It might depend on your insurance and how OHSU is set up. Some policies require referrals for specialists, some don't, and some require referrals for some kinds of specialists but not others.

It may also depend how OHSU is set up. The major medical centers I've had experience with, depending on department/specialty, give you a choice of asking for a specific doctor or getting assigned to one. It may take longer (weeks/months?) to get an appointment with a specific doctor if s/he's in demand. IME, a referral from another doctor doesn't carry any weight unless something is critical/time-sensitive.

It never hurts to ask, and asking is the best way to find out.

All that said, I requested the most experienced PN specialist in the Neurology Dept. at one major medical center, and got him along with the head of Neurology. I still got a dx of idiopathic, and cut loose with a scrip for gabapentin.

Hoping you do better,

Doc