Car accident.

[GloriousGabe]

A CSF leak anywhere can be a very big deal, whether post-trauma, post-surgery, or post spinal/epidural anesthetics. With trauma, besides being a sign of a significant head injury/skull fracture, there can be a very high risk of infection. With post-op or post-anesthesia CSF leaks that persist, patients get very bad headaches.

Yeah the guy I know who used to have his spinal fluid drip out of his nose had the worst headache anyone ever had. He had no trauma- it just happened on its own.