I have a large scar on my arm from a similar incident in my youth. Possibly brain damage as well.

I awoke to a shadowy figure standing over me, so I did what any reasonable person would - I lunged out of bed, screaming incoherently, and tried to tackle it. It was unfortunately imaginary, unlike the hard, wooden floor. I poorly performed a shoulder roll and scraped my arm along one leg of my bureau, tearing the skin from my elbow halfway to my wrist, and cracked my head into the wall.

My parents found me incoherent and covered with blood. A trip to the hospital yielded a diagnosis of a mild concussion and an avulsion wound too ragged to be stitched back together.