Methodology of a controlled clinical study for cerebral aging evaluation.

A multicentre study was planned and executed to evaluate the effect of acetyl-L-carnitine in the treatment of cerebral aging. Using 42 health centres, whose comparability of methodology was ensured through a training seminar and an instructional booklet on the psychometric battery of tests employed, some 400 elderly patients aged 60-80 years were enrolled using strict selection criteria. Treatment was run in four phases over 150 days. The first phase, serving as the baseline evaluation, defined through a battery of tests, consisted of 30-day placebo treatment. In the second phase of 45 days, daily treatment with 1500 mg acetyl-L-carnitine was given followed by a psychometric evaluation. For the next 45 days the same drug therapy was employed with a complete psychometric evaluation on the final day. In the last phase of 30 days the placebo was again administered and a final assessment made of the residual benefits of the 90-day treatment with acetyl-L-carnitine. Using this plan made it possible to evaluate the placebo effects, perform cross-study comparisons and demonstrate the effectiveness of the drug treatment.