I was talking to a doc friend about this. It could have been as innocent at slipping in the shower and banging you head on a towel rack. Or hitting something after bending over to tie your shoes.
A swelling under the back of your skull will press down on your spinal cord.
Just a hypothetical.
he also had an enlarged heart that was 95 percent blocked on one side so he was probably about to have a heart attack soon anyway.