Sydenham's Chorea

Symptoms/Findings

Sydenham's chorea is considered a neurological complication following infection with particular strains of streptococci (i.e., group A beta-hemolytic streptococci). The initial illness is usually characterized by a sore throat (pharyngitis) that may be followed, within approximately 1 to 5 weeks, by the sudden (acute) onset of rheumatic fever. The symptom-free period between recovery from pharyngitis to the onset of acute rheumatic fever (ARF) is known as the "latent period." ARF is an inflammatory disease (i.e., sequelae) following group A streptococcal infection that may affect multiple tissues and organs, including the joints, skin, connective tissues directly beneath the skin (subcutaneous tissues), heart, and brain. Associated symptoms and findings may vary greatly from patient to patient. For example, in about 20% of cases, Sydenham's chorea occurs as the only manifestation of ARF; however, in others, it develops as a late feature of ARF following other characteristic manifestations, such as the following:

Fever, a common initial symptom associated with ARF
Swelling and inflammation (arthritis) of one or more joints that may be characterized by redness, warmth, tenderness, and pain (arthralgia) of affected joint regions. Arthritis and fever are the most common symptoms initially recognized in association with ARF. Without treatment (e.g., anti-inflammatory drugs), the arthritis progressively affects multiple joints in rapid succession, with the onset of symptoms in different joints typically overlapping. Because arthritic involvement may appear to "migrate" from one joint to the next, this condition is often described as "migratory polyarthritis." Joints of the legs, such as those of the knees and ankles, are typically initially affected, followed by involvement of other areas, including the wrists and elbows. In rare instances, joints of the fingers, toes, or spine may also become involved. Due to extreme tenderness of affected joints, children may experience severe discomfort even due to the presence of clothing, blankets, or bed sheets covering affected joints.
Inflammation of the heart (carditis). Although often beginning at approximately the same time as fever and arthritis, carditis may not initially cause symptoms (asymptomatic). It is reported that about 80% of patients with Sydenham's chorea have cardiac lesions. The carditis associated with ARF may involve all heart regions (i.e., pancarditis), including...
- The internal lining of the heart (endocardium)
- The relatively thick, middle layer composed of cardiac muscle (myocardium)
- The fibrous sac (pericardium) surrounding the heart and the roots of its major blood vessels, including the innermost region (i.e., visceral layer) that adheres to the surface of the heart (epicardium)

Carditis may lead to abnormalities in the rate or rhythm of the heart beat (arrhythmias); enlargement of the heart (cardiomegaly) as seen on x-ray imaging; new or changing cardiac murmurs or abnormal heart sounds as heard upon a physician's use of a stethoscope; and, in severe cases, an impaired ability of the heart to pump blood effectively to the lungs and the rest of the body (heart failure). Symptoms of heart failure in affected children may include shortness of breath (dyspnea); nausea and vomiting; a hacking, "nonproductive" cough; and aching or pain within the upper middle (epigastric) or upper right area of the abdomen. In patients with ARF, acute heart inflammation typically gradually subsides within about 5 months. However, in some instances, there may be permanent scarring or damage of certain heart valves, resulting in rheumatic valvular heart disease. In such cases, the mitral valve, located between the left upper and lower heart chambers (left atrium and ventricle), is most commonly affected. As a result, the mitral valve may become abnormally narrow (mitral valve stenosis) and/or may fail to close properly (mitral regurgitation or insufficiency), resulting in a backflow or leakage of blood from the left ventricle into the left atrium during contraction (systole). Less commonly, rheumatic valvular heart disease may also involve other heart valves, such as the valve between the left ventricle and the aorta (aortic valve) and the valve between the right atrium and right ventricle (tricuspid valve).

"Non-itching" (nonpruritic) skin rash (erythema marginatum) characterized by temporary, pinkish or reddish spots (macules), particularly on the trunk, that gradually fade in the centers. This skin rash tends to appear early in the disease course, may persist or recur when other symptoms have subsided, and usually only affects patients with carditis.
Subcutaneous nodules or the development of firm, nontender, "pea-sized," node-like structures beneath the skin at various joints, such as the elbows and knees, as well as over the spine. Like erythema marginatum, this relatively infrequent finding typically affects only those with carditis. The subcutaneous nodules tend to appear after the first weeks of the disease course and usually disappear within a week or two.

Choreic movements and emotional or behavioral disturbances
Chorea may also become apparent in patients with ARF, usually developing by 1 to 6 months (or more) following the initial illness (e.g., pharyngitis). However, the average time interval is about eight weeks. As mentioned earlier, Sydenham's chorea may occur as an apparently isolated condition or subsequent to the development of other characteristic features. Although some patients with Sydenham's chorea may have no other symptoms associated with ARF, thorough diagnostic evaluation may reveal cardiac murmurs. (For further information, please see the section entitled "Diagnosis.") In some patients (about 30%), chorea occurs simultaneously with migratory polyarthritis.

In most patients, choreic movements begin acutely, with sudden onset. In some patients, the symptom begin gradually and subtly (insidious), often progressing over weeks to approximately a month before medical attention is sought. In most children, these irregular, involuntary, jerky movements may initially appear as increasing awkwardness or clumsiness, such as difficulty writing. In addition, certain emotional or behavioral abnormalities often develop days or weeks before the onset of chorea, with affected children often described as unusually restless, aggressive, or "excessively emotional."

More specifically, the choreic movements associated with Sydenham's chorea consist of relatively fast or rapid, irregular, uncontrollable, jerky motions that disappear with sleep and may increase with stress, fatigue, excitement, or other factors. When these movements become severe, they develop a ballistic nature. Both sides of the body are typically affected (bilateral). However, in up to 20 percent of patients, abnormal involuntary movements may be unilateral or limited to one side of the body (hemichorea). Affected areas may include muscle groups of the arms and legs (limbs), the trunk, and, in many instances, the face and neck. Many patients also develop muscle weakness.

Associated findings may be variable, ranging from relatively mild incoordination of certain voluntary movements to severe disruption of the ability to perform certain activities of daily living, potentially resulting in significant disability. For example, the neuromuscular abnormalities associated with Sydenham's chorea--including choreic movements, low muscle tone, and/or muscle weakness--may lead to the following:

Facial grimacing
A significant deterioration in handwriting (in school-aged children)
Slight or significant difficulties dressing, feeding, and walking
Slurred, slowed speech (dysarthria)
Other associated findings

Rarely, Sydenham's chorea may be associated with decreased muscle tone, muscular rigidity, or increasing muscle stiffness and resistance to movement, resulting in severe disability. In the past, these extremely severe cases (about 1.5% of patients) were said to have "paralytic chorea," as a result of extremely decreased muscle tone. Fortunately, therapies are available to help treat chorea in appropriate, selected cases. (For further information, please see the section entitled "Treatment.")

As mentioned above, Sydenham's chorea is also often associated with emotional or behavioral disturbances. Most commonly, affected children may develop obsessive-compulsive behaviors, which are characterized by the performance of certain repetitive actions or rituals (compulsions) in response to persistent thoughts or impulses (obsessions). In some instances, additional behavioral or emotional abnormalities may also become apparent, including the following:

Increased irritability
Frequent mood changes and excessive emotional reactions (emotional lability), including uncontrollable crying episodes
Age-regressed behaviors
Confusion
Easy distractibility, impulsivity, and abnormally increased motor activity (attention deficit hyperactivity)
Transient psychosis

As mentioned previously, the course of the syndrome may be variable from patient to patient. Associated symptoms may tend to begin relatively subtly, progressively worsen over a few weeks to months (usually over 2 to 4 weeks), and gradually spontaneously resolve within approximately 3 to 6 months. However, in some instances, there may be residual signs of chorea and behavioral abnormalities, which may wax and wane over a year or more. In addition, in about 20 percent of patients, Sydenham's chorea may recur, usually within approximately 2 years of the initial occurrence. Recurrences have also been reported during pregnancy in women who had ARF during childhood as well as in association with the administration of certain medications (e.g., estrogen-containing oral contraceptives; phenytoin, an anticonvulsant agent).