Amyotrophic lateral sclerosis: Difference between revisions
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==Clinical Features== | ==Clinical Features== | ||
[[File:Using a head mounted laser to point to a communication board.jpg|thumb|A man with ALS using a head-mounted laser pointer to comunicate. Note asymetic motor weakness.]] | |||
[[File:ALS clinical picture.png|thumb|A man with amyotrophic lateral sclerosis (ALS). (A) He needs assistance to stand. (B) Advanced atrophy of the tongue. (C) There is upper limb and truncal muscle atrophy with a positive Babinski sign. (D) Advanced thenar muscle atrophy.]] | |||
*Acute [[respiratory failure]] | *Acute [[respiratory failure]] | ||
**Predicted by forced VC <25 mL/kg or 50% decrease from normal | **Predicted by forced VC <25 mL/kg or 50% decrease from normal | ||
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==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{Weakness DDX}} | {{Weakness DDX}} | ||
==Evaluation== | |||
[[File:ALS cross.jpg|thumb|MRI (axial FLAIR) demonstrates increased T2 signal within the posterior part of the internal capsule, consistent with the diagnosis of ALS.]] | |||
''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== | ==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== | ==See Also== | ||
*[[Weakness]] | *[[Weakness]] | ||
*[[Intubation]] | *[[Intubation]] | ||
==External Links== | |||
*[https://www.merckmanuals.com/professional/neurologic-disorders/peripheral-nervous-system-and-motor-unit-disorders/amyotrophic-lateral-sclerosis-als-and-other-motor-neuron-diseases-mnds?query=amyotrophic%20lateral%20sclerosis Merk Manual - Amyotrophic Lateral Sclerosis (ALS) and Other Motor Neuron Diseases (MNDs)] | |||
*[http://www.emdocs.net/amyotrophic-lateral-sclerosis-focused-emergency-medicine-review/ emDOCs - Amyotrophic Lateral Sclerosis: A Focused Emergency Medicine Review] | |||
==References== | ==References== | ||
<references/> | <references/> | ||
Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 167. Chronic Neurologic Disorders | *Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e (2010), Chapter 167. Chronic Neurologic Disorders | ||
[[Category:Neurology]] | [[Category:Neurology]] |
Latest revision as of 17:50, 12 October 2022
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