| Co-Investigator(Kenkyū-buntansha) |
NAKASATO Nobukazu Department of Neurosurgery, Tohoku University School of Medicine, Research Assoc, 医学部, 助手 (80207753)
YOSHIMOTO Takashi Department of Neurosurgery, Tohoku University School of Medicine, Professor, 医学部, 教授 (50091765)
|
|---|
| Research Abstract |
In this study, magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) have been applied to basic and clinical brain mapping. Both techniques have been recently developed as non-invasive magnetophysiological tools.
Results are summarized as follows.
Somatosensory evoked field for tongue, digit, hand, low extremities, and urogenital organs indicated somatotopic organization of the primary somatosensory cortex of the brain. fMRI for hand, tongue and lip movement as well as hand sensory stimuli also indicated a certain area responsible for each activity. These data were integrated on MRI-based anatomical images, venography and surface anatomical scan. In cases of glioma, we verified these functional localization of sensori-motor cortices by intraoperative cortical stimulation under the awake condition.
Auditory and visually evoked magnetic fields were applied for patients with various types of intracranial structural lesions. In a certain abnormal conditions, we found delay of peak latency of major components in evoked responses. In some patients, latency of the responses normalized after removal of lesions.
Spatial and temporal resolution of MEG are millimeter and millisecond order respectively. MEG is especially useful to localize pin-point sources spatially and temporally. On the other hand, fMRI is suitable to localize brain activity of spatially extended area and within a certain length of time, of usually a few ten seconds order. For understanding human brain function, both techniques are complementary ; integration of the two techniques will be important especially for clinical application.
|
