Multiple Sclerosis

Multiple sclerosis (M.S.) is a complex condition. The name refers to the multiple points of sclerosis, or tissue hardening, found in the brain and/or spinal cord in someone with the disease. These form when the immune system attacks healthy nerve fibers and a substance called myelin, a protective coating that surrounds nerve fibers in the brain and spinal cord, according to Johns Hopkins Medicine. Myelin helps your nerve fibers conduct impulses in your body quickly and more efficiently, so you can control your muscle movements and decode sensory information—like what you see or hear—without delay, according to the U.S. National Library of Medicine.

Multiple sclerosis can be an unpredictable disease and affect individuals who have it in different ways. However, learning more about the condition can help you manage and live with it or help you support a loved one who has been diagnosed.

Multiple sclerosis can be an unpredictable disease, affecting the spine and nervous system.

Amanda K Bailey

M.S. happens when someone’s immune system mistakenly attacks their healthy nerve fibers, creating chronic inflammation and damaging myelin, according to the Cleveland Clinic. This process can ultimately prevent your central nervous system from working as it should.

“The central nervous system controls pretty much all our major functions,” Ari Green, M.D., medical director of the Multiple Sclerosis and Neuroinflammation Center at the University of California, San Francisco, tells SELF. “It controls our capacity to move our bodies, our capacity to feel [sensations], coordinate movements, go to the bathroom, and to see.”

As these attacks progress, signs and symptoms of M.S. emerge.

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Multiple sclerosis symptoms vary and may change over time. Initially, the most common M.S. symptoms are vision changes and bodily numbness and weakness, Daniel Harrison, M.D., neurologist and director of the University of Maryland Center for Multiple Sclerosis, tells SELF. The symptoms that emerge first depend on where the myelin damage is located—whether it’s in the brain or in the spine. “If there is inflammation in the optic nerve, patients will have difficulty with vision, often accompanied by some pain, especially with eye movement,” Dr. Harrison says. People may notice black spots, have blurred vision, or have difficulty with identifying colors¹.

“If the inflammation is in a portion of the spinal cord, typically they’ll have symptoms from that point down,” he says. For example, if there’s inflammation in the middle of your spinal cord, then your legs may feel weak or numb and you might have trouble walking. Inflammation in the brain stem will interfere with your facial and eye movements, in addition to your balance and coordination, so you could experience dizziness. “You could have weakness in the face, slurring of speech, or imbalance and lack of coordination,” explains Dr. Harrison. Because of M.S.’s unpredictable nature, it is hard to offer a complete list of potential symptoms, but here are some other signs, according to Columbia University:

• Fatigue
• Bladder issues
• Sexual dysfunction
• Muscle stiffness or spasms
• Tremors
• Mood changes
• Inconsistent sleep
• Memory problems

When people have episodes, they experience difficulties with motor and/or sensory skills because their brains and/or nervous systems are struggling to transmit or interpret impulses, explains Dr. Green.

“Typically, these symptoms will present as a very distinct event, with the onset occurring over the course of a few hours or a few days and worsening,” Dr. Harrison says. Symptomatic periods can last anywhere from weeks to months, but many people find their symptoms resolve within eight weeks. The majority of patients will eventually have an M.S. flare-up again, but it’s possible for people to go as long as 12 to 18 months with no symptoms at all. (A smaller subset of people have a different form of the condition that varies from this, which we’ll discuss in a bit.)

But because M.S. is a progressive disease, it’s important to note that true new relapses are marked by the experience of new multiple sclerosis symptoms, according to Dr. Green. “Let’s say a patient notices they have a little bit of weakness in their right hand, but it’s the same weakness every day and it hasn’t changed in 5 or 10 years. Then, they have new weakness in their left hand or new vision loss in their left eye. Well, that's typically a new episode,” Dr. Green says. These new symptoms are indicative of new or worsening damage to myelin. 

But let’s say when that person first had that weakness in their right hand, they also had a weakness in the right leg at the same time. When they recovered, they recovered the strength in their leg, but didn’t quite recover the strength in their hand. This low-grade weakness in their hand would still be classified as a remission, but if the more severe weakness returns without getting worse, it’s what’s known as a pseudo-relapse, Dr. Green explains. (These unfortunately named periods where older multiple sclerosis symptoms return don't do justice to the very real suffering they cause but are an important distinction.)

Usually, pseudo-relapses occur after someone becomes ill. “It’s possible that when a person gets sick, like with a cold or flu, their old symptoms that they had partially recovered from may return,” Dr. Green says. “A lot of patients start to think every time they have a symptom they’re having a relapse, but that's not exactly true,” he says.

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