SOD1 and amyotrophic lateral sclerosis: These differences were statistically significant for verbal fluency (P < 0.001), executive functions (P = 0.01), the amyotrophic lateral sclerosis-specific (P = 0.002) and total score (P = 0.03) compared to SOD1, and for verbal fluency (P = 0.004) compared to sporadic patients.