Amnesia in a patient with bilateral lesions to the thalamus

A case of anterograde amnesia is described in a 38-yr-old man with bilateral thalamic lesions. The patient appeared to have suffered no general intellectual loss and performed normally on standard memory tasks involving immediate recall of new material. There was, however, consistent impairment in recalling material, verbal and non-verbal, over delays as brief as a few seconds. Impairment was especially marked on tests involving free recall and partial cueing procedures; recognition memory was also impaired. Premorbid memory tested normally and susceptibility to interference was less than in other organic amnesics. Various interpretations of the patient's amnesia were considered but a deficit at the initial stages of information processing appeared to be indicated.