrane It is calculated using the Hodgkin–Huxley Model The resting membrane potential is close to the Nernst potential for chloride (Cl) None . 19. [A normal EEG in a 3-month-old infant is expected to show] No identifiable posterior dominant rhythm (PDR) Hypnagogic hypersynchrony Sleep spindles No photic driving None . 20. [Which of the following is the neurotransmitter released for the sympathetic neurons innervating sweat glands?] Epinephrine Norepinephrine Acetylcholine Serotonin None . 21. [Which of the following features is highly suggestive of an acquired demyelinating polyneuropathy?] Prolonged distal latency Severely reduced conduction velocity Abnormal temporal dispersion Severely reduced motor or sensory amplitude None . 22. [Which of the following criteria is considered as significant to cause an “alarm” during intraoperative monitoring (IOM) of brainstem auditory evoked potential (BAEP)?] Amplitude drop of 50% or higher of a waveform measured from the peak to the following trough Amplitude drop of 50% or higher of a waveform measured from the preceding trough to the peak Increase in peak latency by 0.5 ms Increase in Waves I–V interpeak latency (IPL) by 2 ms None . 23. [All of the following statements describe the EEG features during 37–40 weeks conceptional age except] Delta brushes are only seen in quiet sleep (QS), if they are present at all Encoches frontales and monorhythmic frontal delta are prominent, particularly during transition between active sleep (AS) and QS Sporadic multifocal sharps are still normal but rare High-voltage slow (HVS) waves during QS are considered abnormal None . 24. [Amplitude of somatosensory evoked potential (SSEP) waveforms can be increased in all of the following conditions except] Nitrous oxide Benzodiazepines Etomidate Certain focal and generalized epilepsy syndromes None . 25. [Which of the following statements is true regarding hyperventilation (HV) performed during an EEG?] It may induce cerebral hypoxia Persistence of HV-induced slowing beyond 30 seconds after stopping HV is almost always abnormal HV-induced slowing is enhanced by recumbent position HV-induced slowing is enhanced by high blood glucose None .
