Factual error: At the end, Denzel Washington's character has a Grand Mal Seizure. But he is supposed to have a spinal cord injury. He can still have seizures in that the electrical impulses in his brain go haywire, but if he has a spinal cord injury that prevents him from moving, the seizure action in his brain wouldn't translate to his body jerking and shaking.
Suggested correction: You can still have involuntary muscle movement with a spinal cord injury...so if it was a seizure (it wasn't) his muscle could twitch (likely not as much as his did though).
Yes you can get severe involuntary muscle spasms. I have been having more so recently. And his face and recovery is exactly what I am experiencing. I have spinal stenosis and myelomalacia and now on diazepam. Well Done Denzel Washington.
Suggested correction: It isn't a Grand Mal seizure, he's faking an attack of autonomic dysreflexia. (It still wouldn't cause his extremities to shake, he would still only be able to move his head and shoulders).