Frontotemporal mild cognitive impairment.

Mild Cognitive Impairment appears to be a heterogeneous clinical entity comprising patients in the initial phases of distinct neurological disorders. Since frontotemporal dementia (FTD) is a relatively common neurodegenerative disease with an insidious onset, it might be possible to detect the patients in the initial phases of the disorder, before being demented. In the present work we proposed a set of criteria to identify patients with mild cognitive impairment of the frontotemporal type (FT-MCI), applied these criteria retrospectively to a large patient database, and evaluated the progression of the patients. Seven subjects fulfilling the proposed criteria for frontotemporal MCI were identified. They had symptoms of apathy, disinhibition, irritability and aggressiveness, untidiness, difficulties in decision making, obsessions and lack of concern for the others, for 1.5 +/- 0.8 years before the diagnosis of FT-MCI. Brain CT or MRI scan displayed fronto-temporal atrophy in five. Neuropsychological examination revealed deficits in tests dependent upon the frontal lobe, namely attention, verbal, motor and graphomotor initiatives and conceptual thinking. The patients kept their professional and daily activities, and were not demented. It was possible to have the follow-up of all patients. All but one patient diagnosed FT-MCI developed dementia of the frontotemporal type within 1.8 +/- 1.0 years. Application of the proposed criteria for FT-MCI, at least in this clinical neurological setting, can identify a group of patients with a high probability of further cognitive decline to dementia of the frontotemporal type.