REVERSIBLE COGNITIVE DECLINE DURING HIGH-DOSE ALPHA-INTERFERON TREATMENT

The cognitive effects of high-dose human leukocyte alpha-interferon (I FN-alpha) treatment were evaluated among 15 patients with the newly di agnosed spinal form of amyotrophic lateral sclerosis (ALS). To confirm the earlier findings showing reversible effects on cognitive performa nce and to exclude confounding effects, a randomized blinded placebo c ontrolled study was conducted. Twelve patients with continuous intrave nous IFN-alpha-infusion treatment over five days and 3 placebo control patients were neuropsychologically evaluated. The neuropsychological examination included tests of intelligence, memory, complex mental pro cessing, visuoconstructional skills, writing, and calculation. A clear difference in the performance profiles of the placebo and the IFN-alp ha-treated patient groups was detected: The IFN-alpha group showed sig nificant deterioration during treatment in the digit span backwards ta sk, logical verbal memory task, calculation ability, and writing time, while improvement was seen after treatment. Concomitant fever did not explain the findings. In the placebo group an improvement indicating a learning effect in the three consecutive measurements was found. The reversible cognitive deterioration indicates a clear CNS effect durin g the IFN-alpha treatment.