When Multiple Sclerosis Symptoms Don't Mean MS

Tingling hands
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Imagine this: Out of the blue your hands and feet go numb or they start to tingle and your muscles feel weak. You may recognize these sensations as classic symptoms of multiple sclerosis (MS)—and they are. But they also may be an episode known as a clinically isolated syndrome (CIS) event.

In order to be labeled a CIS event, an episode must include one or more MS-like symptoms that last for at least 24 hours. They also have to affect someone who hasn't already been diagnosed with MS—otherwise, they would be considered an MS relapse. Besides muscle weakness and numbness and tingling, other symptoms that can occur during a CIS event include optic neuritis (an often-painful loss of vision, usually in one eye, that may be temporary or permanent); an electric shock-like sensation that starts in the back of the head and shoots down the spine known as L’Hermitte’s sign; and the "MS hug"—a burning or aching that feels as if it's wrapping around the torso.

Could It Be MS?

A CIS event literally can be an experience that occurs just once in a lifetime. It also can be a sign of a future diagnosis of MS. Although in the past the only way to find out if a CIS event was a symptom of impending MS was to wait for another episode to occur (or not). But now doctors can make a fairly accurate diagnosis with magnetic resonance imaging (MRI) of the brain and spinal cord. An MRI scan will show if there are any tell-tale signs of MS—areas of tissue damage called lesions. If one or more lesions show up on an MRI done after a CIS, doctors will do a follow-up scan three months after the first one. If more lesions have developed during that time, a diagnosis of MS can be made even if there hasn't yet been another CIS event.

If no more lesions show up on the first follow-up MRI, another one will be done three to six months later. If the second follow-up MRI is free of new lesions, then the person is considered MS-free and shouldn't need to be monitored with future MRI scans.

To Treat or Not to Treat

A huge advantage of MRI monitoring after a CIS event is that it can allow a person to get a jump start on treatment if it appears MS is in the offing. (The chance a person with a lesion will develop MS after a CIS is 60 percent. If there's no lesion, the odds go down to 20 percent.) Research shows that if a disease-modifying therapy is started early, it can delay a second attack for up to two years.

On the other hand, studies also have found that early treatment may have only a small impact on how severely disabled a person with MS will become. This is important to consider because MS treatment is pricey. It also can be challenging for some people: MS medications must be injected. Given these pros and cons of treatment after a CIS event, you'll want to make sure with your doctor if it's the right thing for you.

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