Hi mikeg,
Have you talked to your doctor about getting tested for a systemic viral infection? A blood test looking for specific types of markers in the blood can show if something is there that shouldn’t be. Your doctor would know more about this.
As far as Gabapentin goes, if your current dose isn’t helping, would your doctor be willing to increase it or try a different nerve pain med. There is a post in the Newbies Guide here that lists different types of them. Perhaps a different one would work better for you. No use taking something that isn’t really helping. Here’s the link to the post Jules made: ES Information- Treatment: Pain Relief
Were you put on steroids & antiviral meds when you had Bell’s Palsy? I recently had my second Shingles vaccination, & it set my spinal nerves to screaming for a couple of days. In retrospect, I am VERY thankful I got the shots & not a full blown case of Shingles.