Professor Brown as appointed as the foundation professor of stroke medicine in 1999. He is also consultant neurologist at University College Hospital and his main research contribution has been the organisation of large multicenter clinical trials aimed at improving the prevention of stroke, particularly from carotid artery narrowing caused by atherosclerosis.
His other interests include the development of NHS services and applications of MRI in stroke - he has been involved in setting up three different stroke units and runs a specialised clinic for rare causes of stroke including moyamoya disease.