Opinion: It took me 13 years to be diagnosed with MS. Christina Applegate’s misdiagnosis doesn’t surprise me

Since the news about Christina Applegate’s multiple sclerosis misdiagnosis was released, texts from friends in disbelief have been popping up on my phone. “How could this happen?” they asked. “I wonder what else it could be?” they questioned. Because it took so long to receive my multiple sclerosis diagnosis, they assume that I might be wondering if I, too, could be misdiagnosed. “I’m not surprised,” I responded each time someone reached out. “MS can be difficult to diagnose.” “She came into my room and said, ‘Congratulations — you don’t have MS,’” Applegate shared on a recent episode of her podcast, “MeSsy.” While the doctor thought this was positive news, Applegate told her listeners that she was not happy at all. “You don’t get misdiagnosed, and all of the sudden I’m better,” she said. I felt her disappointment as if it were my own — because not long ago, it was. I’ll never forget when my neurologist said the words, “I think what we’re dealing with here is MS.” It was 2017. He’d mentioned the possibility at previous appointments, and I’d already been living with debilitating weakness, pain, and fatigue for 13 years, so I wasn’t completely shocked. But I was scared, and also relieved. On that day, those two letters — MS — were so much more than a couple of symbols from the alphabet. They held the weight of 13 years of repeated lab work and office visits. They carried the anger of being told I was exaggerating and the hopelessness of feeling as though there was no solution to the weakness preventing me from walking. They provided the validation I deserved for waking up every day for 13 years and choosing to keep searching despite being told I may never receive an answer. Those letters were definitively spoken after all other possibilities had been ruled out. But what happens when every other possible disease isn’t considered first? Perhaps a misdiagnosis. Across the country, news programs are interviewing doctors to understand how such a critical mistake can be made — and asking what else could be causing her debilitating symptoms. But Applegate is not alone. While data appear to be limited, recent publications from specialized MS centers suggest that around 30% of those originally referred for MS were eventually diagnosed with another disease. There is no one test to confirm MS. It doesn’t yet have a measurable numerical value like high blood pressure or elevated cholesterol does. The McDonald Criteria for diagnosing MS were recently revised to prevent misdiagnoses from occurring. They didn’t provide clarity in my case even as I begged for an answer. Other diseases that cause similar symptoms and findings include lupus, Lyme disease, fibromyalgia, vitamin B12 deficiency, and less common conditions like neuromyelitis optica and MOG antibody disease. During my diagnostic journey, I was tested for these conditions and other, much rarer — and only newly discovered — antibodies that cause diseases of the nervous system. And researchers continue to discover novel antibodies that cause similar neurological autoimmune diseases, so some people diagnosed with MS today could potentially learn they have a disease that falls outside of the MS umbrella in the future. Ongoing research is focusing on finding measurable MS biomarkers that would make diagnosis much clearer. Ultimately, if symptoms continue to worsen on treatment, as they did for Applegate, a new medication or diagnosis should be considered. While some autoimmune conditions — like Sjögren’s, Hashimoto’s thyroiditis, and rheumatoid arthritis — have antibodies that can be measured in the blood and used to confirm diagnosis, MS does not yet have a known antibody. Diagnosis relies solely on symptoms, MRI, and spinal tap findings. But other conditions can present with similar findings and symptoms. Essentially, MS is a diagnosis of exclusion. For years, I was misdiagnosed with fibromyalgia, but I always felt there was more going on. My MRI findings were nonspecific, meaning they could stem from other causes, and they were initially blamed on migraines. But ultimately, my spinal tap showed oligoclonal bands (proteins found in the spinal fluid) and white blood cells, confirming an autoimmune, inflammatory neurological diagnosis. By that point — more than a decade after my symptoms began — other diseases that mimic MS had been ruled out, but only because I was forced to inquire about them after doctors had wrongly written off MS early in my diagnostic search. Perhaps the one — and only — perk of a delayed diagnosis is an eventual definitive one. Michael Levy, a neuroimmunologist at Massachusetts General Hospital, told Boston 25 News it was likely Applegate’s age (diagnosed in her 40s rather than mid-20s) and her lack of response to treatment that prompted doctors to reconsider. But as I texted with friends about her setback, I found myself questioning that reasoning. “Without presenting a new diagnosis, I don’t understand how they can rule out MS,” I contested. If they’d pinpointed a new diagnosis via a measurable marker, one that better explained her symptoms, that would make more sense. But without another clear answer, and already having met the criteria for an MS diagnosis initially, I wasn’t sure how they could discount it completely. I was yearning for more information: What did her MRI show? Was a spinal tap performed? Did she, too, have oligoclonal bands? What medication had she been taking as her symptoms progressed? Did she try another? Internally, I returned to my darkest days as I struggled to stand while doctors failed to help. From one once-undiagnosed patient to another, I wanted to ease her despair of learning she’s once again facing a disease with no name. In my case, so much was ruled out, there was nothing left but MS. And my MS treatment has drastically changed my life, restoring strength and allowing me to return to many activities I was unable to do while undiagnosed and untreated. Applegate feels as though her reason for pushing onward has been taken from her. “It’s weird because I feel like I let everybody down. It’s this weird feeling of like I became this, you and I, the poster children for MS. All that I did, everything that I was doing, I had a f—ing reason as to why my day sucked every day. And now I don’t have a reason,” she said on her podcast. But Applegate is no longer solely impacting the MS community. Through her honesty, she’s also helping those who may soon realize they don’t have MS and every person struggling to find a diagnosis. I hope she realizes that her reason has not been erased — it has multiplied. Lindsay Karp is a freelance writer and essayist with clips in the Washington Post, Boston Globe, Time, USA Today, and other outlets.