Levels of nitric oxide metabolites in cerebrospinal fluid correlate with cognitive impairment in early stage multiple sclerosis

Cognitive impairment is an important clinical symptom of multiple sclerosis (MS) that often becomes an obstacle for employment, school attendance, and other activities of daily living and can occur in the early stage of disease, even in patients with clinically isolated syndrome or radiologically isolated syndrome.1 Recent studies have suggested both neuronal degeneration and central inflammation produce neuropathological damage to the central nervous system (CNS) in MS.2 Oxidative stress has been implicated in MS-related neurodegeneration.2 A previous study showed that nitrite and nitrate (NOx), which are oxidant metabolites of NO, are elevated in cerebrospinal fluid (CSF) from patients with MS.3 The excess production of NO may participate in MS-associated lesion formation and neuronal loss.In order to better elucidate the relationship between NOx and CNS damage in the early stage of MS, we investigated the relationship between cognitive impairment and CSF NOx levels in patients with early stage disease.We enrolled a total of 23 patients who were newly diagnosed with relapsing-remitting MS in accordance with the 2010 McDonald criteria.4 Participants were within 2 years of clinical onset and in remission for more than 3 months since the time of their most recent corticosteroid therapy or acute exacerbation. No patients were receiving disease modifying therapy at the time of CSF sample collection. We excluded patients who had other autoimmune disease …