Editor’s Choice
Editor’s Comment
Task-based approaches to functional localization of the motor cortex have limitations such as long scanning times and exclusion of patients with severe functional or neurologic disabilities and children. Resting-state fMRI may avoid these difficulties because patients do not perform any goal-directed tasks. Nineteen patients were prospectively evaluated by using task-based and resting-state fMRI to localize sensorimotor function. Independent component analyses were performed to generate spatial independent components reflecting functional brain networks or noise. The motor cortex was successfully and consistently identified by using resting-state fMRI. Hand, foot, and face regions were defined in a comparable fashion with task-based fMRI.
Abstract
BACKGROUND AND PURPOSE
The functional characterization of the motor cortex is an important issue in the presurgical evaluation of brain lesions. fMRI noninvasively identifies motor areas while patients are asked to move different body parts. This task-based approach has some drawbacks in clinical settings: long scanning times and exclusion of patients with severe functional or neurologic disabilities and children. Resting-state fMRI can avoid these difficulties because patients do not perform any goal-directed tasks.
MATERIALS AND METHODS
Nineteen patients with diverse brain pathologies were prospectively evaluated by using task-based and resting-state fMRI to localize sensorimotor function. Independent component analyses were performed to generate spatial independent components reflecting functional brain networks or noise. Three radiologists identified the motor components and 3 portions of the motor cortex corresponding to the hand, foot, and face representations. Selected motor independent components were compared with task-based fMRI activation maps resulting from movements of the corresponding body parts.
RESULTS
The motor cortex was successfully and consistently identified by using resting-state fMRI by the 3 radiologists for all patients. When they subdivided the motor cortex into 3 segments, the sensitivities of resting-state and task-based fMRI were comparable. Moreover, we report a good spatial correspondence with the task-based fMRI activity estimates.
CONCLUSIONS
Resting-state fMRI can reliably image sensorimotor function in a clinical preoperative routine. It is a promising opportunity for presurgical localization of sensorimotor function and has the potential to benefit a large number of patients affected by a wide range of pathologies.
Read this article: http://bit.ly/SensorimotorCortex-fMRI
