Table 2.
Dopaminergic Effect of Brain Stimulation in Humans
| Article | Subject (N) | Stimulation Parameters
|
Target Region | Methodology | Regional Changes | Findings | |||
|---|---|---|---|---|---|---|---|---|---|
| Method | Frequency | Intensity | Total Pulses | ||||||
| Strafella and others (2001) | Awake healthy humans at rest (8) | rTMS (round coil) | 10 Hz | 100% RMT | 450 | Left DLPFC | [11C]raclopride PET | Left caudate | 7.36% ↓BP (↑DA) |
| Strafella and others (2003) | Awake healthy humans at rest (6) | rTMS (round coil) | 10 Hz | 90% RMT | 450 | Left M1 | [11C]raclopride PET | Left putamen | 9.49% ↓BP (↑DA) |
| Cho and Strafella (2009) | Awake healthy humans at rest (7) | rTMS (figure-of-eight coil) | 10 Hz | 100% RMT | 750 | Left DLPFC | [11C]FLB 457 PET | Left subgenual ACC Left pregenual ACC Medial OFC |
37.7% ↓BP (↑DA) 45.3% ↓BP (↑DA) 23.6% ↓BP (↑DA) |
| Ko, Monchi, Ptito, Bloomfield, and others (2008) | Awake healthy humans while performing behavioral tasks (10) | cTBS (figure-of-eight coil) | 50 Hz | 80% AMT | 900 | Left DLPFC | [11C]raclopride PET | Left caudate Right caudate Left putamen |
14.67% ↑BP (↓DA) 12.59% ↑BP (↓DA) 12.98% ↑BP (↓DA) |
| Right DLPFC | Striatum | NS | |||||||
| Strafella and others (2005) | Awake patients with PD (off-med) at rest (7) | rTMS (round coil) | 10 Hz | 90% RMT | 450 | More affected M1 Less affected M1 |
[11C]raclopride PET | Ipsilateral putamen | 9.47% ↓BP (↑DA) 12.99% ↓BP (↑DA) |
| Pogarell and others (2006, 2007) | Awake patients with depression (off-med) at rest (9) | rTMS (figure-of-eight coil) | 10 Hz | 100% RMT | 3000 | Left DLPFC | [123I]IBZM SPECT | Bilateral striatum | 9.6% ↓V3 (↑DA) |
| Awake patients with depression (off-med) at rest (4) | 25,500 (3 wk) | NS | |||||||
| Kuroda and others (2006) | Awake patients with depression (off-med) at rest (9) | rTMS (figure-of-eight coil) | 10 Hz | 100% RMT | 10,000 (2 wk) | Left DLPFC | [11C]raclopride (PET) | Striatum | NS |
| Khedr and others (2007) | Awake patients with PD (off-med) at rest (20) | rTMS (figure-of-eight coil) | 25 Hz | 100% RMT | 18,000 (1 wk) | Left and right M1-hand and lower limbs | DA level | Serum | 71.5% ↑DA |
| Shimamoto and others (2001) | Awake patients with PD (on-med) at rest (9) | rTMS (round coil) | 0.2 Hz | 100 ± 10% RMT | 480 (2 mo) | Left and right frontal | DA level Homovanillic acid level |
CSF CSF |
NS 19.9% ↓homovanillic acid level |
| Kim and others (2008) | Awake patients with PD (off-med) at rest (9) | rTMS (figure-of-eight coil) | 5 Hz | 90% RMT | 300 (2 d) | More affected M1 | [11C]raclopride (PET) | Contralateral caudate | 12.1% ↓BP (↑DA) |
AMT = active motor threshold; ACC = anterior cingulate cortex; BP = binding potential; CSF = cerebrospinal fluid; cTBS = continuous theta burst stimulation; ↓ = decrease; DA = dopamine; DLPFC = dorsolateral prefrontal cortex; ↑ = increase; NS = not significant; OFC = orbitofrontal cortex; PD =Parkinson disease; M1 = primary motor cortex; V3 = ratio of specific to nonspecific brain uptake; rTMS = repetitive transcranial magnetic stimulation; RMT = resting motor threshold. For [11C]raclopride PET and [123I]IBZM SPECT, the search region was limited to the striatum. For [11C]FLB 457, the search region was whole brain. Only those regions with significant effect are shown in the table. When no significant effect is observed in the search region, NS is reported.