Cognitive disturbances in non-demented subjects: heterogeneity of neuropsychological pictures

The aim of this study was to individuate different clinical and cognitive pictures among non-demented subjects reporting cognitive disturbances. We evaluated 75 subjects referring to Alzheimer's Disease Assessment Unit of IRCCS C. Mondino, Pavia, who complained memory disturbances in absence of impairment in every day activities, not fitting DSM-IV criteria for dementia (MMSE>24). The subjects underwent neurological examination, blood chemistry and neuroimaging. The neuropsychological evaluation included tests exploring language, short- and long-term memories, logical abilities, attentive and visuo-constructional functions. Fifty-two patients fitted the criteria for mild cognitive impairment (MCI); twenty-three subjects had a neuropsychological evaluation within normal range for age and schooling; they were significantly younger and better educated and presented higher scores at scale for depression and anxiety than the MCI patients. In the MCI group, on the basis of cognitive profile and neuroimaging, different subtypes could be distinguished. Subjective cognitive complaints represent a heterogeneous condition, which can develop into different clinical pictures. It is, therefore, important to individuate specific clinic and neuropsychological profiles, possible predictive of different evolution.