The Effect of Spinal Cord Stimulation on Epileptic Seizures

Spinal cord stimulation (SCS) has been applied to relieve chronic pain for decades. Recent studies suggested that SCS also might alleviate epileptic seizures, but the most effective stimulation parameters are not known. The objective of this work was to investigate the role of SCS frequency in alleviating spike-and-wave (SW) discharges induced in rats by pentylenetetrazole (PTZ) infusion.

The SW discharges were induced in nine rats. An epidural electrode was placed in the spinal canal at the cervical level. SCS was delivered at four frequencies (30, 80, 130 and 180 Hz) and compared with control intervals without stimulation. The effect was evaluated by analyzing electrocorticographic and intracortical (IC) signals. The means of normalized SW spike power (mSP) and frequency (mSF) were derived from the IC recordings and used to estimate the seizure severity.

Compared with the control intervals, SCS conducted at 30 Hz significantly increased the mSP and mSF indicating an increase of the SW spiking activity; 80 Hz did not induce significant changes of the features. In contrast, 130- and 180-Hz SCS reduced both mSP and mSF significantly indicating a reduction of the SW spiking activity.

The present results showed that 130-Hz and 180-Hz SCS reduced the SWs power and frequency which may indicate an anticonvulsive effect of these SCS frequencies, whereas 30-Hz SCS induced the opposite effects and, therefore, may be proconvulsive.