Profound retrograde amnesia following mild head injury: Organic or functional?

This paper describes a 56 year old female patient (JJ) who suffered a minor head injury at work and presented with profound retrograde amnesia for bot h public events and autobiographical material spanning her entire life. In addition, she complained of word-finding difficulties and anterograde memor y impairment and neuropsychological assessment found evidence of mild execu tive dysfunction. Neurological investigations (CT and EEG) were essentially normal although changes indicative of small vessel disease were noted on M RI brain scan. Various forms and aetiologies of remote memory loss were con sidered including, simulated, psychogenic and organic amnesia, but differen tial diagnosis proved difficult. It is proposed that criteria used in clini cal practice to differentiate functional and organic complaints are limited and this may be because (1) both factors can be involved in the aetiology of amnesia, and (2) a similar underlying brain mechanism, such as a retriev al deficit could underlie many instances of organic and psychogenic amnesia ; Future research, complemented by functional brain imaging, is needed to e xplore the nature of retrieval deficits.