Table 1.
Effects of activity enhancement on neurological disorders featuring hyperexcitability
| Condition | Model or patients | Treatment | Effect | References |
|---|---|---|---|---|
| Acquired epilepsy | Multi-electrode arrays recording of neuronal culture in vitro. | Electrical stimulation (0.05–50 Hz) | Higher stimulation frequency transforms burst activity to dispersed spiking reminiscent of the awake cortex in vivo | (Madhavan et al. 2006; Wagenaar et al. 2005) |
| Temporal lobe epilepsy in rats in vivo | Electrical stimulation of subiculum after kindling or pilocarpine injection | 1 Hz stimulation retarded progression of kindling seizures and inhibited chronic spontaneous pilocarpine-induced seizures. | (Han et al. 2014; Zhong et al. 2012) | |
| 191 patients with refractory partial-onset seizures. A double-blind, randomized, controlled trial | Open-loop responsive cortical stimulation for 1 month | Reduction in seizure frequency in the treatment group (− 37.9%) than control group (− 17.3%). | (Morrell 2011) | |
| Alpha (2)-adrenoceptor antagonist atipamezole | Treatment started 1 week after SE induction and lasted for 9 weeks. | Lower seizure frequency and severity, and milder cell damage and mossy fiber sprouting in treatment group. | (Pitkanen et al. 2004) | |
| Neuropathic pain | Spared tibial nerve injury and transient spinal cord ischemia models of neuropathic pain in mice | S1 optogenetic stimulation for 1 week, or S1 activity enhancement by bicuculline. | Reduced pain-like behavior in both models and reduced S1 neuronal [80]excitability. | (Xiong et al. 2017). |
| Eight intractable neuropathic pain patients | TMS (1–50 Hz for 1 h) or electrical stimulation (4–8 Hz) for 1 month. | Significant pain relief in all patients. | (De Ridder et al. 2007) | |
| Tinnitus | 43 intractable tinnitus patients | Implanted electrodes in the primary auditory cortex or secondary auditory cortex | 67% of patients improved with average tinnitus reduction of 53%. Burst stimulation has better effect than tonic stimulation. | (De Ridder et al. 2011) (Meng et al. 2011). |
| 163 tinnitus patients | rTMS at 1 Hz (2000 stimuli, 110% motor threshold) or sham stimulation | This protocol has no effect. | (Landgrebe et al. 2017) | |
| Ten tinnitus patients | rTMS at 1 Hz on auditory cortex for 5 consecutive days | Improvement was associated with increases intracortical inhibition, intracortical facilitation, and prolongation of cortical silent period. | (Langguth et al. 2007) | |
| Tinnitus induced by tone exposure in rats | Auditory cortex electrical stimulation with electrical array. | Tinnitus is suppressed and hearing is improved at the central level | (Zhang et al. 2011) |