Sydenham Chorea in Children

The role of B-cells in immunity against adult Strongyloides venezuelensis

Background

Strongyloides venezuelensis has been used as a tool and model for strongyloidiasis research. Elimination of S. venezuelensis adult worms from mice has been particularly associated with proliferation and activation of intestinal mast cells and eosinophils. To date, the role of B-cells in the protective mechanism against adult Strongyloides infection in experimental animals has not been reported in the literature. Therefore, the present study was carried to investigate the role of B-lymphocytes in immunity against adult S. venezuelensis infection using mice with a targeted deletion of the JH locus.

Methods

JHD knockout mice with its wild-type Balb/c mice were infected by intra-duodenal implantation of adult S. venezuelensis. Fecal egg count, intestinal worm recovery, mucosal mast cells and eosinophils were counted.

Results

At day 11 post infection, parasites in wild-type mice stopped egg laying, while in JHD knockout mice parasites continued to excrete eggs until the end of the observation period, day 107. The higher number of parasite eggs expelled in the feces of JHD knockout infected mice was a consequence of higher worm burdens, which established in the small intestine of these animals. On the other hand worm fecundity was comparable in both groups of mice. Both B-cell-deficient mice and wild-type mice, showed an influx of mucosal mast cells and eosinophils. The absolute numbers in JHD knockout mice were lower than those seen in wild-type mice at day 11, but not to a level of significance. JHD knockout mice could not recover from infection despite the recruitment of both types of cells.

Conclusion

Our findings highlight a role of B cells in mucosal immunity against invasion of adult S. venezuelensis and in its expulsion. Therefore, we conclude that B-cells together with mucosal mast cells and eosinophils, contribute to immunity against adult S. venezuelensis by mechanism(s) to be investigated.

Striatal microinjection of Sydenham chorea antibodies: using a rat model to examine the dopamine hypothesis

We hypothesized that injection of anti-basal antibodies from patients with Sydenham's chorea into rats' striatum will induce behavioral and histological changes. Antibodies from eight Sydenham's chorea patients and eight age-matched controls were injected into the left caudate of 16 rats. Apomorphine- and amphetamine-induced rotations were performed on days 10 and 17, respectively, followed by immunohistochemical studies. Antibodies from patients with Sydenham's chorea, but not controls, bound to a ∼50-kDa molecule in the striatum extract; immunohistology staining demonstrated specific binding to cellular component(s) in rats' striatum. Contrary to our hypothesis, we could not detect in the rats injected with Sydenham's chorea antibodies changes in rotational behavior or immunohistochemistry staining for dopaminergic or GABAergic markers. Injection of small quantities of anti-neuronal antibodies present in patients with Sydenham's chorea into rat striatum is insufficient to alter motor behavior or cause detectable cellular changes.

The PANDAS subgroup of tic disorders and childhood-onset obsessive-compulsive disorder

Diagnosis and treatment of the PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) variant of Gilles de la Tourette syndrome (GTS) and childhood-onset obsessive-compulsive disorder (OCD) are still controversial issues. Most cross-sectional studies confirm a significant association between GTS and the development of an immune response against group A beta-hemolytic streptococcus (GABHS). Moreover, longitudinal retrospective studies suggest that a recent exposure to GABHS might be a risk factor for the onset of tics and obsessive-compulsive symptoms. However, further evidence from longitudinal prospective research is needed to verify whether a temporal association between GABHS infections and symptom exacerbations is a useful and reliable criterion for the diagnosis of PANDAS. In addition, preliminary results suggest that the PANDAS spectrum might be enlarged to include attention deficit/hyperactivity disorder. Although a number of immunological biomarkers have been proposed as markers of the PANDAS variant, at present, none of these has been conclusively proved useful to diagnose and monitor disease course in children with a suspicion of PANDAS. Finally, despite their empirical use in community settings, we still lack conclusive, evidence-based data regarding the usefulness of antibiotic and immunomodulatory treatments in children with PANDAS. Given the relevance of this topic for general pediatric health, additional research efforts to solve all the pending issues and the hottest points of debate are warranted.

[How is Sydenham's chorea treated in Rio de Janeiro?]

BACKGROUND

Sydenham's chorea is the most common cause of acquired childhood chorea in Brazil. Thus it is relevant to know how physicians treat those patients.

OBJECTIVE

To describe the practice patterns of Sydenham's chorea among pediatricians.

METHOD

A descriptive study was undertaken using a questionnaire among specialists and emergency pediatricians who work in public hospitals of Rio de Janeiro district.

RESULTS

74% of the physicians informed not to use any severity scale; 81% informed to always prescribe benzathine penicillin; 64% informed to begin pharmacological treatment for all patients; and Haloperidol was the most remembered drug among all physicians.

CONCLUSION

Physicians do not routinely use severity scales in follow-up of choreic patients; there is a tendency of irregular prescription of benzathine penicillin by younger doctors; and 28.3% prescribe only haloperidol.

Neurologic and cardiac findings in children with Sydenham chorea

This study investigated the association between cardiac and neurologic findings and the long-term prognosis in Sydenham chorea. A retrospective, descriptive study was conducted with 40 patients between 1991 and 2004. Their age, gender, clinical findings, severity of disease, presence of carditis, and neurological findings were evaluated. Patients were predominantly female (70%), and the mean age was 11.3 +/- 2.5 years. The mean duration of chorea was 5.3 +/- 3.1 months (range, 1-12 months). Chorea was mild in 30 patients, moderate in 9, and severe in 1. Carditis was confirmed by echocardiography in 28 cases (70%); the most frequently involved valve was the mitral (35%). Duration of chorea in patients with carditis did not differ significantly from that in patients without carditis. Mean follow-up time was 2.6 +/- 1.5 years. Acute flaring of acute rheumatic fever did not recur in any patient taking penicillin prophylactically. No patient had persistent chorea. Although murmurs in patients with Sydenham chorea predicts carditis with high probability, the absence of murmur does not exclude it. In patients with carditis, the mitral valve is the one most frequently involved.

Seminar on choreas

Chorea is one of the major types of involuntary movement disorders originating from dysfunctional neuronal networks interconnecting the basal ganglia and frontal cortical motor areas. The syndrome is characterised by a continuous flow of random, brief, involuntary muscle contractions and can result from a wide variety of causes. Diagnostic work-up can be straightforward in patients with a positive family history of Huntington's disease or acute-onset hemichorea in patients with lacunar stroke, but it can be a challenging and complex task in rare autoimmune or genetic choreas. Principles of management focus on establishing an aetiological classification and, if possible, removal of the cause. Preventive strategies may be possible in Huntington's disease where genetic counselling plays a major part. In this review we summarise the current understanding of the neuroanatomy and pathophysiology of chorea, its major aetiological classes, and principles of diagnostic work-up and management.

Chorea: non-genetic causes

PURPOSE OF REVIEW

The aim of this article is to review the literature on the non-genetic causes of chorea. The differential diagnosis of the large number of causes of sporadic chorea is often a challenging task. Interest has also been growing in the possibility that the mechanism responsible for Sydenham's chorea plays a role in the pathogeneis of other neuropsychiatric disorders.

RECENT FINDINGS

Stroke is the main cause of sporadic chorea. Sydenham's chorea shares clinical features with tic disorders, such as obsessive-compulsive disorder and attention deficit hyperactivity disorder. However, there are unequivocal differences between Sydenham's chorea and Tourette's syndrome. There is initial evidence suggesting the beneficial effect of immunosuppression in Sydenham's chorea. Other autoimmune causes of chorea include systemic lupus erythematosus as well as paraneoplastic syndromes. The growing list of drugs associated with chorea include lamotrigine, methadone and lithium. Among infectious agents, HIV is the leading reported cause of chorea.

SUMMARY

Patients with sporadic chorea require a thorough work up because numerous causes can lead to this condition. It remains unconfirmed whether the pathogenic mechanisms of Sydenham's chorea are responsible for other conditions such as isolated obsessive-compulsive disorder or Tourette's syndrome. Drugs and infectious agents, especially HIV, are often implicated in the causes of chorea.