Amyotrophic lateral sclerosis.

Therapeutic trials for amyotrophic lateral sclerosis have attracted much attention, but no drug tested has been effective yet. Three major theories of pathogenesis form the basis for these trials: autoimmunity, chronic excitotoxic stimulation due to accumulation of glutamate, and, in the familial form, peroxidation due to subnormal activity of superoxide dismutase. In striking contrast to the negative results of all of the other drug trials, riluzole (a glutamate antagonist) was said to benefit patients with bulbar onset but not those with spinal onset. Problems with the original trial may be clarified by other studies now in progress. The most optimistic news is the response to therapy of multifocal motor neuropathy, a disorder that clinically resembles motor neuron disease. This year, three groups reported benefit from intravenous immunoglobulin therapy.