Pure memory loss with hippocampal lesions: a pneumoencephalographic study.

A case of pure memory loss occurred suddenly following inhalation anesthesia. Examination seven years after the onset of amnesia disclosed a profound and selective impairment of recent memory without concomitant deterioration of other higher functions or evidence of other neurologic abnormalities. Pneumoencephalotomography focused on the temporal horns showed severe atrophic changes confined to both hippocampi. This finding provides a radiologic counterpart of previously reported surgical and pathological observations of bilateral hippocampal lesions in cases with relatively pure loss of memory.