Infection should be ruled out. This can be done via a urine test or urethral swab. STDs like gonorrhea and chlamydia, as well as UTIs can present with this symptom. The prostate can be evaluated with a digital rectal exam or ultrasound.
I would also obtain some blood tests to look for metabolic diseases like diabetes or thyroid disorders.
With a neurology referral, that would make peripheral nerve disorders less likely.
You can consider an ultrasound to evaluate blood flow to the penis.
These options can be discussed with your personal neurologist.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_b