J Korean Acad Rehabil Med.  2000 Apr;24(2):219-224.

The Motor Cortex Mapping Using Transcranial Magnetic Stimulation in Normal Subjects

• Jang SH
• Ahn SH
• Lee SJ
• Ha JS
• Lee H
• Lee JH

Abstract

OBJECTIVE
To investigate the characteristics of the motor cortex map for abductor pollicis brevis muscle (APB) using transcranial magnetic stimulation (TMS) in normal subjects. METHOD: Ten adults without neurological disorder were studied. A piece of cloth which marked at 1 cm interval was fixed on the head of the subject. The motor cortex mapping for APB was done with butterfly magnetic stimulator, and then with round magnetic stimulator.
RESULTS
The average optimal scalp position for left APB was located on lateral 6.2 cm, anterior 0.1 cm from Cz and that for right APB was located on lateral 6.0 cm, anterior 0.1 cm from Cz when stimulated with butterfly magnetic stimulator. The differences between hemispheres were less than 1 cm in the location of optimal scalp position and less than 10% in excitatory threshold (ET) irrespective of magnetic stimulator. The ipsilateral motor evoked potential (MEP) was not evoked in all subjects. The ET when stimulated with butterfly magnetic stimulator was higher to that when stimulated with round magnetic stimulator.
CONCLUSION
We conclude that TMS using butterfly and round magnetic stimulator is useful for the motor cortex mapping.

Keyword

Magnetic stimulation; Motor cortex; Mapping

MeSH Terms

Adult
Butterflies
Evoked Potentials, Motor
Head
Humans
Motor Cortex*
Nervous System Diseases
Scalp
Transcranial Magnetic Stimulation*