[Evaluation of various somatosensory stimulations for functional MRI].
The aim of this functional magnetic resonance imaging (fMRI) study was to test detectability of activated area using various somatosensory stimulations. The following stimulations were performed in normal volunteers: regular or irregular electrical median nerve stimulation (n = 5, each), tactile stimulation to the palm and fingers (n = 8), pain stimulation to the index finger (n = 5) or to the palm and fingers (n = 5). fMRI was acquired with a spoiled gradient echo sequence at 1.5 T. Detectability of activated area was the highest when the pain stimulation was applied to the palm and fingers (80%). A successful rate for the tactile stimulation was 25%, and the other stimulations failed to demonstrate any activation. When successful, the highest signal activation on fMRI was seen on a sulcus, which presumably arose from a vein. The sulcus was defined as the central sulcus by somatosensory evoked field using a median nerve stimulation. Our study indicates that the pain stimulation to the palm and fingers may be a choice for the sensory fMRI.
Hara
K
K
Department of Neurosurgery, Tohoku University, School of Medicine, Aobaku Sendai, Japan.
Shimizu
H
H
Nakasato
N
N
Mizoi
K
K
Yoshimoto
T
T
D000328:Adult; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000294:innervation; D006225:Hand / Q000294:innervation; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008475:Median Nerve / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology*