b'four relapses, I had more MRIs and the radi- To complicate things further, my spinal tap ologist reviewing my scans was the rst tocame back negative. A diagnosis of MS, however, strongly suggest NMOSD as a more likely di- can still be made with a negative spinal tap agnosis based on the location of some of my(lumbar puncture). A spinal tap is often used to lesions, particularly in the area postrema andlook for oligoclonal bands in the cerebrospinal obexareas in the brainstem commonlyuid, which are present in about 85-95 percent affected in NMOSD. This revelation shifted theof people with MS. In the case of NMO or conversation again. The radiologists ndingsNMOSD, a spinal tap can also be negative, indicated that while MS was still a possibility,though certain ndings may help with conrming my lesion pattern was more characteristica diagnosis. For NMO/NMOSD, CSF analysis of NMOSD.is typically less denitive than it is for MS. The neurologist came to see me later thatMore importantly, oligoclonal bands, which morning and explained that while MS seemedare common in MS, are typically absent in the most likely diagnosis, it was crucial to rule outNMOSD. NMOSD. The next step would be further testing,Aquaporin-4antibodiesarepresentin including a blood test for the Aquaporin-4about 70-80 percent of people with NMOSD. antibody, a marker specic to NMOSD. In theFor those who are negative for AQP4 antibodies, meantime, I would stay in the hospital for threea small subset may have myelin oligodendrocyte glycoprotein antibodies. However, there are days to receive intravenous steroid treatmentscases of seronegative NMO/NMOSD, where to reduce inflammation in my brain andneither antibody is detected, making the spinal cordstandard treatment for bothdiagnosis more difficult and requiring reliance MS and NMOSD.on clinical presentation and MRI ndings. The Aquaporin-4 antibody test, which oftenThis new information left my doctors unsure conrms NMOSD, came back negative, whichwhether I have seronegative NMOSD or MS. provided some relief. However, the absenceThe lack of clear markers for either disease of this antibody didnt rule out seronegativemeans Im still living in a state of uncertainty, NMOSD, a form of the disease that is harder tounsure of what my future holds. The treatment diagnose and requires careful observation overoptions for NMOSD and MS can be different, time. My doctors were unsure whether I wasso knowing which disease I have is critical for facing MS or seronegative NMOSD, but for themy long-term care. For now, I continue to be time being, MS seemed the more likely diagnosis.monitored closely by my neurology team while they try to determine whether my disease Lack of clear markers course points more strongly to one diagnosis During those long days in the hospital,over the other. I did what any nurse in my situation wouldEmbracing the unknowndo: I researched. I scoured the internet forLiving with this uncertainty has been one information about MS and NMOSD, trying toof the most challenging parts of my journey. learn everything I could about both diseases.As a nurse, Im used to working in a world where The more I read, the more I realized how easilyclear diagnoses lead to specic treatments, one could be mistaken for the other. The thoughtbut now, Im on the other side, experiencing the that I might be living with an even morefrustration of a diagnosis that remains elusive. severe condition weighed heavily on me.The possibility of seronegative NMOSD has 19 msfocusmagazine.org'