Medication

So my 7yr old son has memory loss more so during the school year when he is under more stress. He has reading and writing difficulties. He only has seizures we can see and where we call 911 about once a year up to two years apart. He had s 24 hr VEEG done and although he didn't sleep much it did show two small spikes less than a second each one on each side of his brain. His neurologist prescribed him Lamotrigine. I am really worried about side effects. Especially memory since in theory we think it's the sleep seizure activity that's affecting his memory. I am also looking into CBD and a new medication that uses it. It's called Epidiolex. Imput on the medication he is about to take would be wonderful as well as any information about Epidiolex too. Thank you. A very worried and scared mom