Table 2.

iMEPs/cMEPs ratios and the frequency of ipsilateral MEPs of upper extremities

	Age (yr)	Left hemisphere		Right hemisphere
		iMEPs/cMEPs ratio	Freq. of iMEPs (%)	iMEPs/cMEPs ratio	Freq. of iMEPs (%)
FDI	13	5.0	100	6.3	100
	14	4.4	100	9.0	100
	15	4.7	100	6.0	100
	19	3.7	100	10.8	100
ECR	13	1.4	100	2.7	100
	14	1.2	100	1.9	100
	15	2.0	100	2.2	100
	19	1.4	100	2.2	100
BB	13	1.2	100	0.7	100
	14	0.5	100	0.5	100
	15	0.9	100	0.2	100
	19	0.1	100	0.3	100
Del	13	0.6	100	0.5	100
	14	0.8	100	0.3	100
	15	0.6	100	0.4	100
	19	0.6	100	0.4	100

MEPs, motor evoked potentials; iMEPs/cMEPs ratio, the ratio of amplitude of ipsilateral MEPs to contralateral MEPs; Freq. of iMEPs, the percentage of trials in which iMEPs are elicited by stimulation of the unilateral hemisphere; FDI, first dorsal interosseous; ECR, extensor carpi radialis; BB, biceps brachii; Del, deltoid.