That is an excellent question and one that should best be answered by your uncle's primary care doctor
or another medical professional. There are a few concerning things about what you have described with regards to your uncle, which make it important that you urge him to go to the doctor to be checked out. The fact that he had some uncontrollable jerking in his body as well as episodes where he doesn't talk or can't breathe are concerning for possible seizures
. Does your uncle have any history of tumors or family members with seizures? Also, it could be possible that he is having extreme episodes of pain which are causing him to act in this way. It is difficult to evaluate him without getting a complete physical and history and so the best way to get the correct diagnosis is to have him evaluated by a medical professional such as a primary care doctor or neurologist
. Depending on what they find, they may want further diagnostic tests such as imaging studies (ie MRI) or blood tests to make sure that he doesn't have any abnormalities related to his blood levels. Regardless, it is important he is evaluated by a doctor as soon as possible.