title: Symmetric corticospinal excitability and representation of vastus lateralis muscle in right-handed healthy subjects.
abstract: The purpose of this study was to determine the size and location of the representations of the anterior thigh muscles on the human motor cortex in the dominant and non-dominant hemispheres. Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation were recorded from the right and left vastus lateralis (rVL, lVL) muscles. A total of ten right-handed healthy volunteers participated in the study. In a single session experiment, we investigated VL muscle corticospinal excitability (motor threshold, MEP size, short interval intracortical inhibition, intracortical facilitation) and cortical representation (map area, volume, and location) in the dominant and non-dominant hemispheres. The motor threshold, MEPs, and intracortical excitability did not differ significantly between the hemispheres (P > 0.05). Furthermore, no difference between sides was found in the location of VL motor representation (mediolateral and anteroposterior axis) or in map area and volume (P > 0.05). Vastus lateralis muscle corticospinal excitability and cortical map were symmetrical in right-handed subjects. Future studies on patients with unilateral lower extremity injuries could examine side-to-side plastic reorganization in corticomotor output and map location in both hemispheres.
authors: New York College of Podiatric Medicine, New York, New York.
authors: Mohomad
authors: M
authors: Al Sawah
authors: Mohammad
authors: M
authors: Rimawi
authors: Carmen
authors: C
authors: Concerto
authors: Bahaa
authors: B
authors: Amer
authors: Yisheng
authors: Y
authors: Cao
authors: Anthony V
authors: AV
authors: D'Antoni
authors: Eileen
authors: E
authors: Chusid
authors: Fortunato
authors: F
authors: Battaglia
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: TMS; cortical representation; hemispheric asymmetry; vastus lateralis