Table 4.

Comparisons of the metabolite ratios of ¹H-MR spectroscopy between chronic migraine patients with and without medication overuse

	Periaqueductal gray			Dorsal pons, right			Dorsal pons, left
	MO−	MO+	P	MO−	MO+	P	MO−	MO+	P
NAA/Cr ratio mean (SD)	1.48 (0.15)	1.47 (0.27)	0.903	1.63 (0.20)	1.64 (0.30)	0.842	1.59 (0.18)	1.64 (0.29)	0.458
Cho/Cr ratio mean (SD)	1.24 (0.18)	1.23 (0.21)	0.820	1.36 (0.17)	1.38 (0.48)	0.668	1.32 (0.17)	1.38 (0.27)	0.291

MO medication overuse, NAA N-acetylaspartate, Cr creatine, Cho choline, SD standard deviation