I have 30 years of experience, and specialize in the field of neurosurgery with specific knowledge in the areas of vascular neurosurgery, brain tumors and head injuries. I have published on such topics as aneurysms, arterio-venous malformations and strokes. I have testified 30 times on topics such as aneurysmal subarachnoid hemorrhage, neurosurgical operative treaments and head injuries. I am professor and chairman of a large neurosurgical department and have an international reputation as a vascular neurosurgeon, treating all causes of stroke.