• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Nm disorder
 

Nm disorder

on

  • 815 views

 

Statistics

Views

Total Views
815
Views on SlideShare
815
Embed Views
0

Actions

Likes
0
Downloads
8
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Nm disorder Nm disorder Presentation Transcript

    • Neuromuscular Disorders
      Saad Al Juma
      R3
    • In MNL :
      Poliomyelitis is the protypicaldisease
      In Poliomyelitis weakness can be asymmetrical or more often symmetrical
      The cerebrospinal fluid analysis resembles that of aseptic meningitis.
      Patients initially have a clinical picture similar to that of viral meningitis
    • In MNL :
      Amyotrophic lateral sclerosis is the prototypical disease
      In Poliomyelitis weakness can be symmetrical or more often asymmetrical
      The cerebrospinal fluid analysis resembles that of viral meningitis.
      Patients initially have a clinical picture similar to that of viral meningitis…..
    • In Amyotrophiclateralsclerosis
      It affects the anterior horn cells and results in lower motor neuron disease without sensory involvement
      Results from a degeneration of the motor neuron with sensory involvement.
      complain of dysarthria or ptosis
      findings include hyporreflexia, muscle wasting, and fasciculation
      Pain is not a component of the clinical picture….
    • In Amyotrophiclateralsclerosis
      Poliomyelitis affects the anterior horn cells and results in lower motor neuron disease without sensory involvement
      Results from a degeneration of the motor neuron without sensory involvement.
      complain of dysarthria or dysphagia
      findings include hyperreflexia, muscle wasting, and fasciculation
      Pain is not a component of the clinical picture….
    • In MNL all are true except:
      lesions at the level of the brainstem or above produce bilateral weakness
      bilateral weakness caused by lesions above the spinal cord is associated with a change in mental status or cranial nerve involvement
      Lesions of the central nervous system result in spasticity, hyperreflexia, and extensor plantar reflexes
      bilateral upper motor neuron signs with normal mental status, neuroimagingshould focus on looking for a lesion in the spinal cord
    • In MNL :
      lesions at the level of the brainstem or above produceunilateralweakness
      bilateral weakness caused by lesions above the spinal cord is generally associated with a change in mental status or cranial nerve involvement
      Lesions of the central nervous system result in spasticity, hyperreflexia, and extensor plantar reflexes
      when bilateral upper motor neuron signs are found in conjunction with normal mental status, diagnostic testing including neuroimaging should focus on looking for a lesion in the spinal cord
    • In Neuropathies , all are true EXCEPT :
      a grip strength or foot-drop may be noted first
      patients usually note a slowly progressive course of symptoms.
      A disorder of transmission often leads to increased production of AChreceptors.
      Patients usually have intact sensation sensation.
    • In Neuropathies :
      a grip strength or foot-drop may be noted first
      patients usually note a slowly progressive course of symptoms.
      A disorder of transmission often leads to increased production of AChreceptors.
      Patients exhibit varying degrees of altered sensation
    • In Myopathies , all are true EXCEPT:
      Myopathies produce generalized, symmetrical weakness
      muscle tone is usually diminished, but sensation is preserved.
      Generally cause muscle pain and tenderness
      Reflexes are present but diminished
    • In Myopathies
      Myopathies produce generalized, symmetrical weakness
      muscle tone is usually diminished, but sensation is preserved.
      Metabolic disorders affecting muscle strength are painless in nature
      Reflexes are present but diminished
    • In MG all the following are true except:
      Normally, vital capacity values range from 60 to 70 mL/kg.
      the forced vital capacity reaches 15 mL/kg, intubation is necessary
      Arterial blood gas is helpful as most of the patients have sufficient protective reserve and hypercapniadevelps early
      presence of swallowing and a strong cough suggests that the patient has sufficient protective and ventilatory reserve
    • In MG :
      Normally, vital capacity values range from 60 to 70 mL/kg.
      the forced vital capacity reaches 15 mL/kg, intubation is necessary
      Arterial blood gas is not necessarily helpful because functional reserve can be severely diminished by the time a patient develops either hypercarbia or hypoxia
      presence of swallowing and a strong cough suggests that the patient has sufficient protective and ventilatory reserve
    • In Diseases of the Neuromuscular Junction Repeated stimulation leads to diminishing motor strength, which is caused by :
      the blockage of the receptors as in organophosphate poisoning
      a decrease in the amount of ACh released as in botulism
      inactivating Ach by irreversibly binding with it as in MG
      Down regulation of the Ach receptors as in Atropinized patients
    • In Diseases of the Neuromuscular Junction Repeated stimulation leads to diminishing motor strength, which is caused by :
      the blockage of the receptors as in MG
      a decrease in the amount of ACh released as in botulism
      inactivating Ach by irreversibly binding with it as in organophosphate poisoning
      Down regulation of the Ach receptors as in Atropinized patients
    • decrease in the release of ACh may produceexcept
      decreased visual acuity
      low-grade fever
      dry, flushed skin
      Bradycardia
      urinary retention
    • decrease in the release of ACh may produce:
      decreased visual acuity
      low-grade fever
      dry, flushed skin
      Tachycardia
      urinary retention
    • All are true about Myopathies , except:
      generalized, symmetrical weakness
      Reflexes are present
      muscle tone is usually diminished
      sensation is lost
      Are always painful
    • All are true about Myopathies :
      generalized, symmetrical weakness
      Reflexes are present
      muscle tone is usually diminished
      sensation is preserved
      Are always painful
    • Lambert-Eatonmyasthenicsyndromeall are false except :
      50% of cases are associated with non small cell carcinoma of the lung
      Clinically includes weakness that improves with use of muscles…..
      autonomic dysfunction, most commonly seen as flushed skin.
      Management with IVIG has been reported to be sufficient.
    • Lambert-Eatonmyasthenicsyndrome:
      50% of cases are associated with small cell carcinoma of the lung
      Clinically includes weakness that improves with use of muscles
      autonomic dysfunction, most commonly seen asdry mouth.
      Management primarily focuses on treating the underlying neoplastic disorder
    • Regarding MG , all are true except:
      Age of onset is bimodal
      MG results from autoantibodies directed against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction
      Ocular symptoms are often the first manifestation of MG
      Bulbar muscles are spared
    • Regarding MG :
      Age of onset is bimodal
      MG results from autoantibodies directed against the nicotinic acetylcholine receptor (AChR) at the neuromuscular junction
      Ocular symptoms are often the first manifestation of MG
      Bulbar muscles may be involved
    • What is Edrophoniumtest ?
    • What is Edrophoniumtest ?
      • Edrophonium (Tensilon) test:
      • measure distance from upper to the lower eyelid before and after IV edrophonium (AChE blocking agent)
      •  give test dose first 1-2mg IV , if no ADR/no improvement
      •  3mg, if no response
      •  5mg (max 10mg)
      • watch for bradycardia (only perform when pt on monitor with Atropine at bedside DUE TO BRADY AND SECRETIONS ISSUES.)
      • contraindicated in COPD/asthma pts because of risk of secretions.
      reports of FP with botulism
    • What is Icepacktest ?
    • What is Icepacktest ?
      it is applied to the affected eye for approximately 2 minutes
      the distance between the lids is measured again
      prospective evaluation of the ice bag approach found the test result to be positive (an improvement in distance of at least 2 mm) in 80% of patients with MG and in no patients without MG.[7]
    • defined as respiratory failure leading to mechanical ventilation
      Occurs in 15 to 20% of patients with MG
      within the first 2 years of disease onset
      precipitant may not be found in 3 % of cases
      In MyasthenicCrisis all are true Except:
    • In MyasthenicCrisis :
      defined as respiratory failure leading to mechanical ventilation
      Occurs in 15 to 20% of patients with MG
      within the first 2 years of disease onset
      precipitant may not be found in 30% of cases
    • BONUS QUESTION
    • Medications precipitate MG crisis
    • Medications precipitate MG crisis
    • Regarding MG Management all are true EXCEPT:
      in the setting of acute exacerbation of MG , The use of intravenous pyridostigmine is recommended
      the initiation of corticosteroids in patients with moderate to severe weakness may improve the outcome
      Thymectomy is recommended for patients younger than 60
      IVIG is preferred over PE due to the side effects of the later.
    • Regarding MG Management:
      in the setting of acute exacerbation of MG , The use of intravenous pyridostigmine is NOT recommended
      the initiation of corticosteroids in patients with moderate to severe weakness may improve the outcome
      Thymectomy is recommended for patients younger than 60
      IVIG is preferred over PE due to the side effects of the later.
    • Regarding P.E in M.G :
      The fall in AChR levels is not associated with improvement in symptoms of MG.
      complications include hypotension or anticoagulation.
      It is safe in children.
      many case series showed long-term benefit in myasthenic crisis.
    • Regarding P.E in M.G :
      The fall in AChR levels is associated with improvement in symptoms of MG.
      There is a risk of complications from hypotension or anticoagulation.
      Because of safety concerns, clinical trials have not been done in children.
      Although there are no randomized controlled studies, a review yielded many case series with short-term benefit, especially in myasthenic crisis.
    • Regarding Botulism , all are true except:
      Most common type is infant Botulism
      Clostridium botulinum is an anaerobic, spore-forming bacterium
      types A, B, and C toxins cause human disease….
      botulinum toxin works by binding irreversibly to the presynaptic membrane of peripheral and cranial nerves, inhibiting the release of ACh at the peripheral nerve synapse
    • Regarding Botulism :
      Most common type is infant Botulism
      Clostridium botulinum is an anaerobic, spore-forming bacterium
      types A, B, and E toxins cause human disease….
      botulinum toxin works by binding irreversibly to the presynaptic membrane of peripheral and cranial nerves, inhibiting the release of ACh at the peripheral nerve synapse
    • In Botulism , all are true except :
      There is no pain
      The onset of symptoms is 6 to 48 hours after the ingestion of tainted food
      descending, symmetrical, flaccid paralysis
      diplopia, dysarthria, and dysphagia are the first signs
      Pupils are often fixed and reactive to light…
    • In Botulism :
      There is no pain
      The onset of symptoms is 6 to 48 hours after the ingestion of tainted food
      descending, symmetrical, flaccid paralysis
      diplopia, dysarthria, and dysphagia are the first signs
      Pupils are often dilated and not reactive to light…
    • Regarding Botulisim antitoxin
      there is a risk of anaphylaxis and serum sickness
      It is known to decrease ventilator dependence
      the antitoxin should be administered once the toxin can be identified in serum and stool
      the antitoxin should be administered as soon as possible
      An intravenous human botulism immune globulin (BIG-IV) has been developed for treatment of wound related botulism
    • Regarding Botulisim antitoxin
      there is a risk of anaphylaxis and serum sickness
      although it is not clear that the antitoxin decreases ventilator dependence
      the antitoxin should be administered as soon as possible (clinical findings and exclusion of other processes)
      An intravenous human botulism immune globulin (BIG-IV) has been developed for treatment of infantile botulism
    • In TickParalysis, all are true except
      an acute, ascending, flaccid motor paralysis
      Usually starts after 6-12 days from female tick has attached and begun to feed
      fixed and dilated pupils associated with the disease.
      Intubation may be necessary after tick removal
    • In TickParalysis
      an acute, ascending, flaccid motor paralysis
      Usually starts after 1-2 days from female tick has attached and begun to feed
      fixed and dilated pupils associated with the disease.
      Intubation may be necessary after tick removal
    • In ThyrotoxicPeriodicParalysis , all are true EXCEPT:
      It is due to decreased sodium-potassium adenosine triphosphatase activity
      Treatment of the hyperthyroid symptoms helps the treatment of the paralysis
      There is probably a genetic feature underlying this disorder
      all patients have thyroid function testing done after a first episode of hypokalemic paralysis
    • In Thyrotoxic Periodic Paralysis
      It is due to increased sodium-potassium adenosine triphosphatase activity
      Treatment of the hyperthyroid symptoms helps the treatment of the paralysis
      There is probably a genetic feature underlying this disorder
      all patients have thyroid function testing done after a first episode of hypokalemic paralysis
    • In Familial Periodic Paralysis all are true EXCEPT:
      autosomal-dominant disorders of ion channels
      intermittent attacks of flaccid extremity weakness associated with either hyperkalemia or hypokalemia
      bulbar and respiratory muscles may be affected.
      The onset of symptoms often follows a high carbohydrate intake and a period of rest.
      An electrocardiogram, which should be done immediately
    • In Familial Periodic Paralysis:
      autosomal-dominant disorders of ion channels
      intermittent attacks of flaccid extremity weakness associated with either hyperkalemia or hypokalemia
      bulbar and respiratory muscles not affected.
      The onset of symptoms often follows a high carbohydrate intake and a period of rest.
      An electrocardiogram, which should be done immediately
    • Which of the following statements is true?
      a. Herpes zoster is often associated with motor dysfunction with or without a rash.
      b. Acute rabies infection typically begins as a Ramsay-Hunt syndrome before progressing to severe throat spasm and to cardiac and renal failure.
      c. Weakness or diplopia when fatigued may be the only complaint with multiple sclerosis.
      d. Treatment for polymyositis is early administration of systemic steroids.
      e. Serum calcium should be measured in patients with recurrent generalized weakness that follows periods of heavy exertion or that is present upon awakening.
    • The answer is c.
      Ramsay-Hunt syndrome refers to herpes zoster involving the tympanic membrane, ear canal, and other areas in the distribution of the sensory branches of the facial nerve.
      Herpetic zoster may result in motor abnormalities in up to 25% of cases.
      Weakness or diplopia only on exertion is a common complaint in early cases of multiple sclerosis. Another early presenting sign is retrobulbar neuritis; in fact, 50–75% of cases occur in patients who develop multiple sclerosis.
      Steroids may transiently exacerbate weakness in patients with polymyositis and should not be started on patients who will be discharged from the ED.
      Acute periodic paralysis appears to involve abnormalities in cellular function, possibly related to potassium transport. The disease is most common in young men. No specific physical findings may be found and it is often misdiagnosed as hysterical in origin
    • 2. A 34-year-old woman with known myasthenia gravis presents in respiratory distress. She is unable to move without assistance. Her vital signs are: temperature 36◦C (96.8◦F), heart rate 50/min, blood pressure 100/60 mm Hg, respiratory rate 35/min and shallow. She is drooling and has upper airway rhonchi and bilateral wheezing. Her respiratory rate appears to be decreasing. You immediately:
      a. Administer 2–4 mg of intravenous edrophonium.
      b. Perform endotracheal intubation.
      c. Administer 1 mg of atropine; if there is an improvement in her wheezing, administer pralidoxime.
      d. Start an intravenous atropine drip.
      e. Arrange emergent hyperbaric therapy.
    • The answer is b
      You should be able to differentiate a myasthenic crisis from a cholinergic crisis.
      Both can present with progressive muscle weakness and respiratory depression, dysphagia, and other physical signs. Bradycardia, wheezing, and salivation suggest cholinergic crisis.
      A common error is to mistake a cholinergic as a myasthenic crisis and administer additional acetylcholinesterase inhibitor.
      The immediate treatment for either type is ABCs and intubation at the first clinical signs of respiratory failure.
      In a cholinergic crisis, atropine can be used for the muscarinic symptoms, but it is not a substitute for airway management and ventilatory assistance.
    • A 13-year-old girl presents with a 3-day history of malaise, low-grade fever, and double vision with unilateral ptosis. The potential diagnosis of botulism is best supported by finding:
      a. Acute renal failure.
      b. Cardiac failure.
      c. Bilateral numbness of hands and feet.
      d. Acute urinary retention.
      e. Pseudomembranouspharyngitis.
    • The answer is d
      Both botulism and diphtheria may present with acute bulbar nerve palsies, weakness of any or all extremities, and cholinergic manifestations, such as urinary retention and colicky pain.
      In both diseases, the most common early neurologic findings are ptosis, double vision, and difficulty in accommodation.
      Diphtheria is an acute febrile illness. A primary symptom is a severe pseudomembranouspharyngitis presenting with severe throat pain and excessive saliva production.
      In diphtheria, cardiotoxic and renal abnormalities are direct results of the elaborated bacterial toxin.
    • A 34-year-old woman with myasthenia gravis presents with flank pain and fever of 103.4◦F. She is allergic to penicillin, and despite boluses of intravenous fluid and antibiotic therapy, she becomes hypotensive. A medicine that you can safely use in her management is:
      a. Gentamicin.
      b. Vecuronium.
      c. Lidocaine.
      d. Procainamide.
      e. Succinylcholine.
    • The answer is c
      Aminoglycoside antibiotics have some curare-type effects on the motor endplate; if they are used in the myasthenic patient, the physician should be prepared to treat paralysis and respiratory arrest. Obviously, these patients are more susceptible to muscle-paralyzing agents as well. Phenytoin, quinidine, procainamide, and lithium can also adversely affect patients with myasthenia gravis.
    • Curare (Chondodendrontomentosum),
      • a South American vine native to the Amazon Basin.
      • The undersides of the leaves are white-tomentose.
      • An extract from the bark and stems is the source of a potent isoquinoline alkaloid used in the deadly poison curare. Amazonian Indians use the gummy extract to coat the poison darts of their blowguns. The alkaloid D-tubocurarine blocks acetylcholine receptor sites at neuromuscular junctions, causing relaxation and paralysis of muscles, including respiratory organs and the heart.
      • In fact, D-tubocurarine has been used to relax the heart muscle during open heart surgery.
      • It has also been used to treat the spastic paralysis of tetanus toxin from the bacterium Clostridium botulinum. Tetanus toxin causes uncontrollable muscle contraction throughout the body.
    • Neuropathy is differentiated from myopathy in that:
      a. Neuropathies progress proximally.
      b. Myopathies affect distal and proximal muscle groups equally.
      c. Myopathies and neuropathies both have prominent sensory findings.
      d. Myopathies often have striking weakness of the small muscles of the hands.
      e. Myopathies have relatively preserved deep tendon reflexes.
    • The answer is a
      Neuropathies tend to have the following characteristics:
      proximal progression of symptoms
      sensory deficits often in a stocking glove distribution
      early loss of DTRs.
      Myopathiescharacteristically present with
      proximal motor weakness
      myalgias
      delayed loss of DTRs
      CPK enzymes may be elevated.
      There are exceptions to these generalizations.
    • Lambert-Eaton MyasthenicSyndrome
      results from an autoimmune attack directed against the voltage-gated calcium channels (VGCCs) on the presynaptic motor nerve terminal.
      This results in a loss of functional VGCCs at the motor nerve terminals. The number of quanta released by a nerve impulse is diminished.
      However, because presynaptic stores of ACh and the postsynaptic response to ACh remain intact, rapid repetitive stimulation or voluntary activation that aids in the release of quanta will raise the endplate potential above threshold and permit generation of muscle action potential.
      As neuromuscular transmission is completed at additional neuromuscular junctions, a transient increase will occur in the strength of the muscle.
      Parasympathetic, sympathetic, and enteric neurons are all affected.
      Clinically, this phenomenon is noted by the appearance of previously absent tendon reflexes following a short period of strong muscle contraction by the patient.
    • Myasthenia Gravis
      Autoantibodies (immunoglobulin G [IgG]) develop against ACh nicotinic postsynaptic receptors for unknown reasons, although certain genotypes are more susceptible.2 Cholinergic nerve conduction to striated muscle is impaired by a mechanical blockage of the binding site by antibodies and, ultimately, by destruction of the postsynaptic receptor.Patients become symptomatic once the number of ACh receptors is reduced to approximately 30% of normal. The cholinergic receptors of smooth and cardiac muscle have a different antigenicity than skeletal muscle and are not affected by the disease.The role of the thymus in the pathogenesis of myasthenia gravis is not entirely clear, but 75% of patients with myasthenia gravis have some degree of thymus abnormality (eg, hyperplasia in 85% of cases, thymoma in 15% of cases). Given the immunologic function of the thymus and the improvement in the clinical condition of patients following thymectomy, the thymus is suspected to be the site of autoantibody formation. However, the stimulus that initiates the autoimmune process has not been identified