Confabulations (I): Concept, classification and neuropathology

Abstract

Introduction. A working definition of confabulation could be that of describing them as false memories due to a retrieval problem, where the patient is unaware that he/she is confabulating, and has the belief that the memory is true. Several types of confabulations have been described, according to a broad variety of criteria. Confabulations can be seen in very different neurological conditions, which have lead to a controversy on their pathophysiological mechanisms. 

Objective: To obtain an updated revision in Spanish of the definitions, types, brain regions involved and neuropsychological correlates of the confabulations. 

Development. After reviewing the concept and several types of confabulations, the damaged brain regions associated to two conditions where confabulations occur, such as Korsakoff syndrome and patients with anterior communicating artery aneurysm, are described. The neuropsychological correlates associated to them are then reviewed. 

Conclusions. Confabulations are a difficult-to-define complex phenomenon. Probably, the most accepted classification, in accordance with how they appear, would be that which distinguishes spontaneous from provoked confabulations, although the validity of this distinction is not clear. Regarding to crucial cerebral regions involved in the confabulations, it seems that prefrontal cortex lesions, specifically in ventromedial and orbitofrontal areas, are necessary. Neuropsychological evidence suggests the presence in most of the cases of executive dysfunction and at least some degree of memory dysfunction as an underlying mechanism of confabulation. Nevertheless, the specific characteristics of these neuropsychological dysfunctions are not well-known.