Sydenham’s Chorea

A rare hyperkinetic autoimmune movement disorder affecting children results in brief, involuntary, jerky, uncontrollable movements of the face, arms, legs, and trunk muscles. The patient is diagnosed clinically but high blood titers of streptococcal antibodies such as ASO are also helpful in making the diagnosis. The prognosis is good in most cases but the duration of symptoms usually varies between 3-6 weeks.

Introduction

  • A rare hyperkinetic autoimmune movement disorder affecting children
  • Phenomenology: brief, involuntary, jerky, uncontrollable movements of the face, arms, legs, and trunk muscles

Affected Population

  • More prevalent in girls more than boys
  • More common between the ages of 5 and 15
  • It affects all races and ethnicities
  • 25% of patients with rheumatic fever develop Sydenham chorea

Clinical Features

  • Acute to subacute onset following streptococcal infection
  • In addition to chorea, symptoms also include behavioral changes, including anxiety, obsessive-compulsive disorder, and attention
  • In rare cases, affected children may become bedridden due to severe muscle weakness, and this condition is called paralytic chorea
  • The symptoms may vary and are presented in Table 1

Signs & Symptoms

  • Choreic movements
  • Muscle weakness
  • Behavioural disturbances such as inattention/obsessions/compulsion/anxiety/ labile mood
  • Facial grimacing
  • Restlessness
  • Slurred speech
  • Diminished muscle tone

Causes

  • The choreiform movement is caused by the autoimmune reaction to the streptococcal infection
  • The antibodies produced by the immune system persist and attack certain cells in the joints, kidneys, heart and in the brain specifically basal ganglia which plays a key role in controlling motor movements

Differential Diagnosis

  • Autoimmune or paraneoplastic: Anti-Hu(ANNA-1); Anti-NMDA; anti-CRMP5; anti-IgLON5; anti-LGI-1
  • Polycythemia vera
  • Endocrinological disorders-hyperparathyroidism, pseudohypoparathyroidism, both hypo or hyperthyroidism, and nonketotic hyperglycemia
  • Neurodegenerative disorders: Huntington's disease, Dentatorubropallidolysian atrophy, C9orf72 disease, and Spinocerebellar ataxias
 
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Related Disorders
  • Abrupt withdrawal of Psychiatric Medications
  • Diseases related to metabolism or mitochondrial function
  • Neuroacanthocytosis, Ataxia-telangiectasia, Anti-NMDA receptor encephalitis

Diagnosis

  • Clinically - acute onset of choreic movements associated with behavioral changes
  • A confirmation of streptococcal infection via swab
  • High blood titres of streptococcal antibodies such as ASO is also useful in making the diagnosis
  • Brain imaging is usually normal in Sydenham Chorea
  • Often during the acute phase SPECT shows striatal hyperperfusion which evolves to hypoperfusion during the illness

Treatment

Symptomatic Medications

  • Bed rest
    • During the period of active movements is recommended for the mildest form
  • When chorea is disabling and interferes with rest
    • Low Dose Anticonvulsants
      • Valporate (20mg/kg/day)
      • Carbamezatpine (15 mg/kg/day)
    • Neuroleptics
      • Symptomatic treatment with neuroleptics can be considered while treating the underlying illness
      • Of note neuroleptics should be used for patients who fail valproic acid or carbamazepine therapy due to negative side effects
      • The most common neuroleptics used are pimozide and haloperidol
      • Atypical antipsychotics, such as risperidone and olanzapine can also be considered

Acute and Prophylactic Penicillin Therapy

  • Treatment with Penicillin at the time of diagnosis of SC, 10 days
    • Prevents additional complications of rheumatic fever
  • The WHO recommends Penicillin G (1.2 million units) IM QDaily for 21 Days
    • Duration depends upon the severity of carditis
  • It is recommended to stop the prophylaxis after 5 years or age 18 (whichever is longer) in patients with no carditis
  • Patients with mild carditis should continue for 10 years or age 21
  • Patients with moderate to severe carditis should receive lifelong prophylaxis

Immunomodulatory therapy

  • Short term immunotherapy such as oral steroids and IV immunoglobulins have been used to treat patients with disabling symptoms and in cases of uncontrolled or persisting chorea,
  • The two most common regimens are:
    • Oral prednisone (2 mg/kg/day) for ~ 21 - 30 days prolonged taper
    • Methylprednisolone (25 mg/kg/day) ~ 21 - 30 days prolonged taper

Prognosis

  • Good with complete recovery in most cases
  • Duration of symptoms usually vary between 3-6 weeks; some children can have symptoms for several months
  • Cardiac complications such as endocarditis may occur in some children
  • 1/3rd of patients will experience recurrence of SC, usually after 1 and a half to 2 years after the initial attack
  • Researchers have noticed an association between Recurrent SC and Rapid onset of PANDAS
    • PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infection)
    • PANDAS is characterized by Obsessive-compulsive disorder, attention deficit/hyperactivity-disorder, tic disorders, and autism

Further Reading

  • Sehar, A., Nasir, S., & Seja, A. (2019). Rheumatic Chorea as the First Presenting Sign in a 13-year-old Female Child. Cureus, 11(8), e5447. https://doi.org/10.7759/cureus.5447
  • https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-021-06005-x

Bibliography

  • Dean, S. L., & Singer, H. S. (2017). Treatment of Sydenham's Chorea: A Review of the Current Evidence. Tremor and other hyperkinetic movements (New York, N.Y.), 7, 456. https://doi.org/10.7916/D8W95GJ2
  • Sydenham chorea. NORD (National Organization for Rare Disorders). (2020, September 1). https://rarediseases.org/rare-diseases/sydenham-chorea/.
  • Sydenham's chorea. Brain Foundation. (n.d.). https://brainfoundation.org.au/disorders/sydenhams-chorea/.
  • U.S. Department of Health and Human Services. (n.d.). Sydenham chorea information page. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/All-Disorders/Sydenham-Chorea-Information-Page.