Neurologists, even MS specialists, sometimes misdiagnose patients with MS when they actually have other common conditions like migraine or fibromyalgia. A new study found 110 cases of misdiagnosed MS from four medical centers over 13 months. Two-thirds of misdiagnoses were for conditions like migraine, fibromyalgia, nonspecific neurological symptoms, psychogenic disorders, or neuromyelitis optica spectrum disorder. Many misdiagnosed patients received unnecessary disease-modifying therapies for years and some participated in clinical drug trials. The study suggests neurologists should avoid over-reliance on MRI findings and apply diagnostic criteria rigorously to avoid misdiagnosing common conditions as MS.