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Contact: 847/378-0500Heather Monroe ([email protected])
Neurosurgeons Use Optical Imaging Techniques to Save Language Function in Bilingual Patients
ROLLING MEADOWS (February 12, 2001) -As the population of bilingual patients in the United States is on the rise, physicians are searching for new methods of treating those patients. Primarily, there is a need to optimally treat bilingual brain tumor patients who require the ability to retain both the English and Spanish language following brain tumor operations. Neurosurgeons find that using novel intraoperative neuroimaging techniques before removal of a brain tumor helps to improve surgical outcome and preserves the bilingual patient's ability to use speech and language in both languages.
In the past, due to a tumor's location in regions that control speech, some tumors have been inoperable because of potential injury to speech function during surgery. In a recent study, "Optical Imaging of Bilingual Cortical Representations," published in the October 2000 issue of the Journal of Neurosurgery, the authors, including Nader Pouratian, BS; Susan Bookhemer, PhD; Alyssa M. O'Farrell, PhD; Nancy L. Sicotte, MD; Andrew Cannestra, MD, PhD; Donald Becker, MD, and Arthur W. Toga, PhD, used a neuroimaging technique called intraoperative imaging of intrinsic signals (iOIS) to remove a brain tumor in the speech cortex of a bilingual patient. The authors were able to show that iOIS corresponded to speech mapping and that different languages are represented in different brain regions.
The authors followed a 43-year-old woman who was initially diagnosed in 1994 with seizures. She was treated with anticonvulsant medications and observed until 1998, when her seizure activity increased, and a brain tumor involving her left temporal lobe (that is in large part responsible for speech) was found. She underwent preoperative speech testing and functional MRI imaging; no impairments in language processing or production were observed. A craniotomy was then performed to surgically remove the tumor. The neurosurgeons used cortical stimulation or Electrocortial Stimulation Mapping (ESM), to map language functions to successfully avoid any damage to language areas while removing the tumor.
During surgery, the surgeons observed that the iOIS maps of English object naming colocalized with those identified with ESM and preoperative fMRI. Spanish object naming activated overlapping regions, but also identified areas distinct from those activated by naming in English. In addition, the spatial extent of activity in Spanish in some brain regions was larger than that observed in English. These findings suggest that cortical language representations in bilingual people may consist of both overlapping and distinct regions.
Postoperative language function was reported normal. One year later, the patient reported no noticeable neurological or language deficits in either English or Spanish, showing that tumors intrinsic to brain regions associated with speech can be safely removed with appropriate functional mapping techniques.
"Some have suggested that a patient's proficiency and age of acquisition of a second language may affect language representations," says Donald Becker, MD, a co-author of this study. "Regardless of cause, we have observed differences in activation patterns across languages, highlighting the significance of testing bilingual patients in both languages during intraoperative mapping."
This study demonstrates the effectiveness of iOIS in detecting topographical (of or relating to the mind) segregation of cognitive functions and the potential usefulness of functional mapping for intraoperative guidance. These results indicate that there are cortical areas that are activated by the use of both English and Spanish languages.
The Journal of Neurosurgery is the scientific publication of the American Association of Neurological Surgeons. Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons is a scientific and educational association with nearly 5,800 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are Board-certified by the American Board of Neurological Surgery. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the spinal column, spinal cord, brain, nervous system and peripheral nerves.
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