Restarting the ketogenic diet?

Would any of you have experience with trying the ketogenic diet, stopping it, and then returning to it again? My son was on a three-month trial with no improvement. As soon as we started weaning him off the diet, however, we saw an uptick in seizures, and they are happening much more frequently than when he was on the diet. We've hesitated to return to it but would appreciate hearing others' experience in that scenario. We'll of course be in touch with our doctors about it, too. Thanks, all!