Hello Thanks for writing in HCM I had gone through your query and understood your concerns. Headache ,dizziness, incordination all point out towards posterior circulatory stroke and they are not diagnosed by CT head (which was normal as in your case) In my clinic i advise MRI brain for patients with such symptoms as that is investigation of choice. Hope this guides you. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries. If you do not have any clarifications, you can please close the discussion. Thank you. Wishing you good health