A 52 year old man us brought to emergency by ambulance. His wife gives a history that while brushing he fell on the floor and she was stable to rouse him. His breathing seemed to stop for about 20s. He then developed jerking movements affecting his arms and legs for about 2 minutes. She noticed that his face became blue and that he was incontinent of urine. He started to recover after few minutes although he remained drowsy with headache. The man has not given history of any symptoms prior to this episode. There is no significant past medical history. He is a driver and smokes 25 cigarettes per day and is an occasional alcoholic.
On examination he looks fit and well nourished. He is afebrile. There is some bleeding from his tongue. His pulse is 84bpm and is regular. No neck stiffness and no focal neurological sign.
What are the differential diagnosis of the episode?