I'm doing some research on VNS and I ran across this study. I don't know if this has been brought up on the board before, or if this study has been proven wrong, but I thought I'd pass it along.
Improvement of epileptic seizure control with treatment of obstructive sleep apnoea.
http://www.ncbi.nlm.nih.gov/pubmed/8777557Sleep deprivation increases the risk of recurrent seizures in epileptic patients. We identified 10 patients with recurrent seizures and sleep disruption related to obstructive sleep apnoea. Two patients were treated with positional therapy and the remaining eight patients were treated with continuous positive airway pressure. Three of the patients became seizure free and a fourth patient had a greater than 95% reduction in seizure frequency following only the initiation of therapy for the sleep apnoea. Three of these four patients responding to therapy, had a state-dependent seizure pattern. Two of the four responders did not exhibit the typical body habitus for obstructive sleep apnoea. Three additional patients improved in seizure frequency with change in anticonvulsant medication and treatment of the obstructive sleep apnoea. The remaining three patients had less than 50% reduction in seizure frequency with treatment of the obstructive sleep apnoea. These results indicate sleep disruption caused by sleep apnoea may increase the seizure frequency in some epileptic patients. Regardless of body habitus, epilepsy patients should be questioned carefully for a history of sleep disturbance and state dependence to their seizures. Treatment of sleep disorders in this population may lower the frequency of recurrent seizures.