Advanced dementia patients may briefly regain memory months before death

Some advanced dementia patients may briefly return to their old selves before death, sometimes as much as six months before, a new study found.

Cases of loved ones and healthcare workers describing people with dementia suddenly becoming lucid and engaging in meaningful conversations and sharing old memories before dying have been documented as far back as the 1850s. But previous research suggested this period of lucidity arrived just hours to days before death.

The new study, published in the journal Alzheimer’s and Dementia, revealed that a number of such patients see their memory briefly return more than six months before they die. This suggests that there are several types of lucid episodes and not all signal impending death.

Some lucidity episodes may also be caused by external stimuli such as the presence of a loved one or music, the study found.

In the study, researchers examined lucid episodes, or LE, among people with latestage Alzheimer’s and related dementias and surveyed 151 bereaved caregivers who reported witnessing such an episode at any time.

Nearly 20 per cent of the caregivers reported that their patient experienced LE within seven days of death, while more than a third said the patient died a week to six months after the LE.

The majority of the patients, almost 48 per cent, lived “more than six months after the LE”, the study found.

“These types of LEs coincided with visits from family, more frequently reported by children who did not reside with the patients and had the lowest frequency of contact.”

The finding suggests that unhabitual or rare visits by family may trigger a lucid response from such a patient.

“Or it is possible that family or friends, unaccustomed to the routine and daily cognitive fluctuations of the patient, either draw meaning from these fluctuations or are primed to pay closer attention to behaviour that routine visitors overlook,” the researchers noted.

Citing a main limitation of the study, they said some subjective interpretations of a patient’s behaviour as constituting LE by caregivers may not be such an episode.

The researchers called for further studies to confirm these types of lucid episodes and to determine whether they are valid in a more diverse sample of patients and caregivers.

“A deeper understanding of temporary reversals of cognitive ability could lead to pathways to induce some types of LEs and extend the duration of others,” they said.

“Further conceptualisation could also help properly educate care providers and family caregivers about their potential occurrence and support family caregivers.”