Sydenham’s chorea

One of the major criteria for Rheumatic fever but can sometimes be seen in isolation. An acute neuropsychiatric condition, that can cause severe functional impairment, but that mostly resolves spontaneously. See Jelly Jumps page for videos and family support.

Classically, involuntary, non-rhythmic movements, associated with emotional lability. Often misdiagnosed initially eg psychogenic [Mary King, ADC 2015]. Adults can get it rarely – tends to be relapse of childhood disease, female hormones seem to a trigger (eg pregnancy, oral or other contraceptives).

Chorea is a particular kind of movement – varies from smooth writhing (athetosis) to rapid, high amplitude jerks (ballism). Typical signs are repeated pouting of lips, milk maid sign (ask to squeeze fingers in hand), hyperextension of wrists, piano playing movements. Fine motor control usually lost, due to these extra movements. Gait disturbance common, can look like hip hop dancing! Ask to stick tongue out (unable to maintain – “motor impersistence”). Movements disappear in sleep. Can be hard to differentiate sometimes from stereotypies and tics, and of course these things are not uncommon so might co-exist.

Can be one side of the body predominantly in 20-30% of cases (hemichorea). Underlying the involuntary movements is often a loss of tone, which may not become obvious until treatment started to suppress the chorea.

In severe cases, the loss of tone and weakness predominate (chorea paralyticum).

Variable severity. May just be some instability on walking, some difficulty with hand writing. Or unable to walk, talk, feed yourself.

The “psychiatric” part of the neuropsychiatric condition is a mixture of different issues. Emotional lability common, mild anxiety and poor attention less so – although developing a new disability without any cognitive impairment may explain some of it. Tics (new) often seen.

Family history often seen, at least in historical reports, where it was almost part of the diagnosis!

Risk of cardiac involvement, as related to rheumatic fever – 20% of cases in BPSU study, but 71% of cases in Turkish study, of which nearly half silent (no findings on clinical examination). Significant risk of long term morbidity, more important than chorea itself, so always echo and give penicillin prophylaxis (see below).

Diagnosis

Essentially clinical, with supportive evidence of recent streptococcal infection (ASO titre, throat swab). But recognised that infection can be up to 6 months before, or too mild to really notice, and ASO hardly reliable.

Other tests are directed at differential diagnosis – lumbar puncture, MRI brain (putaminal enlargement described in SC but not diagnostic) etc.

Although there is evidence of anti-neuronal antibodies directed against the basal ganglia (eg anti D2R, see Church 2003), these are not specific or sensitive (see Sugar 2003, same time as Church) so not used in clinical practice. Swedo and Cunningham (also 2003) found cross reactive antibodies that recognised N-acetyl Beta D glucosamine, the major strep surface epitope, and also lysoganglioside, activating CAMK II which may regulate neurotransmitters. “Cunningham panel” is private test, see PANDAS.

Management

There is a UFMG rating scale for SC, from Brazilian Universidade Federal de Minas Gerais (UFMG), for research purposes but only looks at motor function.

Occupational and physiotherapy useful for maintaining function and muscle tone, especially for getting back to school.

Treatment with valproate is effective for controlling symptoms but doesn’t speed up recovery. May reveal hypotonia. Haloperidol used previously but prob more side effects. Case reports to support carbamazepine and levetiracetam.

One RCT supporting steroids from Paz, Brazil 2006, 22 cases of SC, remission reduced to 54 days from 119 days. Various other reports of use of oral or IV steroids from Israel, Italy [Fusco 2012, 2017], Brazil [Cardoso 2005], immunoglobulin [Holland, 2016, South Africa 2016]. Some of these studies report response with days, and remission within 7 to 54 days, even where cases are severe and have already been treated with anticonvulsants. South African group found less neuropsychiatric complications at 6 months with IVIG treatment (IVIG preferred due to fear of TB reactivation). [Review by Deans and Singer, 2017]

Prophylaxis

A course of penicillin is usually given at diagnosis, to definitively clear any remaining strep but no evidence this really achieves anything and active infection probably long gone. Penicillin prophylaxis, on the other hand, essential if you have other features of rheumatic fever – regimens vary globally.

Penicillin prophylaxis recommendations for rheumatic fever across world

If Sydenhams chorea is not part of broader rheumatic fever diagnosis, then practice varies regarding offering prophylaxis. Evidence is that recurrence is less where penicillin prophylaxis is used, and used reliably, but that it doesn’t always prevent it. Given the high rate of recurrence, the level of disability and potential for long term complications, the benefits seem to outweigh the costs (review in 2017 favours it but does not seem to strictly distinguish non-RF Sydenhams) but not straightforward. Patients find injections painful, and there are restrictions around meal times for oral penicillin (absorption affected by food, so advised best given at least 1 hour before or 2 hours after), which can be challenging.

Recurrence

Recurrence seen in 16-40%. More likely if poor compliance with penicillin prophylaxis, of course. Sometimes associated with rise in ASO or other evidence of new streptococcal infection but certainly not always the case. 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 and possibly with other female hormone treatments eg oral contraceptives or HRT.

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.

Usually recurrence is just chorea, even if you had other features of rheumatic fever to begin with. Just two reports of heart disease worsening after recurrence of chorea [Israel and Thailand]. The Thailand study also had 2 cases where carditis, which had improved after initial diagnosis, came back again. Some suggest that perhaps recurrent chorea is a different disease altogether. [Israel, Arch Neurol. 2004; Turkey, PMID 27209549]

Prognosis

Most resolve within 2-4 months. Improvement tends to be rapid once it begins.

10% reported long term tremor in one study (10 years follow up). Long term neuropsychiatric difficulties increasingly recognised (49 studies so far, {Michael Morton and Nadine Mushet 2016 PMID 25926089] esp Obsessive-compulsive disorder but also Attention-deficit-hyperactivity disorder, affective disorders, tic disorders, executive function disturbances, psychotic features, language impairment.

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

Differential

  • PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infections) – ICD criteria.
  • Tics, Tourettes, stereotypies
  • Benign hereditary chorea (BHC) – rare. In infants low muscle tone, chorea, lung infections, and respiratory distress. In older children, delayed motor and walking milestones, myoclonus, dystonia (esp upper limb), motor tics, and vocal tics. The chorea often improves with time, in some cases myoclonus persists or worsens. Some have learning and behaviour problems, thyroid problems and recurring chest infections. Caused by mutations in the NKX2-1 gene (autosomal dominant)
  • Bilateral striatal necrosis is a rare condition where similar symptoms but chronic and permanent. Various causes, has been seen in association with streptococcus. Has been described in a case of Sydenham’s where symptoms recurred and then persisted, so not clear whether coincidence or it wasn’t really Sydenham’s in the first place.

Patient/family support at Sydenham’s Chorea Association.

[Review article Oosterveer, NL Ped Neuro 2010]

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