Confabulations without amnesia: Impact of dysexecutive syndrome

Abstract

Confabulations are described as “a falsification of memory occurring in clear consciousness in association with an organically derived amnesia”. We describe production of confabulations in long-term memory in a 51-year-old woman who do not present amnesic syndrome typically associated. The patient was admitted in reanimation unit for septic shock. After 8 days of coma, she presented signs of encephalopathy of Gayet-Wernicke, without cerebral damage on T1 MRI. At 6 months of acute episode, the patient presents a severe cognitive and behavioural dysexecutive syndrome, with impulsivity, perseverations and environmental dependency. Capacities of encoding and learning are weakened in episodic memory, without storage alteration. Access to semantic memory is altered, with semantic paraphasias production. In categorical images matching, patient do visual errors in favour of low level processing. Confabulation battery shows that these productions are present in answers to questions concerning semantic memory, but absent in episodic memory. Their contents were characterised by perseverations on environment. Consciousness of memory alteration is partial. The scintigraphy revealed a functional alteration in left frontal areas. This clinical report surprises by dissociations between: – preserved memory capacity and presence of confabulation; – semantic and episodic confabulations. We discuss this case with frontal hypothesis of confabulation. Deficits of the patient can be attributed to a deficit in strategic recovery of information, especially on monitoring process, by left frontal functional alteration. Information would be recovered by associative process provoking wrong recollections by a trouble of information verification.