White matter stimulation for the treatment of epilepsy

• There is a long history of electrical stimulation of neural targets for the treatment of epilepsy.
• Axonal stimulation may allow for activation of a large population of epileptic neurons.
• There is evidence that white matter stimulation may modulate epileptic activity.
• Despite limited clinical data, tract stimulation has potential for treatment of epilepsy.

Electrical stimulation in the treatment of epilepsy has been tried in numerous forms and with a variety of targets. Some of these, such as anterior thalamic stimulation, responsive cortical stimulation, and vagal nerve stimulation, have shown promise. A relatively novel concept, that of white matter stimulation, offers a different mechanism in that a small population of stimulated axons can transmit current to a large population of epileptogenic neurons. In theory, this allows for the modulation of seizure circuits and neural networks using lower stimulation volumes. Although clinical data is currently sparse, we review the relevant studies pertaining to white matter stimulation in epilepsy thus far, and offer explanations as to its effects, potential advantages, and utility.