What is multiple sclerosis? Selma Blair’s diagnosis puts spotlight on disease

Image: Selma Blair

Calling her multiple sclerosis diagnosis “overwhelming,” actress Selma Blair says she’s relieved to at least connect her symptoms to a disease.

“I have MS and I am ok,” Blair, 46, wrote on Instagram Saturday as she went public with her story for the first time.

“I am disabled. I fall sometimes. I drop things. My memory is foggy. And my left side is asking for directions from a broken gps. But we are doing it. And I laugh and I don’t know exactly what I will do precisely but I will do my best.”

Like many MS patients, it was a long journey to get answers: Blair received the diagnosis in August, but she believes she’s probably had multiple sclerosis for at least 15 years, she wrote. That’s not a surprising scenario, said Bruce Bebo, executive vice president of research at the National Multiple Sclerosis Society.

“It’s pretty common for people, when they get diagnosed, to reflect back on symptoms that they had during their lifetime and now see them for what they were,” Bebo told NBC News.

“They may have been ignored, they were perhaps minor… You live your life, move forward and you don’t think much about it.”

What is MS?

Multiple sclerosis is a disease of the central nervous system that affects a person’s brain and spinal cord. The cause is a mystery, but the condition damages the material that surrounds nerve cells, slowing down or blocking communication between the brain and the body.

Almost 1 million people live with MS in the U.S., the National Multiple Sclerosis Society estimated. Most patients are diagnosed between the ages of 20 and 50, and the disease is two to three times more common in women than in men.

“MS is a more common disease than a lot of people think. It affects your neighbors, it affects your friends,” Bebo noted.

What are the symptoms?

The signs depend on where in the body the disease strikes, Bebo said. No two people have the same symptoms, and each person’s experience can change over time, the National Multiple Sclerosis Society noted.

When the inflammation that causes MS attacks the optic nerves, common symptoms can include vision problems, such as blurry vision, double vision or even temporary blindness, Bebo said. Ozzy Osbourne’s son Jack became about 90 percent blind in one eye before his MS diagnosis.

If the attack affects parts of the brain that control sensation, patients may experience numbness or tingling in their hands or feet.

If certain pathways in spinal cord are attacked, it can affect people’s ability to move and walk. Their feet will drop and they may easily