Up to date 6 patients with initial presenile idiopathic cognitive decline (PICD) and 5 suffering from a presenile Alzheimer-type dementia (PAD) with a mean age of 59.5 were admitted to the trial. The 6 PICD patients were assigned to a double-blind nicergoline/placebo 6-month course with an oral dose of 30 mg twice a day. PAD patients were treated in an open design (nicergoline oral dose 30 mg twice a day) for at least 6 months. Until now only 4 PICD and 3 PAD patients have been treated regularly for 6 months. Two of 4 PICD patients showed a progressive enhancement of contingent negative variation (CNV), shorter reaction time (RT) and an improvement of clinical status. The other 2 PICD patients, on the contrary, showed a progressive mild worsening of CNV-RT and clinical patterns. The double-blind trial is not yet completed. CNV activity, RTs and clinical patterns progressively improved also in 2 PAD patients while in the 3rd they remained nearly unchanged or minimally worse during the 6-month treatment. The positive nicergoline effect on CNV-RT and clinical status noted in our patients appeared similar to that observed by other authors with DHEMT in patients with senile dementia of Alzheimer type. No adverse drug-related reactions were seen.