Motor homunculus: passive mapping in healthy volunteers by using functional MR imaging--initial results. Radiology 2009 May;251(2):485-92
Date
03/06/2009Pubmed ID
19261925DOI
10.1148/radiol.2512080231Scopus ID
2-s2.0-66149153845 (requires institutional sign-in at Scopus site) 41 CitationsAbstract
PURPOSE: To determine the concurrence of activation in the primary motor cortex, induced by paradigms of active and passive movement of extremities, by using blood oxygen level-dependent functional magnetic resonance (MR) imaging.
MATERIALS AND METHODS: The HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained from the participating volunteers. Functional MR imaging data were collected from 11 healthy volunteers (four women, seven men; age range, 24-42 years) during active and passive movements of hand, elbow, shoulder, ankle, knee, and hip. These data were then mapped onto three-dimensional anatomic images. Volumes of activation were determined by using cross-correlation analysis at a coefficient threshold of 0.4 (P < .01). Regions of interest were drawn in pre- and postcentral gyri based on anatomic criteria. The mean number of activated voxels in the pre- and postcentral gyri induced by active and passive movements was compared by using Wilcoxon analysis. Concurrence ratios and proportional ratios of activation between active and passive movements were calculated for each somatotopic location.
RESULTS: Primary motor cortex activation tended to increase with active compared with passive movements, although in the precentral gyrus, hand, elbow, and shoulder movements showed no statistically significant difference in mean number of activated voxels. In the postcentral gyrus, only the shoulder revealed a significant difference (P < .05). Concurrence ratios (activation volume overlap of two tasks/combined activation area of both tasks) ranged from 0.44 to 0.57. Proportional ratios (activation volume overlap of passive task with active task/total activation volume of passive task) ranged from 0.64 to 0.82.
CONCLUSION: Passive movement paradigms may be an alternative to or complement to active movement tasks in patient populations.
Author List
Kocak M, Ulmer JL, Sahin Ugurel M, Gaggl W, Prost RWAuthor
Robert Prost PhD Emeritus Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultBrain Mapping
Evoked Potentials, Motor
Female
Humans
Image Interpretation, Computer-Assisted
Magnetic Resonance Imaging
Male
Motor Cortex
Pilot Projects
Reference Values
Reproducibility of Results
Sensitivity and Specificity
