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Case 2
46y female with acute bilateral facial muscle weakness, ptosis, dysarthria, followed by bilateral upper limb weakness. Blurred vision but no other sensory symptoms. No spasticity, decrease deep tendon reflexes.
Vitals: Normal
GCS: 15/15
Perceived weakness - The patient feels that more energy is required to exert a given amount of force, when in fact the actual muscle strength is normal.
Paralysis is the loss of voluntary movement because of interruption of one of the motor pathways at any point from the cerebrum to the muscle fiber.
Paresis is a lesser degree of paralysis.
Clinical Findings
Strength - diminished to absent
Reflexes - increased*
Sensory - Variable
Tone - Increased (spasticity)
Gait - Spastic
Babinski - up going plantar
Clinical Findings
Strength - decreased (LE > UE)
Reflexes - decreased to absent
Sensory - Very common*
Tone - decreased to flaccid
Gait - Normal to unsteady*
Babinski - down going plantars
Other - Autonomic dysfunction
Clinical Findings
Strength - LE > UE > Oculobulbar
Reflexes - Normal*
Sensory - Normal
Tone - Normal
Babinski - down going plantar
Other - Muscle fatigue with repetition
Clinical Findings
Strength - Decreased (prox > dist)
Reflexes - Depends on severity
Sensory - Normal
Tone - Normal
Babinski - Down going plantar
Other - Tenderness on palpation*
- Acute monophasic illness provoked by previous infection
- Rapidly progressive secondary to autoimmune process
- Demyelinating / Axonal Polyneuropathy
Cardinal clinical features of GBS
- Progressive, symmetric muscle weakness
- Absent or depressed deep tendon reflexes.
- Respiratory failure in about 30 percent,
- Dysautonomia occurs in 70% of patients.
- Progresses over 2 weeks on average
- Facial weakness (50%) ocular muscles (15%)
- Often a prominent severe back pain
- Sensory disturbance in 80% (often mild)
- Has multiple variants (AIDP, Miller Fisher, AMAN)
Investigations
LP - Elevated protein count with normal WBC (albuminocytologic dissociation)
EMG/NCS - Evidence of either demyelinating or axonal neuropathy (depends on the variant)
Systemic Antibodies - GQ1b useful for Miller Fisher variant; otherwise of no clinical utility.
Prognosis
Clinical course with no treatment
- Progression of disease up to 2 weeks
- Plateau for 2 weeks
- Recovery 'weeks' to 'months'
Long term
- 85% complete recovery
- 10% delayed and incomplete recovery
- 5% die
- 10% recurrence
Botulism is a neuroparalytic syndrome resulting from the action of a neurotoxin elaborated by the bacterium Clostridium botulinum, .a heterogeneous group of gram-positive, rod-shaped, spore-forming, obligate anaerobic bacteria.
Cardinal clinical features of Botulism
- Acute onset of bilateral cranial neuropathies
- Symmetric descending weakness
- Absence of fever
- The patient remains responsive
- No sensory deficit, except for blurred vision
- Heart Rate normal to slow
- Five forms of botulism exist, including food borne botulism, infant botulism, wound botulism, adult enteric infectious botulism, and inhalation botulism
Investigations
Generally not applicable; clinical diagnosis
Non specific blood markers
spores and/or toxin can be isolated
Prognosis
Requires 1 - 3 months of hospitalization regardless of the type of botulism
Ventilator support in 20-30%
Long term
- 5 - 8% mortality
- 1% newborn mortality
- long term sequelae of perceived weakness 25%
?
Approach to Acute Weakness in Adults presenting to The Emergency Department
Case 1
32y male with progressive (6 days), bilateral muscle weakness (lower extremity > upper extremity), and paresthesia x 4 limbs, accompanied by absent deep tendon reflexes. Bladder retention.
Vitals: Normal
GCS: 15/15
Guillain Barre Syndrome (GBS)
Botulism
"I feel weak"
Treatment
Supportive Therapy
Intubate if impending respiratory failure
Analgesia for neuropathic pain (50%)
Plasma Exchange or IVIG
No role for steroids
Treatment
Supportive Therapy
Intubate if impending respiratory failure
Anti-toxin (Equine serum botulism antitoxin and Human-derived botulinum immune globulin)
Pen G if wound infection (metronidazole if Pen allergy
Manage accordingly
Step 1
Reversible
Causes
Step 1
Compromised
Reversible
Causes
Compromised
Perceived
Paresis
Assess ABC
Assess Level of Consciousness
Shock
Severe Metabolic
Severe Endocrine
Perceived
Paresis
Massive cerebral stroke
Thalamic Stroke/lesion
Brainstem stroke/lesion
Cord inflammation/compression
Guillen Barre Syndrome
Tick Paralysis
Organophosphate toxicity
Botulism
Myopathic Crisis
Assess ABC
Assess Level of Consciousness
Shock
Severe Metabolic
Severe Endocrine
Massive cerebral stroke
Thalamic Stroke/lesion
Brainstem stroke/lesion
Cord inflammation/compression
Guillen Barre Syndrome
Tick Paralysis
Organophosphate toxicity
Botulism
Myopathic Crisis
Normal
Step 2
Perceived
Correct underlying
Cause and revaluate
Perceived
Perceived Weakness vs Paresis
Correct underlying
Cause and revaluate
Perceived Weakness vs Paresis
UMN
Paresis
Cortical - often associated with aphasia, neglect, visual field deficit
Subcortical - often purely motor. Ataxia and 'shaking hand'.
Brainstem - associated with CN deficit (contralateral)
Cord - Rarely pure motor; often associated with sensory level and bowel/bladder dysfunction.
Step 3
Unilateral
Step 3
Unilateral
Unilateral vs Bilateral
Unilateral
Unilateral vs Bilateral
LMN
Physical Exam*
Bilateral
Physical Exam*
Bilateral
Radiculopathy
Plexopathy
Peripheral nerve injury/entrapment
Step 4
UMN
Step 4
UMN
Cortical / Subcortical - Should have been identified on Step 1.
Brainstem - associated with CN deficit (potentially life threatening)
Cord - Rarely pure motor; often associated with sensory level and cord level plegia +/- bowel / bladder signs.
UMN vs non - UMN
Cortical / Subcortical - Should have been identified on Step 1.
Brainstem - associated with CN deficit (potentially life threatening)
Cord - Rarely pure motor; often associated with sensory level and cord level plegia +/- bowel / bladder signs.
UMN vs non - UMN
Non - UMN
Step 5
Guillain Barre
Tick Paralysis
Yes
Step 5
Guillain Barre
Tick Paralysis
Yes
CSF - Normal
Normal sensory exam
Acute course
Variable (single limb to full)
Tick present on PE
CSF - Abnormal
Objective sensory deficit
Subacute course
Always bilateral
No ticks on PE
bladder/bowel common
LMN Signs - LE > UE, sensory symptoms, and dysautonomia
CSF - Normal
Normal sesnory exam
Acute course
Variable (single limb to full)
Tick present on PE
CSF - Abnormal
Objective sensory deficit
Subacute course
Always bilateral
No ticks on PE
bladder/bowel common
LMN Signs - LE > UE, sensory symptoms, and dysautonomia
*Consider Toxins:
Arsenic poisoning / hexane / Thallium / mercury / lead
*Consider Toxins:
Arsenic poisoning / hexane / Thallium / murcury / lead
No
Step 6
Yes
Step 6
Yes
Neuromuscular Junction
Disorders
*Early Ocular and Bulbar weakness
Fatiguibale on excertion
Proximal > distal weakness
*Early Ocular and Bulbar weakness
Fatigable on exertion
Proximal > distal weakness
No
Muscular Pathology
Step 7
Yes
Muscular Pathology
Step 7
Yes
Myositis (inflamatory vs viral)
Alcoholic myopathy
- Asses heart function *
Weakness Proximal > Distal +
No sensory signs +/- myalgia
Myositis (inflamatory vs viral)
Alcoholic myopathy
- Asses heart function *
Weakness Proximal > Distal +
No sensory signs +/- myalgia
Shock /
Relative ischemia
Cardiogenic
Obstructive
Volume depletion
Distributive
Impaired delivery
Psychogenic
Inflammatory
Infection
Cancer
Rheumatologic
Allergy
Metabolic/
endocrine
Acute
Weakness
Manage accordingly
Step 1
Reversible
Causes
Compromised
Paresis
Perceived
Assess ABC
Assess Level of Consciousness
Shock
Severe Metabolic
Severe Endocrine
Massive cerebral stroke
Thalamic Stroke/lesion
Brainstem stroke/lesion
Cord inflammation/compression
Guillen Barre Syndrome
Tick Paralysis
Organophosphate toxicity
Botulism
Myasthenic Crisis
Normal
Step 2
Perceived
Correct underlying
Cause and reevaluate
Perceived Weakness vs Paresis
UMN
Paresis
Cortical - often associated with aphasia, neglect, visual field deficit
Subcortical - often purely motor. Ataxia and 'shaking hand'.
Brainstem - associated with CN deficit (contralateral)
Cord - Rarely pure motor; often associated with sensory level and bowel/bladder dysfunction.
Step 3
Unilateral
Unilateral vs Bilateral
LMN
Physical Exam*
Bilateral
Radiculopathy
Plexopathy
Peripheral nerve injury/entrapment
Step 4
UMN
Cortical / Subcortical - Should have been identified on Step 1.
Brainstem - associated with CN deficit (potentially life threatening)
Cord - Rarely pure motor; often associated with sensory level and cord level plegia +/- bowel / bladder signs.
UMN vs non - UMN
Non - UMN
Step 5
Guillain Barre
Tick Paralysis
Yes
CSF - Normal
Normal sensory exam
Acute course
Variable (single limb to full)
Tick present on PE
CSF - Abnormal
Objective sensory deficit
Subacute course
Always bilateral
No ticks on PE
bladder/bowel common
LMN Signs - LE > UE, sensory symptoms +/- autonomic dysfunction?
*Consider Toxins:
Arsenic poisoning / hexane / Thallium / mercury / lead
No
Step 6
Yes
Neuromuscular Junction
Disorders
*Early Oculobulbar weakness
Fatigable on exertion
Proximal > distal weakness
No
Step 7
Yes
Muscular Pathology
Weakness Proximal > Distal +
No sensory signs +/- myalgia
"The Thinkers"
Cerebral Cortex
Subcortical tract
corona radiata
posterior limb of the internal capsule
Upper Motor
Neuron
Differential Diagnosis
Brain Stem
Ischemia
Hemorrhage
Tumor
Infections (Polio/ West Nile)
Inflammatory (MS / transverse myelitis)
Migraine - hemiplegic (rare)
Post-ictal (Todd's) paralysis
Oculobulbar - exit on the
contralateral side.
Decussation
Medulla
Spinal Cord
Transition of the UMN
to LMN - anterior horn
Muscular
Lower Motor
Neuron
Differential Diagnosis
Inflammatory Myopathy
Rhabdomyolisis
Differential Diagnosis
Radiculopathy
- Direct compression/impingement
- Lyme disease (late in disease)
Plexopathy
- Direct compression/impingement
- Tick Paralysis*
Neuropathy (poly/mono)
- Guillain Barre
- Diphtheria
- Arsenic / hexane / Thallium / mercury / lead / Tick exotoxin
- vasculitis/sarcoidosis
- Porphyria / paraneoplastic
Myofibril
Muscle fiber
Muscle fascicle
Muscle
Tendon
Neuromuscular
Junction
Differential Diagnosis
Botulism / Snake Venom
Hypocalcemia / Hypermagnesemia
Organophosphate / Carbamates poisoning
Myasthenia Gravis/ Myasthenic Crisis
Tick Paralysis* (LMN)
Ehab Eshtaya, MD
Objectives
Gain an algorithmic approach to 'acute weakness' as a presenting complaint in the Emergency Department
Basic understanding of the clinical presentation and differential diagnosis for the different components of the Neuromuscular pathway
Highlights of Guillain Barre Syndrome and Botulism as example of LMN and NMJ disorders.
Aknowledgments
Dr Fisher - Internal Medicine Staff
Dr Smyth - Neurology Staff
Dr Lefebvre - Emergency Medicine