Adult epileptics tend to react better to higher ratios of THC, finding their ideal ratios between 1:2 (CBD/THC) and 1/30 (CBD/THC), using primarily indica strains.
It is common knowledge that epileptics should be cautious with sativas but some epileptics DO report preferring sativas, particularly high CBD varieties.
A common method for adult sufferers of epilepsy is keeping a joint or vaporizer handy for when they feel the onset of shock coming on. A few inhalations is usually enough to derail an episode.
Many adult epileptics also use low dose edibles consumed in small amounts throughout the day in order to avoid epileptic shock as well.
Disclaimer: The following contains anecdotal information gathered while providing dignified and appropriate access to cannabis throughout the course of many years. Them following information has not been scientifically verified and should be used with caution and at your own risk.