Experimental and clinical studies showed that Phosphatidylserine--special preparation from cow's brain by FIDIA, Abano Terme, Italy--is able to influence cerebral changes contributed to the symptoms of senile dementia of Alzheimer's type. The application of the computerized EEG method DYNAMIC BRAIN MAPPING (HZI Research Center, Tarrytown, New York) is able to proof the therapeutic effect of Phosphatidylserine: the acceleration of a slowed EEG in Parkinsonian patients with SDAT. These reactions were seen previous to the favourable clinical influence documented by the Sandoz Clinical Assessment Geriatric Scale (SCAG), which showed a significant amelioration in anxiety, motivation and affectivity by the verum drug. Acute and long-term CEEG results--till 18 months--showed that the so-called Theta anteriorisation can be reduced or even abolished; this is replaced by Alpha waves. Even in preclinical cerebral changes this method open the possibility to show incipient alterations of the brain metabolism. Preliminary therapeutic results leads to this and not prooven hypothesis that prevention or retardation of cerebral ageing might be possible.