Lateralisation of memory functions in epileptic patients by use of the sodium amytal (Wada) technique.

Lateralisation of speech and memory functions was determined in 27 patients, being assessed for surgical treatment of unilateral temporal lobe epilepsy, using the sodium amytal procedure. The most common outcome with regard to language was the retention of normal left hemisphere dominance, regardless of handedness or side of lesion. In contrast, memory functions were most often to be found only in the unaffected hemisphere, also regardless of handedness or side of lesion. A lesion of either hemisphere appeared capable of interfering with language and verbal memory functions in an unexpectedly high proportion of patients.