The scan I had last week confirms that I did not have a stroke, and that I do not have brain cancer.
I met with a neurologist, and we looked over the images from the scan. I, apparently, have a pocket of spinal fluid in my temporal lobe. The doctor asked me a lot of questions (particularly about my history of migraines), and did a battery of in-office tests (most of which I had seen Robb do -- touch your nose with your eyes closed, that sort of thing). The doctor was interested, but not freaked out.
More tests are forthcoming.
I'm choosing not to expend any excess emotional energy on worrying. It accomplishes nothing, and just stresses me out. I'm taking a positive outlook about the whole thing.