Altered sensations (paresthesias), such as numbness or tingling, are some of the most common symptoms in MS. Paresthesias may affect the arms and legs, the body, and face and are the result of damage to nerves that transmit sensations from body surfaces to the brain. Numbness or tingling may be the first symptom for many people who are eventually diagnosed with MS. In most instances, numbness is simply an annoyance. However, in some cases it can be severe and debilitating, making tasks such as walking, writing, and dressing difficult.
Numbness and tingling are the most common examples of paresthesias in MS. Other examples include tickling, burning, pricking, or the sensation of ‘pins and needles’ or of a limb ‘falling asleep.’ These symptoms can be chronic (persisting for long periods of time) or transient (lasting for only a short period of time).
Severe symptoms warrant caution
In cases where numbness is severe—where there is loss of normal sensation—you should exercise caution. For instance, facial numbness that affects the inside of the mouth increases the chance that a person may bite their own tongue while eating. Similarly severe numbness affecting other parts of the body increases risk for burns from fire or scalding water.
What happens to cause numbness or tingling?
The symptoms of numbness and tingling, as well as other paresthesias, occur in MS due to damage to nerves resulting from demyelination. Demyelination results in loss of the myelin covering or sheath surrounding neurons, exposing part of the nerve called the axon. Without the myelin covering, nerve impulses traveling along axons can escape in the same way electricity escapes from a wire that has lost its plastic covering, causing a short-circuit. The abnormal sensations of numbness and tingling are a kind of short-circuiting of electrical nerve impulses that happens when nerves are damaged.
Are there treatments for numbness?
Pharmaceutical treatments for numbness or tingling are available. However, because these symptoms are typically mild and harmless, treatment is usually not required. In cases where the symptom is severe, or caused by a relapse, corticosteroids may be used to decrease CNS inflammation and provide temporary relief. Neurontin® (gabapentin) or Elavil® (amytriptyline) may also be useful in some cases. In most cases, numbness will clear up as an MS attack or exacerbation resolves.