To determine whether or not the occurrence of sporadic amyotrophic lateral sclerosis (sALS) is associated with both excess nitric oxide (NO) metabolites and decreased protective superoxide dismutase (SOD) activity in the cerebrospinal fluid (CSF), we measured nitrate concentration and SOD activity in the CSF of sALS patients and in age- and gender-matched controls. We found stable NO metabolite levels to be significantly higher and SOD activity lower in the CSF of sALS patients. In addition, SOD showed a negative correlation with motor neuron axonal damage expressed as the amplitude of motor action potentials in upper limbs. Our results provide new evidence in vivo suggesting that NO products and SOD activity play a role in oxidant/ antioxidant imbalance in sporadic ALS.
