Hippocampal contribution to verbal recent memory following dominant-hemisphere temporal lobectomy.

The effects of hippocampal encroachment in the language dominant-hemisphere were studied in 41 patients who underwent previous temporal lobectomy (TL). Patients undergoing dominant-hemisphere TL including anterior hippocampus (n = 13) performed significantly worse than nondominant TL patients (n = 16) on a verbal learning test (Selective Reminding; p less than or equal to .00001), thereby confirming the sensitivity of this procedure to lateralized temporal-lobe dysfunction. However, no significant difference was present on this or other primary measures of material-specific memory when contrasting dominant TL patients in whom the anterior hippocampus was spared (n = 12) to those in whom anterior hippocampus was resected. These data suggest that more extensive and posterior mesial temporal-lobe resection is not necessarily associated with a greater verbal material-specific memory deficit following dominant-hemisphere temporal lobectomy.