She spent nearly 20 years believing she had MS. Then her diagnosis changed.

Key Points:

• DeMonica Amerson was misdiagnosed with multiple sclerosis (MS) in 2001 after a difficult diagnostic process, only to discover nearly 20 years later that she actually has neuromyelitis optica spectrum disorder (NMOSD), a rare autoimmune disease with similar symptoms to MS.
• Studies show that 15% to 20% of patients initially diagnosed with MS are later found not to have the condition, highlighting the challenges in diagnosing MS due to overlapping symptoms with other autoimmune diseases.
• NMOSD differs from MS in severity and diagnosis, as many NMOSD patients have a detectable antibody in their blood, which can aid in distinguishing the two conditions when specifically tested.
• Amerson has adapted to her corrected diagnosis by starting new treatment and focusing on advocacy to raise awareness about NMOSD, emphasizing resilience and positivity despite the challenges of living with a rare autoimmune disorder.
• The issue of MS misdiagnosis gained mainstream attention recently when actress Christina Applegate revealed she was incorrectly diagnosed with MS for nearly five years, illustrating the ongoing difficulties in accurately diagnosing complex neurological conditions.