Table 5.
Characteristics of included human studies.
| References | Experimental subjects | Control group | Intervention | Protocol of stimulation | Ganglion target | Outcome of interest | Results |
|---|---|---|---|---|---|---|---|
| Khurana et al. (60) (ImpACT-1) | Ischemic stroke patients (n = 98) | Historical control (n = 165) |
Invasive electrical stimulation | Frequency: 10 Hz Intensity: 5 to 25 mA Pulse: 100–400 s Parameter: 3–4 h for 5–7 consecutive days |
Sphenopalatine ganglion | mRS NIHSS | mRS: Patients treated with SPG stimulation had an average mRS lower by 0.76 than the historical controls(CMH test p = 0.001). NIHSS: The binary NIHSS success rate was 45%(38/84) in ImpACT-1 compared to 23.6%(39/165) in the NINDS controls (p = 0.0006). Functional outcomes were better in people treated with the Ischemic Stroke System |
| Bornstein 2019 (ImpACT-24A) (61) | Ischemic stroke patients (n = 202) | Sham stimulation (n = 101) |
Invasive electrical stimulation | Frequency: 10 Hz Intensity: 5 to 25 mA Pulse: 100–400 s Parameter: 4-h session for 5 consecutive days |
Sphenopalatine ganglion | Improved mRS score*; Substantial neurological recovery** Functional independence*** | (1) No statistical significance improve 3-month disability above expectations (2) Cortical involvement subtype showed statistical significance in improved mRS score, substantial neurological recovery but not functional independence |
| Bornstein 2019 (ImpACT-24B) (62) | Ischemic stroke patients (n = 555) | Sham stimulation (n = 519) |
Invasive electrical stimulation | Frequency: 10 Hz Intensity: 5 to 25 mA Pulse: 100–400 s Parameter: 4-h session for 5 consecutive days |
Sphenopalatine ganglion | Improved mRS score*; Functional independence***; | (1) No statistical significance improve 3-month disability above expectations (2) Cortical involvement subtype showed statistical significance in improved mRS score but not functional independence |
| Saver et al. (ImpACT-24M) (63) | Ischemic stroke patients (n = 50) | Historical control (n = 50) |
Invasive electrical stimulation | Frequency: 10 Hz Intensity: 5 to 25 mA Pulse: 100–400 s Parameter: 4-h session for 5 consecutive days |
Sphenopalatine ganglion | CBF NIHSS | CBF: Stimulation was associated with increase in CBF velocity and flow volume in the CCA during both peak systole and end-diastole with a 44% increase mean from baseline (p < 0.0001) NIHSS: The normalized change in NIHSS from day 1 to day 7 was significantly more favorable in the SPG stimulation than control patients. Evolution of the NIHSS in the SPG stimulation patients was from median 5 (IQR, 4–5) on day 1 to median 1 (IQR, 1–2) on day 7. |
| Sanchez et al. (52) | Healthy volunteers (n = 37) | N/A | Non-invasive magnetic stimulation | Frequency: 10 Hz Intensity: 1.0, 1.3, 1.6, 1.9T (0.8 and up) Pulse: 280 μs Parameter: Stimulation for 3 min after limit reached. |
Geniculate ganglion | CBF | CBF: Clear responders to stimulation (i.e., a CBF increase of ≥ 25%) represents about a third of all volunteers. |
*
Improved mRS score at 3 months beyond expectation.
**
(NIHSS score ≤ 1 or improved ≥9) at 3 months.
***
(mRS 0–2) at 3 months.
CCA, common carotid artery; mRS, Modified Rankin scale; NIHSS, NIH Stroke scale; SPG, Sphenopalatine ganglion.