Monozygotic twins with Alzheimer's disease treated with melatonin: case report

Monozygotic twins with Alzheimer's disease of 8 years duration were studied . The onset of the disease differed by about 6 months between twins and was characterized by a primary impairment of memory function. Clinical evaluat ion at the time of diagnosis indicated a similar cognitive and neuroimaging alteration in both patients, as well as a similar neuropsychologic impairm ent. A possible genetic origin of the disease was suggested by a similar di sease suffered by the mother. Patients were initially treated with vitamin E (800 I.U./day). Starting at approximately the same time (about 3 years ag o), they received 50 mg/day thioridazine because of the behavioral and slee p disorder. One of the patients was treated with melatonin (6 mg orally) at bed time daily for 36 months. Evolution of the disease in the melatonin-tr eated patient indicated a milder impairment of memory function, with substa ntial improvement of sleep quality and reduction of sundowning. This led to discontinuance (after 3 months) of thioridazine treatment. Present clinica l evaluation indicated a difference in functional stage of the disease betw een the twins (Functional Assessment Tool For Alzheimer's Disease, FAST), w ith a score of 5 in the twin who received melatonin and of 7b in the twin w ho did not receive it. Since experimental data on melatonin in animals indi cated its antioxidant, antiapoptotic, and beta-amyloid-decreasing activity, the hypothesis that melatonin has a beneficial effect in Alzheimer's disea se patients should be considered.