Sustained attention in the preclinical phase of Alzheimer's disease

Introduction. Deterioration of attention in the preclinical phase of dementia of Alzheimer's type (DAT) is not very well-known neither available studies are conclusive. Objective. 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. Patients and methods. 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. Results. 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. Conclusion. 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.