Chronic traumatic encephalopathy, or CTE, is a progressive disease that's linked to head injuries, most recently found in former NFL star Junior Seau. 

The lesser-known arteriovenous malformation, or AVM, is a congenital brain injury, a malformation of arteries and veins in the brain that can cause seizures, strokes and severe neurological problems.  It's a rare condition which affects only about one percent of the population. 

Ashok Rajamani discovered he was part of that one percent when he was just 25 years old.

His new book, "The Day My Brain Exploded," looks at how AVM changed his life, and not entirely for the worse.