I too, went to a pain clinic for a while. It was under the dept of
anesthesiology at Hopkins. My neuro was out on sick leave
and a substitute, who had no time for my problems,
referred me to the Pain Clinic.
After 4 different med trials, injections of different sorts
and no relief - I went back to my neurologist (Hopkins' neuro dept head)

Anesthesiologists have tunnel vision. They use numbing drugs for everything.
If it can't be done with knock-out drugs, they're not interested.

You need a neuro who specializes in PN, with a good number of satisfied PN patients, as referrals.
Check references.
Ask specifics.
Don't settle for less.