Table 3. Metabolites with differences in cerebrospinal fluid concentrations between two or more disease groups^a.

Metabolite	Potential Pathway(s) Involved	Adjusted P-value
Formateb	1-carbon metabolism/acetate synthesis	0.0003
Glycinec	1-carbon metabolism/glutathione synthesis/excitotoxicity	0.005
Choline	1-carbon metabolism/lipid turnover	0.043
Serine	1-carbon metabolism/protein catabolism	0.038
Glutaminec	Amino acid metabolism	0.023
Pyroglutamateb	Amino acid/glutathione metabolism	0.0003
N-Acetylneuraminate	Amino sugar metabolism/innate immunity	0.013
Betaine	Cell volume/1-carbon metabolism/choline oxidation	0.008
NAAG	Cell volume/neurotransmitter	0.021
2-Oxoglutarate	Cell volume/TCA cycle/amino acid metabolism	0.030
Glutamate	Cell volume/TCA cycle/neurotransmitter	0.0003
Methanold	Drug metabolite; microbial metabolism	0.043
Glucoseb	Energy metabolism	0.002
Lactatec	Energy metabolism	0.039
Pyruvateb	Energy metabolism	0.003
Carnitine	Fatty acid catabolism	0.002
2-Hydroxybutyrateb	Glutathione synthesis/energy metabolism	0.002
3-Hydroxybutyrateb	Ketone bodies	0.031
Acetoacetate	Ketone bodies	0.009
Acetonec	Ketone bodies	0.002
Dimethyl sulfone	Microbial metabolism	0.011
Isopropanol	Microbial/ketone metabolism	0.002
2-Hydroxyisovalerate	Organic acid	0.018
Phenylalanine	Protein catabolism	0.033
Quinolinate	Tryptophan metabolism/excitotoxicity	0.018
3-Hydroxyisobutyrate	Valine metabolism	0.010
Acetamide		0.002

Abbreviation: NAAG, N-Acetylaspartylglutamic acid. ^aKruskal-Wallis test for nonparametric one-way analysis of variance, adjusted for multiple tests using the false discovery rate correction.

^bDifference in median concentrations confirmed after log transformation of the data improved homoscedasticity. ^cAssumption of equal variances not met.

^dTentatively assigned.