Abstracts

Most group studies have demonstrated that patients undergoing dominant temporal lobe (TL) resection for the control of intractable epilepsy experience at least mild declines in naming, with less decline occurring in those with childhood onset of seizures. As our epilepsy surgery program increasingly evaluates more potentially complex cases of temporal lobe epilepsy (TLE), we are suspecting that such individuals are at greater risk for decline in naming ability (i.e., patients with MRI results that are normal, patients with diffuse neurologic conditions or injury, such as traumatic brain injury or HSV encephalitis). The current study explores the relationship between such patient characteristics and naming functioning in TLE patients both pre- and post-operatively., Seventeen dominant TL patients completing 1-year post-operative neuropsychological (NP) testing during the past year were administered the Boston Naming Test (BNT). Seizure onset was determined using a combination of video-EEG monitoring, neuroimaging, NP testing, and, when necessary, invasive EEG monitoring. All patients were left-hemisphere dominant for language based on Wada results. Rates of significant decline on the BNT, assessed using Reliable Change Indices, were compared across subgroups based on neuroimaging findings (i.e., (a) normal MRI results (n=8), (b) extratemporal brain abnormalities (n=6), and (c) classic mesial temporal sclerosis (MTS) (n=3)., Significant BNT declines were observed in 76.5% of the total dominant TL resection sample. However, using chi square analysis and Fisher[apos]s Exact Test to examine decline rates for the MRI subgroups indicated that the MTS group showed a smaller rate of decline than did the other two groups ([italic]p[/italic][lt].02). The rates of decline for the three groups were as follows: Normal MRI = 6 of 8 (75%: mean decline = -11.9, [italic]SD[/italic] = 9.7); Extratemporal Abnormality = 8 of 8 (100%: mean decline = -13.8, [italic]SD[/italic] = 8.4); MTS = 1 of 3 (33%: mean decline = -6.0, [italic]SD[/italic] = 9.2)., These results suggest that patients with extratemporal lesions or normal results on MRI who undergo dominant TL resection for the control of intractable seizures are at a much greater risk of decline on visual confrontational naming tasks than classic MTS patients. These findings have implications for predicting outcome following TL resection and may lead to changes in neurosurgical intervention (smaller resections in at risk patients)., (Supported by NIH/NINDS (K23 NSO49100-01).)