A 65 year old man presents to your clinic after suffering a seizure.an hour back he developed jerking in his right arm and leg which lasted 5 minutes. he also lost consciousness for a brief period.he has smoked> 40 cigarettes daily for over 30 years.he is normal on examination. in this case. A.What is your provisional diagnosis? B.What is the most likely underlying cause for the seizure? C.How will you investigate and manage?