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Mental Health

Paediatric acute-onset neuropsychiatric syndrome (PANS)

Specific pediatric obsessive–compulsive disorder (OCD) phenotypes that include acute onset of OCD symptoms, restricted eating or tics comorbid with multiple psychiatric and neurological symptom.

Introduction

Specific pediatric obsessive–compulsive disorder (OCD) phenotypes that include acute onset of OCD symptoms, restricted eating or tics comorbid with multiple psychiatric and neurological symptom.

History:

In his monograph “On Chorea and Choreiform Affectations” (1894), Osler first described obsessive-compulsive behavior in Sydenham’s chorea (SC). Half a century later, this observation was confirmed in larger case series. In 1965, Langlois and Force reported in a 6-year-old the coexistence of tics and SC precipitated by infections, subsequently treated successfully with antibiotics and neuroleptics. In 1978, Kondo and Kabasawa reported in an 11-year-old boy a tic disorder started abruptly about 10 days after a febrile illness associated with elevated antistreptolysin O (ASO) antibody titers and good response to corticosteroids; this case prompted the discussion on the role of biological stressors in tic disorders, representing relevant background information for the first description of PANDAS. Kiessling LS reported an association of tics during pediatric GABHS outbreaks. During the same period, clinical researchers at the National Institutes of Mental Health (NIMH) reported SC cases that often exhibited OCS with a fluctuating clinical course. Allen AJ identified a subgroup of children who presented OCD and/or tic disorders following an infectious illness without fulfilling the criteria for SC; they summarized the essential features of their cases in the acronym PITANDs (pediatric, infection-triggered, autoimmune neuropsychiatric disorders). The PITANDs subgroup was soon renamed “PANDAS” by Swedo and colleagues in 1998 in their seminal article where they proposed their set of working diagnostic criteria.


Aetiology

PANS criteria define a broad spectrum of neuropsychiatric conditions, the syndrome is presumed to result from a variety of disease mechanisms and to have multiple etiologies, ranging from psychological trauma or underlying neurological, endocrine, and metabolic disorders to postinfectious autoimmune and neuroinflammatory disorders, such as pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS), cerebral vasculitis, neuropsychiatric lupus, and others.

Evolution criteria of PANDAS and PANS | Swedo S. E., Leckman J. F., Rose N. R. From research subgroup to clinical syndrome: modifying the PANDAS criteria to describe PANS (pediatric acute-onset neuropsychiatric syndrome). Pediatrics & Therapeutics. 2012;2:113.

Pathophysiology

Model of pathogenesis for PANDAS: The postulated pathophysiology of Sydenham chorea and PANDAS involves a series of factors, including the ‘rheumatogenic’ GAS bacteria, genetic susceptibility, and abnormal immune responsivity. | Swedo, S. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Mol Psychiatry 7, S24–S25 (2002). https://doi.org/10.1038/sj.mp.4001170
Simplified illustration of a potential pathogenic mechanism of antibody mediated neuronal cell signaling in Sydenham chorea and PANDAS. Antineuronal antibody (IgG) may bind to receptors (blue triangle) on the surface of neuronal cells and trigger the signaling cascade of CaMKII, tyrosine hydroxylase, and dopamine release, which may potentially lead to excess dopamine and the manifestations of Sydenham chorea. | Cunningham M. W. Streptococcus and rheumatic fever. Current Opinion in Rheumatology. 2012;24(4):408–416.

Clinical features

Swedo diagnostic criteria:

Pediatric condition defined by an unusually abrupt onset of obsessive-compulsive symptoms and/or severe eating restrictions and at least 2 concomitant cognitive, behavioral, or neurological symptoms | Swedo SE, Leckman JF, Rose NR: From research subgroup to clinical syndrome: Modifying the PANDAS criteria to describe PANS (pediatric acute-onset neuropsychiatric syndrome). Pediatr Therapeut 2:1–8, 2012
  • Presence of OCD or a tic disorder
  • Prepubertal/pediatric (2-12 years) onset of symptom exacerbations
  • Episodic course of symptom severity and abrupt onset of symptoms;
  • Symptom association with group A β-hemolytic streptococcal (GABHS) infection; and
  • Association with neurologic abnormalities

Management

Treatment of PANS depends on three complementary modes of intervention:

  • Treating symptoms: Psychoactive medications, psychotherapies (particularly cognitive behavioral therapy), and supportive interventions.
  • Removing source of inflammation: Antimicrobial interventions.
  • Treating immune system: Immunomodulatory and/or anti-inflammatory therapies
The PANS treatment triangle. PANS, pediatric acute-onset neuropsychiatric syndrome. | Swedo, S. E., Frankovich, J., & Murphy, T. K. (2017). Overview of Treatment of Pediatric Acute-Onset Neuropsychiatric Syndrome. Journal of child and adolescent psychopharmacology, 27(7), 562–565. https://doi.org/10.1089/cap.2017.0042

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