Therapy of Alzheimer disease: symptomatic or neuroprotective?

Therapeutic strategies aimed to treat Alzheimer disease (AD) may either produce an attenuation of symptoms or slow down deterioration by attenuating progression of the disease. Presently, cholinesterase inhibitors (ChEI) have shown the most promising therapeutical effects. The best documented clinical efficacy of ChEI are studies of THA (tacrine, tetrahydroaminoacridine). The results of five recent studies in a total of 1,242 patients are reported here. Based on differences from placebo in scoring, a gain of 2-12 (MMSE) or 5-6 (ADAS) months in deterioration can be seen for a THA treatment of 2-3 months duration. This suggests that if treatment with THA will be extended to a longer period, the drug effect may not be only a symptomatic improvement but a slow-down of disease course. A similarity of THA's effect in AD with L-deprenyl effects in Parkinson is suggested.