There is no reason for a person with MS to avoid
local anesthesia when needed, unless the person happens to be allergic to the commonly used
local anesthetics, such as Novocaine. One study reviewed 98 patients who together had received more than 1,000 doses of local anesthetics. In only four instances was the dose followed by an exacerbation—a sudden worsening of an MS symptom or symptoms. An exacerbation is also known as a relapse, attack, or flare."
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http://www.