Test-retest reliability of cortical language mapping in a patient with refractory focal epilepsy: 11 years later.

Electrical stimulation mapping (ESM) is considered the gold standard for identification of essential language cortex and is especially important in patients for whom classic language landmarks are less useful because of reorganization in response to epileptogenic or neoplastic cortex. However, little is known regarding the reliability of the procedure, particularly over extended time intervals. The authors present the case of a young man with refractory left temporal lobe epilepsy in the setting of a low-grade left temporal tumor who had undergone intraoperative language mapping at age 14 years and repeat mapping at age 25. Results from both the initial ESM and the repeat ESM 11 years later revealed a positive auditory description naming site in the same location on the superior temporal gyrus, at the anterior aspect of the tumor. This case provides support for the reliability of ESM and underscores intraindividual reliability in the location of language cortex over a prolonged period.