Version May 2024
INTRODUCTION — Sydenham chorea (SC), or rheumatic chorea, is one of the major clinical manifestations of acute rheumatic fever (ARF) and is the most common form of acquired chorea in childhood. It is a movement disorder characterized by chorea (involuntary brief, random, and irregular movements of the limbs and face), emotional lability, and hypotonia.
This topic reviews the clinical manifestations, diagnosis, and treatment of SC. Other clinical manifestations of ARF and the approach to diagnosis and treatment of rheumatic fever are presented separately. (See "Acute rheumatic fever: Clinical manifestations and diagnosis" and "Acute rheumatic fever: Treatment and prevention".)
PATHOPHYSIOLOGY — Although SC is clearly related to group A streptococcal (GAS) infection [1], its pathogenesis is not completely understood. Molecular mimicry, in which antibodies directed against part of the GAS bacterium crossreact with host antigens in susceptible subjects, is thought to play an important role.
In acute rheumatic fever (ARF), antibodies are mounted against N-acetyl-beta-D-glucosamine (NABG or GlcNAc), the immunodominant carbohydrate antigen of GAS. These antibodies likely play a role in valvular injury in rheumatic carditis, and in other manifestations of ARF. (See "Acute rheumatic fever: Epidemiology and pathogenesis", section on 'Molecular mimicry'.)
Different subsets of NABG antibodies appear to correlate with distinct clinical manifestations of ARF. In SC, the antibodies bind to lysoganglioside on the neuronal cell surface [2,3], where they are capable of triggering a signaling cascade [4]. These antibodies also recognize the intracellular protein tubulin [5]. Tubulin-specific antibodies are not found in patients with ARF without SC, or in patients who have recovered from SC. The genes encoding these antibodies are similar to the genes encoding antibodies implicated in the pathogenesis of motor neuropathies [6]. Thus, tubulin appears to be an important neuronal target in the pathogenesis of SC.
From a pathophysiologic viewpoint, the available data suggest involvement of the basal ganglia and cortical structures [7]. In individual case reports, magnetic resonance imaging (MRI) studies performed during and after an acute episode of SC demonstrated reversible abnormalities of the striatum [8], and positron emission tomography and single-photon emission computed tomography (SPECT) imaging showed striatal hypermetabolism and hyperperfusion [9,10].
EPIDEMIOLOGY — The incidence of acute rheumatic fever (ARF) and SC has declined dramatically in resource-rich settings since the early 20th century due to improvements in living conditions and routine use of antibiotics for group A streptococcal (GAS) infections; however, ARF remains an important public health concern in resource-limited settings [11,12]. Chorea is a common manifestation of rheumatic fever, particularly in resource-limited countries. In the United States, chorea was reported in 18 to 36 percent of cases of rheumatic fever [13-16].
SC occurs most commonly in patients between 5 and 13 years of age [17-19]. Females are affected more frequently than males by a ratio of 2:1 [17,19]. Chorea appears to be less common in adults, particularly men [14-16].
SC appears to have a familial predisposition: a family history of rheumatic fever occurs in up to 30 percent of families with a history of chorea [17,20].
The epidemiology of ARF is discussed in greater detail separately. (See "Acute rheumatic fever: Epidemiology and pathogenesis".)
CLINICAL MANIFESTATIONS
Neuropsychiatric symptoms — SC is a movement disorder characterized by emotional lability, hypotonia, and chorea (involuntary brief, random, and irregular movements of the limbs and face). In contrast to carditis and arthritis, which typically present within 21 days, the onset of chorea usually occurs one to eight months after the inciting infection [11]. In one large series, the median latency from pharyngitis to chorea onset was eight weeks [19].
The onset of SC is typically insidious but may be abrupt. Mild cases of SC without other manifestations of acute rheumatic fever (ARF) may be mistakenly ascribed to behavioral or emotional disorders, Tourette syndrome, or clumsiness [15]. (See "Acute rheumatic fever: Clinical manifestations and diagnosis".)
●Motor symptoms (chorea) – The main feature of SC is chorea, which is characterized by rapid, random-appearing, continuous, fragmentary movements of the limbs and restlessness of the trunk. The chorea typically worsens over hours to days. Symptoms are continuous while awake, worsen with attempted action, and improve with sleep. The chorea usually is generalized but may be more prominent on one side; 20 to 30 percent have hemichorea (ie, unilateral chorea) [11,17,20-22]. Patients experience these movements as involuntary, not compulsive or urge driven.
Other motor symptoms, including ballismus, facial grimacing, and restless movements of the tongue, are often observed. These symptoms are associated with motor impersistence (characterized by "milkmaid's grip"), interference with gross and fine motor control, muscle weakness, and hypotonia [17].
●Psychiatric symptoms – SC is often associated with a variety of psychiatric symptoms, including irritability, emotional lability, outbursts of inappropriate behavior, obsessive-compulsive behavior, and distractibility [23-28]. Emotional changes (eg, easy crying or inappropriate laughing) and obsessive-compulsive symptoms are common and may precede, be concurrent with, or follow the development of chorea [27]. In a report of 50 children with rheumatic fever (30 with chorea and 20 without), obsessive-compulsive symptoms occurred in 70 percent of the patients with chorea but in none of those without chorea [27]. This finding may vary geographically, however. Another study of 48 youths with rheumatic fever (21 with chorea and 27 without) reported a much lower prevalence (4 percent in both groups) [29].
The psychiatric symptoms typically occur during the first two months of rheumatic fever [27]. They tend to wax and wane with the motor symptoms. Rarely, these symptoms may be severe, resulting in transient psychosis or delirium.
Findings on neurologic examination — On neurologic examination, mental status is typically normal. A confusional state suggests an alternative diagnosis (eg, encephalitis). (See 'Differential diagnosis' below.)
The child may be reluctant to speak, and usually appears restless or fidgety while sitting unsupported on the examination table. Speech may be dysarthric. Reduced verbal fluency is common and may correlate with severity of motor signs [30].
Cranial nerve function and sensory examination are normal.
Motor examination should include the four maneuvers described below, with the child attempting to sit up straight unsupported on the examination table. Each of these findings tends to become more pronounced if the examiner concurrently gives the child a separate motor task (eg, asking the child to speak during the first three maneuvers):
●Spooning – The child is seated with arms extended fully forward from the shoulders, hands pronated, fingers spread wide. The typical finding suggestive of SC is symmetric hyperextension at the metacarpophalangeal joint (so arm and hand look like a spoon). This finding is most often symmetric, but may be seen more prominently on one side. Both proximal and distal limb chorea may also be noted.
●Touchdown – The child is seated with arms and hands fully extended up and palms facing one another (as if making a "touchdown" sign). The typical finding is pronation of one or both hands and flexion of the elbows.
●Milkmaid's grip – The child is asked to use both hands to grip both of the examiner's index and middle fingers. Choreic and hypotonic "intrusions" occur, causing the child to partly release his or her grip, only to re-grip again, repeatedly, giving a "milking the cow" type feeling.
●Darting tongue – The child is asked to stick his or her tongue out with mouth open. Similar to the grip, the motor command cannot be consistently maintained. The tongue withdraws repeatedly, resulting in a darting, snake-like appearance. Children may spontaneously use their teeth to grab the tongue, to try to keep the tongue protruded.
The patellar reflexes are unaffected or may be "hung up" due to a combination of hypotonia and sustained contraction/delayed relaxation after eliciting the patellar reflex [31]. Gait may be lurching or unsteady due to choreic intrusions into locomotion. This is distinct from gait ataxia but may be confusing, as in both cases gait may appear broad based.
Association with other manifestations of rheumatic fever — Other manifestations of ARF include carditis and valvulitis, migratory polyarthritis, subcutaneous nodules, and erythema marginatum (picture 1A-B). These findings typically occur earlier in the course, whereas SC occurs one to eight months after the inciting infection. (See "Clinical manifestations and diagnosis of rheumatic heart disease".)
SC can occur without arthritis or carditis [13,16,20]. In case series, SC was reported as an isolated finding in approximately 30 to 50 percent of cases [14-16,20]. However, many of these reports defined carditis as clinically apparent cardiac involvement (eg, murmur). Routine use of echocardiography may identify subclinical carditis in a considerable proportion of patients with apparently isolated SC [13,32,33]. In one report of 53 children with apparently isolated SC (ie, no other clinically apparent manifestations of ARF), echocardiography identified mitral regurgitation in 57 percent [13]. (See "Clinical manifestations and diagnosis of rheumatic heart disease".)
DIAGNOSTIC EVALUATION — Diagnostic evaluation of patients with suspected SC should be directed toward diagnosing acute rheumatic fever (ARF) according to published guidelines [34]. This includes testing for group A streptococcal (GAS) infection and a cardiac evaluation. In addition, inflammatory markers (ie, C-reactive protein [CRP] and/or erythrocyte sedimentation rate [ESR]) should be measured at the time of initial presentation, though these tests are typically normal by the time patients present with SC. (See "Acute rheumatic fever: Clinical manifestations and diagnosis", section on 'Diagnosis'.)
In patients with atypical features (eg, fever or delirium), cerebrospinal fluid (CSF) analysis, neuroimaging, and/or additional testing may help exclude other causes of chorea. Referral to a child neurologist or movement disorder specialist can help guide the diagnostic evaluation, particularly in atypical cases.
Testing for GAS infection — Testing for active or recent GAS infection should be performed in all patients with suspected SC; however, evidence of current or prior GAS infection is not always present. Throat cultures are often negative by the time chorea appears; however, they should be routinely obtained because it is important to identify recurrent GAS infection [16]. (See "Acute rheumatic fever: Clinical manifestations and diagnosis", section on 'Evidence of preceding GAS infection'.)
In addition to the throat culture, blood tests for both streptococcal antibodies antistreptolysin O (ASO) and antideoxyribonuclease B (anti-DNAse B) should be obtained to assess for preceding streptococcal infection. Either or both antibodies may remain elevated for months after a GAS infection, and a rising titer on serial tests more accurately defines a recent acute infection than does a single elevated titer [35]. The false-positive rate is high, given the high prevalence of GAS infections and long duration of antibody elevation. Thus, the diagnostic value of antibody testing is greatest when the history and examination support a diagnosis of ARF with chorea. In this case, a single positive blood test is adequate to confirm the diagnosis.
Cardiac testing — All patients with suspected SC should have a detailed cardiac evaluation to assess for carditis. We obtain an electrocardiogram and echocardiogram in all patients [34]. The presence of carditis in a patient with new-onset chorea confirms the diagnosis of SC. (See "Acute rheumatic fever: Clinical manifestations and diagnosis", section on 'Cardiac evaluation'.)
Inflammatory markers — Inflammatory markers (eg, CRP, ESR) are included in the diagnostic criteria for ARF (table 1) and should be obtained in all patients; however, most patients show little evidence of acute inflammation at the time of presentation with SC [16]. (See "Acute rheumatic fever: Clinical manifestations and diagnosis", section on 'Diagnostic criteria'.)
Elevated CRP and/or ESR may be seen in patients with recurrent chorea due to recurrent GAS infection. Alternatively, elevated inflammatory markers may be an indication of another diagnosis as the underlying cause of the chorea (eg, systemic lupus erythematosus [SLE], encephalitis). (See 'Differential diagnosis' below.)
Cerebrospinal fluid analysis — Lumbar puncture is generally not necessary in children with suspected SC. CSF cell counts, protein, and glucose are typically normal in SC [15]. In patients with fever, encephalopathy, or other atypical features, lumbar puncture may be performed to exclude other causes of chorea (eg, encephalitis). (See 'Differential diagnosis' below.)
Neuroimaging — In patients who have clinical features consistent with SC, neuroimaging usually does not provide additional diagnostic or prognostic information [17]. However, neuroimaging may be necessary to exclude other causes of chorea in patients with atypical clinical findings (eg, hemichorea), in those with risk factors for cerebrovascular disease (eg, sickle cell disease, mitochondrial disease), or in the absence of supporting evidence of GAS infection [17].
Magnetic resonance imaging (MRI) is the preferred modality for neuroimaging. Findings in SC are variable, and no MRI findings can confirm the diagnosis of SC [36,37]. MRI is normal in many patients. MRI abnormalities reported in some patients with SC include foci of T2 hyperintensity in the basal ganglia and/or cerebral white matter, which may be isolated or multifocal [36,37].
Although not routinely done, positron emission tomography and single-photon emission computed tomography (SPECT) may demonstrate abnormal basal ganglia metabolism or perfusion and may be helpful in patients with atypical clinical presentations [10,38].
Other tests — Additional testing may be required to exclude other causes of chorea, particularly in patients with atypical features. (See 'Differential diagnosis' below.)
If there is any uncertainty about the diagnosis, and in all cases of recurrent chorea, we screen for SLE and antiphospholipid syndrome with antinuclear antibodies. (See "Childhood-onset systemic lupus erythematosus (SLE): Clinical manifestations and diagnosis" and "Diagnosis of antiphospholipid syndrome".)
In patients with seizures, atypical psychiatric features (eg, hallucinations), altered sensorium, and/or progressive neurologic symptoms, and in those without evidence of GAS infection, we evaluate for anti-N-methyl-D-aspartate (NMDA) receptor encephalitis by measuring specific anti-NMDA receptor antibodies in the serum and CSF. (See "Autoimmune (including paraneoplastic) encephalitis: Clinical features and diagnosis".)
CLINICAL DIAGNOSIS — The diagnosis of SC is made clinically based on the characteristic findings (eg, chorea, emotional lability, and hypotonia) in the absence of other identifiable causes [17]. The presence of carditis and/or evidence of recent group A streptococcal (GAS) infection are supportive findings, but are not necessary to establish the diagnosis; their absence should increase vigilance for other autoimmune, vascular, or metabolic diagnoses. (See 'Differential diagnosis' below.)
The diagnosis of acute rheumatic fever (ARF) is discussed in detail separately. (See "Acute rheumatic fever: Clinical manifestations and diagnosis", section on 'Diagnostic criteria'.)
DIFFERENTIAL DIAGNOSIS — Subacute or insidious onset of chorea in childhood nearly always is autoimmune in nature, and the vast majority of these cases in children are SC. Subacute chorea can also result from other acquired causes (table 2) (eg, viral or autoimmune encephalitis, systemic lupus erythematosus [SLE], stroke, hyperthyroidism) or from drugs (table 3). In most cases, SC can be distinguished from these disorders on the basis of the history of the illness, family history, and neurologic examination. In patients with atypical features, neuroimaging, cerebrospinal fluid (CSF) analysis, and/or additional testing (eg, antinuclear antibodies to screen for SLE, anti-N-methyl-D-aspartate [NMDA] receptor antibodies to test for autoimmune encephalitis) may be necessary to exclude alternative diagnoses. Referral to a child neurologist or movement disorder specialist can be helpful if there is uncertainty about the diagnosis. The approach to children with chorea is discussed in greater detail separately. (See "Hyperkinetic movement disorders in children", section on 'Chorea, athetosis, and ballismus' and "Overview of chorea".)
Tics that occur in childhood (eg, Tourette syndrome) can be distinguished from chorea by history and physical examination. The patterned, repetitive appearance; the ability to temporarily suppress tics; and the premonitory sensations that often precede tics help to differentiate these movements from chorea. In SC, tics and chorea may co-occur. (See "Tourette syndrome: Pathogenesis, clinical features, and diagnosis".)
TREATMENT — Treatment of patients with SC consists of chronic antibiotic therapy to prevent recurrence and minimize the risk of rheumatic heart disease. In addition, patients with significant impairment related to their chorea may be treated with chorea-suppressing medication and/or with immune-suppressing treatment (ie, corticosteroids). In patients with moderate to severe chorea, referral to a child neurologist or movement disorder specialist can help guide management.
Antibiotic therapy — Pending throat culture results and/or serologic markers of group A streptococcal (GAS) infection, patients with SC are started on antibiotic therapy to eradicate GAS carriage. Treatment should proceed as delineated for management of acute GAS pharyngitis, whether or not pharyngitis is present at the time of diagnosis (table 4). In practice, the most convenient and sensible approach to initiating antibiotics in a patient with SC is to administer long-acting intramuscular penicillin G benzathine. This serves two purposes: to eradicate GAS carriage and also as the first dose of secondary prophylaxis. (See "Acute rheumatic fever: Treatment and prevention", section on 'Eradication of GAS carriage'.)
Patients with SC should be treated with chronic antibiotics to prevent further GAS infections, which reduces the likelihood of recurrence. In addition, antibiotic therapy limits progression of rheumatic heart disease. Antibiotic therapy for acute rheumatic fever (ARF) and prophylaxis are discussed separately. (See "Acute rheumatic fever: Treatment and prevention", section on 'Secondary prevention (antibiotic prophylaxis)'.)
Patients and their household contacts who develop acute episodes of GAS pharyngitis during the course of prophylaxis should be evaluated and treated promptly. Clinicians should have a low threshold for initiating empiric antibiotic therapy pending throat culture in children with SC who present with fever with or without pharyngitis. (See "Treatment and prevention of streptococcal pharyngitis in adults and children".)
Treatment of chorea — Symptomatic treatment for chorea, as with other movement disorders, should be based upon the extent to which symptoms interfere with physical and emotional function. Chorea can interfere with dressing and other activities of daily living, as well as with school tasks, such as writing. If interference is moderate to severe, particularly if gait is affected and there is a risk of falls, short-term treatment may be warranted. We typically use a low-dose, high-potency dopamine 2 (D2) receptor blocking agent (eg, fluphenazine, haloperidol, pimozide, risperidone). A potential complication of this therapy is an acute drug-induced movement disorder such as akathisia or dystonia. If this develops, anticholinergic treatment with benztropine or diphenhydramine followed by withdrawal or reduction of the D2 blocking agent is appropriate.
In milder cases of SC, or when clinicians or families are reluctant to try D2 blocking agents, other reasonable alternatives include levetiracetam, valproic acid, carbamazepine, clonidine, or guanfacine.
Most treatment studies involve small series of patients treated open-label, making it difficult to distinguish the benefit of medication from the expected spontaneous improvement over time. Agents that have been reported to be effective in SC include:
●Haloperidol [39-41]
●Levetiracetam [43]
●Carbamazepine [44]
Management of chorea is discussed in greater detail separately. (See "Overview of chorea", section on 'Management of chorea'.)
Immune modulation — In moderate to severe cases, immune suppression with corticosteroids is a reasonable treatment option and may shorten the duration of symptoms. Oral prednisone 1 to 2 mg/kg is given once daily for two weeks and then tapered over two to three weeks. In severe cases, intravenous immune globulin (IVIG) or plasmapheresis have been used; however, data are limited [47-52].
Corticosteroids appear to shorten the course of SC [39,53-57]. The use of prednisone for SC was assessed in a controlled trial in which 37 children and adolescents were randomly assigned to placebo or treatment with prednisone (2 mg/kg per day) for four weeks followed by a gradual taper [56]. Patients in both groups improved with time, but those in the prednisone group improved more rapidly and achieved earlier complete remission (54 versus 120 days). The occurrence of relapses was similar between groups. No severe adverse events were observed in the prednisone group.
PROGNOSIS
Recovery — SC typically improves gradually, with symptoms typically lasting 12 to 15 weeks [58,59]. Full recovery occurs in almost all patients, but symptoms occasionally persist for two years or more [16,21,60].
Recurrent chorea — Chorea recurs in 15 to 30 percent of cases [16,60]. Most relapses occur within two to three years but can occur as late as 10 years [61]. Repeated recurrences are less common. Most relapses are due to repeat group A streptococcal (GAS) infections. Patients not receiving continuous antibiotic prophylaxis are at increased risk and, in some reports, recurrence was seen only in such patients [41,60].
Other mechanisms that have been suggested to play a role in recurrent chorea include autoimmunity, permanent damage to the basal ganglia, and subclinical GAS infections [61-64].
Recurrence should prompt the clinician to consider other autoimmune or metabolic/mitochondrial diagnoses. (See 'Differential diagnosis' above.)
The risk of chronic rheumatic heart disease is increased among patients with recurrent GAS infections and those with recurrent SC. (See "Clinical manifestations and diagnosis of rheumatic heart disease", section on 'Clinical manifestations'.)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Acute rheumatic fever and rheumatic heart disease".)
SUMMARY AND RECOMMENDATIONS
●Definition – Sydenham chorea (SC) is a movement disorder characterized by chorea, emotional lability, and hypotonia. It is one of the major clinical manifestations of acute rheumatic fever (ARF). (See 'Introduction' above and 'Pathophysiology' above.)
●Epidemiology – SC is seen in approximately one-third of cases of ARF, most often in school-aged children. (See 'Epidemiology' above.)
●Clinical manifestations – Symptoms of SC usually begin one to eight months after the inciting infection. The onset is typically insidious but may be abrupt.
•Neurologic symptoms include chorea, motor impersistence (characterized by "milkmaid's grip"), and interference with gross and fine motor control. (See 'Neuropsychiatric symptoms' above and 'Findings on neurologic examination' above.)
•Psychiatric symptoms include emotional changes (easy crying or inappropriate laughing), irritability, distractibility, and obsessive-compulsive symptoms. These may precede, occur concomitant with, or occur after the onset of chorea. (See 'Neuropsychiatric symptoms' above.)
•Carditis (either clinically apparent or detected with echocardiography) is present in most cases. (See 'Association with other manifestations of rheumatic fever' above and "Acute rheumatic fever: Clinical manifestations and diagnosis".)
●Diagnostic evaluation – Patients should be tested for group A streptococcal (GAS) infection and undergo a detailed cardiac evaluation, including electrocardiogram and echocardiography. Inflammatory markers (ie, C-reactive protein [CRP] and/or erythrocyte sedimentation rate [ESR]) should be measured, although these tests are typically normal in patients presenting with SC. (See 'Diagnostic evaluation' above.)
In patients with atypical features (eg, hemichorea, fevers), cerebrospinal fluid (CSF) analysis, neuroimaging, and/or additional testing may help exclude other causes of chorea. (See 'Cerebrospinal fluid analysis' above and 'Neuroimaging' above and 'Other tests' above.)
●Diagnosis – SC is a clinical diagnosis based on the characteristic findings (ie, chorea, with or without emotional lability, and hypotonia) in the absence of other identifiable causes. The presence of carditis and/or evidence of recent GAS infection are supportive findings but are not necessary to establish the diagnosis. (See 'Clinical diagnosis' above.)
●Differential diagnosis – Other causes of subacute chorea should be considered, particularly systemic lupus erythematosus (SLE), other acquired causes (table 2), and drugs (table 3). Referral to a child neurologist or movement disorder specialist can be helpful if there is uncertainty about the diagnosis. (See 'Differential diagnosis' above.)
●Management
•Antibiotic therapy – For all patients with ARF, including those with SC, treatment consists of chronic antibiotic therapy to eradicate GAS, prevent recurrence, and minimize the risk of rheumatic heart disease. (See 'Antibiotic therapy' above and "Acute rheumatic fever: Treatment and prevention".)
•Symptomatic therapy – For patients with moderate to severe chorea that is associated with significant impairment and/or risk of falls, we suggest both chorea-suppressing treatment with a dopamine 2 (D2) receptor blocking agent (eg, fluphenazine, haloperidol, pimozide, risperidone) and immune modulation with oral prednisone (Grade 2C).
Valproic acid, carbamazepine, clonidine, or guanfacine are reasonable alternative agents that can be used to suppress the chorea; however, limited pediatric data are available. Oral prednisone 1 to 2 mg/kg is given daily for two weeks and then tapered over two to three weeks. (See 'Treatment of chorea' above and 'Immune modulation' above.)
●Prognosis – Most patients with SC recover fully without treatment, with symptoms lasting from a few weeks to one year or more. SC recurs in 15 to 30 percent of patients, usually within a few years of the initial episode. The risk is reduced, but not eliminated, by chronic treatment with prophylactic antibiotics. (See 'Prognosis' above.)
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Robert P Cruse, DO, who contributed to an earlier version of this topic review.
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