Table 1.
Design and parameters of clinical studies of invasive cortical stimulation in stroke
| Study [ref.] | Design | Lesion | Baseline function | Localization | Intra-cortical mapping | Parameters | Duration of rehabilitation | Endpoint | Efficacy results |
|---|---|---|---|---|---|---|---|---|---|
| Brown et al. [19] | Case study | Subcortical | Fugl–Meyer = 36 | fMRI activation in peri-rolandic M1 | Intraoperative confirmation of functioning pathways from fMRI target | 3 × 3 array, 50 Hz, 100-ms pulses current ~4.5 mA | 3 wks | Case report | ∆ Fugl–Meyer = 10 |
| Brown et al. [20] | Unblinded, phase I, multicenter clinical trial. Investigational and control groups |
Cortical or subcortical | Fugl–Meyer: investigational = 36 ± 9 Fugl–Meyer: control = 41 ± 5 |
fMRI activation in peri-rolandic M1 | Intraoperative confirmation of functioning pathways from fMRI target in 83 % of patients in investigational group | 3 × 3 array, 50 Hz, 50 % movement threshold. Biphasic pulses. Outer rows anode and cathode |
2 × 1.5-h sessions, daily × 3 wks | Safety | ∆ Fugl–Meyer = 10 in investigational vs 1.9 in control group |
| Levy et al. [18] Huang et al. [17] | Unblinded, phase II, randomized 7-center trial. Investigational and control groups |
Cortical, capsular, or pontine | Fugl–Meyer: investigational = 34.4 ± 8.9 Fugl–Meyer: control 30.5 ± 7.3 |
fMRI activation in peri-rolandic M1 | Intraoperative confirmation not discussed, but during thresholding in rehabilitation, stimulation elicited contralateral response in 42 % of patients in investigational group | 2 × 3 array, 50 or 101 Hz, 50 % movement threshold. Outer rows anode and cathode. 2.7 × 2.6 cm2 area | 2.5 h daily for 6 wks | Efficacy = ∆ Fugl–Meyer = 3.5 | ∆ Fugl– Meyer = 5.5 in investigational vs 1.9 in control. 67 % had clinically meaningful ∆ in investigational group |
| Harvey et al. (2009) [21] (results in press release Northstar Neuroscience Inc.) | Single-blinded, randomized multicenter phase III trial. Investigational and control groups |
Cortical or subcortical above midbrain | Fugl–Meyer: investigational = 37.6 Fugl–Meyer: control 37.6 |
fMRI activation in peri-rolandic M1 | Intraoperative confirmation not discussed, but during thresholding in rehabilitation, stimulation elicited contralateral response in 15.3 % of patients in investigational group | 2 × 3 array, 50 Hz, 50 % movement threshold. Outer rows anode and cathode | 2.5 h daily for 6 wks | Efficacy = ∆ Fugl–Meyer = 4.5 points + ∆ Arm Motor Ability Test of 0.21 | ∆ Fugl–Meyer + Arm Motor Ability = 4.3 and 0.37 in investigational group vs = 4. 0 and 0.26 in control group. 30.8 % had clinically meaningful ∆ in investigational group |
fMRI functional magnetic resonance