GABA/W concentration, grey matter, white matter, and CSF percentages before and after TMS
| Timing; mean ± SD or no. (%) | ||
|---|---|---|
| Measure; group | Pre-TMS | Post-TMS |
| All participants, n = 23 | ||
| ACC GABA/W | 2.66 × 10−3 ± 0.53 × 10−3 | 2.98 × 10−3 ± 0.60 × 10−3* |
| ACC Glx/W | 2.14 × 10−3 ± 0.41 × 10−3 | 2.15 × 10−3 ± 0.43 × 10−3 |
| ACC water | 1.75 × 1012 ± 0.52 × 1012 | 1.79 × 1012 ± 0.48 × 1012 |
| Grey matter | 53.1 (2.8) | 52.8 (2.9) |
| White matter | 31.5 (2.9) | 32.0 (3.2) |
| CSF | 15.4 (2.1) | 15.1 (2.0) |
| TMS responders, n = 8 | ||
| ACC GABA/W | 2.68 × 10−3 ± 0.66 × 10−3 | 3.08 × 10−3 ± 0.60 × 10−3 |
| ACC Glx/W | 1.98 × 10−3 ± 0.44 × 10−3 | 2.16 × 10−3 ± 0.32 × 10−3 |
| ACC water | 1.71 × 1012 ± 0.47 × 1012 | 1.90 × 1012 ± 0.48 × 1012 |
| Grey matter | 51.4 (2.3) | 50.7 (2.0) |
| White matter | 32.3 (1.9) | 33.9 (2.2) |
| CSF | 16.3 (1.0) | 15.4 (1.9) |
| TMS nonresponders, n = 15 | ||
| ACC GABA/W | 2.65 × 10−3 ± 0.48 × 10−3 | 2.92 × 10−3 ± 0.61 × 10−3 |
| ACC Glx/W | 2.23 × 10−3 ± 0.38 × 10−3 | 2.14 × 10−3 ± 0.49 × 10−3 |
| ACC water | 1.77 × 1012 ± 0.56 × 1012 | 1.73 × 1012 ± 0.49 × 1012 |
| Grey matter | 53.9 (2.7) | 54.0 (2.6) |
| White matter | 31.1 (3.3) | 31.0 (3.2) |
| CSF | 15.0 (2.5) | 15.0 (2.1) |
ACC = anterior cingulate cortex; CSF = cerebrospinal fluid; GABA/W = γ-aminobutyric acid level relative to unsuppressed voxel tissue water; Glx = combined resonance of glutamate and glutamine; SD = standard deviation; TMS = transcranial magnetic stimulation.
↵* Significantly increased ACC GABA in the whole group before compared with after TMS (p = 0.01).