TABLE 3.
MRS imaging of rTMS effects in patient population.
| rTMS |
MRS |
||||||
| Author | Subjects (N) | Hz, intensity | Sessions, pulses | Target region | Field strength, Sequence | Voxel location | Results |
| Fregni et al., 2011 | N = 17, chronic pain | 1 Hz, 70% MSO | 10 sessions, 1600 pulses/session | R S2 | 3T, PRESSS | L S2 R S2 |
L and R S2: ↑ Glu |
| Marjańska et al., 2013 | N = 29, dystonia | 5 Hz, 90% RMT | Single session, 1600 pulses | Dominant M1 | 3T, MEGA-PRESS | Bilateral M1 | Dominant M1: ↓ Glx and ↓ GABA |
| Di Lazzaro et al., 2017 | N = 3, ALS | cTBS, 80% AMT | 120 sessions, 600 pulses/session | Bilateral M1 | 3T, PRESS and MEGA-PRESS | L M1 WM |
No significant changes |
| Luborzewski et al., 2007 | N = 17, MD | 20 Hz, 100% RMT | 10 sessions, 2000 pulses/session | L DLPFC | 3T, PRESS | L DLPFC ACC | L DLPFC: lower baseline Glu in responders. ↑ Glu post-rTMS in responders ACC: non-significant change Glu |
| Croarkin et al., 2016 | N = 10, MD | 10 Hz, 120% RMT | 30 sessions, 3000 pulses/session | L DLPFC | 3T, PRESS and 2DJ-PRESS | L DLPFC ACC | L DLPFC and ACC: ↑ Gln/Glu 6 months post-rTMS compared to baseline and post-rTMS |
| Dubin et al., 2016 | N = 23, MD | 10 Hz, range of 80–120% RMT | 25 sessions, 3000 pulses/session | L DLPFC | 3T, MEGA-PRESS | mPFC | ↑ GABAa post-rTMS. Greater GABAa increase in responders |
| Baeken et al., 2017b | N = 36, MD | 20 Hz, 110% RMT | 20 sessions, 1560 pulses/session | L DLPFC | 3T, PRESS | L DLPFC R DLPFC L ACC |
L DLPFC: Positive correlation between GABA ↑ and clinical improvement. |
| Erbay et al., 2019 | N = 18, MD | 10 Hz, – | 20 sessions, 2 sessions per day, 3000 pulses/session | L DLPFC | 3T, PRESS | L DLPFC | No significant ↑ Glu/Cr |
| Levitt et al., 2019 | N = 26, MD | 10 Hz, 80–120% RMT | 30 sessions, 3000 pulses/session | L DLPFC | 3T, MEGA-PRESS | L DLPFC | ↑ GABA post-rTMS, greater GABA increase post-rTMS in responders. |
↓, decrease; ↑, increase; ACC, anterior cingulate cortex; ALS, amyotrophic lateral sclerosis; DLPFC, dorsolateral prefrontal cortex; Glx, glutamate + glutamine; IPL, inferior parietal lobe; L, left; M1, motor cortex; MD, mood disorder; mPCC, medial posterior cingulate cortex; R, right; RMT, resting motor threshold; S2, secondary somatosensory; V1, visual cortex.
aExpresses GABA ratio of peak areas relative to the area of the unsuppressed voxel water signal.