Trace elements in cerebrospinal fluid in motor neurone disease.

Concentrations of sodium, chlorine, potassium, chromium, iron, cobalt, zinc, rubidium, silver, caesium, and selenium in cerebrospinal fluid from 14 control subjects and 20 patients with motor neurone disease were measured by in vitro neutron activation analysis. No statistically significant correlation was found between the concentrations of any two elements other than sodium and chlorine in either the patient or control group (r = 0.9905; p less than 0.001). The mean cobalt concentration was significantly lower in the patients (p = 0.0015). No other statistically significant difference was shown. The relevance of this finding was examined in relation to current concepts of the pathogenesis of motor neurone disease and the role of cobalt in cellular metabolism.