You might have a dwarf squirrel. Can you post a picture of him in your hands and a full face photo? What does he weigh and what is his current age? Is he still taking formula? And how long did he take formula?
Dwarf squirrels are very special. They can’t climb well and are non-releasable. Please share more about him so we can determine if this is what he is.
In the meantime how close are you to Vancouver, WA? There is a member with a Squirrel Refuge located there.
As for the possible seizure, he may already have MBD. Please begin the emergency MBD treatment immediately. Here’s the link.
https://thesquirrelboard.com/forums/...-MBD-Treatment The treatment will not hurt him if it’s not MBD and May save his life.