IMPAIRED EPISODIC MEMORY RETRIEVAL IN A CASE OF PROBABLE PSYCHOGENIC AMNESIA

A patient with severe, selective retrograde amnesia for personal mater ial, diagnosed as probable psychogenic amnesia, was investigated inten sively neuropsychologically with cranial computed tomography (CCT), ma gnetic resonance imaging (MRI), and single photon emission tomography (SPECT). The patient was of average intelligence and memory with no an terograde amnesia. No evidence for structural brain damage was detecte d in CCT and MRT. SPECT, performed about 3 weeks after the onset of sy mptoms, demonstrated reduced perfusion in right temporal and frontal a reas, that is, in areas which have been suggested as critical for epis odic memory retrieval. To study episodic memory retrieval, positron-em ission-tomography (PET) blood flow (rCBF) measurements were performed 6 months after the onset of symptoms. During episodic memory retrieval bilateral neuronal activations were observed in the precuneus, the la teral parietal and the right dorsolateral and polar prefrontal cortex. Compared to the results of previous functional imaging studies on epi sodic memory retrieval, our findings suggest an underlying functional disturbance of brain areas previously demonstrated to be involved in e pisodic memory retrieval. (C) 1997 Elsevier Science Ireland Ltd.