Table 1.

Database results and takeaways

Source	Journal	Year	Country	Design/Article Type	Author’s Conclusion
Batthyány and Greyson [12]	Psychology of Consciousness: Theory, Research, and Practice	2021	Multi-national	Survey/Qualitative Study	Lucid episodes are primarily a near-death phenomenon. Discussion of relationship between paradoxical and terminal lucidity.
Benson et al. [13]	Alzheimer Disease & Associated Disorders	2023	United States	Case Report	Lucid episode is distressful to the patient. Episodes exist along a continuum in the disease progression.
Bostanciklioglu [14]	Alzheimer’s & Dementia	2021	Türkiye	Theoretical Article	Sudden changes to neuromodulatory circuits in advanced dementia can produce neurotransmitter discharge triggering arousal &attention. Lucid dreaming may be a mechanistic model for studying lucidity in dementia.
Bostanciklioglu [15]	Alzheimer’s & Dementia	2020	Türkiye	Theoretical Article	Conventional hippocampus-centered memory theory may not be valid. Researching the relationships of the raphe nucleus, locus coeruleus, main mediators of serotonin level in brain, and memory retrieval may make progress in the study of lucidity and treatment of ADRD.
Eldadah, Fazio, and McLinden [16]	Alzheimer’s & Dementia	2019	United States	Perspective	Research resources offer potential for understanding mechanisms of ADRD and consciousness
Gilmore-Bykovskyi et al. [17]	The Gerontologist	2023	United States	Qualitative Study	Episodes of lucidity are distinct from routine fluctuations of the disease process. Caregiver interpretations vary. Observation is the best way to study the phenomenon; caregivers are central to the discussion. Qualitative appraisal instruments needed.
Gilmore-Bykovskyi et al. [18]	Journal of Gerontological Nursing	2021	United States	Letter to the Editor	Episodes of lucidity could occur when the person is alone. Scope of definition must be broad because meaning of episode is not limited to the caregiver.
Gilmore-Bykovskyi et al. [19]	Alzheimer’s & Dementia	2023	United States	Perspective	Guiding questions, considerations, possible hypotheses &flowchart of event characteristics. Potential for disambiguating between paradoxical and terminal lucidity.
Gilmore-Bykovskyi et al. [20]	Alzheimer’s & Dementia	2023	United States	Qualitative Study	Episodes of lucidity are both positive and negative experiences for caregivers.
Gotell, Brown, and Ekman [21]	International Psychogeriatrics	2003	Sweden	Comparative Study	Music can arouse lucid episodes. A unifying mechanism is nebulous.
Griffin et al. [22]	Alzheimer’s & Dementia	2022	United States	Qualitative Study	Caregiver experience with lucid episodes are usually positive and sometimes stressful.
Klapman [23]	The University of Western Ontario	2021	Canada	Thesis/Quantitative Study	Experiment gives framework for studying the effect of music on lucidity. Tempo-specified or familiar music had no effect on the variable of divergent thinking.
Mashour et al. [24]	Alzheimer’s & Dementia	2019	United States	Theoretical Article	Upon systematic verification, lucid episodes can show that the brain can assess functional networks to reach the outside world even in the setting of severe dementia. Ethical and research frameworks proposed.
Meeks [25]	University of Dayton Law Review	2018	United States	Law Journal Comment	Lack of objective measurement of lucid episodes creates legal ambiguities which can be resolved by the creation of Certified Alzheimer’s Legal Specialists. This can avoid serious legal quandaries.
Morris and Bulman [26]	Journal of Gerontological Nursing	2020	Canada	Concept analysis/Literature Review	The concept of lucidity has a basis in law and dream study. A theoretical definition is proposed, distinguished by spontaneity in the context of neurodegenerative disease and meta-awareness.
Nahm et al. [5]	Archives of Gerontology and Geriatrics	2012	United States	Review	Repots of lucidity prevalent in 19th century medical literature. Mechanisms of lucidity are elusive; more research and neuroscientific models are needed.
Nahm [27]	Alzheimer’s & Dementia	2022	Germany	Letter to the Editor	Paradoxical lucidity and terminal lucidity sometimes overlap. Terminal lucidity does not necessitate a neurodegenerative disorder. Paradoxical lucidity is germane to advanced neurodegenerative disorders and may or may not be expressed shortly before death.
Nahm [28]	Journal of Anomalous Experience and Cognition	2022	Germany	Perspective	Memory and consciousness is elusive, as demonstrated in individuals with malformed brains. Anomalous events are crucial to study. Implications for enhancing the understanding of consciousness.
Ney, Peterson, and Karlawish [29]	Journal of the American Geriatric Society	2021	United States	Case Study	Paradoxical lucidity has vast ethical implications. Preliminary ethical framework for patient, caregiver(s), and family proposed. Humility in approach is foundational.
Normann et al. [30]	Journal of Clinical Nursing	2006	Sweden	Population Prevalence Study	Episodes of lucidity were observed in every second resident, in a sample of people living with severe dementia in institutions
Normann, Asplund, and Norberg [31]	Journal of Advanced Nursing	1998	Norway	Survey/Qualitative Study	Lucid episodes are an important phenomenon of caregiving for people with severe dementia. Research of episodes of lucidity must be based on systematic observational criteria. Dementia does not destroy personhood or selfhood.
Normann et al. [32]	Journal of Clinical Nursing	2005	Norway	Case Study	Focus should be given to the topics raised by the person with dementia if they can communicate. Supportive, kind attitude important. Results cannot be generalized because this article is a case study.
Normann, Norberg, and Asplund [33]	Journal of Advanced Nursing	2002	Norway	Case Study	Supportive attitude towards the patient and avoiding making demands paramount. It is crucial that the person with dementia experience relatedness and being a part of. The connection between supporting and avoiding demands and lucidity/non-lucidity during conversation needs further study.
Peterson et al. [34]	Alzheimer’s & Dementia	2022	United States	Letter to the Editor	Terminal lucidity is a type of paradoxical lucidity.
Peterson et al. [3]	Alzheimer’s & Dementia	2022	United States	Perspective	The provisional definition of paradoxical lucidity given by the National Institute on Aging 2018 expert workshop is unsatisfactory: refined definition proposed. Debate is important to establish the relationship between basic concepts within the provisional definition &how paradoxical lucidity is measured.
Ramirez et al. [35]	Aging & Mental Health	2023	United States	Survey/Qualitative Study	Collaborative work of an External Advisory Board, modified focus groups with staff and family caregivers, and structured cognitive interviews with health professionals were used to create a revised version of the lucidity measure.
Rice, Howard, and Huntley [36]	International Psychogeriatrics	2019	United Kingdom	Systematic Review	Awareness is relational according to caregivers. Systematized training of caregivers to assess awareness is desirable. All studies used a qualitative approach and there was significant variations of research questions, sample sized &methods.
Robnett et al. [37]	The American Journal of Occupational Therapy	2021	United States	Mixed Methods Survey	Music may be a catalyst for episodes of paradoxical lucidity. Directed stimulation should be researched to make lucid episodes more common.
Shulman et al. [38]	Journal of the American Academy of Psychiatry and the Law Online	2015	United States	Law Journal Comment/Research Article	The application of the legal concept of the lucid interval is invalid in the setting of dementia and should not be used by courts to establish testamentary capacity.
Teresi et al. [39]	Journal of Gerontological Nursing	2023	United States	Pilot Study/Survey	The idiosyncratic nature of lucid episodes make them challenging to study systematically; reliance on caregivers’ and healthcare professionals’ reports is necessary. Most of them have seen unexpected lucid episodes. Structured interview instrument is designed. Systematic studies needed to permit elucidation of physiological or psychological mechanisms.