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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. DISCUSSION: Findings suggest that multiple types of lucid episodes exist; not all signal impending death; and some, but not all, are precipitated by external stimuli.

Caregiver appraisals of lucid episodes in people with late-stage Alzheimer's disease or related dementias.

Introduction: Little is known about how family caregivers who witness unexpected and spontaneous communication among people in late stages of Alzheimer's disease and related dementias (ADRD) appraise these episodes of lucidity (EL). Methods: In an electronic, cross-sectional survey for former and current caregivers who participate in UsAgainstAlzheimer's A-LIST®, participants who reported witnessing an EL were asked how positive and stressful ELs were, if they made or changed decisions based on an EL, and what resources they sought out to explain ELs. Results: Caregivers reported 72% of ELs to be quite a bit or very positive, 17% to be stressful, and 10% to be both stressful and positive. Twelve percent of caregivers changed care plans because of ELs and 13% sought out information about ELs. Discussion: These exploratory data suggest caregiver reactions to EL vary. Caregivers may change or postpone care decisions due to EL, and few resources exist to address caregiver queries about EL.

Paradoxical lucidity: A potential paradigm shift for the neurobiology and treatment of severe dementias.

Unexpected cognitive lucidity and communication in patients with severe dementias, especially around the time of death, have been observed and reported anecdotally. Here, we review what is known about this phenomenon, related phenomena that provide insight into potential mechanisms, ethical implications, and methodologic considerations for systematic investigation. We conclude that paradoxical lucidity, if systematically confirmed, challenges current assumptions and highlights the possibility of network-level return of cognitive function in cases of severe dementias, which can provide insight into both underlying neurobiology and future therapeutic possibilities.