Initial Heart Rate Reactivity to Socioemotional Pictures in Early-Onset Alzheimer's Disease.

Patients with Alzheimer's disease (AD) often have generalized anxiety, particularly in early-onset AD (EOAD) or the first stages of their disease. This increased anxiety could be associated with decreased sensorimotor gating with increased attention to significant stimuli from AD pathology in the entorhinal cortex. We investigated whether widening initial attention to socioemotional stimuli was association with anxiety among 16 patients with first stage EOAD compared to 19 normal controls (NCs). The participants underwent assessment of their initial heart rate deceleration ("orienting response"; OR), a measure of attentional refocusing, to pictures (International Affective Picture Stimuli) varying in pleasant-unpleasant valence and social-nonsocial content. The results showed group differences; the EOAD patients had significantly larger ORs than the NCs across conditions, with larger ORs in each valence and social condition. In addition, the EOAD patients, but not the NCs, showed ORs to normally less threatening stimuli, particularly pleasant, but also less significantly, social stimuli. On the Neuropsychiatric Inventory, the ORs among the EOAD patients significantly correlated with anxiety scores. Together, these findings suggest that anxiety in mild EOAD may be associated with widening attentional refocusing to socioemotional stimuli, possibly reflecting decreased sensorimotor gating in the entorhinal cortex. This finding could be a potential biomarker for the first stages of AD.