Students who struggle with attention and sitting too long are given the opportunity to take a break and do high knees or walk up the hall quickly. Having students sit for a long period of time when they have a diagnosed illness is something that many of these students are incapable of doing.
Mixing up the class time with different teaching styles will help students that learn differently. Start with an icebreaker to help pull the students in then make it fun and engaging. When it comes to homework give students work that is educationally relevant and enough work to understand concept mastery. Adjusted assignments and time limits are accommodations that have been seen in many different IEP and 504 plans. These can have a massive effect on students and hopefully give them some of the help they need.