Serum nitric oxide concentrations in patients with multiple sclerosis and patients with epilepsy.

Nitric oxide (NO), a neurotransmitter and a free radical, has been purported to be involved in numerous neurological diseases. We investigated the serum nitric oxide concentration in 30 patients with multiple sclerosis (MS), in 30 patients with epilepsy and in 30 control subjects. The aim was also to determine whether a statistically significant difference in serum NO concentrations exists between the groups of interest. The total serum nitric oxide concentration was measured using the Griess reaction after reducing nitrates to nitrites with elemental zinc. In the group multiple sclerosis, the mean NO concentrations were X ± SEM = 31.02 ± 1.79 μmol/l, in the control group X ± SEM = 25.31 ± 1.44 μmol/l and in the group epilepsy X ± SEM = 22.51 ± 1.28 μmol/l. Student's t test showed a statistically significant difference between subjects with multiple sclerosis and the control group (p = 0.013), as well as between the groups multiple sclerosis and epilepsy (p = 0.0002). This data confirms that NO may play an important role in the pathogenesis of multiple sclerosis, whereas its role in epilepsy still remains unclear.