Memory

Abstract

The presence and degree of permanent memory changes following temporal lobectomy have pragmatic implications such as the ability to return to work, as well as conceptual issues involving our present understanding of memory mechanisms and the specialized role attributed to the hippocampus. The 5 original reports describing post-resection memory impairment remain the primary source of information on this potential complication, although several anecdotal reports also exist. Unfortunately, the patients’ clinical histories or cognitive abilities were not always adequately described. Several papers described sub-acute memory impairment following surgery, while memory was either normal or subjectively decreased at follow-up. In other cases, mild language impairment may have been interpreted as poor memory. None of these patients displayed the magnitude of memory impairment associated with bitemporal lobectomy seen in patient H.M. Failure to distinguish memory impairment from anterograde amnesia has made it impossible to estimate the risk of post-surgical amnesia following temporal lobectomy.