Hi Flustered, the inability to think clearly when suffering pain is something we all experience, and here's a recent article about it. when I asked my Dr about the brain fog, he suggested a lack of sleep. I hadn't thought of that-can't think-but he was so right. The constant pain causes a very restless sleep. Taking meds to sleep then gives an unsatisfying sleep and a hangover!
I suggest that in the waiting interval you make a note of any questions or queries that you have, and take this with you to the appointment. AND write the answers down!