One of the major criteria for Rheumatic fever. See Jelly Jumps page.
Classically, involuntary, non-rhythmic movements, associated with emotional lability. Often misdiagnosed initially eg psychogenic [PMID 26374756].
Movements disappear in sleep. Typical signs are lip protrusion, milk maid sign (ask to squeeze fingers in hand), extension of wrists, ask to stick tongue out (unable to maintain).
Can be one side of the body predominantly (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.
Emotional lability well described, although developing a new disability without any cognitive impairment may explain some of it.
Pregnancy is associated with first onset but also relapse.
High risk of cardiac involvement, as type of rheumatic fever – 71% of cases in Turkish study, of which nearly half silent (no findings on clinical examination). Significant risk of long term morbidity, even if chorea never comes back, so always echo and give penicillin prophylaxis.
Diagnosis
Essentially clinical, with supportive evidence of recent streptococcal infection (ASO titre, throat swab). Other tests directed at differential diagnosis – lumbar puncture, MRI brain.
Although there is evidence of anti-neuronal antibodies directed against the basal ganglia (eg anti D2R), these are not specific or sensitive and only used in research.
Management
There is a rating scale for SC, from the Universidade Federal de Minas Gerais (UFMG), for research purposes.
Occupational and physiotherapy useful for maintaining function and muscle tone.
Treatment with valproate is effective for controlling symptoms but doesn’t speed up recovery. Haloperidol used previously but prob more side effects. Case reports to support carbamazepine and levetiracetam.
Good evidence for immunosuppression eg oral or IV steroids from Italy [PMID 29287833 ], immunoglobulin [Holland, PMID 26837939, South Africa 25987537]. Some improvement can be seen within a few days of IV steroids. In Utah and Italy, prednisolone reduced average duration of symptoms from 9 weeks to 4 weeks, and these were severe cases [PMID 22197452]. South African group found less neuropsychiatric complications at 6 months with IVIG treatment.
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, as for rheumatic fever, on the other hand essential.
Recurrence
Recurrence seen in 16-30%. 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. More likely if failure to remit in initial 6 months, can recur with pregnancy. [Turkey, PMID 27209549]
Usually recurrence is just chorea, even if you had other features of rheumatic fever to being 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.
Prognosis
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]
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.
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)
Patient/family support at Sydenham’s Chorea Association.
[Review article Oosterveer, NL Ped Neuro 2010]