Confabulations in Cases of Dementia: Atypical Early Sign of Alzheimer’s Disease or Misleading Feature in Dementia Diagnosis?

Abstract

Confabulations, also known as false memories, have been associated with various diseases involving mainly the frontal areas, such as Wernicke-Korsakoff syndrome or frontal epilepsy. The neuropsychological dysfunctions underlying mechanisms of confabulation are not well known. We describe two patients with memory impairment and confabulations at the onset speculating about neuropsychological correlates of confabulations and self-awareness. Both patients, a 77-year-old woman and a 57years-old man, exhibited confabulations as first symptom of cognitive decline. She later developed memory impairment without awareness of her memory deficits and her cognitive and imaging profile suggested an amnesic mild cognitive impairment due to Alzheimer's disease (AD). Unlike her, he developed a prevalent involvement of frontal functions despite a clear consciousness of his cognitive deficits. However, the clinical diagnostic hypothesis of behavioral variant of frontotemporal dementia was not supported by imaging findings, which suggested AD. Both patients underwent neuropsychological evaluation including the Confabulation Battery. Despite that the exact anatomical correlation of confabulations is still not defined, imaging data shown by our patients is consistent with recent theories according to which at the origin of confabulatory tendency in AD there is an impairment of the connections between crucial hubs in frontal and mediotemporal areas, mainly involving the right hemisphere. Besides, it would be reasonable to hypothesize that self-awareness and confabulations should not be considered as necessarily associated dimensions.

Clinical Heterogeneity in Alzheimer’s Disease: A Possible New Amnesic Phenotype

“…Taken together, all these considerations inform us that one of the main goals of future research is to confirm the occurrence of the CM-phenotype in a larger sample of patients. Actually, we found in the scientific literature a recent study that presents patients with AD who show a phenotype very similar to the CMphenotype, but it is only two cases [40]. Furthermore, since we (re)discovered the CM-phenotype by studying elderly patients in a geriatric setting, the cases we observed were exclusively late-onset AD (LOAD) due to selection bias.…”

Traditional Psychological Assessment during COVID-19: Ethical Violations and Problems in Practice

“…Medical history taking from the patient's relatives is crucial for making differential diagnosis especially in the assessments conducted with patients having cognitive destruction. When it is taken into consideration that the dementia patients cannot express their complaints due to the loss of insight and that they confabulate (Belli et al, 2020), patient relatives provide important information about the patients. Not to consult the companions regarding the patient's daily like activities can cause problem in the decision making.…”

Diencephalic versus Hippocampal Amnesia in Alzheimer’s Disease: The Possible Confabulation-Misidentification Phenotype

“…This complex phenotype closely resembled the historical description of presbyophrenia, a well-known dementia syndrome at the beginning of the last century that then however passed into oblivion [ 2, 3 ]. This fact, together with the discovery in the literature of other sporadic cases of patients with AD who presented an unusual tendency to confabulation [ 4, 5 ], in some cases even early [ 6 ], suggested to us the idea that the FM phenotype might be an example of a defined syndrome rather than an idiosyncrasy of a single patient. Thus, we hypothesized the return of presbyophrenia [ 1 ].…”