Table 2.
a. Concentrations of metabolites by group, as measured by proton magnetic resonance spectroscopy (1H-MRS) in bilateral thalami and left DLPFC.
| ASD | TD | ASD male | ASD female | TD male | TD female | Main effect of diagnosis P | Main effect of gender P | Interaction effect P | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary analyses | |||||||||||||||
| Thalami | N | N | N | N | N | N | |||||||||
| GABA/Water (×10−5) | 19 | 4.57 ± 0.77 | 21 | 4.85 ± 1.16 | 12 | 4.62 ± 0.83 | 7 | 4.50 ± 0.74 | 12 | 5.33 ± 0.64 | 9 | 4.21 ± 1.41 | 0.49 | 0.049* | 0.11 |
| Left DLPFC | |||||||||||||||
| GABA/Water (×10−5) | 18 | 4.34 ± 1.25 | 20 | 3.25 ± 1.29 | 10 | 4.85 ± 1.24 | 8 | 3.71 ± 1.00 | 13 | 3.04 ± 1.26 | 7 | 3.63 ± 1.34 | 0.027* | 0.51 | 0.041* |
| Secondary analyses | |||||||||||||||
| Thalami | N | N | N | N | N | N | |||||||||
| GABA/Cr + PCr | 19 | 5.08 ± 0.81 | 21 | 5.44 ± 1.51 | 12 | 5.06 ± 0.78 | 7 | 5.12 ± 0.93 | 12 | 5.70 ± 1.07 | 9 | 5.09 ± 1.96 | |||
| GABA/Glx | 18 | 5.73 ± 0.81 | 14 | 5.97 ± 2.33 | 11 | 5.67 ± 1.43 | 7 | 5.84 ± 1.61 | 7 | 5.56 ± 1.64 | 7 | 6.38 ± 2.94 | |||
| NAA/Cr + PCr | 26 | 1.54 ± 0.21 | 26 | 1.49 ± 0.31 | 15 | 1.61 ± 0.17 | 11 | 1.45 ± 0.24 | 16 | 1.43 ± 0.32 | 10 | 1.58 ± 0.27 | |||
| Glx/Cr + PCr | 21 | 0.98 ± 0.34 | 17 | 1.00 ± 0.29 | 12 | 1.06 ± 0.43 | 9 | 0.88 ± 0.13 | 10 | 1.05 ± 0.22 | 7 | 0.94 ± 0.37 | |||
| Cr + PCr (×108) | 27 | 1.49 ± 0.80 | 26 | 1.45 ± 0.59 | 16 | 1.37 ± 0.75 | 11 | 1.66 ± 0.88 | 16 | 1.46 ± 0.64 | 10 | 1.44 ± 0.54 | |||
| Left DLPFC | |||||||||||||||
| GABA/Cr + PCr | 18 | 3.39 ± 0.99 | 20 | 2.92 ± 1.71 | 10 | 3.51 ± 1.07 | 8 | 3.23 ± 0.92 | 13 | 2.41 ± 1.13 | 7 | 3.87 ± 2.26 | |||
| GABA /Glx | 14 | 2.83 ± 1.06 | 18 | 2.04 ± 1.12 | 9 | 2.88 ± 1.08 | 5 | 2.72 ± 1.13 | 12 | 1.82 ± 1.22 | 6 | 2.47 ± 0.86 | |||
| NAA/Cr + PCr | 24 | 1.42 ± 0.23 | 24 | 1.32 ± 0.37 | 14 | 1.39 ± 0.25 | 10 | 1.46 ± 0.22 | 16 | 1.28 ± 0.41 | 8 | 1.41 ± 0.25 | |||
| Glx/Cr + PCr | 18 | 1.30 ± 0.33 | 21 | 2.14 ± 2.73 | 12 | 1.32 ± 0.39 | 6 | 1.25 ± 0.19 | 14 | 1.71 ± 0.89 | 7 | 3.02 ± 4.66 | |||
| Cr + PCr (×108) | 26 | 1.82 ± 1.05 | 28 | 1.72 ± 0.80 | 16 | 1.75 ± 1.06 | 10 | 1.93 ± 1.08 | 18 | 1.73 ± 0.72 | 10 | 1.70 ± 0.98 | |||
| b. Quality control parameters for magnetic resonance spectra determined from LCModel | |||
|---|---|---|---|
| Cramer Rao lower bound (CRLB) | |||
| Thalami | ASD | TD | P |
| Cho | 3.95 ± 1.28 | 4.25 ± 2.02 | 0.588 |
| Glx | 21.24 ± 10.55 | 21.01 ± 18.83 | 0.798 |
| mI | 23.71 ± 11.65 | 18.78 ± 8.52 | 0.081 |
| NAA | 6.86 ± 3.90 | 6.75 ± 3.53 | 0.932 |
| Cr + PCr | 4.24 ± 1.09 | 4.94 ± 3.77 | 0.423 |
| Left DLPFC | |||
| Cho | 5.29 ± 2.39 | 5.93 ± 3.39 | 0.606 |
| Glx | 15.82 ± 12.10 | 19.95 ± 20.76 | 0.241 |
| mI | 14.41 ± 7.23 | 15.29 ± 7.35 | 0.935 |
| NAA | 8.41 ± 4.62 | 7.27 ± 3.69 | 0.272 |
| Cr + PCr | 4.12 ± 1.90 | 5.00 ± 2.90 | 0.341 |
| Signal-to-noise ratio (SNR) and full width at half maximum (FWHM) | |||
|---|---|---|---|
| Thalami | ASD | TD | P |
| SNR | 16.59 ± 6.65 | 15.59 ± 6.11 | 0.559 |
| FWHM | 0.071 ± 0.018 | 0.077 ± 0.026 | 0.270 |
| Left DLPFC | |||
| SNR | 15.56 ± 6.35 | 17.75 ± 8.09 | 0.299 |
| FWHM | 0.096 ± 0.029 | 0.114 ± 0.043 | 0.105 |
Note: a: Values reported are mean ± SD. P values reported are from two-way ANOVAs: Thalami: F(3,36) = 2.78; Left DLPFC: F(3,34) = 4.18. *P < 0.05.
TD typically developing, Cr + PCr creatine and phosphocreatine, GABA gamma aminobutyric acid, Glx glutamine and glutamate, mI myo-inositol, NAA N-acetylaspartate.
Note: b: Values reported are mean ± SD. P values are from Welch two-sample T-test performed between ASD and TD groups. Cho choline, Glx sum of glutamine and glutamate, mI myo-inositol, NAA N-acetylaspartate, Cr + PCr creatine + phosphocreatine.