What is a stroke? What are the common causes of a stroke? What is a congenital aneurysm of the circle of Willis? What is a neural tube defect? How can it be recognized before birth? What is meant by...

What is a stroke? What are the common causes of a stroke? What is a congenital aneurysm of the circle of Willis?

What is a neural tube defect? How can it be recognized before birth? What is meant by the following terms: arachnoid, subdural hemorrhage, anencephaly, and meningioma?