Christina Applegate says she was wrongfully diagnosed with MS

Dr Marwa Kaisey, a guest on Tuesday’s episode, said MS misdiagnoses are not uncommon because symptoms are inconsistent and there is no universal testing.

“It’s not like we have something like a pregnancy test that says ‘yes, you have it. No, you don’t,'” Kaisey said. “It’s a list of criteria.”

About 15 to 20 percent of patients diagnosed with MS do not actually have the disease, research suggests, according to Elena Grebenciucova, a neuroimmunology physician at Northwestern Medicine in Chicago.

Dr Grebenciucova said the illness is typically diagnosed by finding a number of lesions – or white matter spots – with an MRI of the brain or spinal cord.

But she said those white matter spots can sometimes be signs of different health problems or illnesses, like migraines, high blood pressure, high blood sugar and high cholesterol.

The neurology doctor said another health condition, a vitamin B12 deficiency, can also lead to neurological problems that closely mirror MS symptoms, including cognitive decline, tingling and balance issues.

MS is a diagnosis of exclusion, with doctors combing through a patient’s medical history and many laboratory tests to make a determination, explained Dr Philip De Jager, the director of the Multiple Sclerosis Center at Columbia University Vagelos College of Physicians and Surgeons.

Because misdiagnoses can happen, Dr De Jager said that patients should seek second opinions.

Applegate was first diagnosed with MS in August 2021, after experiencing symptoms for a while, saying at the time: “It’s been a tough road. But as we all know, the road keeps on going.”

Years later, she described being in a “real depression” and said in a 2024 episode of her podcast that “I don’t enjoy living. I don’t enjoy it. I don’t enjoy things anymore”.

She had said in a New York Times interview that she could not walk without a cane and used a wheelchair during filming of the Netflix series Dead To Me.