Memory function after temporal lobectomy for seizure control: A comparative neuropsychiatric and neuropsychological study

This chapter deals with often differing data and prognosis provided by the neuropsychiatrist and the neuropsychologist. It also reflects the general psychology literature which raises the question as to whether laboratory testing of memory function truly reflects memory function in everyday life. Current practice in surgical epilepsy centers is a preoperative neuropsychological evaluation, particularly of memory function. This demand was stimulated by the occurrence of a devastating amnesia which occurred in the 1950s in the wake of temporal lobe surgery. The amnesia was attributed to hippocampal dysfunction, either from removal of both hippocampi at surgery or from removal of one hippocampus when the other was dysfunctional. Subsequently, to avoid a memory calamity, testing of the hippocampus to remain has become mandatory prior to excision. The literature is replete with prediction reporting of memory impairment post temporal lobectomy, even though the remaining hippocampus has been reported as functional, by preoperative memory testing. The general psychology literature also raises the question as to whether laboratory testing of memory function truly reflects memory function in everyday life. Our longitudinal study of epilepsy patients who have undergone temporal lobectomy at the Medical College of Ohio has emphasized utilization of neuropsychiatric evaluation as well as neuropsychological testing. Data and prognosis reported by the neuropsychologist are frequently in contrast with neuropsychiatric assessment, which provides subjective reports by the patient as well as review of performance-demanding memory ability, in the spheres of education and work. Comparisons of neuropsychological and neuropsychiatric data were expressed in terms of concordant or discordant findings. Data for this study were gathered between 1996 and 1998.