Cortical tongue area studied by chronically implanted subdural electrodes--with special reference to parietal motor and frontal sensory responses.
Extensive data on cortical tongue representation were analyzed in 100 patients who underwent craniotomy and cortical mapping by electrical stimulation for surgical treatment of epilepsy. As noted in the literature, the tongue is extensively represented within the central nervous system with a highly organized sensorimotor system and the data from this study corroborate a large cortical representation of the human tongue over the postcentral gyrus. The tongue was found to have a clear somatotopic organization over the postcentral area and to be represented bilaterally to a significant degree. Furthermore, the tongue appears to have an asymmetrical sensory cortical representation, as cerebral dominance for speech is more extensively represented on the dominant hemisphere. Cortical tongue mapping has proved extremely useful in determining the point of junction of the central and Sylvian sulci, a crucial landmark during surgical cortical resections.