BRAIN ELECTRICAL-ACTIVITY (QUANTITATIVE EEC AND BIT-MAPPING NEUROCOGNITIVE CNV COMPONENTS), PSYCHOMETRICS AND CLINICAL FINDINGS IN PRESENILE SUBJECTS WITH INITIAL MILD COGNITIVE DECLINE OR PROBABLE ALZHEIMER-TYPE DEMENTIA

Clinical, neuropsychological and neuropsychophysiological data (Q-EEG, ERPs and CNV/RT activity) were obtained from 24 patients who had more or less severe presenile primary cognitive decline without depression , and compared with similar data from IO age-matched healthy volunteer s (mean age, 59.4 years). All of the patients (15 M and 9 F; mean age 59.6 years) were selected according to the DSM III-R, ICD-10 and NINCD S-ADRDA criteria and underwent CT and MRI scanning, in addition to a s tandard clinical examination, a battery of psychometric tests, spectra l EEG, and bit-mapped CNV complex and RT to S2 analyses. Twelve of the 24 patients presented an initial presenile idiopathic cognitive decli ne (PICD) but did not wholly fulfil the clinical and neuropsychologica l criteria for primary dementia or for a diagnosis of probable AD; the remaining 12 patients showed characteristic clinical signs and sympto ms of a very probable early stage of presenile Alzheimer-type dementia (PAD). ANOVA, correlational and discriminant analyses of the neuropsy chological test scores, and the neurophysiological and RT to S2 data r evealed 22 highest-ranked between-group discriminant factors (all with a significance level of p<0.01). The conclusive discriminant analysis retained 13 of these factors as final canonical functions, and these showed a 97% grouping accuracy (33 of the 34 subjects examined); the s ame percentage of correct classifications was also achieved using only the 15 best indicators in the group of CNV/RT findings. Using both of these sets of highest-ranked discriminators, all of the normal subjec ts and all of the PAD patients were correctly classified; only 1 PICD patient was misclassified as normal when the first group of 13 factors was used, and another PICD patient was misclassified as PAD using the second group of 15 factors. Our findings suggest that, providing they are correctly performed and interpreted, these non-invasive technique s may be an important tool for identifying incipient stages of preseni le Alzheimer-type dementia.