Purpose: Anterior temporal lobectomy (ATL) is an effective surgical option for managing pharmacoresistant temporal lobe epilepsy. Many patients with left ATL develop postsurgical difficulties with proper name retrieval, although curiously, some patients have entirely intact proper naming following left ATL. Here, we tested the hypothesis that early age of seizure onset would be a reliable factor "protecting" patients from developing proper naming defects following left ATL.
Methods: Proper naming of unique persons (Famous Faces Test, 155 items) and places (Landmark Test, 65 items) was measured in 23 patients who had undergone left ATL for pharmacoresistant epilepsy. Data were collected for a number of variables, including age of seizure onset, age at surgery, handedness, IQ, and seizure outcome. The patients were sorted into two groups based on proper naming performance: (1) Unimpaired: 7 patients performed normally on both the Faces and Landmark tests; (2) Impaired: 16 patients performed abnormally on one or both of the tests.
Results: In support of our hypothesis, the Unimpaired group had a significantly earlier age of seizure onset (M = 2.1 years) than the Impaired group (M = 15.1 years). Moreover, a correlation analysis indicated a strong association between age of seizure onset and naming outcome (R =-0.569). The groups were comparable (and statistically indistinguishable) on nearly all other variables.
Conclusions: These findings document the importance of age of seizure onset in predicting proper naming outcome following left ATL (with earlier being better), and extend understanding of brain reorganization and plasticity.