Seizures can happen but it does not mean it will. Seizures also don't necessarily mean lifelong complications or disability. It's highly unlikely you would be vegetative, it would have to be an incredibly serious seizure without adequate medical attention. If you survive and were not found, you'll likely wake up and just feel like shit. You'll probably weak and sick for a few days. If you are hospitalized and saved you may be institutionalized. With any CTB attempt you have to be prepared to be saved and end up in a mental hospital. This does not mean you will but it is a possibility.