OVERVIEW

To understand rheumatic chorea, first clarify what acute rheumatic fever is

Group A streptococcal (GAS) infection can cause streptococcal pharyngitis and may lead to a non-suppurative sequela 2-4 weeks later.

The disease primarily manifests as arthritis, carditis, chorea (characterized by brief, random, irregular involuntary movements of the limbs and face), erythema marginatum, and subcutaneous nodules. This is known as acute rheumatic fever.

What is rheumatic chorea?

Rheumatic chorea, also called Sydenham's chorea (SC), is a clinical manifestation of central nervous system involvement in acute rheumatic fever (ARF).

It presents as sudden, arrhythmic involuntary movements, muscle weakness, and emotional disturbances, typically appearing 1–8 months after streptococcal infection. It is the most common acquired chorea in children aged 5–13, with a higher incidence in females (female-to-male ratio of 2:1). It is rare in adults.

Is rheumatic chorea common?

With improved living conditions and antibiotic use, GAS infection rates have declined, leading to fewer cases of rheumatic fever. However, ARF remains prevalent in resource-limited areas. As one of the manifestations of ARF, chorea has also become relatively common. In the U.S., 18%–36% of rheumatic fever cases report chorea.

SYMPTOMS

What are the symptoms of rheumatic chorea?

Rheumatic chorea typically appears 1–8 months after a streptococcal infection, often with an insidious onset. Its characteristic manifestations include choreiform movements, emotional instability, and decreased muscle tone, as detailed below:

• Basal ganglia symptoms:

  • Sudden, abrupt, irregular, and purposeless choreiform involuntary movements.
  • Initially affecting one limb before spreading to the opposite side, with more pronounced symptoms in the upper limbs. Irregular finger flexion and extension, arm twisting, leg kicking, knee bending, and other movements may occur. Grimacing, tongue protrusion, and trunk twisting are also common, possibly accompanied by dysarthria. Symptoms worsen with emotional excitement and disappear during rest or sleep.
  • Severe cases may persist almost continuously throughout the day, disrupting daily activities and making standing, sitting, or lying down difficult.

• Cerebral cortex symptoms: Emotional instability, irritability, and disturbances in sleep and rest. Severe cases may involve confusion and agitation. Without other rheumatic fever symptoms, misdiagnosis as behavioral or emotional disorders may occur.

• Cerebellar symptoms: Markedly reduced muscle tone, weakened or absent tendon reflexes, clumsiness, and ataxia.

• Some patients may exhibit psychiatric symptoms alongside neurological manifestations, such as irritability, inappropriate behavioral outbursts, distractibility, and obsessive-compulsive tendencies, usually without delirium. These typically appear within the first 2 months of rheumatic fever.

• Other features: Unlike other forms of rheumatic fever, rheumatic chorea (SC) often lacks accompanying arthritis or carditis.

CAUSES

What are the causes of rheumatic chorea?

As mentioned above, the occurrence of rheumatic chorea is clearly related to infection with group A hemolytic streptococcus, but the specific pathogenic mechanism remains unclear.

Is rheumatic chorea contagious?

Rheumatic chorea is a central nervous system disorder caused by acute rheumatic fever and is not itself an infectious disease.

Is rheumatic chorea hereditary?

Rheumatic chorea is not a genetic disease, but it has familial susceptibility, with up to 30% of families with a history of chorea also having a family history of rheumatic fever.

DIAGNOSIS

What tests are needed to diagnose rheumatic chorea?

• C-reactive protein and erythrocyte sedimentation rate tests: To determine if there is an infection.
• Throat swab culture, anti-streptolysin O (ASO), and anti-deoxyribonuclease tests: To confirm whether it is a streptococcal infection.
• Electrocardiogram and echocardiogram: To check for cardiac involvement such as myocarditis.
• For patients with symptoms like fever or encephalopathy, a lumbar puncture for cerebrospinal fluid analysis is needed: To determine if brain tissue is affected and for differential diagnosis.
• For those with hemichorea or other cerebrovascular issues, MRI or PET scans can be performed: To rule out other brain disorders.

How is rheumatic chorea diagnosed?

In the absence of other identifiable causes, a clinical diagnosis of SC (Sydenham's chorea) can be made based on characteristic manifestations such as choreiform movements, emotional instability, and hypotonia.

What diseases can rheumatic chorea be easily confused with?

• Habit spasm: Habit spasm mainly presents as rapid, stereotyped, repetitive, and localized involuntary movements of the same muscle, without muscle tone abnormalities or emotional changes, and no evidence of rheumatic fever.
• Tourette syndrome: It mostly occurs in children, with symptoms including rapid, stereotyped, repetitive, and purposeless multiple muscle tics. Patients may make strange noises or swear.
• Huntington's chorea: It usually begins in middle age, accompanied by dementia and a family history of Huntington's disease, with symptoms worsening progressively. Imaging shows characteristic caudate nucleus atrophy.
• Other causes, such as drugs, infections, cerebral hypoxia, and kernicterus, can also lead to symptomatic chorea and should be carefully differentiated.

TREATMENT

Does rheumatic chorea require hospitalization?

Patients with severe symptoms, especially those complicated by carditis, require hospitalization.

What are the treatment options for rheumatic chorea?

The treatment for SC patients includes long-term antibiotic therapy to prevent disease recurrence and minimize the risk of rheumatic heart disease. Additionally, patients with significant impairment related to chorea may receive chorea-suppressing medications and/or immunosuppressive therapy.

• Patients in the acute phase need bed rest and should avoid light and sound stimulation. For those with severe muscle movements, soft padding can be added to the bedside to prevent injuries.
• Antibiotic therapy: Penicillin or other antibiotics can be used, with a prolonged course to prevent further GAS infections and reduce recurrence risk. The treatment should last at least 10–14 days.
• For suppressing choreiform movements, low-dose high-potency dopamine 2 (D2) receptor blockers (e.g., fluphenazine, haloperidol, pimozide) can be used. For patients unwilling to take these medications, alternative treatments such as valproic acid or carbamazepine may be considered.
• Immunosuppressive therapy: For moderate to severe cases, corticosteroids may be administered for immunosuppression. For example, oral prednisone at 1–2 mg/kg once daily for 14 days, or intravenous dexamethasone for 7–10 days. Hormone therapy can shorten the course of rheumatic chorea.

Can rheumatic chorea go untreated?

The disease is self-limiting, with chorea movements usually disappearing gradually within 3 months, though in rare cases, they may persist for 6–8 months. Timely and proper treatment can effectively shorten the course. About 1/4 of patients experience one or multiple recurrences, most commonly within 1–2 years after recovery.

Can rheumatic chorea be cured?

Yes, most patients fully recover within 6 weeks of treatment, with the longest recovery time being 8 months.

Will there be any sequelae after rheumatic chorea is cured?

After recovery from rheumatic chorea, there are generally no sequelae.

Can rheumatic chorea recur after being cured?

Recurrence of rheumatic chorea is not uncommon, with a recurrence rate of about 15%–30%. Most recurrences occur 2–3 years after the initial episode and are associated with repeated group A streptococcal infections. Sometimes, recurrence may be related to pregnancy or oral contraceptive use. Patients who did not receive standardized antibiotic treatment are at higher risk of recurrence.

Does rheumatic chorea affect fertility?

Rheumatic chorea does not affect fertility.

DIET & LIFESTYLE

What should patients with rheumatic chorea pay attention to in daily care?

• For children, attention should be paid to guiding their emotions, strengthening communication, and understanding changes in their psychological state. Soothing music can be used to alleviate fear.
• Implement safe and effective protective measures. Keep sharp objects out of the room to prevent falls, falling out of bed, and other accidents. When involuntary movements are severe, place soft padding around the bed rails.
• Maintain a quiet and tidy environment, creating a comfortable and safe living space to reduce negative stimuli.
• Engage in muscle function exercises during recovery, paying attention to gradual progression during training.
• Arrange a reasonable diet. Focus on high-protein, high-fiber, and easily digestible foods, and strictly avoid spicy, hard, or other irritating foods. When movements are frequent, delay eating to prevent aspiration.

PREVENTION

How to prevent rheumatic chorea?

Standardized antibiotic treatment can effectively prevent the occurrence and recurrence of this disease and reduce the risk of rheumatic heart disease.