due to mutation in the superoxide dismutase enzyme, leading to exitotoxin damage
involve alpha motor neurons (lower motor) of anterior horm of spinal cord, leading weakness, faciculations, and wasting. Also involves lateral corticospinal tracts leading to weakness, spasticity, hyperreflexia, and Babinski signs
No sensory deficits, eye movements unaffected.
Tx: riluzole slows deterioration.
Things that mimic ALS: stenosis of spinal canal (EMG testing), hereditary spastic paraparesis (HTLV-1 testing), severe nutritional deficiency.
Things that affect alpha motor neurons but w/o spasticity or sensory deficits - spinal muscular atrophies