Treatment with an antisense oligonucleotide increases survival in mouse models of two epileptic encephalopathies, according to a recent study. The antisense oligonucleotide was against the SCN8A transcript, which encodes the sodium channel NaV1.6. Mutations in this channel lead to a gain of function that causes SCN8A encephalopathy, characterized by severe, frequent seizures. The condition is similar to Dravet syndrome, which is caused by mutations in SCN1A. Guy Lenk and colleagues used the antisense oligonucleotide to treat mice with Scn8a mutations or Dravet syndrome. Mean survival increased from 15 days to 65 days in the model of SCN8A encephalopathy and from 3 weeks to >5 months in the model of Dravet syndrome. The results suggest that this approach is promising as a therapy for intractable childhood epilepsies.