Confabulation following rupture of posterior communicating artery.

In this study we report a patient, MG, who following rupture of left posterior communicating artery exhibited an amnesic-confabulatory syndrome. Neuropsychological examination showed severe impairment on episodic memory tasks, which were marred by florid but plausible and semantically appropriate confabulation. Performance on tasks involving various kinds of semantic knowledge was normal or only mildly impaired. Performance on tasks traditionally considered sensitive to frontal dysfunction was severely impaired with the exception of Cognitive Estimates where MG's performance was completely normal. There was no evidence of structural (CT scan) or metabolic (SPECT) damage to the frontal lobe. It is argued that tasks traditionally considered sensitive to frontal dysfunction are not specifically implemented by cognitive resources based on frontal structures. MG's confabulation is discussed in terms of a possible disruption of cognitive functions involved in the control of the subjective experience of feeling of remembering.