[Sustained attention in the preclinical phase of Alzheimer's disease]

Deterioration of attention in the preclinical phase of dementia of Alzheimer s type (DAT) is not very well known neither available studies are conclusive.

We outline if would be possible to identify a deficit of sustained attention in preclinical phase of DAT and if this attentional dysfunction could help to identify those patients, referred by subjective memory complaints (SMC), who will progress in a few years to DAT.

We compared basal exploration in a task of sustained attention (CPT) of 70 patients referred by SMC and followed longitudinally for 2 years. Twenty seven patients developed probable DAT and forty three remained clinically stable.

Patients who will be diagnosed 2 years later with DAT performed significantly more poorly than patients who did not develop DAT. Patients who will be diagnosed 2 years later with DAT made a higher number of omission errors and obtained a lower number of correct responses.

CPT paradigm is a vigilance task that detects deterioration of sustained attention in the preclinical phase of DAT and could be an objective indicator of the cognitive decline in the preclinical phase of Alzheimer s disease.