Developing and describing a typology of lucid episodes among people with Alzheimer's disease and related dementias.

Abstract

This study examined lucid episodes among people living with late-stage Alzheimer's disease and related dementias (PLWD) and then developed a typology of these episodes to help characterize them. Family caregivers of PLWD provided information about witnessed episodes, including proximity to death, cognitive status, duration, communication quality, and circumstances prior to lucid episodes on up to two episodes (caregiver N=151; episode N=279). Latent class analysis was used to classify and characterize empirically distinct clusters of lucid episodes. Four lucid episode types were identified. The most common type occurred during visits with family and among PLWD who lived>6 months after the episode. The least common type coincided with family visits and occurred within 7 days of the PLWD's death. Findings suggest that multiple types of lucid episodes exist; not all signal impending death; and some, but not all, are precipitated by external stimuli.