LP puncture looks for oligoclonal bands. It can confirm if you have MS.

Depends on if they meet McDonald criteria. And large lesions on your spine could be NMOSD, or MOGAD, or about 20 white matter diseases. Aren't you thankful for good neurologists.

Having brain lesions does not necessarily mean multiple sclerosis

Alexis,
To the best of my knowledge they always combine MRI W/WO contrast and Spinal Tap for definitive diagnosis.

Yes, and be thankful because when the spine starts getting damaged that is when things get worse, like transitioning to SPMS