Sydenham Chorea

Overview

Sydenham chorea (SC), also historically known as “St. Vitus’ dance,” is a neurological disorder characterized by rapid, jerky, involuntary movements and muscle weakness. It is the most common cause of acquired chorea in children and represents a major manifestation of acute rheumatic fever (ARF), occurring in 20-30% of ARF cases^{1Sydenham chorea: a practical guide2021 · Pediatr Neurol · DOI 10.1016/j.pediatrneurol.2021.05.012Open reference}. The condition is named after Thomas Sydenham, the English physician who first described it in 1686^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}.

Sydenham chorea is classified as a manifestation of rheumatic fever according to the revised Jones criteria and serves as a major diagnostic criterion. It typically follows streptococcal infection by a latency period of weeks to months, through an autoimmune mechanism involving molecular mimicry between streptococcal antigens and neuronal tissues in the basal ganglia^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}.

Epidemiology

Sydenham chorea predominantly affects children between the ages of 5 and 15 years, with a mean age of onset around 9 years^{1Sydenham chorea: a practical guide2021 · Pediatr Neurol · DOI 10.1016/j.pediatrneurol.2021.05.012Open reference}. There is a female predominance, with females affected approximately twice as often as males. The condition is more common in developing countries and in populations with limited access to healthcare, where rheumatic fever remains prevalent^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}.

The incidence of Sydenham chorea has declined dramatically in industrialized nations since the mid-20th century due to antibiotic use and improved living conditions. However, it remains an important cause of childhood chorea worldwide, particularly in resource-limited settings^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}.

Pathophysiology

Autoimmune Basis

Sydenham chorea results from an autoimmune response triggered by group A β-hemolytic streptococcus (GABHS) infection^{1Sydenham chorea: a practical guide2021 · Pediatr Neurol · DOI 10.1016/j.pediatrneurol.2021.05.012Open reference}. The mechanism involves:

1. Molecular mimicry: Antibodies against streptococcal M protein cross-react with neuronal antigens in the basal ganglia (particularly the caudate nucleus and putamen)^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}

2. Dopaminergic dysfunction: This cross-reactivity leads to dysfunction of dopaminergic neurons in the striatum

3. Inflammatory response: Local neuroinflammation contributes to neuronal dysfunction

Neuropathology

Post-mortem studies have shown:

• Perivascular lymphocytic infiltrates in the basal ganglia

• Loss of neurons in the caudate and putamen

• Gliosis without overt necrosis^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}

Neuroimaging Findings

MRI may show:

• T2 hyperintensities in the caudate nucleus, putamen, or globus pallidus

• Diffusion restriction in acute cases

• Atrophy of the basal ganglia in chronic cases^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}

Clinical Features

Core Symptoms

The movement disorder in Sydenham chorea has characteristic features^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}0:

Chorea:

• Sudden, jerky, purposeless movements

• Randomly distributed across the body

• Facial involvement: grimacing, tongue protrusion, difficulty speaking

• Limb involvement: clumsiness, difficulty with fine motor tasks

• Truncal involvement: instability, difficulty sitting still

• Movements worsen with voluntary activity and emotional stress

• Movements cease during sleep

Motor Weakness:

• Reduced muscle tone

• Decreased coordination

• “Choreic hand” - dropped wrist, hyperextended fingers

• “Milkmaid grip” - inability to maintain grip

Other Features:

• Emotional lability (irritability, crying, anxiety)

• Obsessive-compulsive symptoms

• Reduced attention span

• In severe cases, mutism or severe motor impairment^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}1

Disease Course

• Onset: Usually insidious, developing over days to weeks

• Duration: Typically 2-6 weeks, but can persist for months

• Recurrence: Up to 25% of patients experience recurrence, often associated with subsequent streptococcal infections^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}2

• Recovery: Most children make a complete recovery, though some may have residual motor or behavioral issues

Diagnosis

Clinical Criteria

According to the 2015 revised Jones criteria, Sydenham chorea is a major manifestation of acute rheumatic fever. Diagnosis requires^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}3:

• Evidence of preceding streptococcal infection (positive throat culture, rapid antigen test, or elevated ASO/anti-DNase B titers)

• PLUS either:

  • Two major manifestations, OR

  • One major and two minor manifestations

Laboratory Findings

Supporting evidence of streptococcal infection^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}4:

• Elevated anti-streptolysin O (ASO) titer

• Elevated anti-DNase B titer

• Positive throat culture for GABHS

Other laboratory findings (nonspecific):

• Elevated erythrocyte sedimentation rate (ESR)

• Elevated C-reactive protein (CRP)

• Mild anemia

• Leukocytosis

Differential Diagnosis

Condition	Distinguishing Features
Huntington disease	Family history, progressive course, cognitive decline
Wilson disease	Kayser-Fleischer rings, hepatic dysfunction
Chorea gravidarum	Occurs in pregnancy
Drug-induced chorea	Temporal relation to medications
Autoimmune encephalitis	Psychiatric symptoms, seizures, specific antibodies
PANDAS	Younger age, abrupt onset, OCD features

Treatment

General Management

Supportive care^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}5:

• Safe environment to prevent injury

• Nutritional support if feeding difficulties

• Physical therapy to maintain function

• Psychological support for emotional lability

Antimicrobial Therapy

• Penicillin V or erythromycin for streptococcal eradication^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}6

• Long-term antibiotic prophylaxis may be considered to prevent recurrence

Immunomodulatory Therapy

First-line^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}7:

• Corticosteroids: Prednisone 1-2 mg/kg/day for 2-4 weeks, then taper

• May reduce duration of symptoms and prevent recurrence

Second-line^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}8:

• Intravenous immunoglobulin (IVIG): For severe or steroid-refractory cases

• Plasma exchange: May be considered in refractory cases

Symptomatic Treatment

For chorea^{2Streptococcal infections and movement disorders2020 · Mov Disord · DOI 10.1002/mds.28014Open reference}9:

• Valproic acid: First-line for movement symptoms

• Carbamazepine: Alternative

• Benzodiazepines: For anxiety and mild chorea

• Tetrabenazine: Reserved for severe, persistent cases

For behavioral symptoms^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}0:

• SSRIs for OCD symptoms

• Behavioral interventions

Prognosis

Long-Term Outcomes

The prognosis for Sydenham chorea is generally favorable^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}1:

• Complete recovery in 70-80% of cases within weeks to months

• Recurrence in approximately 25% of cases

• Persistent chorea in 10-15% of patients

• Most long-term neurological deficits are mild

Cardiac Complications

The major concern in Sydenham chorea is concurrent or subsequent carditis^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}2:

• 60-70% of SC patients have evidence of carditis

• Mitral valve disease may develop years later

• Regular cardiac follow-up is essential

Relationship to PANDAS

Sydenham chorea is closely related to the PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) spectrum^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}3^{3PANDAS and Sydenham chorea: a comparison2019 · J Pediatr · DOI 10.1016/j.jpeds.2019.04.031Open reference}4. Both conditions:

• Follow GABHS infection

• Involve autoimmune mechanisms targeting the basal ganglia

• May present with choreiform movements and behavioral symptoms

• May respond to immunomodulatory therapy

However, Sydenham chorea is defined in the context of acute rheumatic fever, while PANDAS encompasses a broader spectrum of post-streptococcal neuropsychiatric disorders without meeting ARF criteria.

Related Conditions

• Chorea gravidarum - Chorea occurring during pregnancy

• Huntington disease - Genetic neurodegenerative chorea

• Benign hereditary chorea - Non-progressive familial chorea

• Hemiballismus - Acute violent choreic movement

• Hemichorea - Unilateral chorea

See Also

• Chorea gravidarum

• Huntington disease

• Benign hereditary chorea

• Hemiballismus

• Hemichorea

External Links

• PubMed

• KEGG Pathways

Recent Research (2024-2026)

Recent research on Sydenham Chorea includes:

• 2024: Title - Description