I was diagnosed with neurosarcoidosis after a CT scan. Also bronchioscope, no confirm. I believe cauda equina. How to test for this? 2 yrs with this.

2nd opinion time. Neurosarcoidosis is a complication of sarcoidosis. Sarcoidosis almost always begins with lung involvement. You said you had bronchoscopy. Did you have a chest ct scan to rule-out lung involvement? You should. For diagnosis of neurosarcoidosis a ct scan showing a lesion of the cauda equina is inadequate. You should at least have a spinal tap & probably a brain & spine MRI scans. Good luck.
Help. Get into a neurologist who specializes in your condition(s)! it might take a bit of research and phone calls to find the right neurologist to help you, but it is better than just seeing a doctor, not getting any answers, then receiving a large bill in the mail.