The [[localization]] of [[cortical]] sites essential for [[language]] was assessed by [[stimulation mapping]] in the left, [[dominant hemisphere]]s of 117 patients. Sites were related to language when [[stimulation]] at a current below the threshold for afterdischarge evoked repeated statistically significant errors in [[object naming]]. The [[language center]] was highly localized in many patients to form several mosaics of 1 to 2 sq cm, usually, one in the [[frontal lobe]] and one or more in the temporoparietal lobe. The area of individual mosaics and the total area related to language were usually much smaller than the traditional [[Broca]]-[[Wernicke]] areas. There was substantial individual variability in the exact location of [[language function]], some of which correlated with the patient's sex and [[verbal intelligence]]. These features were present for patients as young as 4 years and as old as 80 years, and for those with lesions acquired in early life or adulthood. These findings indicate a need for revision of the classical model of [[language localization]]. The combination of discrete [[localization]] in individual patients but substantial individual variability between patients also has major clinical implications for [[cortical resection]]s of the [[dominant hemisphere]], for it means that [[language]] cannot be reliably localized on anatomic criteria alone. A maximal [[resection]] with minimal risk of postoperative [[aphasia]] requires individual localization of [[language]] with a technique like [[stimulation mapping]]
((Ojemann G, Ojemann J, Lettich E, Berger M. Cortical language localization in
left, dominant hemisphere. An electrical stimulation mapping investigation in 117
patients. J Neurosurg. 1989 Sep;71(3):316-26. PubMed PMID: 2769383.
)).