SOD1 and amyotrophic lateral sclerosis: In subtypes of ALS associated with the SOD1 mutation and the sporadic disease, there have been several reports indicating that the involvement of mitochondria in pathogenesis includes the generation of intracellular free radical species, ultrastructral changes in mitochondrial morphology, swollen and vacuolar mitochondria and increased activity of complex I, III and IV in the Upper and lower MNS, frontal cortex and spinal cord (von Lewinski and Keller, 2005).