Material-specific memory changes after anterior temporal lobectomy as predicted by the intracarotid amobarbital test

Purpose: The intracarotid amobarbital test (IAT) has been shown to predict verbal memory changes after anterior temporal lobectomy (ATL). Seeking to e xtend these findings, we examined two questions: (a) What is the relationsh ip between material-specific aspects of IAT memory and material-specific me mory changes after ATL? and (b) Which IAT memory score(s) optimally predict memory changes after surgery, the memory score after injection ipsilateral to the seizure focus, the memory score after injection contralateral to th e seizure focus, or the LAT asymmetry score, comprising the ipsilateral min us contralateral injection scores? Methods: Seventy left hemisphere language-dominant patients undergoing ATL for treatment If medically refractory seizures were administered a verbal a nd visuospatial recognition memory test before surgery and 3 weeks after su rgery. LAT memory recognition scores for words and designs were used to pre dict verbal and visuospatial memory changes after surgery. Results: After surgery, left ATL patients declined in verbal memory, wherea s right ATL patients declined in visuospatial memory. IAT total recognition memory scores (collapsed across all types of materials) and IAT word memor y scores were associated with postoperative verbal memory decline. This rel ationship was significant for the IAT ipsilateral injection memory scores a nd the IAT hemispheric asymmetry scores. IAT memory performances were not r elated to visuospatial memory changes. Conclusions: Results indicate IAT memory measures to be related to postoper ative verbal, but not visuospatial, memory change. A specific relationship was found between postoperative verbal memory change and IAT verbal memory after injection ipsilateral to the seizure focus, when relying primarily on the contralateral hemisphere. This finding is consistent with the function al reserve model of memory change in ATL.