What is paradoxical lucidity? The answer begins with its definition

Abstract

Paradoxical lucidity in dementia is a clinically significant but understudied phenomenon. A provisional definition was proposed by the 2018 National Institute on Aging expert workshop and published in Alzheimer's and Dementia. However, several conceptual features of this definition remain vague, creating barriers to robust clinical research. Here, we critically analyze the provisional definition and present a refined definition that can be applied in clinical research. The refined definition is based on an analytic process our research group recently undertook to operationalize paradoxical lucidity for our own study protocol. Our goal is to facilitate debate and potentially harmonize interpretations of paradoxical lucidity among research groups.

Terminal lucidity: mysteries at the end of life

“…Of course, we also need to address the elephant in the room: why does this phenomenon tend to happen prior to one's death? Peterson et al (2021) suggested that although the current statistics support terminal cases being the majority in paradoxical lucidity, biases of observation may also contribute to the numbers. However, considering many personal stories from caregivers, I personally do not think this is too much of a significant factor.…”

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Paradoxical lucidity in general refers to episodes of unexpected cognitive improvement in people with severe dementia, although the exact definition as well as the identification process are complicated and under debate (Peterson et al, 2021). Such patients are often believed to have lost the capacity for coherent communicative behaviors from irreversible brain damage.

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Is there a difference between terminal lucidity and paradoxical lucidity?

“…1 Terminal lucidity, he asserts, "refers to any kind of unusually enhanced mental clarity before death," whereas paradoxical lucidity is mental clarity that occurs in persons with neurodegenerative diseases, such as This distinction contrasts with our assertion that all instances of terminal lucidity are paradoxical, but not all instances of paradoxical lucidity are also instances of terminal lucidity. 2 Nahm believes we are incorrect. Why?…”

“…Without further evidence and conceptual work to substantiate Nahm's argument, our original assertion that terminal lucidity is a type of paradoxical lucidity still stands. 2…”

Terminal lucidity versus paradoxical lucidity: A terminological clarification

“…1 Contrastingly, the second authors suggested that terminal lucidity should be regarded as an instance of paradoxical lucidity. 2 While I thoroughly appreciate that the subjects of terminal and paradoxical lucidity have found their way into professional medical research venues, a clarification regarding the precise meaning of these terms seems apt to avoid nurturing further misunderstandings. This clarification is of particular topicality because in several research projects that have recently been launched by the National Institute on Aging, the elaboration of more refined and detailed definitions for paradoxical lucidity is a crucial objective that is supposed to lay foundations for future research (for details, see NIA 3 ).…”