Question category: Neurology
A 35 year old gentleman, previously well, collapses and begins to shake violently. His eyes are closed and his head is shaking from side to side. When a witness checks on him, his arms begin to flail more violently. He then gradually stops shaking. His eyes open and he is unaware of what happens but has not sustained any injury and has not been incontinent. What is the most likely diagnosis?