The main components of the CNV complex and reaction time (RT) to imperative signals are sensitive to the changes in behaviour, alertness, concentration, memory and motivation.Clinical neurophysiologists proved that CNV/RT and P300 are useful tools for the diagnosis and the evaluation of dementia and mental impairment related to aging. In particular CNV/RT complex can constitute a valuable clue to find out and characterize the early stages of pressnile mental deterioration.The aim of the study was to verify the effects of long-term nicergoline treatment (eight years) on CNV/RT activity and mental impairment of patients with presenile Idiopathic cognitive decline (PICD) or with early symptoms of presenile Alzheimer-type dementia (PAD).So far the CNV/RT activity was recorded and analyzed with topographic bit-mapping method in 11 patients with initial PICD, 6 with early symptoms and signs of probable PAD and 10 healthy age-matched controls. All patients underwent through medical and laboratory assessments, including CT-scan or MRI examinations, EEG spectral analysis and a battery of psychometric tests. A simple CNV paradigm (S1 clicks-2 sec ISI-S2 visual signals motor response with RT to S2) was used and each artifact-free response with 7 leads and linked mastoid reference was analyzed with a method of spariotemporal topographic CNV complex, mapping separately at 4 indipendent temporal window-areas (WA) of 200 ms duration ([mu ]V.s) corresponding to the most important and known CNV components. EOG, RT and S1, S2 signals were also recorded.Positive effects on CNV/RT activity and on clinical status were observed for a long time in PICD patients and are still present in 5 out of 11 cases after 8-year nicergoline treatment. A transitory electro-clinical improvement was initially found also in 2 PAD patients, but after one-year treatment all PAD patients progressively worsened. No important drug-related adverse reactions were recorded.These findings, together with some preclinical data indicating a cerebral metabolic activity of nicergoline, permit to postulate a selective effect of the drug on arousal and mental alertness as well as on affectivity and behaviour.