[Functional magnetic resonance imaging-integrated neuronavigation and protection of brain function]

To investigate the reliability and clinical value of functional magnetic resonance imaging (fMRI)-integrated neuronavigation in minimally invasive neurosurgery and protection of brain function. We demonstrate the correlation between the lesion-to-fMRI activation distance and occurrence of new postoperative deficit.

fMRI-integrated neuronavigation was used for minimally invasive neurosurgery in 20 patients with intracranial lesions located in or near eloquent brain areas. During standardized paradigms for hand, foot, and tongue movement, language and visual activation, echo-planar imaging T2 blood oxygen level dependent sequences were acquired by Siemens Medical Systems Trio 3.0 T and processed with SPM2. Neuronavigation was performed with Stealth station.

fMRI data was integrated into neuronavigation successfully in all cases, functional neuronavigation with integration of fMRI allowed easy and precise identification of the eloquent brain areas and lesions except for 1 case for brain shift because of tumor stroke just before the operation. The localization of the tumor was corrected by intraoperative ultrasonography. Gross total resection was achieved in 18 patients, 2 patients had a subtotal resection. Neurological deterioration was seen in 4 patients, tumors all located in eloquent brain areas, 2 patients were recovered in 3 months the morbidity was 10.0%. The distance of a lesion to fMRI activation was more than 10 mm in 14 cases. The functional maps were located in left Brodmann's 9, 46, 17, 18 and 19 areas in 11 cases when the patients reading and understanding the Chinese words.

Functional neuronavigation with integration of fMRI allows precise identification of the eloquent brain areas protects the brain function and decreases the morbidity especially for Chinese patients because of our special functional area of language. Our data suggest that the distance of a lesion to fMRI activation was more than 10 mm, complete resection can be achieved safely.