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Question 1 of 10
1. Question
A 17-year-old man presents to the Emergency Department with the complaint of generalized weakness several hours after completing a 10 kilometer race. He prepared for his run by “carb-loading” the night before. He states his father also experiences similar episodes after heavy exercise. Which of the following tests will most likely determine the diagnosis?
Correct
Periodic paralysis is a rare neuromuscular disorder related to a defect in muscle ion channels. There are several types of periodic paralysis: hypokalemic, hyperkalemic, and thyrotoxic. The hallmark of periodic paralysis is painless muscle weakness precipitated by heavy exercise, fasting, stress, high-carbohydrate meals, or in the case of hyperkalemic periodic paralysis, consumption of potassium rich foods. Hypokalemic periodic paralysis occurs typically in the first or second decade of life and will last from hours to days. It is caused by an autosomal dominant defect in calcium or sodium channels on the membranes of myocytes. Diagnosis can be made with a basic metabolic panel in the presence of paralysis. The potassium level will be < 3.5 mEq/L. A transtubular potassium gradient ((UK+ x POSM) / (UOSM x PK+)) can also be used to diagnose hypokalemic periodic paralysis , a value < 3 mEq/L is highly suggestive of hypokalemic periodic paralysis (normal range is 8 to 9 mEq/L). Hypokalemic periodic paralysis is more common in men and can be treated with carbonic anhydrase inhibitors or potassium-sparing diuretics.
An edrophonium test (C) is used to diagnose myasthenia gravis, a neuromuscular disease causing muscle weakness due to antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction. Edrophonium blocks the breakdown of acetylcholine by inhibiting acetylcholinesterase, thereby temporarily reversing the weakness caused by myasthenia gravis. This test is rarely performed due to the potential of life threatening bradycardia. Magnetic resonance imaging of the brain (D) is helpful in the diagnosis of multiple sclerosis, a demyelinating disease of the brain and spinal cord characterized by neurologic deficits that change over time, but plays no part in the diagnosis of hypokalemic periodic paralysis. Cerebrospinal fluid (CSF) protein and cell count (B) are useful in the evaluation of Guillain-Barré syndrome (GBS), a rapid-onset ascending paralysis resulting from autoimmune damage to the peripheral nervous system nerves and myelin. Common causes are recent infection, upper respiratory infections, or gastroenteritis with Campylobacter jejuni. Cytomegalovirus has also been linked to GBS, but up to a third of cases of GBS are idiopathic. Treatment is supportive and includes airway protection if the paralysis rises to the level of the diaphragm. CSF analysis will show an elevated protein level with low numbers of white blood cells.
Incorrect
Periodic paralysis is a rare neuromuscular disorder related to a defect in muscle ion channels. There are several types of periodic paralysis: hypokalemic, hyperkalemic, and thyrotoxic. The hallmark of periodic paralysis is painless muscle weakness precipitated by heavy exercise, fasting, stress, high-carbohydrate meals, or in the case of hyperkalemic periodic paralysis, consumption of potassium rich foods. Hypokalemic periodic paralysis occurs typically in the first or second decade of life and will last from hours to days. It is caused by an autosomal dominant defect in calcium or sodium channels on the membranes of myocytes. Diagnosis can be made with a basic metabolic panel in the presence of paralysis. The potassium level will be < 3.5 mEq/L. A transtubular potassium gradient ((UK+ x POSM) / (UOSM x PK+)) can also be used to diagnose hypokalemic periodic paralysis , a value < 3 mEq/L is highly suggestive of hypokalemic periodic paralysis (normal range is 8 to 9 mEq/L). Hypokalemic periodic paralysis is more common in men and can be treated with carbonic anhydrase inhibitors or potassium-sparing diuretics.
An edrophonium test (C) is used to diagnose myasthenia gravis, a neuromuscular disease causing muscle weakness due to antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction. Edrophonium blocks the breakdown of acetylcholine by inhibiting acetylcholinesterase, thereby temporarily reversing the weakness caused by myasthenia gravis. This test is rarely performed due to the potential of life threatening bradycardia. Magnetic resonance imaging of the brain (D) is helpful in the diagnosis of multiple sclerosis, a demyelinating disease of the brain and spinal cord characterized by neurologic deficits that change over time, but plays no part in the diagnosis of hypokalemic periodic paralysis. Cerebrospinal fluid (CSF) protein and cell count (B) are useful in the evaluation of Guillain-Barré syndrome (GBS), a rapid-onset ascending paralysis resulting from autoimmune damage to the peripheral nervous system nerves and myelin. Common causes are recent infection, upper respiratory infections, or gastroenteritis with Campylobacter jejuni. Cytomegalovirus has also been linked to GBS, but up to a third of cases of GBS are idiopathic. Treatment is supportive and includes airway protection if the paralysis rises to the level of the diaphragm. CSF analysis will show an elevated protein level with low numbers of white blood cells.
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Question 2 of 10
2. Question
Which of the following should prompt you to consider an elective intubation in a 70-kg patient with weakness due to a neuromuscular disease?
Correct
In the emergency department intubating a patient with a NM disease is made less on hard numbers and more on the patient’s overall clinical picture. However, guidelines do exist for these disorders which indicate that an elective intubation should be performed. The Negative Inspiratory Force (NIF) or Maximal Inspiratory Pressure (MIP) test is one we can perform in the ED if we ask RT for assistance. As the name implies it measures the force of inhalation, it is measured in terms of “negative” values, and >-30 cmH2O indicates the need for likely intubation. FVC (B) is also a metric that can be used, however the normal FVC for an adult ranges from 3,000-5000 mL. There is not a hard indication for intubating a NM disease patient based on PCO2 (C) alone. While 47 is slightly elevated, it is not an isolated reason to intubate this patient. While requiring previous intubations in the past (D) may increase this patient’s risk for respiratory failure, it is not an indication to intubate.
Other metrics for respiratory failure in patient’s with NM disease:
FVC: A forced vital capacity is the total volume exchanged from maximal inhalation/exhalation (i.e. the biggest breath you can take). An FVC less than 15-20 mL/kg in the sitting position. The normal adult human has an FVC of about 3,000-5,000 mL.
NIF or MIP: Maximal negative pressure generated on inspiration. It is an indirect measure of the diaphragm’s force. In general values > -30 cmH2O (i.e. between 0 to -30) should raise concern for impending respiratory failure. For reference, -60 cmH2O is equivalent to “a weak cough” and predicts some difficulty with clearing secretions, and normal is < -100 cm H2O
MEP: Maximal expiratory pressure, which is the opposite of the MIP or NIF as it measures the expiratory force. In general values < 40 cm H2O is a worrisome sign of respiratory failure.
*In concert the above three values comprise the “20-30-40” rule: FVC <20mL/kg, MIP >-30 cmH2O, MEP >40 cmH2O. These parameters are NOT hard and fast rules… they are guidelines and should never override a strong clinical inclination to intubate.
Progressively worsening respiratory acidosis
Inadequate clearing of secretions
Clinical respiratory distress
Incorrect
In the emergency department intubating a patient with a NM disease is made less on hard numbers and more on the patient’s overall clinical picture. However, guidelines do exist for these disorders which indicate that an elective intubation should be performed. The Negative Inspiratory Force (NIF) or Maximal Inspiratory Pressure (MIP) test is one we can perform in the ED if we ask RT for assistance. As the name implies it measures the force of inhalation, it is measured in terms of “negative” values, and >-30 cmH2O indicates the need for likely intubation. FVC (B) is also a metric that can be used, however the normal FVC for an adult ranges from 3,000-5000 mL. There is not a hard indication for intubating a NM disease patient based on PCO2 (C) alone. While 47 is slightly elevated, it is not an isolated reason to intubate this patient. While requiring previous intubations in the past (D) may increase this patient’s risk for respiratory failure, it is not an indication to intubate.
Other metrics for respiratory failure in patient’s with NM disease:
FVC: A forced vital capacity is the total volume exchanged from maximal inhalation/exhalation (i.e. the biggest breath you can take). An FVC less than 15-20 mL/kg in the sitting position. The normal adult human has an FVC of about 3,000-5,000 mL.
NIF or MIP: Maximal negative pressure generated on inspiration. It is an indirect measure of the diaphragm’s force. In general values > -30 cmH2O (i.e. between 0 to -30) should raise concern for impending respiratory failure. For reference, -60 cmH2O is equivalent to “a weak cough” and predicts some difficulty with clearing secretions, and normal is < -100 cm H2O
MEP: Maximal expiratory pressure, which is the opposite of the MIP or NIF as it measures the expiratory force. In general values < 40 cm H2O is a worrisome sign of respiratory failure.
*In concert the above three values comprise the “20-30-40” rule: FVC <20mL/kg, MIP >-30 cmH2O, MEP >40 cmH2O. These parameters are NOT hard and fast rules… they are guidelines and should never override a strong clinical inclination to intubate.
Progressively worsening respiratory acidosis
Inadequate clearing of secretions
Clinical respiratory distress
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Question 3 of 10
3. Question
A 30-year-old woman with a history of intravenous drug abuse presents with three days of back pain and leg weakness. Her vital signs are within normal limits for her age. She has no meningeal signs or midline bony tenderness on examination. Which of the following findings on history or physical examination is concerning for cauda equina syndrome?
Correct
Cauda equina syndrome is a neurologic emergency and is the result of external compression of the cauda equina by a tumor, abscess, herniated disc, expanding hematoma, or other mass. Because the cauda equina is composed of spinal nerve roots, compression results in a peripheral neuropathy as opposed to a central neuropathy. Signs and symptoms include back pain, urinary retention (measured by a post-void residual bladder volume usually > 100 cc), overflow urinary incontinence, saddle or perianal anesthesia, and lower motor neuron findings such as lower extremity hyporeflexia and flaccidity, which are usually unilateral. Patients with findings concerning for cauda equina syndrome need emergent neurosurgical consultation and advanced imaging with MRI.
Conus medullaris syndrome is another neurosurgical emergency that may present with similar features as cauda equina syndrome, including saddle anesthesia and bladder incontinence. However, because the conus medullaris is the terminal spinal cord and, by definition, a central structure, exam findings will be consistent with upper motor neuron deficits such as lower extremity hyperreflexia or a positive Babinski sign (upgoing toes). A positive straight leg raise test indicates sciatica.
Incorrect
Cauda equina syndrome is a neurologic emergency and is the result of external compression of the cauda equina by a tumor, abscess, herniated disc, expanding hematoma, or other mass. Because the cauda equina is composed of spinal nerve roots, compression results in a peripheral neuropathy as opposed to a central neuropathy. Signs and symptoms include back pain, urinary retention (measured by a post-void residual bladder volume usually > 100 cc), overflow urinary incontinence, saddle or perianal anesthesia, and lower motor neuron findings such as lower extremity hyporeflexia and flaccidity, which are usually unilateral. Patients with findings concerning for cauda equina syndrome need emergent neurosurgical consultation and advanced imaging with MRI.
Conus medullaris syndrome is another neurosurgical emergency that may present with similar features as cauda equina syndrome, including saddle anesthesia and bladder incontinence. However, because the conus medullaris is the terminal spinal cord and, by definition, a central structure, exam findings will be consistent with upper motor neuron deficits such as lower extremity hyperreflexia or a positive Babinski sign (upgoing toes). A positive straight leg raise test indicates sciatica.
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Question 4 of 10
4. Question
A 25-year-old man presents to the ED with difficulty swallowing and blurry vision after eating canned tuna for lunch. On physical exam, he is noted to have slurred speech and nonreactive dilated pupils. Which of the following is the most likely diagnosis?
Correct
Botulism is a neuromuscular disorder caused by Clostridium botulinum. Through a toxin-mediated process, the release of acetylcholine is inhibited, leading to muscle weakness and paralysis. Classically, botulism causes a symmetric descending paralysis. Cranial nerves and bulbar muscles are often the first to be affected. As the disease progresses, patients can develop respiratory failure through paralysis of respiratory muscles. Patients will typically present with diplopia, dysarthria, and dysphagia. On physical exam, patients with often have dilated pupils that are nonreactive to light. In adults, botulism can occur after the ingestion of canned foods contaminated with Clostridium botulinum. Symptoms typically present within six to 48 hours of exposure to the toxin.
An ischemic stroke can present with signs and symptoms similar to botulism. However, a history of recent ingestion of canned food product and nonreactive dilated pupils is most consistent with botulism, also given this patient’s age a stroke is far less likely. Myasthenia gravis is a neuromuscular disorder caused by antibodies that lead to ineffective acetylcholine at the neuromuscular junction. It can present similarly to botulism, but symptoms of botulism will develop more rapidly. Also, patients with myasthenia gravis will have reactive and normal-appearing pupils. Scrombroid poisoning is associated with larger game fish such as tuna, and causes a histamine reaction including flushing, headaches, blurred vision, cramping abdominal pain, and GI upset.
Incorrect
Botulism is a neuromuscular disorder caused by Clostridium botulinum. Through a toxin-mediated process, the release of acetylcholine is inhibited, leading to muscle weakness and paralysis. Classically, botulism causes a symmetric descending paralysis. Cranial nerves and bulbar muscles are often the first to be affected. As the disease progresses, patients can develop respiratory failure through paralysis of respiratory muscles. Patients will typically present with diplopia, dysarthria, and dysphagia. On physical exam, patients with often have dilated pupils that are nonreactive to light. In adults, botulism can occur after the ingestion of canned foods contaminated with Clostridium botulinum. Symptoms typically present within six to 48 hours of exposure to the toxin.
An ischemic stroke can present with signs and symptoms similar to botulism. However, a history of recent ingestion of canned food product and nonreactive dilated pupils is most consistent with botulism, also given this patient’s age a stroke is far less likely. Myasthenia gravis is a neuromuscular disorder caused by antibodies that lead to ineffective acetylcholine at the neuromuscular junction. It can present similarly to botulism, but symptoms of botulism will develop more rapidly. Also, patients with myasthenia gravis will have reactive and normal-appearing pupils. Scrombroid poisoning is associated with larger game fish such as tuna, and causes a histamine reaction including flushing, headaches, blurred vision, cramping abdominal pain, and GI upset.
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Question 5 of 10
5. Question
A 45-year-old man with a history of alcohol abuse presents as a medical code for numbness and weakness of the left hand. He states he slept on a bench last night and awoke this morning with the symptoms. Physical examination reveals decreased sensation over the dorsum of the first, second, and third digits as well as weakness with wrist extension, otherwise strength and sensation are intact elsewhere. You do not appreciate any other focal neurologic deficits. He does not have any pain to palpation throughout the affected extremity. What management is indicated?
Correct
This patient presents with a radial neuropathy also called “Saturday Night Palsy.” The radial nerve arises from the C5-T1 roots. It controls extension of the fingers, thumb, wrist and elbow. Symptoms of radial neuropathy depend on the location of compression. Compression in the axilla (typically from improper use of crutches) causes weakness of extension at the elbow, wrist and fingers. More typically, the nerve is compressed between the humeral shaft and another hard surface and results in weakness with extension at the wrist and fingers. This typically occurs from deep sleep (often secondary to inebriation). About 90% of radial nerve mononeuropathies that occur during sleep, coma or anesthesia recover within 6-8 weeks. Patients should be placed in a wrist splint with 60 degrees of dorsiflexion to prevent atrophy and contractures.
Radiographic imaging and pain control are not necessary as the patient does not have any concerning physical exam findings or history of trauma. Activation of stroke protocol would be inappropriate for several reasons. He is outside of any TPA window as he awoke with these symptoms, the symptoms are consistent with a nerve palsy, and his NIHSS scale is low (likely just a 1 for his sensory deficit). Consultation of neurology and MRI of the brain is not needed emergently as the patient has a clinical diagnosis of a radial nerve palsy, he can follow up as an outpatient.
Peripheral Neuropathies
• Sciatic: buttock injury, hip dislocation, ↓ knee flexion, foot drop, rx: analgelsics, physical therapy,
• Common peroneal: proximal fibula injury, footdrop, rx: ankle splint
• Radial: crutches, wrist/finger drop, rx: wrist splint
• Ulnar: elbow injury, ↓ finger adduction/thumb grasp, 4th/5th digit paresthesias
• Lateral femoral cutaneous: inguinal ligament entrapment, upper thigh dysesthesia/numbnessIncorrect
This patient presents with a radial neuropathy also called “Saturday Night Palsy.” The radial nerve arises from the C5-T1 roots. It controls extension of the fingers, thumb, wrist and elbow. Symptoms of radial neuropathy depend on the location of compression. Compression in the axilla (typically from improper use of crutches) causes weakness of extension at the elbow, wrist and fingers. More typically, the nerve is compressed between the humeral shaft and another hard surface and results in weakness with extension at the wrist and fingers. This typically occurs from deep sleep (often secondary to inebriation). About 90% of radial nerve mononeuropathies that occur during sleep, coma or anesthesia recover within 6-8 weeks. Patients should be placed in a wrist splint with 60 degrees of dorsiflexion to prevent atrophy and contractures.
Radiographic imaging and pain control are not necessary as the patient does not have any concerning physical exam findings or history of trauma. Activation of stroke protocol would be inappropriate for several reasons. He is outside of any TPA window as he awoke with these symptoms, the symptoms are consistent with a nerve palsy, and his NIHSS scale is low (likely just a 1 for his sensory deficit). Consultation of neurology and MRI of the brain is not needed emergently as the patient has a clinical diagnosis of a radial nerve palsy, he can follow up as an outpatient.
Peripheral Neuropathies
• Sciatic: buttock injury, hip dislocation, ↓ knee flexion, foot drop, rx: analgelsics, physical therapy,
• Common peroneal: proximal fibula injury, footdrop, rx: ankle splint
• Radial: crutches, wrist/finger drop, rx: wrist splint
• Ulnar: elbow injury, ↓ finger adduction/thumb grasp, 4th/5th digit paresthesias
• Lateral femoral cutaneous: inguinal ligament entrapment, upper thigh dysesthesia/numbness -
Question 6 of 10
6. Question
A 27-year-old woman presents with a complaint of transient vision loss in her right eye. She states that she has had multiple similar episodes in the past six months. She also complains of incomplete bladder emptying, intermittent tremors and intermittent weakness in her left arm. Which of the following is the best diagnostic test for the suspected diagnosis?
Correct
MRI is the diagnostic modality of choice for multiple sclerosis (MS). Multiple sclerosis is characterized by demyelination of axons within the central nervous system. Patients present with symptoms that are “scattered in time and space” meaning that they have intermittent symptoms in anatomically disparate locations. Patients may have patchy motor and sensory deficits and bladder dysfunction. Spinal cord lesions typically involve the posterior columns, lateral spinothalamic tracts and the corticospinal tract. Spinal MRI is the diagnostic modality of choice because it can be used to rule out causes of cord compression while also showing lesions diagnostic for MS.
CT scan may be performed but is NOT a diagnostic test for MS. Carotid duplex scans are used when there is concern for TIA, not in MS. CSF oligoclonal bands are helpful in the diagnosis of MS, but are not the diagnostic test of choice, furthermore serum oligoclonal bands are of no help.
Incorrect
MRI is the diagnostic modality of choice for multiple sclerosis (MS). Multiple sclerosis is characterized by demyelination of axons within the central nervous system. Patients present with symptoms that are “scattered in time and space” meaning that they have intermittent symptoms in anatomically disparate locations. Patients may have patchy motor and sensory deficits and bladder dysfunction. Spinal cord lesions typically involve the posterior columns, lateral spinothalamic tracts and the corticospinal tract. Spinal MRI is the diagnostic modality of choice because it can be used to rule out causes of cord compression while also showing lesions diagnostic for MS.
CT scan may be performed but is NOT a diagnostic test for MS. Carotid duplex scans are used when there is concern for TIA, not in MS. CSF oligoclonal bands are helpful in the diagnosis of MS, but are not the diagnostic test of choice, furthermore serum oligoclonal bands are of no help.
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Question 7 of 10
7. Question
A 34-year-old man presents with complaints of progressive lower extremity weakness over the past 2 days associated with 2 weeks of diarrhea that has since resolved. Vital signs are HR 89, BP 160/95, and RR 12. On exam, you note symmetric lower extremity weakness with intact sensation and absent ankle reflexes. Which of the following would help to support the most likely diagnosis?
Correct
The patient is most likely suffering from Guillain-Barré syndrome, a progressive, ascending demyelinating polyneuropathy that typically begins with lower extremity weakness. Classically, GBS presents with symmetric lower extremity weakness, decreased or absent deep tendon reflexes, and little or no sensory involvement (although variable). It follows a respiratory or gastrointestinal infection by weeks to days. Common organisms implicated include Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus, and Mycoplasma pneumoniae. Elevated protein with only a mild pleocytosis on cerebrospinal fluid analysis (termed albuminocytologic dissociation) is highly specific in the clinical setting of suspected GBS. Patients with probable GBS should receive a neurology consult and be admitted for either intravenous immunoglobulin (IVIG) therapy or plasma exchange. Both IVIG and plasma exchange have been demonstrated to be more effective than placebo has, but no advantage is incurred upon administration of both therapies. Neither therapy has been proven more effective than the other.
The edrophonium test is used for myasthenia gravis, not for GBS. Corticosteroids alone are no longer recommended, but IV steroids coadministered with IVIG may speed recovery. Regardless, steroids have no role in the diagnosis of GBS. Pleocytosis and oligoclonal bands of immunoglobulin G is characteristic of MS
Incorrect
The patient is most likely suffering from Guillain-Barré syndrome, a progressive, ascending demyelinating polyneuropathy that typically begins with lower extremity weakness. Classically, GBS presents with symmetric lower extremity weakness, decreased or absent deep tendon reflexes, and little or no sensory involvement (although variable). It follows a respiratory or gastrointestinal infection by weeks to days. Common organisms implicated include Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus, and Mycoplasma pneumoniae. Elevated protein with only a mild pleocytosis on cerebrospinal fluid analysis (termed albuminocytologic dissociation) is highly specific in the clinical setting of suspected GBS. Patients with probable GBS should receive a neurology consult and be admitted for either intravenous immunoglobulin (IVIG) therapy or plasma exchange. Both IVIG and plasma exchange have been demonstrated to be more effective than placebo has, but no advantage is incurred upon administration of both therapies. Neither therapy has been proven more effective than the other.
The edrophonium test is used for myasthenia gravis, not for GBS. Corticosteroids alone are no longer recommended, but IV steroids coadministered with IVIG may speed recovery. Regardless, steroids have no role in the diagnosis of GBS. Pleocytosis and oligoclonal bands of immunoglobulin G is characteristic of MS
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Question 8 of 10
8. Question
A 45-year-old woman complains of two days of fluctuating diplopia and dysphagia. Her exam reveals a left cranial nerve VI palsy, ptosis, and proximal muscle weakness in her extremities. She notes significant exercise intolerance over the past two days as well. What is the pathophysiology of her disease?
Correct
This patient has myasthenia gravis, caused by antibodies to the acetylcholine receptor (AChR) at the neuromuscular junction. Failure to respond to acetylcholine stimulation leads to decreased muscle fiber activationand muscle weakness. The antibodies cause AChR degradation, dysfunction, and blockade. Ptosis and diplopia are most commonly the first symptoms. Patients may also experience dysphagia, proximal muscle weakness, and dyspnea. A full myasthenic crisis may lead to respiratory failure due to flaccid paralysis of the muscles of respiration.
Botulinum toxin inhibits acetylcholine release at the synapse (B). It is produced by Clostridium botulinum, an anaerobic spore-forming bacterium. C. botulinum occurs naturally in the soil and causes human disease when ingested. Botulism is associated with a descending symmetric paralysis. Amyotrophic lateral sclerosis (ALS) is caused by a mutation of superoxide dismutase (C) leading to an abnormal response to stress and cell death. Central and peripheral nerves are affected with sparing of sensory and cognitive function. Initial symptoms are muscle weakness, atrophy, fasciculations, dysarthria, and dysphagia. Parkinson’s disease is associated with depigmentation and dopaminergic neuron loss (D) in the midbrain, especially the substantia nigra. It is also characterized by Lewy bodies, which are cytoplasmic inclusions seen under the microscope. Parkinson’s disease is characterized by tremor, cogwheel rigidity, bradykinesia or akinesia, and postural and equilibrium impairment.
Incorrect
This patient has myasthenia gravis, caused by antibodies to the acetylcholine receptor (AChR) at the neuromuscular junction. Failure to respond to acetylcholine stimulation leads to decreased muscle fiber activationand muscle weakness. The antibodies cause AChR degradation, dysfunction, and blockade. Ptosis and diplopia are most commonly the first symptoms. Patients may also experience dysphagia, proximal muscle weakness, and dyspnea. A full myasthenic crisis may lead to respiratory failure due to flaccid paralysis of the muscles of respiration.
Botulinum toxin inhibits acetylcholine release at the synapse (B). It is produced by Clostridium botulinum, an anaerobic spore-forming bacterium. C. botulinum occurs naturally in the soil and causes human disease when ingested. Botulism is associated with a descending symmetric paralysis. Amyotrophic lateral sclerosis (ALS) is caused by a mutation of superoxide dismutase (C) leading to an abnormal response to stress and cell death. Central and peripheral nerves are affected with sparing of sensory and cognitive function. Initial symptoms are muscle weakness, atrophy, fasciculations, dysarthria, and dysphagia. Parkinson’s disease is associated with depigmentation and dopaminergic neuron loss (D) in the midbrain, especially the substantia nigra. It is also characterized by Lewy bodies, which are cytoplasmic inclusions seen under the microscope. Parkinson’s disease is characterized by tremor, cogwheel rigidity, bradykinesia or akinesia, and postural and equilibrium impairment.
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Question 9 of 10
9. Question
A 75-year-old male presents to the ED with his son. The son reports a gradual loss of mental capacity and recent falls. His father now has to wear a diaper because of urinary incontinence. Exam is significant for a confused male with a wide-based shuffling gait. What is the expected Head CT finding?
Correct
Normal pressure hydrocephalus (NPH) is characterized by the following characteristics: wet, wacky, and wobbly. More specifically, it includes a triad of progressive dementia, ataxia and urinary frequency or incontinence. It is a reversible cause of dementia and results from defective uptake of CSF. Head CT will reveal ventricular enlargement. Atrophy may occur in chronic alcoholics or the elderly, but is neither sensitive nor specific for NPH. A brain mass can cause a variety of symptoms, but headache with a neurologic deficit would be a more common presentation
Incorrect
Normal pressure hydrocephalus (NPH) is characterized by the following characteristics: wet, wacky, and wobbly. More specifically, it includes a triad of progressive dementia, ataxia and urinary frequency or incontinence. It is a reversible cause of dementia and results from defective uptake of CSF. Head CT will reveal ventricular enlargement. Atrophy may occur in chronic alcoholics or the elderly, but is neither sensitive nor specific for NPH. A brain mass can cause a variety of symptoms, but headache with a neurologic deficit would be a more common presentation
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Question 10 of 10
10. Question
A 62 yo female patient with a history of myasthenia gravis presented with extreme weakness and difficulty in breathing. She was initially hypoxic to 88% with shallow respirations. The decision was made to intubate the patient. What treatment should be initiated for the patient?
Correct
A patient in myasthenic crisis should receive immunomodulatory therapy. This includes either IVIG or plasmapharesis. The decision to start either should be made in concert with a consulting neurology service. The literature does show a benefit of IVIG over placebo, however the difference in IVIG vs. plasmapharesis is unclear. In general, if resources are available, plasmapharesis is preferred as it directly removes the AChR ab from the blood, whereas IVIG acts by both binding harmful ab, as well as downregulating the patient’s immune response. This is a costly medication and requires repeated doses.
Pyridostigmine and neostigmine are used orally for outpatient maintenance and not for acute crisis. They act by inhibiting AChE, increasing the amount of ACh at the NMJ. The IV dose might cause complications from the cholinergic excess such as increased secretions. Rituximab is not a first line treatment in MG, though it may play a role in outpatient therapy by decreasing the production of ab from B-cells. Edrophonium is used for the diagnosis of MG, and this patient already has established MG. It is a short-acting AChEi . Administration in patients with MG should lead to decreased symptoms in 30-90 seconds. Use of edrophonium can result in potentially significant complications, such as symptomatic bradycardia and bronchospasm. These effects can be reversed with atropine. It should be used with caution, if at all, in older patients, those with asthma/COPD and those with underlying cardiac disease.
Incorrect
A patient in myasthenic crisis should receive immunomodulatory therapy. This includes either IVIG or plasmapharesis. The decision to start either should be made in concert with a consulting neurology service. The literature does show a benefit of IVIG over placebo, however the difference in IVIG vs. plasmapharesis is unclear. In general, if resources are available, plasmapharesis is preferred as it directly removes the AChR ab from the blood, whereas IVIG acts by both binding harmful ab, as well as downregulating the patient’s immune response. This is a costly medication and requires repeated doses.
Pyridostigmine and neostigmine are used orally for outpatient maintenance and not for acute crisis. They act by inhibiting AChE, increasing the amount of ACh at the NMJ. The IV dose might cause complications from the cholinergic excess such as increased secretions. Rituximab is not a first line treatment in MG, though it may play a role in outpatient therapy by decreasing the production of ab from B-cells. Edrophonium is used for the diagnosis of MG, and this patient already has established MG. It is a short-acting AChEi . Administration in patients with MG should lead to decreased symptoms in 30-90 seconds. Use of edrophonium can result in potentially significant complications, such as symptomatic bradycardia and bronchospasm. These effects can be reversed with atropine. It should be used with caution, if at all, in older patients, those with asthma/COPD and those with underlying cardiac disease.
Ahhhh well well well, the time has come, the neurology block is upon us! Can you feel the tingles of excitement running down your spine or is that just your sciatica acting up? Review those dermatomes, get that accucheck, and when in doubt always activate stroke protocol.
This block will cover a large spectrum of disorders, including: NMJ disorders, peripheral neuropathies, demyelinating disorders, SC disorders, movement disorders, and AMS/delirium/dementia. This week’s FLIP brought to you by Drs. Warpath Warpinski, Check out the Big Brain on Braaaaad Smith, and James VandenMe. The AMS station will integrate a special type of deep dive called “algorithm building”, where we will discuss our own decision trees for management of the altered patient. Required reading below!
*Required Material*
- Rosen’s Chapter 94, Delirium/Dementia
or - Harwood Nuss: Chapter 237: Altered Mental Status
*Below is a supplementary EMRAP: C3 podcast on AMS, I highly recommend it and C3 in general!
Core Content: Harwood & Nuss
- Chapter 30: Spinal Cord Injuries-briefly review
- Chapter 158: Peripheral Neuropathies
- Chapter 159: Bell’s Palsy and Trigeminal Neuralgia
- Chapter 160: Myopathies and Disorders of Neuromuscular Transmission
- Chapter 161: Demyelinating Disease
- Chapter 162: Parkinsonism and Other Movement Disorders
- Chapter 237: Altered Mental Status
- Chapter 238: Ataxia
Core Content: Rosen’s
- Chp 94: Delirium/Dementia
- Chp 95: Brain/CN disorders
- Chp 96: SC disorders
- Chp 97: PN disorders
- Chp 98: NMJ disorders
Supplementary MATERIAL
EM RAP
—C3 AMS 1
—C3 AMS 2
—PN pt 1
—PN pt 2
EMCrit:
–-Everything Myasthenia
—GBS/MG respiratory status
CRACKCAST:
—Chapter 104 – Delirium and Dementia
–Chapter 105 – Brain and Cranial Nerve Disorders
–Chapter 106 – Spinal Cord Disorders
–Chapter 107 – Peripheral Nerve Disorders
–Chapter 108 – Neuromuscular Disorders