What is Sydenham's Chorea?

Sydenham’s chorea is a complication that may occur with strep throat if this illness develops into acute rheumatic fever (ARF). It isn’t a very common illness in most developed countries because there is access to diagnostic tools and antibiotics to treat strep in its early stages. Where these are unavailable or when strep diagnosis is missed, about 20% of ARF cases can develop this complication of rheumatic fever. This illness is significant, causing sudden muscle movements that may be violent and dramatic changes to mood, cognition or behavior. There is treatment, and many people with this condition fully recover given the right medical assistance.

The presence of strep bacteria is thought to cause the body to produce an autoimmune response that begins to negatively affect some forms of healthy function. Inflammation in some parts of the brain and in other areas may result, and this is paired with higher than normal production of certain antigens. While total cause of Sydenham’s chorea is not completely understood, it is certain that the body’s response to strep germs tends to be medically negative, which can lead to the symptoms associated with this condition.

The first symptoms of Sydenham’s chorea usually occur after certain manifestations of acute rheumatic fever are present. These are fever, inflammation in the heart, joint swelling and pain, rash, and swelling or nodes that develop around some of the joints. ARF symptoms occur an average of two months after incidence of strep throat, but sometimes it can take much longer for these symptoms to develop.

When Sydenham’s chorea develops as a complication of ARF, there are many symptoms that may indicate it. As mentioned, sudden violent movements, often called choreic movements, can occur. Various areas of the body may have difficulty moving smoothly, and people may seem overly clumsy or they can have difficulty performing fine motor tasks like writing. Sometimes facial grimacing or gestures appear and these may be most active when people are awake and excited.

Things like speech can also be affected, and mood and cognition are definitely impacted. People may have outbursts of emotion, be difficult to comfort, have a hard time concentrating, be hyperactive, or show frequent confusion. There may be some regression in maturity levels, most noted when this illness impacts children and teens. Some people also experience psychotic episodes when they have Sydenham’s chorea.

There are two treatment approaches to managing these symptoms. The first is to get the strep infection cleared with antibiotics, though this may not cause chorea symptoms to disappear right away. Especially to tame movement disorders, certain anticonvulsants, like valproic acid (Depakote®) are often recommended. As the antibiotic fights strep and the body recovers, continued medication is generally discontinued.

While the more overt signs of Sydenham’s chorea are usually cured in a few months, some people have recurrence of the illness some years later, which isn’t common. Doctors advocate for preventing ARF by paying attention to illnesses that may be strep throat. Strep throat needs early treatment to avoid progression to ARF.