Amyotrophic lateral sclerosis
(Redirected from Amyotrophic Lateral Sclerosis (ALS))
Background
- Progressive muscle atrophy/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
- Involvement of the anterior horn cells
Clinical Features
- Acute respiratory failure
- Predicted by forced VC <25 mL/kg or 50% decrease from normal
- Aspiration pneumonia
- Trauma related to extremity weakness
- Asymmetric weakness without sensory findings with mixed upper and lower motor nerve findings
Differential Diagnosis
Weakness
- Neuromuscular weakness
- Upper motor neuron:
- CVA
- Hemorrhagic stroke
- Multiple sclerosis
- Amyotrophic Lateral Sclerosis (ALS) (upper and lower motor neuron)
- Lower motor neuron:
- Spinal and bulbar muscular atrophy (Kennedy's syndrome)
- Spinal cord disease:
- Infection (Epidural abscess)
- Infarction/ischemia
- Trauma (Spinal Cord Syndromes)
- Inflammation (Transverse Myelitis)
- Degenerative (Spinal muscular atrophy)
- Tumor
- Peripheral nerve disease:
- Neuromuscular junction disease:
- Muscle disease:
- Rhabdomyolysis
- Dermatomyositis
- Polymyositis
- Alcoholic myopathy
- Upper motor neuron:
- Non-neuromuscular weakness
- Can't miss diagnoses:
- ACS
- Arrhythmia/Syncope
- Severe infection/Sepsis
- Hypoglycemia
- Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
- Respiratory failure
- Emergent Diagnoses:
- Symptomatic Anemia
- Severe dehydration
- Hypothyroidism
- Polypharmacy
- Malignancy
- Aortic disease - occlusion, stenosis, dissection
- Other causes of weakness and paralysis
- Acute intermittent porphyria (ascending weakness)
- Can't miss diagnoses:
Evaluation
Evaluate for complications of ALS or other treatable causes of progressive weakness
Labs
- CBC
- Evaluate for anemia/infection
- CPK
- Elevation associated with myopathy
- BMP
- Electrolyte abnormalities (hypercalcemia, hypokalemia, etc.) can cause weakness
- UA
- Evaluate for source of infection
- ABG
- Helps identify respiratory failure
Imaging
- CXR
- May identify aspiration, pneumonia, or other comorbid conditions
Other
- FVC
- Sensitive indicator of respiratory muscle weakness
- FVC <50% typically requires ventilatory support
Management
- Nebulized medications
- Steroids
- Antibiotics for infectious complications
- Assisted ventilation / intubation if in respiratory failure and aligned with goals of care
Disposition
- Admission
- Admit if patient requires respiratory support or has other complications requiring admission
- Evaluate patient's ability to be cared for at home; admit if needed
- Discharge
- If stable, and new onset ALS is suspected, discharge with a referral for outpatient evaluation by neurologist
- If stable, and ALS has previously been diagnosed, discharge if outpatient treatment remains available for patient
See Also
External Links
- Merk Manual - Amyotrophic Lateral Sclerosis (ALS) and Other Motor Neuron Diseases (MNDs)
- emDOCs - Amyotrophic Lateral Sclerosis: A Focused Emergency Medicine Review
References
- Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 167. Chronic Neurologic Disorders