Sydenham's chorea

Sydenham's chorea
Other names	Chorea minor, St Vitus' dance
Specialty	Neurology

Sydenham's chorea, also known as chorea minor and historically and occasionally referred to as St Vitus' dance, is a disorder characterized by rapid, uncoordinated jerking movements primarily affecting the face, hands and feet.^[1] Sydenham's chorea is an autoimmune disease that results from childhood infection with Group A beta-haemolytic Streptococcus. It is reported to occur in 20–30% of people with acute rheumatic fever and is one of the major criteria for it, although it sometimes occurs in isolation. The disease occurs typically a few weeks, but up to 6 months, after the acute infection, which may have been a simple sore throat (pharyngitis).

Sydenham's chorea is more common in females than males and most cases affect children between the ages of 5 and 15 years of age. Adult onset of Sydenham's chorea is comparatively rare, and the majority of the adult cases are recurrences following childhood Sydenham's chorea.

Signs and symptoms[]

Sydenham's chorea is characterized by the abrupt onset (sometimes within a few hours) of neurologic symptoms, classically chorea, which are non-rhythmic, writhing or explosive involuntary movements. Usually all four limbs are affected, but there are cases reported where just one side of the body is affected (hemichorea). Typical chorea includes repeated wrist hyperextension, grimacing, lip pouting. The fingers can move as if playing the piano. There may be tongue fasciculations ("bag of worms") and motor impersistence for example the "milk maid sign" (grip strength fluctuates, as if hand milking), or inability to sustain tongue protrusion or eye closure. There is usually loss of fine motor control, particularly obvious in handwriting if the child is of school age. Speech is often affected (dysarthria), as is walking; legs will suddenly give way or flick out to one side, giving an irregular gait and the appearance of skipping or dancing. Underlying the abnormal movements is often low tone (hypotonia) which may not become obvious until treatment is started to suppress the chorea. In severe cases, the loss of tone and weakness predominate (chorea paralyticum).

The severity of the condition can vary from just some instability on walking and difficulty with hand writing, to the extreme of being wholly unable to walk, talk, or feed yourself.

Movements cease during sleep. The eye muscles are not affected, curiously.^{[citation needed]}

It is a neuropsychiatric disorder, so besides the motor problems there is classically emotional lability (mood swings, or inappropriate mood), anxiety, attention deficit. These can precede the motor symptoms.^[2]

Non-neurologic manifestations of acute rheumatic fever may be present, namely carditis (up to 70% of cases, often subclinical, so echocardiography required), arthritis, erythema marginatum, and subcutaneous nodules.

Erythema marginatum

Differentiating these signs from other involuntary movements such as tics and stereotypies can be difficult, and since these things are not uncommon they can potentially co-exist. Diagnosis is often delayed and attributed to another condition such as tic disorder or conversion disorder. The PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) syndrome has overlapping clinical features but Sydenham's chorea is one of the exclusion criteria. PANDAS can present with chorea but more typically there are tics, stereotypies with a psychological component (e.g., OCD).^[3]

Differential diagnosis[]

Other disorders that may be accompanied by chorea include benign hereditary chorea, , abetalipoproteinemia, ataxia–telangiectasia, biotin-thiamine-responsive basal ganglia disease, Fahr disease, (Bird–Raskind syndrome) due to an ADCY5 gene mutation, glutaric aciduria, Lesch–Nyhan syndrome, mitochondrial disorders, Huntington's disease, Wilson disease, hyperthyroidism, lupus erythematosus, pregnancy (chorea gravidarum), drug intoxication and side effects of certain anticonvulsants (e.g. phenytoin) or psychotropic agents. Although some of these can similarly present in an acute way, there will typically be other neurological signs (such as ataxia or cognitive impairment), or other disease manifestations, or positive family history, which will help distinguish between them.^[4]

Pathology[]

One of the important manifestations of acute rheumatic fever, Sydenham's chorea is similarly caused by an autoimmune response following infection by group A β-hemolytic streptococci. ^[5]

Two cross reactive streptococcal antigens have been identified, the M protein and N-acetyl-beta-D-glucosamine, whereby infection leads to autoantibodies being produced against host tissues (molecular mimicry) causing a variety of streptococcal related diseases including Sydenham's chorea but also rheumatic heart disease and nephritic syndrome.^[6] Autoantibodies against basal ganglia proteins have been found in Sydenham's chorea but these are non-specific.^[7] Dopamine receptor autoantibodies have been reported to correlate with clinical symptoms.^[8] Whether these antibodies represent an epi-phenomenon or are pathogenic, remains to be proven.^{[citation needed]}

Epidemiology[]

As with rheumatic fever, Sydenham's chorea is seen more often in less affluent communities, whether in the developing world or in aboriginal communities in the global North. High rates of impetigo are a marker for widespread streptococcal transmission.

Diagnosis[]

Chorea is distinctive, if the health care provider is familiar with it. The diagnosis is then made by the typical acute onset in the weeks following a sore throat or other minor infection, plus evidence of inflammation (raised CRP and/or ESR) and evidence of recent streptococcal infection.

To confirm recent streptococcal infection:

• Throat culture
• Anti-DNAse B titre (peaks at 8–12 weeks after infection)
• Anti-streptolysin O titre (peaks at 3–5 weeks)

None of these tests are 100% reliable, particularly when the infection was some months previously.

Further testing is directed more towards alternative diagnoses and other manifestations of rheumatic fever:

• Echocardiography
• EEG
• Lumbar puncture
• Magnetic resonance imaging or computed tomography scan of the brain (alterations in caudate nucleus and putaminal enlargement have been described in some patients)^[9][10]

Management[]

Penicillin

Management of Sydenham's chorea is based on the following principles:

1. Eliminate the streptococcus – it may not be of any use for the index patient but further spread of that specific clone will be prevented.
2. Treat the movement disorder
3. Immunosuppression
4. Prevention of relapses and further cardiac damage
5. Manage the disability

There is a UFMG rating scale for Sydenham's chorea, from Brazilian Universidade Federal de Minas Gerais (UFMG), for research purposes, but it only looks at motor function not psychiatric/behavioural symptoms.

Occupational therapy and physiotherapy is useful for maintaining function and muscle tone.

Treatment with sodium valproate is effective for controlling symptoms, but it doesn’t speed up recovery. Haloperidol was used previously, but caused serious side effects e.g. tardive dyskinesia. Case reports exist to support carbamazepine and levetiracetam; other drugs tried include pimozide, clonidine, and phenobarbitone.

Immunosuppression[]

Immunosuppression is used inconsistently in Sydenham's chorea. The model of an autoimmune disorder would support its use. One randomized controlled trial of steroids from Paz, Brazil in 2006 (22 cases) showed remission reduced to 54 days from 119 days.^[11] Various other reports of use of oral or IV steroids from Israel, Italy and Brazil .^[12][13][14] Immunoglobulin has been used in Holland and South Africa.^[15][16] Some improvement can be seen within a few days of IV steroids. In Italy, prednisolone reduced average duration of symptoms from 9 weeks to 4 weeks, and these were severe cases.^[17] South African group found less neuropsychiatric complications at 6 months with IVIG treatment (IVIG preferred due to fear of TB reactivation).^[18]

A course of penicillin is usually given at diagnosis to definitively clear any remaining streptococci, but there is no evidence that this is an effective treatment. Active infection is usually cleared by diagnosis. Penicillin prophylaxis, on the other hand, is essential to treat cardiac features of rheumatic fever, even if subclinical (American Heart Association guideline).^[19] If the case is of isolated chorea, it is arguable whether cardiac risk justifies prophylaxis or not, however it is likely to reduce recurrence.

There are several historical case series reporting successful treatment of Sydenham's chorea by inducing fever.^[20][21]

Prognosis[]

Motor problems including chorea settle within an average of 2-3 months.

Recurrence seen in 16–40% of cases. Recurrence is more likely with poor compliance with penicillin prophylaxis. Intramuscular penicillin is given every 2–3 weeks superior to 4 weekly regime, and oral penicillin is also prescribed. Recurrences are sometimes associated with rise in ASO titre or other evidence of new streptococcal infection. There is no obvious clinical parameter that might predict those at risk of recurrence. More likely if failure to remit in initial 6 months, can recur with pregnancy (chorea gravidorum).

Higher recurrence rates seen in longest follow up – can recur up to 10 years after the initial episode, so might be underestimated by series with shorter follow up.

Recurrence is usually only chorea, even if the original case was associated with rheumatic fever. There are two total reports of heart disease worsening after recurrence of chorea. The Thailand study also had 2 cases where carditis, which had improved after initial diagnosis, came back again. Some suggest that recurrent chorea is a different disease altogether.^[22]

10% reported long term tremor in one study (10 years follow up). Long term neuropsychiatric difficulties are increasingly recognized (49 studies so far, especially obsessive-compulsive disorder but also attention-deficit hyperactivity disorder, affective disorders, tic disorders, executive function disturbances, psychotic features, and language impairment).^[23]

Heart involvement improves in about a third of cases (whether silent or not).[PMID 22734303]

Family support[]

Sydenhams Chorea Association

History[]

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Sydenham's chorea became a well-defined disease entity only during the second half of the nineteenth century. Such progress was promoted by the availability of large series of clinical data provided by newly-founded paediatric hospitals. A 2005 study examined the demographic and clinical features of patients with chorea admitted to the first British paediatric hospital (the Hospital for Sick Children, Great Ormond Street, London) between 1852 and 1936. The seasonal and demographic characteristics of Sydenham's chorea during this time appear strikingly similar to those observed today, Great Ormond Street hospital case notes provide detailed descriptions of the "typical cases" of Sydenham's chorea, and show that British physicians working in the early age of paediatric hospitals recognized the most distinctive clinical features of this condition.^[24]

Throughout the nineteenth century the term "chorea" referred to an ill-defined spectrum of hyperkinesias, including those recognised today as chorea, tics, dystonia, or myoclonus. William Osler stated, "In the whole range of medical terminology there is no such olla podrida as Chorea, which for a century has served as a sort of nosological pot into which authors have cast indiscriminately affections characterised by irregular, purposeless movements."^[24]

Sydenham's chorea, a frequent cause of paediatric acute chorea, is a major manifestation of rheumatic fever. The association of chorea with rheumatism was first reported in 1802, and confirmed in the following decades by several French and English authors.^[24] The inclusion of chorea under the rheumatic umbrella helped discriminate Sydenham's chorea from other "choreic" syndromes. The incidence of acute rheumatic fever and rheumatic heart disease is not declining. Recent figures quote the incidence of Acute Rheumatic Fever as 0.6–0.7/1,000 population in the United States and Japan compared with 15–21/1,000 population in Asia and Africa.^[25] The prevalence of Acute Rheumatic Fever and Sydenham's Chorea has declined progressively in developed countries over the last decades.^[26][27] Physicians working in early children's hospitals recognised new clinical syndromes through the definition of "typical clinical cases". Complex multi-systemic diseases, such as rheumatic fever, were categorised only after the observation of large, hospital based series. Therefore, paediatric hospitals gradually became an important setting for the application of a modern "statistical averaging" technique to paediatric syndromes. Historical authorities in paediatrics, such as Walter Butler Cheadle and Octavius Sturges, worked at London's Hospital for Sick Children, and their clinical notes help elucidate how the typical case of Sydenham's chorea was defined.^[24]

Between 1860 and 1900 the proportion of choreic patients ranged between 5% and 7% of the total number of patients admitted (mean per year, 1003), whereas from 1900 to 1936 it was constantly below 4% (mean per year). Chorea was the fourth most frequent cause of admission between 1860 and 1900, and in the 1880s temporarily became the second most frequent diagnosis among inpatients. Contemporary articles report a homogeneous distribution of paediatric chorea all over England However, since many choreic children were "cured" at home, the hospital based rates probably underestimate the incidence of chorea in the general paediatric population.^[24]

A higher number of cases were admitted during the colder months, consistent with the reference epidemiological report on chorea at the end of the century. In the 1950s and 1960s the highest frequency of chorea was recorded during the winter months in several Northern and Central European countries. The incidence of rheumatism among Great Ormond Street Hospital inpatients peaked in October, preceding chorea by approximately two months. This is consistent with the current knowledge that most of the rheumatic fever symptoms appear about 10 days after the streptococcal infection, whereas Sydenham's chorea occurs typically 2–3 months after infection.

More than 80% of choreic patients were aged between 7 and 11 years (mean 9.2). Due to a referral bias, this age may be falsely low. Indeed, the British Medical Association (1887) reported the peak age between 11 and 15 years. In the present series, the female:male ratio was 2.7, in accordance with the general choreic population of Britain towards the end of the 1800s. In children below age 7, the female preponderance is less manifest. This was observed also by Charles West (founder physician of Great Ormond Street Hospital), and subsequently by Osler, who stated that "the second hemi-decade contains the greatest number of cases in males, and the third the greatest number in females". In the majority of the 20th century studies, female preponderance is evident only in children over 10 years of age. These observations suggest a role for oestrogen in Sydenham's chorea expression. Supporting this view, oral contraceptives and pregnancy can cause relapses of disease.^[24]

Ten percent of the 1,548 patients whose records were researched for the British study were subsequently admitted with a relapse of chorea. Given that relapse admissions had a negative impact on the hospital cure rate, this rate might underestimate the actual relapse incidence in the general population of patients.^[24]

Etymology[]

It is named after British physician Thomas Sydenham (1624–1689).^[25][28] The alternate eponym, "Saint Vitus Dance", is in reference to Saint Vitus, a Christian saint who was persecuted by Roman emperors and died as a martyr in AD 303. Saint Vitus is considered to be the patron saint of dancers, with the eponym given as homage to the manic dancing that historically took place in front of his statue during the feast of Saint Vitus in Germanic and Latvian cultures.^[29]

References[]

Further reading[]

• Martino D, Tanner A, Defazio G, et al. (May 2005). "Tracing Sydenham's chorea: historical documents from a British paediatric hospital". Archives of Disease in Childhood. 90 (5): 507–11. doi:10.1136/adc.2004.057679. PMC 1720385. PMID 15851434.

External links[]