Application of focal cerebral cooling for the treatment of intractable epilepsy.

Epilepsy is usually treated with medication, but adequate seizure control is still not achieved in over 30% of epilepsy patients, even with the best available agents. Surgical treatment is also performed for such patients, but is not always successful. Focal cooling of the brain using a thermoelectric device has recently been evaluated as an alternative to epilepsy surgery. Brain cooling was first proposed approximately 50 years ago as an effective method for suppressing epileptic discharges (EDs). Recent studies indicate that focal cooling of the brain to a cortical surface temperature of 20°C to 25°C terminates EDs without inducing irreversible neurophysiological dysfunctions or neuronal damage in the brain tissue. Several mechanisms have been proposed for the antiepileptic effects of focal cooling, including reduction in neurotransmitter release, alternation of activation-inactivation kinetics in voltage-gated ion channels, and the slowing of catabolic processes. Developments in the implantable cooling device with closed-loop cooling systems for seizure detection and focal cooling have been promoted in the field of neuromodulation, but several aspects remain uncharacterized concerning the hardware. Recent advances in precision devices have enabled the optimization of the implantable local cooling system, which may become clinically applicable in the near future.