Neutron activation analysis of trace elements in motor neuron disease spinal cord

Levels of 10 trace elements were analysed in autopsied lumbar spinal cords of 38 motor neuron disease patients and 22 control subjects using instrumental neutron activation analysis. Statistically significant elevations of iron, selenium and zinc, and depletions of mercury and cesium were found in the spinal cords of motor neuron disease patients compared with control subjects. No significant correlations were found between disease duration, clinical severity or lumbar motor neuron counts and iron and selenium levels, suggesting that accumulation of these elements occur early as well as late in the disease process and therefore are not a consequence of end stage pathology. Increased iron in motor neuron disease spinal cord could act to enhance formation of reactive oxygen species. Our study supports the free radical hypothesis of neuron degeneration in motor neuron disease.