Sydenham's chorea (SC) is characterised by chorea, emotional lability and hypotonia. In this study, we investigated the incidence and clinical presentation of childhood SC in Ireland (years 2006–2014). Nineteen cases were diagnosed. Five patients had rheumatic fever. An increasing trend with an incidence of 0.23/100 000 is reported. As most referral diagnoses included psychogenic illness, head injury and stroke, modern physicians may not be aware of this age old illness. A review of the manifestations and diagnosis of SC is presented.
- movement disorder
- rheumatic fever
- group A streptococcus
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What is already known on this topic
Sydenham's chorea is a common cause of childhood-onset chorea characterised by the triad of chorea, hypotonia and neuropsychiatric symptoms.
Sydenham's chorea usually occurs weeks or months after a group A streptococcal infection and is diagnosed in the presence of the ‘Modified Jones Criteria’.
What this study adds
The incidence of Sydenham's chorea appears to be rising in Ireland.
Sydenham's chorea is often not recognised by paediatricians and general practitioners and there is uncertainty about optimum mode of treatment.
Chorea is a movement disorder characterised by abrupt, involuntary, irregular, purposeless, non-rhythmic, unsustained movements that flow from one part of the body to another. Sydenham's chorea (SC), first described in 1686, is the commonest cause of childhood chorea, denoted by chorea, hypotonia and neuropsychiatric symptoms (usually emotional lability).1 SC mainly affects children, usually occurring weeks following group A streptococcal (GAS) infection and is often diagnosed in the presence of ‘Modified Jones Criteria’ for rheumatic fever. However, isolated SC also occurs. There are few reports of current trends in incidence and pattern of presentation of SC in developed countries. An observed rise in diagnosed cases of SC presenting to our paediatric neurology department prompted us to retrospectively review the pattern of presentation and incidence of childhood SC in Ireland.
A retrospective observational study was performed of Irish children (including Northern Ireland) aged <14 years, diagnosed with SC between July 2006 and July 2014. Cases were ascertained through review of neurology clinical records in four regional paediatric neurology referral centres. Detailed review of each patient's case was performed by the authors and using a questionnaire proforma capturing key demographic, clinical, investigative, management and outcome data of children presenting with SC. The incidence was calculated per children per 100 000, from census data of the Republic of Ireland and Northern Ireland. Antistreptolysin titre and anti-DNAase B positivity were defined as levels >200 U/mL.
Nineteen cases of SC were diagnosed over the 8-year period, giving an estimated childhood incidence of 0.23/100 000 children aged <14 years. In the largest centre, only one case was diagnosed between 1995 and 2005 compared to the study period (2006–2014) where eight cases were diagnosed at this centre and a further 11 cases nationally. All patients were referred by general paediatricians (n=11) or general practitioners (n=8). A tentative diagnosis of the movement disorder ‘chorea’ was made in five cases, with SC specifically featuring in the differential diagnosis in three cases. Table 1 illustrates the main characteristics of the cohort and referring physicians’ diagnoses.
All 19 patients had significant motor impairment interfering with activities of daily living. Five patients fulfilled criteria for rheumatic fever. Sixteen cases had evidence suggestive of preceding GAS infection. In those who had no evidence of preceding GAS infection, there was no clinical or laboratory evidence of other disorders such as systemic lupus erythematosus at presentation or follow-up. We assume that in these patients serology had normalised by the time of presentation.
Eighteen patients received chorea-specific pharmacological therapy. First-line treatment included valproate alone in 11 (61%) of whom six required additional immunotherapy. Corticosteroids were used alone in five (26%) and in combination with valproate as first line in two (11%). Resolution occurred in all patients (median 4 months) with no difference in time to resolution in treatment groups. Three patients relapsed, two upon weaning valproate. Fourteen patients were treated acutely with penicillin (for 7–14 days), 11 of these were prescribed longer term penicillin (daily prophylaxis >10 months).
This is the first study to document the incidence (0.23/100 000 children) and pattern of presentation of SC in Ireland, a disorder identified at presentation to general practitioners and hospital-based paediatricians in 3 of 19 cases. As SC is rarely considered at presentation, it is likely that SC is thought to have disappeared from ‘modern illness’ in the developed world. It may be that choreiform movements appear bizarre to some physicians, and when accompanied by emotional lability in a relatively ‘well-appearing’ child as the main clinical manifestation of this disorder, they are not recognised as SC. An unusual higher incidence of hemi-chorea observed in this study may have made initial differential diagnosis even more difficult. An accurate diagnosis of SC is clearly important not only to (a) treat the acute motor and neuropsychiatric symptoms and (b) diagnose or prevent rheumatic heart disease but also (c) follow-up for longer term neuropsychological symptoms which may be disabling.
While investigations may support the diagnosis of SC, the diagnosis is predominantly clinical and based on (1) the phenomenology of the chorea, that is abrupt, involuntary, uncoordinated, irregular, non-stereotyped movements of the extremities and face that disappear in sleep (the child may appear restless or fidgety or attempt to hide or incorporate the chorea into other movements), (2) pattern of presentation, that is, age, female preponderance, recent upper respiratory tract infection (usually within weeks or months) and (3) associated neuropsychiatric symptoms (mainly emotional lability). This constellation of signs (see online supplementary video 1A, B) and symptoms should lead one to suspect SC as the primary diagnosis. Detailed history and neuroimaging will exclude other causes of acute/subacute ‘isolated’ chorea. Although there is ongoing debate about overlapping pathogenic mechanisms between SC and other paediatric autoimmune disorders, in practice, SC is easily distinguished. In paediatric autoimmune neuropsychiatric disorder associated with streptococcus infection (PANDAS), there is a more unique neuropsychiatric profile with a predominance of obsessions and/or compulsions, often sudden onset of motor or vocal tics, and rheumatic fever does not occur.1 Given the severity of the neurological presentation it is most unlikely that cases of SC would not have been referred to paediatric neurology services and we suggest that our findings, although retrospective, indicate that SC is rising in Ireland. In Scotland, a similar trend was noted.2 The reason for a presumed rise in rate of SC in Ireland is difficult to determine, but may be related to the significant rise in rate of GAS infection observed compared to previous years,3 in contrast to a decreasing incidence rate of GAS in the USA.
There are no uniform guidelines regarding treatment or management of SC. Sodium valproate was the first-line anti-chorea treatment in our population and in keeping with literature reports, had variable efficacy, as some patients required additional corticosteroid treatment. Other drugs to treat movement disorders (eg, haloperidol) as well as input by experienced allied healthcare professionals may enhance functional recovery in SC.4
A proportion of patients with isolated chorea are at risk of rheumatic heart disease at later follow-up. The WHO recommends penicillin prophylaxis for patients with proven carditis for 5 years or until 18 years (whichever is longer).5 There is a paucity of literature regarding the optimum treatment and prophylaxis in patients with isolated chorea. This uncertainty is reflected in our patients where more than half remained on long-term penicillin.
Our observation demonstrates that SC is often not recognised by paediatricians and general practitioners, and that uncertainty exists about the optimum mode of treatment (both anti-chorea and penicillin prophylaxis for patients with isolated chorea). The retrospective nature of this paper is a limitation; this study may not capture all cases of SC and therefore our calculated incidence can only be taken as a crude estimate. Further prospective surveillance studies examining the trends in incidence, host factors, chorea-specific treatments, rheumatic fever preventative strategies and motor and psychological outcomes in children with SC are warranted. We hope this report increases awareness of the features of chorea and when to suspect it.
Contributors DW, AB, NMS, DP, ST and MDK contributed cases to the study. MC and NMA drafted the manuscript. NMA and MDK edited the manuscript. All authors approved the manuscript prior to submission.
Competing interests None declared.
Patient consent Obtained.
Ethics approval Temple St Children's University Hospital Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.