TABLE 1.

Demographic data.

	EMCI	LMCI	NC	statistics
N (N of analysis)	101 (87)	96 (82)	204 (176)
Age	73.3 ± 9.0	73.9 ± 7.1	74.5 ± 9.2	n.s.
Sex (female/male)	52/49	45/51	121/83	n.s.
MMSE	28.2 ± 1.8	27.9 ± 1.8	28.9 ± 1.5	EMCI, LMCI < NC
Conversion time (months) (N)	23.6 ± 16.3 (8)	25.3 ± 14.8 (13)	–	n.s.
Follow-up duration (months)	21.4 ± 24.6	13.7 ± 19.4	8.8 ± 17.2	n.s.

The two-sample t-test for age, chi-squared test for sex and Kruskal–Wallis test for Mini-Mental State Exam (MMSE) were used. The values in parentheses for N indicate the numbers of subjects who had no excessive head movement (<4.5 mm). The values in parentheses for conversion time indicate the numbers of subjects who converted to Alzheimer’s disease. NC, normal control; EMCI, early mild cognitive impairment; LMCI, late mild cognitive impairment.