Christina Applegate's MS Misdiagnosis Highlights Diagnostic Challenges

Christina Applegate recently shared that she was misdiagnosed with multiple sclerosis (MS) after undergoing treatment for five years, a revelation that is bringing attention to the challenges in diagnosing the disease. The actress, 54, discussed her experience on her podcast "MeSsy," expressing shock at the news that she does not have MS, despite having been diagnosed in 2021 after experiencing significant symptoms and undergoing tests including MRIs and a spinal tap.

Applegate recounted that her initial MS diagnosis was based on numerous lesions found on her brain scans. However, her doctor eventually re-examined her case, noting that her B cell levels did not change with treatment, which prompted further investigation. "And my B cells didn't change. They didn't go higher, they didn't go lower, they didn't change, and she had never seen that. So I guess that began kind of a study into my diagnosis," Applegate explained.

Following additional scans, her doctor informed her that she did not have MS. Applegate noted that this news was not a relief, as her debilitating symptoms persisted and, in some ways, had worsened. "Because you don't get misdiagnosed and then all of a sudden [you’re] better," she said. "I haven't gotten better … If anything, I've gotten worse in some ways."

Applegate stated that she experiences "every symptom" associated with MS, and that many other conditions can closely mimic the disease. She recalled having around 30 lesions on her MRIs, but a specific feature identified by her neurologist led to the conclusion that it was not MS. This has left her feeling uncertain about her health condition.

Challenges in MS Diagnosis

Dr. Marwa Kaisey, an associate professor of neurology at Cedars-Sinai, stated that MS misdiagnoses are "fairly common." A study of patients referred to MS clinics found that nearly one in five ultimately did not have the disease, with some having been misdiagnosed for decades and undergoing treatment.

Kaisey explained that there is no single definitive test for MS, unlike some other conditions. The diagnosis relies on a set of criteria, some of which can be subjective. Many patients who are misdiagnosed did exhibit white matter spots or lesions on their MRI scans, which can also be caused by other conditions.

Advancements in Imaging

Newer imaging techniques are helping physicians differentiate MS lesions from white matter spots caused by other factors. The "central vein sign," an MRI finding that identifies a specific blood vessel within lesions, is characteristic of MS and has been incorporated into updated diagnostic criteria. Richard Ransohoff, MD, a neurologist and member of the Board of Directors for the American Brain Foundation, described the central vein sign as a significant advancement in distinguishing MS lesions.

Despite these advancements, many common symptoms of MS, such as fatigue, numbness, and cognitive issues, overlap with symptoms of numerous other conditions. "To distinguish MS from its mimics can be challenging, and doctors, even with the best intentions … can sometimes still get it wrong," Kaisey said. She emphasized the need for both characteristic symptoms and specific MRI findings consistent with MS for an accurate diagnosis.

Mimicking Conditions and Patient Experience

Conditions that can mimic MS include certain types of strokes in younger individuals, neuromyelitis optica spectrum disease, MOG antibody disease, lupus, and migraine. Migraine, in particular, is frequently mistaken for MS as it can also cause white spots on MRI scans, though typically smaller and in different locations. "If you're not looking closely at the MRI or you don't know exactly what to look for, you can confuse the two," Kaisey noted.

For patients like Applegate, being told they do not have MS after years of living with a diagnosis can be particularly difficult. Kaisey described this as potentially "earth-shattering" and life-changing, especially when no alternative diagnosis is immediately clear. She advised patients to ask questions and seek second opinions when they feel something is not right.

Ransohoff stressed the importance of physician humility and an open mind. "If things start going differently from your expectations, if the person begins to have symptoms that really don't fit in with MS, or they don't respond to treatment, then you really start to put on your thinking cap and say, ‘What else could this be?’" he said.

Importance of Specialized Care

To mitigate misdiagnosis, Ransohoff recommends that individuals diagnosed with MS be evaluated by specialists at dedicated MS centers. These specialists have extensive experience recognizing the varied presentations of the disease. He also highlighted the significant advancements in MS treatment over his career, with a wide range of medications now available. "The person who's diagnosed with MS today is totally different from 40 years ago," Ransohoff stated, adding that with an accurate diagnosis and appropriate treatment, patients can expect a significantly better prognosis.