NMJ BinAmir 2

A 25-year-old male with a history of brachial plexopathy presents to the Neuromuscular lab for electromyography. The video below is a recording of his EMG of the triceps muscle when activated. The abnormal findings shown represent which of the following?

Fibrillations and positive waves are first seen on electromyography (EMG) at which point following a nerve transection?

A 30-year-old female with a history of Charcot-Marie Tooth disease, diagnosed with genetic testing that showed a duplication of the peripheral myelin protein (PMP22) gene, returns to the clinic for a routine follow-up. She expresses interest in starting a family and wants to know what is the risk of her children having the same issues. Which of the following is the most appropriate response?

Submaximal muscle stimulation is used during which of the following aspects of the nerve conduction study?

A 65-year-old man comes to the clinic with a one-year history of difficulty walking. More recently, he has also noticed a tendency to drop things. On examination, he was found to have weakness in his bilateral lower limbs, predominantly in his quadriceps muscles, along with finger flexion weakness that is worse on the left side. His sensory examination was normal. Which of the following is the most likely diagnosis?

A 57-year-old woman with a past medical history of hypothyroidism was referred to the EMG lab with a one-year history of right-hand numbness. Based on the EMG data shown below, what is the most appropriate next step in medical management?

A 47-year-old former football player with a history of diabetes and hypertension presents to the EMG lab with left upper extremity weakness and pain. Motor and sensory nerve conduction studies were normal. An EMG was performed and shown below. What is the most likely diagnosis?

A 19-year-old male was admitted to the hospital with a 2 weeks history of progressive lower extremity weakness. CSF studies showed an elevated CSF protein and normal WBC count. MRI of the lumbar spine showed contrast enhancement of the cauda equina. His nerve conduction study (NCS) is shown below. What is the most appropriate next step in medical management?

A 24-year-old with a history of a motor vehicle accident and a broken leg is referred to the EMG lab with a left leg foot drop. Based on the EMG table outlined below, where is the most likely site of neuronal injury?

Eteplirsen is an effective treatment in patients with Duchenne muscular dystrophy (DMD) that have which of the following dystrophin mutations?

Which of the following is classically seen on electromyography in a patient with an acute neuronal injury?

Which of the following is the first abnormal EMG/NCS finding seen in a patient with carpal tunnel syndrome?

Which is the following potentials on EMG has an irregular firing pattern?

A 5-year-old male presents because of muscle stiffness. His symptoms are worse during the colder winter months and with gym class at school. He sometimes becomes so stiff he can hardly breathe. Examination shows no muscle atrophy or hypertrophy but myotonia is present. Upon further questioning, you learn he has an older brother with similar symptoms. What is the likely dysfunctional gene in this patient?

A 66-year-old right-handed male presents to the EMG/NCS lab with right upper extremity pain, numbness, and weakness. Based on the data collected, what is the most likely diagnosis?

Based on the findings on the muscle biopsy (trichrome stain) shown below, which of the following is most likely seen on examination of this patient?

Which of the following medications, when taken alongside statin therapy, increases the risk of statin-induced myopathy?

This muscle biopsy is most consistent with which myopathic disease?

Which of the following is classically seen on electromyography in a patient with a chronic neuronal injury?

A 49-year-old male presents with numbness and tingling of the right hand. A median nerve conduction study is completed and shown below. Which of the following is the correct interpretation of its results?

A 42-year-old man with a 6-month history of progressive muscle weakness has a nerve biopsy performed. Based on the toluidine blue (left) and trichrome (right) stain slides shown, which of the following is the most likely diagnosis?

A 49-year-old female has had a 6-month history of difficulty swallowing and weight loss. On examination, she has generalized muscle loss. On strength examination, she has 3/5 proximally and 4/5 distally in the bilateral upper extremities. There are normal tongue movements and a normal jaw jerk reflex. Deep tendon reflexes in the bilateral upper extremities are normal and sensation is intact. An EMG is performed and outlined below. What is the most likely diagnosis?

The following EMG video was captured from the left tibialis anterior muscle at rest. Which of the following is appreciated during this recording?

A 57-year-old male with recently diagnosed small cell lung cancer (SCLC) is presenting to the electromyography lab with a one-month history of muscle cramps and muscle pain. Percussive myotonia is appreciated on examination. Electromyography showed myokymic discharges. Autoantibodies against which of the following channels are likely present in this case?

Charcot Marie Tooth disease (CMT) is associated with which of the following pathologic findings?

A 65-year-old male is referred to the EMG lab with a recent right leg injury and associated weakness. Based on the EMG shown below, where is the most likely site of neuronal injury?

A four-year-old boy with no significant past medical history is brought to your clinic due to difficulty walking. His mother states that he began walking at 12 months of age, but in the past few months, he seems to be more fatigued and weak when walking. On physical exam, his calves seem to be abnormally large. This disorder is caused by what mutation?

A 57-year-old navy veteran with a history of PTSD presents with a 2-year history of progressive, asymmetric weakness. The patient states that symptoms started in his left arm. Six months later he started to have falls due to tripping over his right foot. His neurological examination shows weakness of the intrinsic hand muscles of the left arm, ⅖ strength on dorsiflexion of the right ankle, and no sensory disturbances. Reflexes were mute in the left upper extremity and there were several beats of clonus at the right ankle. Fasciculations were present in the tongue, right gastrocnemius, and left tibialis anterior. An EMG is recommended for diagnosis. Which of the following EMG findings are most likely seen in this patient?

Which of the following statements is correct regarding F-waves?

Patients with Charcot-Marie Tooth disease that have the CMT1A phenotype will have which of the following genetic mutations?

Which is the following findings on EMG is suggestive of a chronic neurogenic lesion?

A 57-year-old male with recently diagnosed small cell lung cancer (SCLC) is presenting to the electromyography lab with a one-month history of muscle cramps and muscle pain. Percussive myotonia is appreciated on examination. Electromyography showed myokymic discharges. Autoantibodies against which of the following channels are likely present in this case?

A 45-year-old man with a past medical history of cardiac arrhythmia requiring pacemaker placement is referred to the clinic with a twenty-five-year history of slowly-progressive bilateral ptosis and diplopia. On examination, he has bilateral ptosis, decreased range of motion of the extraocular muscles, and mild proximal weakness in his upper and lower extremities. Which of the following is the most likely diagnosis?

This muscle biopsy is most consistent with which myopathic disease?

A 48-year-old male with a history of a gunshot wound to the shoulder presents with left arm pain and weakness. The video below is a recording of his EMG of the brachioradialis muscle with activation. Based on the EMG findings, how long ago did the patient’s gunshot injury most likely occur?

A 55-year-old male with a recent history of losing 50 pounds after gastric bypass is referred to the EMG lab with difficulty walking. He has noticed that his left foot drags occasionally causing him to trip and that he has numbness on the top of his left foot up to the middle of his shin. Which of the following statements is the most accurate based on the EMG findings shown below?

A 35-year-old male with balance issues is referred for an EMG/NCS. Distal sensory loss of the feet, high-arched feet, and diffuse hyporeflexia are appreciated on the exam. His nerve conduction studies are shown below. Based on the available information what is the most likely diagnosis?

A 47-year-old female presents to the clinic with the chief complaint of slowly progressive proximal muscle weakness. Electromyography showed short duration, low amplitude motor unit action potentials. A muscle biopsy was performed and shown below. A diagnosis is made and the patient is started on a therapeutic agent. What is the most likely medication initiated?

With of the following CMT types present with an axonal pre-dominant peripheral neuropathy?

Cool limbs during a nerve conduction study will have which of the following effects on the data recorded?

A 6-month-old full-term female is referred to the clinic with persistent right shoulder and elbow weakness since birth. Which of the following is the most likely pathologic lesion?

A 27-year-old female with a history of cataracts and an unknown family history was referred to the neurology clinic for excessive daytime sleepiness. On examination facial weakness and grip myotonia were appreciated. Genetic testing revealed a mutation in the DMPK gene. Based on her diagnosis, which of the following tests should be performed annually?

A 49-year-old male with a chronic history of myalgias was referred to the EMG lab with progressive muscle weakness. Based on the EMG table shown below what is the most likely diagnosis?

A 52-year-old woman is brought to the emergency room in respiratory distress. She is accompanied by her husband who stated that they were eating at a high-end sushi restaurant when his wife started to complain of perioral numbness and tingling. Two hours later she started to complain of generalized weakness and trouble breathing. Accidental poisoning is suspected. Based on the available information, what is the mechanism of action of the poison ingested?

What is the earliest NCS/EMG abnormality found in AIDP?

A 45-year-old male with a history of C6 radiculopathy presents to the neuromuscular lab for electromyography. The video below depicts spontaneous findings while evaluating the biceps brachii muscle during electromyography. What is the abnormal pattern shown?

Which of the following is correct regarding the H-reflex?

Congenital muscular dystrophies are most often associated with which of the following pathophysiologies?

Which of the following nerve conduction study abnormalities is least likely to be seen during the initial phase of acute inflammatory demyelinating polyneuropathy (AIDP)?

Which of the following is the resting membrane potential of a neuron?

A 47-year-old female presents to the clinic with the chief complaint of slowly progressive proximal muscle weakness. Electromyography showed short duration, low amplitude motor unit action potentials. A muscle biopsy was performed and shown below. A diagnosis is made and the patient is started on a therapeutic agent. What is the most likely medication initiated?

A 21-year-old female was admitted to the hospital with a 3 weeks history of progressive lower extremity weakness. An EMG was performed and the results were shown below. Based on the clinical history, examination, and diagnostic testing, the patient was started on plasma exchange (PLEX) therapy. After completing her PLEX therapy there was a marked improvement in her weakness. Although not shown below, which of the following additional NCS/EMG results were also likely present on the day of recording?

A 19-year-old male with a history of a motorcycle accident 6 weeks ago with several bone fractures of the arms and legs was referred to the EMG lab with right arm numbness since the accident. Where is the most likely site of this patient’s neuronal injury?

A 38-year-old male with a history of sarcoidosis and a one-week history of subacute onset of progressive weakness was admitted to the hospital with difficulty ambulating. On examination, you appreciate bilateral lower extremity weakness and hyporeflexia. Based on the clinical history and EMG findings shown below what is the most likely diagnosis?

The patient is a 79-year-old male with a past medical history of myocardial infarction who was referred for a nerve conduction study (NCS) to evaluate his slowly progressive lower extremity numbness and weakness. Which of the following pathologies is most commonly associated with the findings shown in the (NCS) shown below?

This muscle biopsy is most consistent with which myopathic disease? 

Which of the following is the antibody associated with dermatomyositis that is known to confer the highest risk of cancer?

A patient with Duchenne muscular dystrophy (DMD) most likely has which of the following findings on electromyography (EMG)?

Mild cases of carpal tunnel syndrome will have which of the following findings on electromyography (EMG)?

A 37-year-old female with a PMH of Sjogren’s, and a recent motor vehicle accident (MVA) is referred to the EMG Lab for evaluation of right arm pain/weakness. The patient endorses right head pain which radiates down her neck into the right shoulder and wrist. Examination shows 5/5 strength in the upper extremities except for 4+/5 deltoid and 4+/5 biceps strength in the right upper extremity. Sensation to light touch was intact throughout. Sensory nerve conduction studies of the right upper extremity were normal. Based on the patient’s EMG results outlined below what is the most likely diagnosis?

Which of the following is seen on muscle biopsy in patients with steroid myopathy?

Which of the following is most likely to show temporal dispersion of the action potential?

A 50-year-old female with a history of small cell lung cancer treated with chemotherapy and radiation presents to the neuromuscular lab with progressive right upper extremity weakness. The video below is a recording of her EMG of the biceps brachii at rest. What is the abnormal pattern shown?

Which of the following is the most likely diagnosis based on the EMG provided below?

You are evaluating a 1-year-old who has had delayed motor development and diffuse weakness since birth and presents now to the hospital for a first-time seizure. The physical exam is notable for 3/5 deltoid abduction, 4-/5 hip abduction, 4-/5 hip flexion, and 4-/5 hip extension. He is unable to walk but is meeting cognitive milestones. An MRI brain is done and shows diffuse scattered T2 FLAIR white matter hyperintensities.

If genetic testing is performed, a mutation in which of the following genes would be most expected?

Congenital muscular dystrophies are most often associated with which of the following pathophysiologies?

Which of the following is seen on muscle biopsy in patients with steroid myopathy?

A neurology consult was placed for a 35-year-old male who was admitted overnight after a motor vehicle accident that occurred earlier in the day. He experienced multiple bone fractures, including the right humerus at the spiral groove. The primary team is concerned about a radial nerve injury. Which of the following findings are most likely to be found on EMG/NCS?

A 62-year-old man comes to the clinic complaining of a 2-month history of difficulties getting up from a chair, climbing steps at work, and lifting objects above his head. His primary care physician also noticed a rash on sun-exposed areas of the man’s body. EMG of proximal muscles on this patient with likely reveal which is the following?

A patient with right leg weakness presents to the neuromuscular lab for electromyography. The image below depicts a spontaneous finding while evaluating the right tibialis anterior muscle. This finding is most consistent with which of the following?

Which of the following medications is effective in the treatment of myotonia?

Which of the following is the most classic finding of early inclusion body myositis?

A 20-year-old male presents to your clinic for weakness. He is the star baseball player at the local university, but during the season his batting average has been dropping, and he finds he is having trouble standing on his toes, performing overhead shoulder presses, and more recently ascending steps. You give him a script for some blood testing and an EMG/NCS and schedule a follow-up in 2 weeks.

Unfortunately, shortly after returning home he had a fall down a flight of stairs and sustained a compound radius fracture. He was taken to the emergency room where an open reduction and fixation (ORIF) was performed. Shortly after the surgery, he developed tachycardia, tachypnea, and masseter muscle contractions, which then progressed to fever and rigidity.

Which of the following test results is most likely to be seen in this patient?

A 71-year-old male with a history of mild ankle weakness and balance issues for the last 6 years is referred to the lab for a nerve conduction study (NCS). While performing the testing the patient states that a few of his siblings, as well as his father, had similar issues. Examination showed high arches and hammertoes. Based on the clinical history and NCS, what is the most likely diagnosis?

A 45-year-old female who is a professional pianist was referred to the EMG lab for right-hand numbness and tingling. Based on the EMG data outlined below where is this patient’s pathological lesion?

This muscle biopsy is most consistent with which myopathic disease?

EMG abnormalities in which of the following muscles can not localize to the brachial plexus?

The F wave response is an:

This pathology slide is most consistent with which of the following diseases?

A 66-year-old female comes to the EMG lab with the chief complaint of muscle cramps in the right lower extremity. She started having symptoms after treatment with a cholesterol-lowering medication but despite discontinuing the medication her symptoms persisted. Reflexes are 2+ in upper and lower extremities, except 1+ in the right Achilles. Nerve conduction studies of both lower extremities were normal. An EMG was performed and shown below. What is the most likely diagnosis?

A 57-year-old male with a past medical history of progressive weakness affecting all extremities and dysphagia for the past 6 months is admitted to the hospital. An EMG was completed as part of his workup and is shown below. Based on the available information what is the most likely diagnosis?

A 63-year-old woman with a history of right-sided breast cancer status post-mastectomy, chemotherapy, and radiation presents to your clinic with a 2 months history of right arm pain and paresthesias. Which of the following findings on EMG/NCS would most likely suggest a radiation-induced plexopathy over a recurrent neoplastic plexopathy?

This EMG video of the biceps femoris muscle at rest could be associated with which of the following pathologies?

The following EMG video was captured from the right tibialis anterior muscle at rest. Which of the following is appreciated during this recording?

A 50-year-old male has noted winging of his right scapular and pain for the past four months following a hyperextension injury. Based on the EMG data outlined below where is this patient’s pathological lesion?