10. Duvoisin RC. The evaluation of extrapyramidal disease. In: de Ajuriagerra J, ed. Monoamines, nyaux gris centraux et syn- drome de Parkinson. Paris: Masson, 1970:313-325. 11. Chan GLY, Morrison KS, Holden JE, Ruth TJ. Plasma ~-[~~Fl6-fluorodopa input function: a simplified method. J Cereb Blood Flow Metab 1992;12:881-884. 12. Brooks DJ, Ibanez zyxwvutsrqp V, Sawle GV, et al. Striatal D2 receptor status in patients with Parkinson's disease, striatonigral de- generation, and progressive supranuclear palsy, measured with llC-raclopride and positron emission tomography. Ann Neurol 1992;3 1: 184-192. 13. Nelson K, Golnick J , Korn T, Angle C. Manganese encephalop- athy: utility of early magnetic resonance imaging. Br J Indust Med 1993;50:510-513. 14. Shinotoh H, Snow BJ, Hewitt KA, et al. MRI and PET studies of manganese-intoxicated monkeys. Neurology 1995;45:1199 zy - 1204. 15. Eriksson H, Tedroff J, Thuomas KA, et al. Manganese in- duced brain lesions in Macaca fascicularis as revealed by positron emission tomography and magnetic resonance imag- ing. Arch Toxicol 1992;66:403-407. 16. Yamada M, Ohno S, Okayasu I, et al. Chronic manganese poisoning: a neuropathological study with determination of manganese distribution in the brain. Acta Neuropathol (Berl) 17. Olanow CW, Good PF, Shinotoh H, et al. Manganese intoxica- tion in the rhesus monkey: a clinical, imaging, pathologic, and biochemical study. Neurology 1996;46:492-498. 1986;70:273-278. A direct comparison of PET activation and electrocortical stimulation mapping for language localization S.Y. Bookheimer, PhD; T.A. Zeffiro, MD, PhD; T. Blaxton, PhD; B.A. Malow, MD; W.D. Gaillard, MD; S. Sato, MD; C. Kufta, MD; P. Fedio, PhD; W.H. Theodore, MD Article abstract-Mapping eloquent language cortex in presurgical patients typically is accomplished using highly invasive direct cortical stimulation techniques. Functional imaging during language activation using positron emission tomography (PET) is a promising, noninvasive alternative that requires validation. In seven patients undergoing surgical evaluation for intractable epilepsy, we performed both direct cortical stimulation and PET activation mapping of language cortex using identical tasks. MRI, PET, and CT scans were coregistered to directly compare the location of language centers determined by cortical stimulation versus activation PET. We found that cortical regions that showed increased cerebral blood flow during both visual and auditory naming tasks were located in the same regions as subdural electrodes which disrupted language during electrical stimulation. Cortical regions underlying electrodes that did not disrupt language also showed no consistent changes in regional cerebral blood flow during PET activation. Used cautiously, PET activation produces language maps similar to those obtained with direct cortical stimulation, with more complete brain coverage and considerably less invasion. NEUROLOGY 1997;48:1056-1065 One important application of functional neuroimag- ing studies is their potential to reduce the need for invasive cortical mapping procedures. In neurologi- cal disorders such as brain tumors and intractable epilepsy, treatment frequently requires removal of potential language c0rtex.l To avoid post-operative deficits, the surgeon may perform one of several functional-anatomical mapping techniques, designed to locate eloquent language structures precisely and spare them in the surgical resection; these include intra-operative corticography with the awake pa- tient, and stimulation with chronically implanted electrode~.l-~ In both methods, electrical stimulation is applied directly to the cortical surface while the patient performs language tasks. If stimulation pro- duces speech arrest or paraphasic errors, the cortex is presumed essential for normal language process- ing and is spared in the resection. Both methods of electrical stimulation mapping (ESM) are invasive, require considerable cooperation from the patient, and can sample only a limited brain territory, pri- marily on the exposed cortical surface. Intraopera- tive cortical stimulation has a further disadvantage in that it can only be performed for a brief period during which the patient is subject to stresses of craniotomy, anesthesia and the operating room envi- ronment. Chronic subdural or depth electrode im- plantation involves the risk of complications such as infection and local changes in t i s ~ u e . ~ - ~ Noninvasive functional neuroimaging techniques From the Epilepsy Research Branch (Drs. Bookheimer, Blaxton, Malow, Gaillard, Sato, and Theodore), National Institute of Neurological Disorders and Stroke, the Laboratory of Diagnostic Radiology Research (Dr. Zeffiro), the Surgical Neurology Branch (Dr. Kufta), and the Office of the Clinical Director (Dr. Fedio), the National Institutes of Health, Bethesda, MD. Received May 17, 1996. Accepted in final form October 3, 1996. Address correspondence and reprint requests to Dr. S.Y. Bookheimer, Brain Mapping Division, UCLA School of Medicine, 710 Westwood Plaza, Los Angeles, CA 90024. 1056 Copyright zyxwvutsrqp 0 1997 by the American Academy of Neurology