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Neurological emergencies
This document provides an overview of neurological emergencies related to seizures, status epilepticus, and neuromuscular weakness. It reviews the pathophysiology of seizures and status epilepticus and approaches to treatment. Common causes of neuromuscular weakness are categorized as upper motor neuron, lower motor neuron, neuromuscular junction, muscle, or non-neuromuscular. Key diagnoses that must not be missed like Guillain-Barré syndrome, botulism, and myasthenia gravis are discussed in detail with regards to presentation, diagnosis, and management. Management of weakness focuses on localization of the lesion and treatment of underlying etiologies.
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Neurological emergencies
- 1. NEUROLOGICAL EMERGENCIES Seizures &Status Epilepticus Neuromuscular Weakness Farooq Khan MD FRCPC Oct 14th 2014
- 2. Objectives • Review seizurepathophysiology • Manage Status Epilepticus • Be comfortable with anticonvulsant drugs and adjuncts • Use an anatomic approach to neuromuscular weakness • Manage emergent potentially life threatening weakness • Review and differentiate diagnosis and management of select causes of weakness
- 3. Case 1 • 23yo F brought to ED by friend confused, lethargic but rousable • Triage VS: HR 115 BP 118/80 RR 20 T 37.5 Sat 97% • PMH: Migraines • Nurse calls you to bedside as she is having generalized tonic/clonic seizures • How would you manage this patient?
- 4. Initial Labs • Glucose6.5 • β-HCG negative • VBG pH 7.1 pCO2 50 HCO3 12 • Lactate 5.0 • Na 137 K 4.1 Cl 99
- 5.
- 6. Case 2 • 63yo M homeless found down at shelter • Unknown PMH/meds except EtOH abuse and recent depression • Appears dishevelled and mumbling at triage • HR 112 BP 168/87 RR 20 T 37.1 Sat 96% • ABCs intact • Glucose 7.7 GCS 11-12
- 7. Examination • H+N :no sign of trauma, vomitus around mouth, neck supple • Chest: decreased AE at bases • CV: unremarkable • Abdo: unremarkable • Ext: erythematous skin lesion on arm • Neuro exam: non focal
- 8. Investigations • Bedside CXR:normal • EKG: sinus tachycardia • Nurse sends CBC, lytes, blood gas, tox screen • Patient starts to seize • Please outline your management
- 9. Labs • Na 141K 4.8 Cl 95 • pH 7.0 HCO3 9 pCO2 30 • Lactate 7 • Tox screen: negative • Ethanol level : 20 • APAP and ASA levels negative • Rest of labs are within normal limits
- 10. SEIZURES & STATUSEPILEPTICUS
- 12. Seizure pathophysiology • Excessiveabnormal cortical neuronal activity • Recruitment • Propagation
- 14. Focal seizures • Provideclues to underlying lesion
- 15. Balancing inhibition andexcitation GABA Glycine GABA receptors Acetylcholine Glutamate NMDA receptor
- 16.
- 17.
- 18. Status epilepticus • Continuousseizures >5 min • >2 discrete seizure without intervening recovery of consciousness • Can cause neuronal damage • Can become refractory over time • Underlying pathology determines M&M
- 19. Treatment goals • ManageABCs – A: position, NPA, intubate – B: 100% O2, prevent prologed hypocapnia/acidosis, BMV may be impossible – C: IV/IO access ASAP, monitoring may be impossible • Abort seizure (use IM/intranasal/buccal/rectal routes prn) • Treat underlying cause
- 20. Non convulsive statusepilepticus • Can occur after prolonged status epilepticus or incomplete treatment • Small amplitude twitching/jerking of eyes • No visible motor activity with seizure activity on EEG • NCSE present in up to 9% hospitalized patients with prolonged AMS • Mortality 30% if seizing >1hour
- 21. Anticonvulsant “cocktails” • Benzodiazepines •Benzodiazepines • Benzodiazepines • Phenytoin/VPA/Keppra* • Barbiturate/Propofol (Intubate)
- 22.
- 25. The “cocktail” workswell for: Etiology • Epilepsy, neurodegenerative diseases, stroke, CNS vasculitis • Structural causes (trauma, ICH, masses • Infectious (HIV, meningitis, encephalitis, parasites) • Most toxic seizures and withdrawal Definitive Management • Targeted therapies (antiepileptics, tPA, steroids, etc.), Neurology assessment • CT, ICP management, Neurosurgery • LP, antibiotics, antivirals, antimalarials/antifungals • Supportive care, decontamination, enhanced elimination, antidote
- 26. Seizures persist: thinkoutside the box Etiology • Hypoglycemia • Hyponatremia (<120 mEq/l) • Hypocalcemia (<1.9 mmol/l) • Hypomagnesemia (<0.4 mmol/l) • Eclampsia • Na-Channel blockers intox • INH intox • Cholinergic (OP/nerve agent) intox Immediate management • D50W (50ml IVP) • 3% NS (100ml over 10min) • CaCl 10% (10ml over 10min) • MgSO4 (2g over 15 min) • MgSO4 (4-6g over 15min) • NaHCO3 (1-2 mEq/kg IVP) • Pyridoxine (5g empiric, or 1g/kg, or 1:1 if known dose) • Atropine (1g q5min) 2-PAM (1-2g over 5-10min)
- 28. Case 3 • 68yo F in ED feeling “weak and dizzy” • Evaluated by previous MD • Signed over to you as “probable viral illness, exam and x-rays normal, cleared for discharge if labs normal” • Nurse relates CBC extended electrolytes, renal and liver function are normal, except patient unable to get up complaining of numbness in legs
- 29. Exam • ABCs intact •VS: HR 78 BP 132/78 RR 15 Sat 99 T 36.9 • GCS 15 PERRLA • Chest: unremarkable • CV: unremarkable • Abdo unremarkable • Ext: no swelling tenderness or deformity • Please outline your next steps in management
- 30. Case 4 • 42yo M presents with weakness and diplopia • PMH: unremarkable • Meds: none • Social: admits to occasional IVDU • HR 80 BP 135/90 RR 15 Sat 98% • A: intact • B: good AE bilat • C: well perfused • GCS 15 Pupils 5mm bilat
- 31. Exam • Neuro exam: •CN: diplopia with EOM, dysconjugate gaze, mild slurred speech, rest of CN normal • Power: UE 3/5 LE 4/5 • Sensory normal • Reflexes: diminished in UE, normal in LE • Gait/cerebellar normal • Rest of exam unremarkable • Outline your management
- 32.
- 33. Approach to weakness Weakness Neuromuscular UMN(CNS) Cortical Brainstem Spinal CordLMN (PNS) NMJ Muscle Non- neuromuscular Wide differential
- 34. Exam - localization Brain •Weakness - variable • Bowel/Bladder - • Reflexes - increased • Sens - diminished • Pain - no • Asymmetric/ unilateral Brainstem • “Crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis Spinal Cord • Weakness - fixed level • Bowel/Bladder - yes • Reflexes - increased • Sens - diminished • Pain - +/-
- 35. Exam - localization LMN- Nerve • Weakness - distal > proximal and ascends • Bowel/Bladder - NO • Reflexes - diminished • Sens - nl/paresthesias • Pain - no NMJ – motor end plate • Weakness - ocular, bulbar and descends, fatigable • Bowel/Bladder - NO • Reflexes - nl/diminished • Sens - nl • Pain - no Muscle • Weakness - proximal > distal • Bowel/Bladder - NO • Reflexes - nl/diminished • Sens - nl • Pain - +/-
- 36. Cannot miss diagnoses UMN •CVA • ICH • MS • ALS (UMN & LMN) Spinal Cord • Infection (Epidural Abscess) • Tumor • Infarction/ Trauma - Cord Syndromes • Transverse Myelitis PNS • GBS • Toxins (Ciguatera) • Tick Paralysis • DM neuropathy (non- emergent) NMJ • MG • Botulism • OP • Lambert- Eaton Myasthenic Syndrome Muscle • Rhabdo • Dermato- myositis • Poly- myositis • Alcoholic myopathy
- 37. Cannot miss diagnoses UMN •CVA • ICH • MS • ALS (UMN & LMN) Spinal Cord • Infection (Epidural Abscess) • Tumor • Infarction/ Trauma - Cord Syndromes • Transverse Myelitis PNS • GBS • Toxins (Ciguatera) • Tick Paralysis* • DM neuropathy (non- emergent) NMJ • MG • Botulism • OP • Lambert- Eaton Myasthenic Syndrome Muscle • Rhabdo • Dermato- myositis • Poly- myositis • Alcoholic myopathy
- 38. APPROACH TO PNSDISORDERS
- 39.
- 40. APPROACH TO LMN(PNS) AIDP: GBS, HIV, diptheria DSPN: DM, EtOH, toxins, vitamin deficiency, porphyria Mixed Plexopathy/radiculopathy/ & Mononeuropathy: structural/MSK causes Mononeuropathy multiplex: vasculitis, Lyme, lead Motor neuropathy: ALS, MND, polio Sensory neuropathy: Herpes (simplex, zoster) paraneoplastic
- 41. Intubation Indications • Severefatigue • Inability to protect airway • Rapidly increasing pCO2 • Hypoxemia despite O2 • FVC <15 mL/kg • NIF <20 cm H2O
- 42.
- 43. Background • Acute polyneuropathydue to immune-mediated peripheral nerve myelin sheath destruction • Associated with: – viral or febrile illness – campylobacter infection – vaccination • Symptoms: – worst 2-4wk after onset, – plateau for 2-4wk – remit from wks-months
- 44. Clinical Features • Viralillness -> ascending, symmetric weakness or paralysis and loss of DTRs • May progress to diaphragm resulting in need for mechanical ventilation (33% of pts) • Autonomic dysfunction occurs in 50% of pts • Miller-Fisher Syndrome – Associated w/ campylobacter infection – More likely to be preceded by diarrhea than viral prodrome – Consists of ophthalmoplegia and ataxia – Weakness is less severe but descending; disease course milder than classic GBS
- 45. Diagnosis • Required – Progressiveweakness of more than one limb – Areflexia • Suggestive – Progression over days to weeks – Recovery beginning 2—4 wk after cessation of progression – Relative symmetry of symptoms – Mild sensory signs and symptoms – CN involvement (Bell's palsy, dysphagia, dysarthria, ophthalmoplegia) – Autonomic dysfunction – Absence of fever at onset – Cytoalbuminologic dissociation of CSF (high protein (>45) and low WBC count (<10)) – Typical findings on electromyogram and nerve conduction studies
- 46. Treatment • Intubation indications: –Vital capacity <15mL/kg – PaO2 <70 mm Hg on room air – Bulbar dysfunction (difficulty with breathing, swallowing, or speech) – Aspiration • IVIG or plasmapheresis (provide equivalent but not additive effects)
- 47. Disposition • Indications foradmission to ICU: – Autonomic dysfunction – Bulbar dysfunction – FVC <20 mL/kg – NIF <30 cm H2O – Decrease of >30% of FVC or NIF – Inability to ambulate – Treatment with plasmapheresis – Anticipated clinical course requiring mechanical ventilation
- 48.
- 49. Background • Clostridium botulinumproduces toxin that blocks Ach release from presynaptic membrane • Cases due to: – Improper canning – Black-tar heroin use – Wound infection (contaminated wounds, C- section, tooth abscess, sinus infection) • Symptoms begin 6-48hr after exposure
- 50. Clinical Features • GI –N/V, abdo cramps, diarrhea or constipation – Not seen in pts who contract botulism from heroin or contaminated wound • Paralysis – Descending, symmetric – Cranial nerves and bublar muscles are affected first: diplopia, dysarthria, dysphagia • Will progress to respiratory depression if not treated • Anticholinergic signs – Urinary retention, dry skin/eyes, hyperthermia • Dilated pupils (in contrast to pts w/ MG)
- 51. Infantile Botulism • Background –Due to consumption of botulinum spores (usually from honey) • Higher GI tract pH of infants makes them more susceptible – Most cases occur in <1yr, 90% occur in <6m • Clinical Features – GI • Constipation • Poor feeding – Lethargy – Weak cry – Floppy infant
- 52. Management • Ventilatory support –Consider intubation when FVC <30% predicted or <15cc/kg • Antitoxin/immune globulin • Infant – Supportive care only (no benefit from antitoxin or abx) • Wound – Antitoxin, wound irrigation & debridement, Pen G 10- 20 mil units/day • Disposition – ICU
- 53.
- 54. Background • Autoantibody degradation,dysfunction, and blockade of acetylcholine receptor at the NMJ • Thymus is abnormal in 75% of pts – Thymectomy resolves or improves symptoms in most pts, especially those with a thymoma • No sensory, reflex, pupillary, or cerebellar deficits
- 55. Myasthenic Crisis vs.Cholinergic Crisis • Myasthenic Crisis – Respiratory failure is feared complication – Much more common – Triggers: • med non-compliance, infection, surgery, tapering of immunosuppressants, meds (corticosteroids, thyroxine, BBs, CCBs, Na-channel blockers, aminoglycosides, tetrayclines, clindamycin) • Cholinergic Crisis • Excessive anticholinesterase medication may cause weakness and cholinergic symptoms • Rarely seen w/ dose limitation of pyridostigmine <120mg q3hr • If on usual dose of meds assume exacerbation due to MG even w/ cholinergic side effects • Edrophonium (Tensilon) test to distinguish the two is controversial – Side effects of Edrophonium: Arrhythmias, Hypotension, Bronchospasm – Treatment: Atropine
- 56. Clinical Features • Fatigablesymptoms: worsen with repetitive use / as the day progresses – Ice Pack Test- 2 min should improve symptoms temporarily (usually ptosis; high specificity) • Muscle weakness – Proximal extremities – Neck extensors – Facial/bulbar muscles (dysphagia, dysarthria, dysphonia) • Ocular weakness – Ptosis – Diplopia – CN III, IV, or VI weakness
- 57. Treatment • Always evaluateFVC, NIF, ability to handle secretions • Meds – Pyridostigmine • If pt's usual dose has been missed the next dose is usually doubled • PO route: 60-90mg q4hr • IV route: 1/30th of the PO dose (2-3mg) by slow IV infusion – Neostigmine • 0.5mg IV • Intubation – If possible avoid depolarizing AND non-depolarizing agents • If pt requires paralysis use non-depolarizing agent at smaller dose • If must use depolarizing agents, will need higher doses • Plasmapherisis • IVIG
- 58.
- 59. Background • Autoantibodies againstCa-channels of axon nerve terminals responsible for ACh release • Epidemiology – Predominantly a disease a/w older men w/ history of cigarette smoking and lung cancer • 50% of pts have concurrent small-cell lung cancer – Syndrome can precede detection of malignancy by several years
- 60. Clinical Features • Fluctuatingsymmetric weakness and fatigue, esp of proximal leg muscles • Improvement in strength with sustained or repeated exercise (in contrast to MG) – Lambert sign: handshake strength increases over several seconds • Myalgias • Muscle stiffness (especially in hip and shoulders) • Paresthesias • Metallic taste • Autonomic symptoms (dry mouth, impotence) • Eye movements are unaffected • Sensory examination normal
- 61. Treatment • Supportive (progressionto respiratory or bulbar failure is rare) • Acetylcholinesterase inhibitors (e.g. pyridostigmine) can improve symptoms • Disposition – Admission required when infectious complications occur or when severe disability requires inpatient immunotherapy
- 62.
- 63. • Background – Causedby neurotoxin produced by certain ticks in the US and Australia – Most cases reported in children • Clinical Features – Symptoms begin 2-6d after attachment of tick • Ataxia -> symmetric ascending flaccid paralysis w/ loss of DTRs – Presentation can be identical to Guillain-Barre including progression to resp paralysis – Unlike GBS, may have ocular signs (e.g. fixed and dilated pupils)
- 64. • Diagnosis – Sensoryabnormalities and elevation of CSF protein level do not occur – Progression and resolution of sx (w/ tick removal) is faster than in Guillain-Barre • Treatment – Remove tick as quickly as possible with tweezers – Supportive care (resolves on its own)
- 65.
- 66. Background • Inflammatory disorderthat involves a complete transverse section of the spinal cord – Results from viral infection, postvaccination or as part of MS, SLE, or cancer • May present exactly like a compressive lesion of the spinal cord
- 67. Clinical Features • Mayprogress over days-weeks • Neck or back pain + neuro complaints: – Bilateral motor, sensory, and autonomic disturbances – Fecal/urinary retention and incontinence
- 68. Diagnosis & Management •Neurologic findings that are c/w epidural compression but normal MRI • Must rule-out compressive lesion of the cord • MRI – May show cord swelling • LP – Lymphocytosis, elevated protein • Admit for corticosteroids and plasma exchange
- 69.
- 70. Background • CNS myelindestruction causes variable motor, sensory, visual and cerebellar dysfunction • Types – Relapsing/remitting (most common) • Relapse (days-months) followed by remission – Secondary progressive • Relapses and partial recoveries occur, but disability doesn't fade away between cycles – Primary progressive • Symptoms progress slowly and steadily without remission – Progressive relapsing • Similar to primary progressive but with superimposed flares
- 71. Clinical Features • Classicpt has multiple presentations for neuro symptoms of different areas of pathology – Pt often has resolution of the earlier symptoms • Symptoms worsen w/ increases in body temperature • Muscle/sensory signs: – Lower extremity weakness usually worse than upper extremity – Upper motor neuron signs: • Hyperreflexia • Positive Babinski – Decrease in proprioception / pain/temp sensation – Lhermitte sign • Electric shock sensation radiating down back into arms/egs from neck flexion
- 72. Clinical Features • Opticneuritis – Initial sign in 30% of pts – Vision loss (usually unilateral) often preceded by retrobulbar pain – Blurred vision – Nystagus – Diplopia – Internuclear ophthalmoplegia • Abnormal eye adduction bilaterally and horizontal nystagmus • Dysautonomia – Urinary retention (increased risk of UTI/pyelo) – Constipation or incontinence – Sexual dysfunction (males)
- 73. Diagnosis • MRI – Multiplelesions in supratentorial white matter, paraventricular area, spinal cord • CSF – Elevated protein and gamma-globulin (increased oligoclonal bands)
- 74. Management • Treatment – Fevermust be reduced to minimize weakness assoc w/ elevated temperature – Abx for UTI/pyelo – High-dose steroid therapy for relapses • Disposition – Hospitalization indicated for: • Any disease exacerbation a/w significant morbidity • IV abx or steroid therapy required • Depression and significant risk of suicide
- 75.
- 76. Background • Progressive muscleatrophy/weakness due to degeneration of upper and lower motor neurons • Patients will rarely present to the ED undiagnosed • Likely related to mutated superoxide dismutase (SOD1) gene
- 77. Clinical Features • Acuterespiratory failure – Predicted by FVC <25 mL/kg or 50% decrease from normal • Aspiration pneumonia • Trauma related to extremity weakness
- 78. Management • Nebulized medications •Steroids • Antibiotics • Assisted ventilation / intubation
- 79. References • Rosen’s EmergencyMedicine 8th Ed. Chapters 102, 107, 108 • Wikem.org pages – https://www.wikem.org/wiki/Weakness – https://www.wikem.org/wiki/Lambert- Eaton_myasthenic_syndrome – https://www.wikem.org/wiki/Amyotrophic_Lateral_Sclerosis_(A LS) – https://www.wikem.org/wiki/Multiple_sclerosis – https://www.wikem.org/wiki/Transverse_Myelitis – https://www.wikem.org/wiki/Guillain-Barre_syndrome – https://www.wikem.org/wiki/Tick_paralysis – https://www.wikem.org/wiki/Myasthenia_gravis – https://www.wikem.org/wiki/Botulism
Editor's Notes
- #12 Seizures are very common presenting complaint to the ED Know how to differentiate seizures from syncope and pseudoseizures
- #13 Understanding the basics here gives insight into how the therapies work
- #14 Clinically it is easy to recognize this
- #15 Important to ask if witnessed generalized seizures began as focal ones
- #16 Any neuron is potentially a focus of seizure activity depending on this balance. Seizure thresholds can be modified by temperature, injury, changes in nutrient or oxygen supply, metabolic disturbances, toxins etc.
- #17 This graphic shows which channels, neurotransmitters and receptors are involved on the excitatory side. A large proportion of anticonvulsants blocking recruitment and propagation by acting on the voltage-gated Na-Channel Most of these drugs are used in preventative and maintenance therapy
- #18 Many other anti-convulsants work on potentiating inhibition These are more often used in aborting seizures
- #19 It is important to know this well in EM because treatment is time dependent and life threatening Often you are in the resuscitation room and must think on your feet and not make mistakes
- #20 Aborting the seizure is often the key to being able to assess and manage the ABCs
- #21 Can be subtle and missed. Must have high index of suspicion to look for it.
- #22 Many sources/institutions have slightly different recipes but most resemble this *Use of Keppra as an abortive agent is relatively novel, 3 small size open label RCTs (1 adult and 2 pediatric) show benefit of 20mg/kg over 15 min But large RCT is needed before it becomes standard of care
- #24 Know this table well because it summarizes adult and pediatric doses and potential side effects of most commonly used anticonvulsants in a resuscitation scenario (i.e. when you shouldn’t be wasting time looking stuff up)
- #25 Memorizing Rosen’s exhaustive list of etiologies of status, however, is more akin to medieval forms of torture While many things can cause seizures, there are relatively fewer therapeutic interventions for seizures It is easier to think of the causes in relation to what can be done about them
- #27 Besides the cocktail, there is a short list of other acute interventions that may abort refractory seizures
- #28 We’ll switch gears
- #34 Weakness is a VERY common and often vague complaint in the ED While the vast majority of these complaints are non-focal generalized non-neuromuscular weakness, for which there are a myriad causes, once in a while there will be true neuromuscular weakness The differential for this is also unfortunately quite wide and it is useful to try quickly to categorize symptoms into anatomic components of the neuromuscular chain as shown
- #35 Lesions in each area exhibit specific patterns and clusters of signs and symptoms that are important to recognize
- #36 Complaints of neuromuscular weakness require more detailed neurological evaluation At the minimum these 5 areas of questioning and examination should allow broad categorization
- #37 Once you have localized the lesions, the list of cannot miss emergent diagnoses is relatively small, and while there are long lists of other potential pathologies, their evaluation and final diagnosis is often not made in the ED Bear in mind some conditions have overlapping symptoms (e.g. MS and ALS)
- #38 We will focus on conditions you are likely not to be taught in the context of other sessions (e.g. Stroke, trauma, toxicology, connective tissue diseases) Of the remaining conditions (which occur relatively rarely) the most common and potentially acutely life threatening are Guillain Barre Syndrome, Mysathenia Gravis and Botulism *Tick paralysis is acutely life threatening but rare
- #39 Rosen has an additional approach to peripheral nerve disorders that is symptom pattern based and can be useful sometimes but the problem is the 7 categories which I find particularly confusing
- #41 It’s a little easier if you know some of the more common conditions in each category but if you look at all the causes it is actually quite overwhelming. Each category has a wide differential including many rare and esoteric diagnoses as well as several others that cannot be confirmed in the ED.
- #42 One thing that is common to the 3 major Emergent causes of neuromuscular weakness is that they all require evaluation of the airway using conventional approaches as well as blood gas monitoring and spirometry, and in cases of known or highly suspected GBS, MG or botulism, this evaluation should be done first.
- #46 Autonomic dysfunction: Tachycardia, bradycardia, dysrhythmias, wide variations in BP, postural hypotension Urinary retention Constipation Facial flushing
- #64 Death from paralysis can occur before tick is found if not suspected. Look at hairline.