[Confabulation: a symptom which is intriguing but not adequately known]

Confabulation has been defined as the falsification of memory occurring in clear consciousness in association with an organically-derived amnesia. It was first described by Korsakoff in 1889 in alcoholic amnesic patients. Later studies showed that confabulation is also seen in a variety of other pathologies, such as anterior communicating artery rupture, traumatic brain injury, Alzheimer's disease, and brain tumors. Two forms of confabulation have been described: Momentary (provoked) confabulation which is produced in response to questions, for compensating the gaps in memory; and fantastic (spontaneous) confabulation consisting of grandiose and wish-fulfilling characteristics. There is no specific localization for provoked confabulations. However spontaneous confabulations appear as a result of basal forebrain and posterior orbitofrontal cortex lesions. There are numerous hypotheses for explaining the specific nature of confabulations with reference to impairment of general executive dysfunction, temporality, and memory-control processes. Commonly, these interpretations explain memory distortion in terms of frontal network dysfunction. There is a general consensus that confabulation is primarily the result of a deficit of memory retrieval, rather than one of encoding, consolidation, or storage. The normal process of memory recall consists of the evaluation of the cues for retrieval, matching the cues with episodic memory, and reality monitoring. One possible explanation for confabulation is that these patients have lost the checking procedure in memory retrieval, i.e. reality monitoring. This article aimed to describe confabulation and to review its clinical, neuroanatomical, and neuropsychological correlates in an effort to raise clinicians' awareness of the phenomenon and the problematic areas that need to be clarified.