Estimated incidence of 1-3:100,000.

Mean age of onset is in the 60s, but ALS can occur as early as the 20s.

Disease duration is approximately 3 y from the time of diagnosis to death.

While there is slight male predominance of sporadic spinal ALS, slight female predominance is found in bulbar ALS

Most cases are sporadic but 5% to 10% are familial.

Risk of anesthesia increases as the FVC falls below 50%, ALS pts can be stratified as low risk if the FVC >50%, moderate risk if the FVC is 30% to 50%, and high risk if the FVC <30%.

Aspiration.

Respiratory depression.

Inability of pt to communicate secondary to bulbar weakness.

Aspiration.

Respiratory depression.

Inability of pt to communicate secondary to bulbar weakness.

Succinylcholine-induced hyperkalemia.

Prolonged resp depression with inability to extubate, even without use of muscle relaxants.

Hypersensitivity to nondepolarizing neuromuscular blockers.

Disease exacerbation with use of regional anesthesia.

Disease of unclear etiology that leads to progressive degeneration of the upper and lower motor neurons causing amyotrophy (muscle wasting) and lateral sclerosis (gliosis of the corticospinal tracts).

Located in the motor cortex (upper motor neurons) and anterior horn (lower motor neurons) of the spinal cord.

ALS has a relenting course that leads to weakness of all skeletal muscles in the body.

Typically, ALS is asymmetric involving the distal extremities first followed by bulbar muscle weakness as the disease progresses.

After diagnosis in an adult, pts are usually wheelchair bound by 18 mo and die after 3-5 y from resp suppression.

Juvenile forms of ALS do exist, present early in life, and are rare.

Upper motor neuron signs include spasticity, hyperactive reflexes, and upgoing plantar response; lower motor neuron signs include muscle atrophy and fasciculations.

Disease does not affect ocular muscles, bladder, bowel, and sensation.

ALS variants include:

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  Primary lateral sclerosis: Progressive degeneration of upper motor neurons;

  
  
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  Progressive muscular atrophy: Progressive degeneration of lower motor neurons;

  
  
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  Progressive bulbar palsy: Progressive motoneuron loss from lower cranial nerve nuclei and cervical spine.