A functional magnetic resonance imaging study of factors influencing motor function after surgery for gliomas in the rolandic region.

BACKGROUND: Pre- and postoperative fMRI was performed in patients with rolandic gliomas to evaluate factors influencing motor function after surgery. METHODS: The study population consisted of 9 right-handed patients (mean age, 43.3 years; range, 25-67, 2 female/7 male) affected by high-grade gliomas growing within or adjacent to the rolandic cortex. Patients had a diverse onset and evolution of their disease. All patients underwent morphological imaging and fMRI on a 3-T scanner before and after surgery. Postprocessed imaging data were analyzed off-line using SPM. RESULTS: Patterns of activation in real-time maps and SPM were similar when coregistered head motion artifacts did not exceed more than 50% voxel size of the echo-planar imaging sequence. Movements of the hand opposite the affected hemisphere showed activation of the cMI in all patients. Coactivation of the iMI occurred in 5 patients. The cMII was activated in 4 patients, all with excellent postoperative motor function. The iMII and SMA were activated in patients with a good functional outcome. When the unaffected hand was tested, this activation pattern was similar. Postoperative fMRIs were comparable with the preoperative scans. CONCLUSIONS: Postoperative evaluation is feasible and may add confirmatory information to preoperative findings in selected patients. Bilateral activation of primary and secondary motor areas may be the correlate for compensatory recruitment of additional functional areas and a predictor for better functional outcome.

Human brain structures related to plantar vibrotactile stimulation: a functional magnetic resonance imaging study.

The purpose of this study was to investigate the sensorimotor cortex response to plantar vibrotactile stimulation using a newly developed MRI compatible vibration device. Ten healthy subjects (20-45 years) were investigated. Vibrotactile stimulation of the sole of the foot with a frequency of 50 Hz and a displacement of 1 mm was performed during fMRI (echo-planar imaging sequence at 1.5 T) using an MRI compatible moving magnet actuator that is able to produce vibration frequencies between 0 and 100 Hz and displacement amplitudes between 0 and 4 mm. The fMRI measurement during vibrotactile stimulation of the right foot revealed brain activation contralaterally within the primary sensorimotor cortex, bilaterally within the secondary somatosensory cortex, bilaterally within the superior temporal, inferior parietal, and posterior insular region, bilaterally within the anterior and posterior cingular gyrus, bilaterally within the thalamus and caudate nucleus, contralaterally within the lentiform nucleus, and bilaterally within the anterior and posterior cerebellar lobe. The advantages of the new MRI compatible vibration device include effective transmission of the stimulus and controlled vibration amplitudes, frequencies, and intensities. The results indicate that plantar vibration can be a suitable paradigm to observe activation within the sensorimotor network in fMRI. Furthermore, the method may be used to determine the optimal responsiveness of the individual sensorimotor network.