Welcome to your Neurophysiology Name Email 1. [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 . 2. [A 20-year-old basketball player noticed painless shoulder weakness when a heavy dumbbell fell on his neck while lifting weights. He was able to play but has noticed difficulty performing push-ups. A nerve conduction study revealed decreased median and radial sensory amplitudes. These findings best localize to] C5 root injury C6 root injury Upper trunk brachial plexopathy Spinal accessory nerve injury None . 3. [In addition to voltage-gating, what is the other main gating mechanism for neuronal ion channels?] Light-gating Temperature-gating Ligand-gating Mechanosensitivity None . 4. [Shortened Waves I–V interpeak latency (IPL) is seen in which of the following conditions?] Multiple sclerosis (MS) plaque in brainstem Brainstem glioma Cochlear hearing loss Conductive hearing loss None . 5. [A 61-year-old African American man presented with recent onset eyelid droopiness and weakness over 4 weeks. He used to lift heavy weights but recently noticed difficulty lifting small objects above his head. A few days before coming to the hospital, he noticed a mild right eye droop. Initial examination was significant for right eye ptosis, facial weakness, mild weakness of neck flexion, and proximal limb weakness. The rest of the strength examination, reflexes, and sensation were normal. What does the study obtained from the ulnar nerve shown below reveal in this patient?] Abnormal decrement consistent with myasthenia gravis (MG) Normal ulnar slow repetitive nerve stimulation Abnormal increment consistent with Lambert–Eaton myasthenic syndrome (LEMS) Normal ulnar fast repetitive stimulation None . 6. [Decreased limb temperature may cause the following electrodiagnostic changes on motor nerve conduction studies:] Increased motor amplitudes Prolonged distal latencies Slowed nerve conduction velocities All of the above None . 7. [A patient is referred to the neuromuscular clinic for evaluation of a brachial plexopathy. On examination, he was noted to have weakness in the deltoid and triceps; however, the pronator teres muscle and biceps brachii were strong. Presuming that the pathology is in the brachial plexus, these findings are best localizable to which of the following structures?] Medial cord Lateral cord Posterior cord C5–C6 roots None . 8. [A 42-year-old woman underwent right anterior temporal lobectomy 6 months ago, and has remained seizure free since the surgery on lamotrigine monotherapy. She wants to drive since she satisfies the local law of 6 months of seizure freedom to be able to drive. Her neurologic examination is normal. An EEG shows rare right temporal sharp waves. The most appropriate recommendation would be to] Continue the driving restriction and repeat another routine EEG in 6 months Remove the driving restriction if she continues to take lamotrigine as prescribed Obtain inpatient video-EEG monitoring for 3 days while on lamotrigine to see if seizures occur spontaneously Obtain inpatient video-EEG monitoring after stopping lamotrigine to see if seizures can be induced None . 9. [An appropriate montage for recording median somatosensory evoked potential (SSEP) includes all of the following channels except] CPc–EPc CPi–EPc C5S–EPc EPi–EPc None . 10. [When performing a 3-point ulnar nerve stimulation (at the wrist, below elbow, and above elbow), it is important to perform the study with the elbow flexed. Otherwise, it will result in] Artifactual increase in conduction velocity across the elbow Artifactual decrease in conduction velocity across the elbow Artifactual increase in ulnar compound muscle action potential (CMAP) amplitude Artifactual decrease in ulnar CMAP amplitude None . 11. [As infants grow, the posterior dominant rhythm (PDR) changes. All of the following regarding evolution of the PDR are true except] 1 month: No clear PDR 3 months: 3 Hz 5 months: 5 Hz 12 months: 12 Hz None . 12. [Excess variability of motor unit potentials is seen in which of the following conditions?] Amyotrophic lateral sclerosis (ALS) Chronic inflammatory demyelinating polyneuropathy (CIDP) Polymyositis Myasthenia gravis None . 13. [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 . 14. [Magnetoencephalography (MEG) is a measure of] Magnetic fields caused by tangential current dipoles Magnetic fields caused by radial current dipoles Cortical current dipoles on the convexity of gyri Summated volume currents None . 15. [What mechanism helps to define the absolute refractory period?] Inactivation of the sodium (Na)+ channels Activation of the potassium (K)+ channels Inactivation of the chloride (Cl)– channels Activation of the calcium (Ca)+ channels None . 16. [A 43-year-old male, otherwise healthy, was running a 10K marathon when he had awitnessed generalized tonic–clonic seizure. He was able to stand and walk to the carwith minimal support but was noted to be “not himself.” When he arrived to the closestemergency department (ED) 30 miles away, he was still confused. A stat EEG (filter:1–70 Hz), as shown below, was significant for bitemporal independent and bifrontalindependent spike-wave discharges, as well as periodic seizures consistent with nonconvulsive status epilepticus. Considering the clinical scenario and EEG results, which of the following is the most likely etiology for his presentation? (fig)] Herpes simplex virus (HSV) type II Autoimmune disorder Stroke Anoxic brain injury None Comment . 17. [By 3 months of age, what is the frequency of the posterior dominant rhythm (PDR)?] There is no clear PDR 2 Hz 3 Hz 5 Hz None . 18. [Indications for intraoperative monitoring (IOM) of brainstem auditory evoked potentials (BAEPs) include all of the following except] Resection of acoustic neuroma Resection of cerebellopontine angle (CPA) meningioma Resection of superior temporal gyrus glioma Microvascular decompression for trigeminal neuralgia None . 19. [Capacitors have all of the following characteristics except] They permit and restrict flow of ions through the lipid bilayer They indirectly produce neurophysiological potentials They contribute to impedance Their capacitive reactance is directly proportional to frequency None . 20. [The standard paper speed for EEG recording in the United States is] 15 mm/sec 30 mm/sec 45 mm/sec 60 mm/sec None . 21. [Small sharp spikes (SSS) are] Seen in wakefulness Most prominent in childhood Associated with some risk of epileptic seizures Predominant in the temporo-occipital region None . 22. [What is the best interpretation of the posterior activity seen on the following EEG (filter 1–70 Hz; sensitivity 15 μV/mm; solid vertical lines are 1 second apart) of a 4-year-old boy? (fig)] Posterior slow waves of youth Lambda waves Occipital spike-wave discharge Normal posterior dominant rhythm (PDR) None Comment . 23. [Which of the following criteria is required for scoring an arousal?] Presence of stable sleep for at least 30 seconds before the arousal Elevation of chin EMG signal for at least 3 seconds if arousal is scored during REM sleep Presence of leg EMG signal changes for at least 3 seconds A sudden shift in EEG frequencies lasting at least 3 seconds None . 24. [A 24-year-old administrator with hypothyroidism has noticed numbness in her hands. She frequently wakes up at night with tingling in her fingers and hands. Her primary care physician diagnosed her with carpal tunnel syndrome (CTS) and referred her for electrodiagnostic studies. Her median and ulnar motor studies were normal. Her median and ulnar antidromic sensory studies with recording from 2nd and 5th digits were normal. Which of the following is the best step to find evidence of CTS in this patient?] Perform median and ulnar mixed palmar studies Measure median and ulnar digit 4 sensory latencies Median nerve study with inching across the wrist Any of the above None . 25. [Neuronal ceroid lipofuscinosis (NCL) is characterized by] High amplitude EEG Occipital spike-wave discharges in response to 1–2 Hz photic stimulation Generalized spike-wave discharges in response to 13 Hz photic stimulation Normal visual evoked potentials None .
