Multiple sclerosis misdiagnosis rates highlighted by celebrity testimony

The difficulty of diagnosing multiple sclerosis (MS) has gained attention following testimony from American actress and producer Christina Applegate, who revealed she was incorrectly diagnosed with the condition in 2021.

Because MS is often a diagnosis of exclusion—requiring clinicians to rule out all other possible causes of central nervous system damage—misdiagnosis is a significant challenge. A 2024 systematic review of 3,910 publications found that approximately 15% of MS diagnoses may be incorrect, though estimates vary between 5% and 41% across different studies. Correcting these errors can take anywhere from several months to 16 years.

Confusion often arises because MS symptoms, such as visual disturbances, tingling, muscle weakness, balance issues, and intense fatigue, overlap with other conditions. According to the MS International Federation and research from the University of Vermont, approximately 22% of misdiagnosed cases involve individuals actually suffering from migraines. Other conditions that can be confused with MS include fibromyalgia, neuromyelitis optica, and psychogenic disorders.