Paediatric acute-onset neuropsychiatric syndrome in children and adolescents: an observational cohort study

Reliability and validity of a newly developed PANDAS/PANS questionnaire

OBJECTIVE

This study aimed to examine the reliability and validity of a newly developed questionnaire for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS) and Pediatric Acute-onset Neuropsychiatric Syndrome (PANS). The aim was to contribute to future standardisation of screening methods for symptoms and comorbidity, as well as the measurement of symptom severity, daily life impairment, and treatment effectiveness in individuals diagnosed with PANDAS/PANS.

METHODS

27 items from the PANDAS/PANS questionnaire concerning symptoms and comorbidities associated with PANDAS/PANS were divided into ten domains. To assess the external validity, 119 PANDAS/PANS questionnaires from a cohort of 65 children with PANDAS/PANS were correlated with three well-known validated questionnaires: the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS), Attention Deficit Hyperactivity Disorder Rating Scale (ADHD-RS), and the Strengths and Difficulties Questionnaire (SDQ). The internal validity of the PANDAS/PANS questionnaire was assessed by correlating the PANDAS/PANS items with the domains.

RESULTS

Internal consistency of the PANDAS/PANS questionnaire was high, measuring moderate to very strong correlations. The external correlations for the PANDAS/PANS questionnaire showed a higher correlation with the ADHD-RS and CY-BOCS (rs ≥ 0.60) than with the SDQ (rs < 0.40).

CONCLUSION

The validity and clinical feasibility of the PANDAS/PANS questionnaire were confirmed as an effective tool for screening symptoms, assessing symptom severity, and evaluating comorbidity and daily life impairment in individuals with PANDAS/PANS. These findings can potentially enhance the management of PANDAS/PANS patients in both clinical and research settings.

Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS): Immunological Features Underpinning Controversial Entities

Pediatric acute-onset neuropsychiatric syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS), represent an overlapping group of disorders which is characterized by acute-onset obsessive compulsive disorders, eating restriction, tics, cognitive and behavioral deterioration which typically follows a relapsing-remitting course but some patients have a primary or secondary persistent progress. This condition is likely caused by heterogeneous inflammatory mechanisms (autoantibodies, complement activation, pro-inflammatory cytokine production) involving the basal ganglia as evidenced by imaging studies (patients vs. controls), sleep studies that found movements and/or atonia during REM sleep, and neurological soft signs that go along with basal ganglia dysfunction. The condition causes significant psychiatric and behavioral symptoms, caregiver burden and sleep abnormalities. Autoantibodies resulting from molecular mimicry of infectious agents (namely group A Streptococcus) and neuronal autoantigens that map to the basal ganglia play also a subtle role. This narrative review aims to describe the key immunological features documented thus far and that likely play a role in the pathogenesis and clinical manifestations of this disorder.

Psychometric Properties of the PANS 31-Item Symptom Rating Scale

Objectives: Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by sudden onset of obsessive-compulsive disorder and/or eating restriction with associated neuropsychiatric symptoms from at least two of seven categories. The PANS 31-Item Symptom Rating Scale (PANS Rating Scale) was developed to identify and measure the severity of PANS symptoms. The objective of this study was to define the psychometric properties of the PANS Rating Scale. Methods: Children with PANS (N = 135) and their parents participated. Parents completed the PANS Rating Scale and other scales on Research Electronic Data Capture. The PANS Rating Scale includes 31 items that are rated on a Likert scale from 0 = none to 4 = extreme. Pearson's correlations were run between the PANS Total score and scores on the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), Yale Global Tic Severity Scale (YGTSS), Modified Overt Aggression Scale (MOAS), Columbia Impairment Scale (CIS), PANS Global Impairment Score (GIS), and Children's Global Assessment Scale (CGAS). Results: Convergent validity was supported by significant correlations between the PANS Total and scores on the CY-BOCS, YGTSS, MOAS, CIS, GIS, and CGAS. The largest correlations were with measures of functional impairment: PANS Total and CIS (r = 0.81) and PANS Total and GIS (r = 0.74). Cronbach's alpha was 0.89 which demonstrates strong internal consistency of the 31 items. PANS Total score was significantly higher in children in a flare of their neuropsychiatric symptoms compared to children who were not in a flare. Conclusions: This study provides preliminary support for the PANS Rating Scale as a valid research instrument with good internal consistency. The PANS Rating Scale appears to be a useful measure for assessing children with PANS.

Mental and physical health in children of women with a history of anorexia nervosa

Few studies have investigated the offspring of women with anorexia nervosa (AN). The aim of this study was to examine perinatal status, mental and physical health in the offspring of mothers with a history of AN. Fifty-one individuals with adolescent-onset AN and 51 matched controls (COMP) have been followed prospectively. Presently, 30 years after AN onset, at a mean age of 44 years, female participants who had given birth (nAN = 40, nCOMP = 40) were interviewed regarding psychiatric health in their offspring using the Developmental and Well-Being Assessment and the MINI International Neuropsychiatric Interview. In addition, information on the offspring's perinatal status, psychiatric- and physical health was obtained from the Swedish Medical Birth Register and The Swedish National Patient Register. Data regarding mental and physical health were available for 83 and 86 offspring in the AN and COMP groups, respectively. At birth, all of weight, length, head circumference and ponderal index were significantly reduced in the offspring of mothers with a history of AN. In adolescence, parental interviews indicated an overrepresentation of current psychiatric diagnoses in the offspring of mothers with AN. Compared with the offspring in the COMP group, endocrinological, immune and metabolic disorders were much more common in the offspring of the AN group. In conclusion, a history of AN increases the risk of worse perinatal outcome of the offspring. Later on, in childhood and adolescence, psychiatric and physical morbidity may be overrepresented in the offspring of women with AN.

Baseline characteristics of children in the International PANS Registry (IPR) Epidemiology Study

PURPOSE

The International PANS Registry (IPR) Epidemiology Study is a registry-based, longitudinal study. We designed this study to improve phenotyping and characterisation of children with paediatric acute-onset neuropsychiatric syndrome (PANS) and PANS-like features and facilitate multidisciplinary and translational health research. This cohort provides new opportunities to address unresolved research questions related to the broad spectrum of heterogenous PANS-like conditions.

PARTICIPANTS

Inclusion in the IPR Epidemiology Study remains open indefinitely via IPR enrolment online. Participants include children with PANS or who have PANS-like features and their healthy siblings. We collected cross-sectional survey data based on parent report, including details on phenotypic traits and characteristics that, to our knowledge, have not been previously collected for this patient population. We describe the baseline characteristics of cases and their healthy siblings here.

FINDINGS TO DATE

The IPR Epidemiology Study currently includes 1781 individuals (1179 cases, 602 siblings; from 1010 households). Many households include a sibling (n=390, 39%) and some include multiple cases (n=205, 20%). Mean enrolment age was 11.3±4.3 years for cases and 10.1±5.3 for siblings. Leading PANS-like features include anxiety (94%), emotional lability (92%) and obsessions (90%). Onsets were sudden and dramatic (27%), gradual with a subsequent sudden and dramatic episode (68%) or a gradual progression (5%). The mean age at early signs/symptom onset was 4 years and 7 years at sudden and dramatic increases, respectively. Infection/illness was the most common suspected symptom trigger (84%). Nearly all cases had been treated with antibiotics (88%) and/or non-steroidal anti-inflammatory drugs (79%). Parents reported immune-related conditions in cases (18%) and their nuclear, biological family (48%; 39% in biological mothers).

FUTURE PLANS

Future plans include increasing sample size, collecting longitudinal survey data, recruiting appropriate study controls and expanding the scope of the database, prioritising medical record data integration and creating a linked biorepository. Secondary data analyses will prioritise identifying subgroups by phenotypic traits, maternal health and disease characteristics.

Factors Associated with Symptom Persistence in PANS: Part I-Access to Care

Objective: Pediatric acute-onset neuropsychiatric syndrome (PANS) presents with abrupt neuropsychiatric symptoms, often after an immunologic trigger. A 2017 survey of 698 subjects found diagnostic delays to be associated with recurrences, suggesting that timely care impacts course. This secondary analysis explores the impact of barriers to care on symptom persistence. Methods: A 146-question online survey gathered history, symptomatology, intervention, and outcome data from subjects with PANS. Multivariate analyses examined associations between symptom persistence over the entire reported disease course, measured as % days symptom-free over reporting periods averaging approximately 4 years, and access-to-care history, reflected in availability of medical expertise and affordability of care. The impacts of time from symptom onset to treatment and effectiveness of initial antibiotics were also examined. Results: Among the 646 subjects analyzed, greater symptom persistence was associated with longer intervals between symptom onset and treatment (F = 4.43, p = 0.002). Thirty-four percent of subjects with the least symptom persistence (>75% symptom-free days), versus 13% of those with the most (symptoms every day), had been diagnosed by the first practitioner seen (likelihood ratio [L-R] χ2 = 36.55, p < 0.0001, for comparison across all groups). Diagnosis and treatment had not been impeded by lack of access to expertise for 52% of subjects with the least persistent symptoms, versus 22% of those with the most (L-R χ2 = 22.47, p < 0.0001). Affordability had not impacted diagnosis and treatment for 76% of subjects with the least persistent symptoms, versus 42% of those with the most (L-R χ2 = 27.83, p < 0.0001). The subjects whose PANS symptoms resolved with antibiotic treatment of the inciting infection experienced less symptom persistence than others (χ2 = 23.27, p = 0.0001). More persistently symptomatic subjects were more likely to have discontinued intravenous immunoglobulin (IVIG) treatment for access-to-care reasons. Conclusions: Unimpeded access to care for PANS is associated with more symptom-free days over reporting periods averaging approximately 4 years. Difficulty reaching expert providers, missed opportunities for diagnoses, and financial limitations may worsen outcomes. Practitioners, particularly primary providers, should adhere to published diagnostic and treatment guidelines promptly upon presentation.

Factors Associated with Symptom Persistence in PANS: Part II-Presenting Features, Medical Comorbidities, and IVIG Treatment History

Objective: Individuals with Pediatric Acute Onset Neuropsychiatric Syndrome (PANS) experience neuropsychiatric symptoms following an infection or other trigger. Although PANS is typically described as relapsing-remitting, a large community-based 2017 study revealed a range of courses. The present study examined clinical predictors of symptom persistence, measured as % days symptom-free, in this same sample. Methods: A 146-question online survey gathered histories (infections and other triggers, medical and developmental comorbidities), symptomatology, interventions, and outcomes (including school functioning) of PANS patients. Multivariate analyses were applied to examine associations between these variables and % days symptom-free across the disease course. Results: Among the 646 subjects included, significant relationships were found between greater symptom persistence and higher rates of medical comorbidities (especially rashes, headaches, chronic sinusitis, frequent diarrhea, and immune deficiencies), developmental diagnoses, and respondent-perceived developmental lags. Subjects with greater symptom persistence were significantly more likely to report PANS exacerbations associated with infections in close contacts, vaccinations, environmental triggers, and exacerbations of comorbidities and were more likely to report PANS recurrences triggered by Epstein Barr Virus, mycoplasma, and sinus infections. More persistent PANS was also associated with significantly higher frequencies of certain symptoms (sleep disturbance, urinary incontinence, muscle pain, brain fog, sensory defensiveness, irritability, and aggression-related symptoms), less effectiveness of intravenous immunoglobulin in combating symptoms, and more difficulty attending school. Conclusions: Our results suggest high symptom persistence in PANS to be associated with more pervasive medical and neuropsychiatric symptoms. Differences in symptom persistence are associated with both intrinsic (e.g., immune competence) and extrinsic (e.g., infections, treatment) factors. Because extrinsic factors are potentially modifiable, it is critical that providers be aware of current guidelines on PANS evaluation and treatment.

Postinfectious Inflammation, Autoimmunity, and Obsessive-Compulsive Disorder: Sydenham Chorea, Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection, and Pediatric Acute-Onset Neuropsychiatric Disorder

Postinfectious neuroinflammation has been implicated in multiple models of acute-onset obsessive-compulsive disorder including Sydenham chorea (SC), pediatric acute-onset neuropsychiatric syndrome (PANS), and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). These conditions are associated with a range of autoantibodies which are thought to be triggered by infections, most notably group A streptococci (GAS). Based on animal models using huma sera, these autoantibodies are thought to cross-react with neural antigens in the basal ganglia and modulate neuronal activity and behavior. As is true for many childhood neuroinflammatory diseases and rheumatological diseases, SC, PANS, and PANDAS lack clinically available, rigorous diagnostic biomarkers and randomized clinical trials. In this review article, we outline the accumulating evidence supporting the role neuroinflammation plays in these disorders. We describe work with animal models including patient-derived anti-neuronal autoantibodies, and we outline imaging studies that show alterations in the basal ganglia. In addition, we present research on metabolites, which are helpful in deciphering functional phenotypes, and on the implication of sleep in these disorders. Finally, we encourage future researchers to collaborate across medical specialties (e.g., pediatrics, psychiatry, rheumatology, immunology, and infectious disease) in order to further research on clinical syndromes presenting with neuropsychiatric manifestations.

Evaluation of C4 Gene Copy Number in Pediatric Acute Neuropsychiatric Syndrome

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt-onset neuropsychiatric disorder. PANS patients have an increased prevalence of comorbid autoimmune illness, most commonly arthritis. In addition, an estimated one-third of PANS patients present with low serum C4 protein, suggesting decreased production or increased consumption of C4 protein. To test the possibility that copy number (CN) variation contributes to risk of PANS illness, we compared mean total C4A and total C4B CN in ethnically matched subjects from PANS DNA samples and controls (192 cases and 182 controls). Longitudinal data from the Stanford PANS cohort (n = 121) were used to assess whether the time to juvenile idiopathic arthritis (JIA) or autoimmune disease (AI) onset was a function of total C4A or C4B CN. Lastly, we performed several hypothesis-generating analyses to explore the correlation between individual C4 gene variants, sex, specific genotypes, and age of PANS onset. Although the mean total C4A or C4B CN did not differ in PANS compared to controls, PANS patients with low C4B CN were at increased risk for subsequent JIA diagnosis (hazard ratio = 2.7, p value = 0.004). We also observed a possible increase in risk for AI in PANS patients and a possible correlation between lower C4B and PANS age of onset. An association between rheumatoid arthritis and low C4B CN has been reported previously. However, patients with PANS develop different types of JIA: enthesitis-related arthritis, spondyloarthritis, and psoriatic arthritis. This suggests that C4B plays a role that spans these arthritis types.

Pediatric Acute-Onset Neuropsychiatric Syndrome: Current Perspectives

Pediatric acute-onset neuropsychiatric syndrome (PANS) features a heterogeneous constellation of acute obsessive-compulsive disorder (OCD), eating restriction, cognitive, behavioral and/or affective symptoms, often followed by a chronic course with cognitive deterioration. An immune-mediated etiology is advocated in which the CNS is hit by different pathogen-driven (auto)immune responses. This narrative review focused on recent clinical (ie, diagnostic criteria, pre-existing neurodevelopmental disorders, neuroimaging) and pathophysiological (ie, CSF, serum, genetic and autoimmune findings) aspects of PANS. We also summarized recent points to facilitate practitioners with the disease management. Relevant literature was obtained from PubMed database which included only English-written, full-text clinical studies, case reports, and reviews. Among a total of 1005 articles, 205 were pertinent to study inclusion. Expert opinions are converging on PANS as the effect of post-infectious events or stressors leading to "brain inflammation", as it is well-established for anti-neuronal psychosis. Interestingly, differentiating PANS from either autoimmune encephalitides and Sydenham's chorea or from alleged "pure" psychiatric disorders (OCD, tics, Tourette's syndrome), reveals several overlaps and more analogies than differences. Our review highlights the need for a comprehensive algorithm to help both patients during their acute distressing phase and physicians during their treatment decision. A full agreement on the hierarchy of each therapeutical intervention is missing owing to the limited number of randomized controlled trials. The current approach to PANS treatment emphasizes immunomodulation/anti-inflammatory treatments in association with both psychotropic and cognitive-behavioral therapies, while antibiotics are suggested when an active bacterial infection is established. A dimensional view, taking into account the multifactorial origin of psychiatric disorders, should suggest neuro-inflammation as a possible shared substrate of different psychiatric phenotypes. Hence, PANS and PANS-related disorders should be considered as a conceptual framework describing the etiological and phenotypical complexity of many psychiatric disorders.

Understanding parental stress among parents of children with Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) in Sweden

Purpose

Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) is a relatively new diagnosis characterized by an abrupt and dramatic onset of obsessive-compulsive disorder (OCD), together with neuropsychiatric symptoms. Very little research has been done to understand the experience of being a parent of a child with PANS. The current study aimed to explore aspects related to parental stress in parents of children with PANS.

Method

The study employed in-depth semi-structured individual interviews with 13 parents of children diagnosed with PANS. Parents were recruited via an announcement on the websites of patient organizations, and in waiting rooms at child medical clinics. An inductive qualitative content analysis approach was used as a guide for analysis of data.

Results

The analysis of interviews identified five categories of parents’ experiences of stress related to: (1) being effected by the symptoms; (2) experiencing the symptoms over and over again; (3) having no control; (4) obtaining medical treatment is challenging; and (5) managing problems. The results are discussed in relation to the Transactional Theory of Stress and Coping.

Conclusions

the study illuminates how parents’ perceptions of the child’s symptoms, parents’ strategies for managing problems, as well as experiences related to healthcare providers, may increase or decrease parental stress.

Youth with severe mental illness and complex non-somatic motor abnormalities: conflicting conceptualizations and unequal treatment

Two emerging diagnostic concepts promote distinct treatments for youth with acute-onset motor abnormalities and severe concurrent psychiatric symptoms: Pediatric acute-onset neuropsychiatric syndrome (PANS) and pediatric catatonia. Both have institutional approval in parts of Europe and in the USA, meriting an unconditional comparison of supporting evidence. Here we report results of qualitative and quantitative analyses of literature and Swedish National Registry Data suggesting that (1) catatonic patients are liable to fulfilling diagnostic criteria for PANS, (2) three conservatively assessed PANS case-reports present with possible unrecognized catatonia, (3) lithium and electroconvulsive therapy usage frequencies in Swedish minors (exclusively recommended for severe mental illness) are strongly intercorrelated and unequally distributed across Swedish counties, (4) established severe mental disorders are rarely overtly considered amongst PANS-specific research and (5) best-available evidence treatments appear markedly superior for pediatric catatonia compared to PANS in both childhood and adolescence. Prioritizing treatments for pediatric catatonia in concerned subjects could markedly improve treatment outcomes.

Sex and Aggression Characteristics in a Cohort of Patients with Pediatric Acute-Onset Neuropsychiatric Syndrome

Objective: This study describes for the first time the characteristics by sex of patients with Pediatric Acute-onset Neuropsychiatric Syndrome (PANS), including clinical phenotype, treatment, and psychosocial aspects of disease. Methods: This cross-sectional study included 205 consecutive community patients evaluated between January 1, 2012 and March 30, 2019 and compared 87 females with 118 males. Our primary hypothesis was that males would display more aggression, as measured by the Modified Overt Aggression Scale (MOAS) and would be treated with immunotherapy earlier than females. The MOAS began to be administered 5 years into the study period, and 57 of the 205 families completed the MOAS for this study. Results: Our analysis revealed that males had a higher median MOAS score in the first year of clinic when compared with females (median 11, interquartile range [IQR] [4-24] vs. median 3, IQR [1-9]; p = 0.03) and a higher median subscore for physical aggression (median 4, IQR [0-12] vs. median 0, IQR [0-8]; p = 0.05). The median time from PANS symptom onset to first administration of immunotherapy, which did not include nonsteroidal anti-inflammatory drugs or short bursts of oral steroids, was 6.9 years for females and 3.7 years for males (p = 0.20). The two groups did not differ significantly in age of PANS onset, time from onset to clinic entry, other psychiatric symptom measures, or laboratory markers of inflammation. Conclusion: Among patients with PANS, males exhibit more aggressive behavior when compared with females, which may advance the decision to treat with immunotherapy. Scores that capture a more global level of functioning show that despite there being a higher level of aggression in males, female patients with PANS have similar levels of overall impairment.

Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) and intravenous immunoglobulin (IVIG): comprehensive open-label trial in ten children

BACKGROUND

Treatment with intravenous immunoglobulin (IVIG) in children with Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) has for many years been used on clinical indications, but the research evidence for its efficacy is insufficient.

METHODS

Open-label prospective in-depth trial including ten children (median age 10.3 years) with PANS, who received IVIG treatment 2 g/kg monthly for three months. Primary outcomes were changes in symptom severity and impairment from baseline to first and second follow-up visits one month after first and one month after third treatment, using three investigator-rated scales: Paediatric Acute Neuropsychiatric Symptom (PANS) scale, Clinical Global Impression - Severity and Improvement (CGI-S and CGI-I) scales. Secondary outcomes reported here were changes in Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) scores, and side effects.

RESULTS

All ten children received three treatments at one-month intervals according to study plan. From baseline to second follow-up marked reductions were seen in mean total PANS scale scores (p = .005), and CGI-S scores (p = .004). CGI-I ratings showed much to very much global improvement (mean CGI-I 1.8). Nine children had clinical response defined as > 30% reduction in PANS Scale scores. Improvements were also noted for CY-BOCS scores (p = .005), and in school attendance. Three children suffered moderate to severe temporary side effects after the first treatment, and the remaining seven had mild to moderate side effects. Side effects were much less severe after second and third treatments.

CONCLUSIONS

Considerable and pervasive improvements in symptoms and clinical impairments were seen in these ten children after three monthly IVIG treatments. Moderate to severe transient side effects occurred in three cases.

TRIAL REGISTRATION

EudraCT no. 2019-004758-27, Clinicaltrials.gov no. NCT04609761, 05/10/2020.

Children With PANS May Manifest POTS

Objectives

Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by an abrupt-onset of severe psychiatric symptoms including OCD, anxiety, cognitive difficulties, and sleep issues which is thought to be a post-infection brain inflammatory disorder. We observed postural orthostatic tachycardia syndrome (POTS) which resolved with immunomodulation in a patient with Pediatric acute-onset neuropsychiatric syndrome (PANS). Here, we aim to present a case of POTS and to examine the prevalence of (POTS) in our PANS cohort, and compare the clinical characteristics of patients with and without POTS.

Study Design

We conducted this cohort study of patients meeting PANS criteria who had at least three clinic visits during the study period. We included data from prospectively collected questionnaires and medical record review. We present a case followed by statistical comparisons within our cohort and a Kaplan-Meier analysis to determine the time-dependent risk of a POTS diagnosis.

Results

Our study included 204 patients: mean age of PANS onset was 8.6 years, male sex (60%), non-Hispanic White (78%). Evidence of POTS was observed in 19/204 patients (9%) with 5/19 having persistent POTS defined as persistent abnormal orthostatic vitals, persistent POTS symptoms, and/or continued need for pharmacotherapy for POTS symptoms for at least 6 months). In this PANS cohort, patients with POTS were more likely to have comorbid joint hypermobility (63 vs 37%, p = 0.04), chronic fatigue (42 vs 18%, p = 0.03), and a family history of chronic fatigue, POTS, palpitations and syncope. An unadjusted logistic regression model showed that a PANS flare (abrupt neuropsychiatric deterioration) was significantly associated with an exacerbation of POTS symptoms (OR 3.3, 95% CI 1.4–7.6, p < 0.01).

Conclusions

Our study describes a high prevalence of POTS in patients with PANS (compared to the general population) and supports an association between POTS presentation and PANS flare within our cohort.

Pediatric neuropsychiatric syndromes associated with infection and microbiome alterations: clinical findings, possible role of the mucosal epithelium, and strategies for the development of new animal models

INTRODUCTION

: Subsets of pediatric obsessive-compulsive disorder (OCD) and autism spectrum disorder (ASD) respectively have been associated with respiratory tract infections and alterations in the intestinal microbiome. Pediatric Acute-onset Neuropsychiatric Syndromes (PANS) refers to the sudden onset of neuropsychiatric symptoms that are triggered by several different infectious and non-infectious factors. Clinical studies and animal modeling are consistent with the proposal that inflammation plays an important etiological role in PANS, as well as in ASD associated with gut dysbiosis.

AREAS COVERED

The authors provide an overview of clinical studies of PANS and ASD associated with gastrointestinal symptoms, as well as the current strategies for studying these syndromes in rodent models. Finally, the authors highlight similarities between these syndromes that may provide clues to common etiological mechanisms.

EXPERT OPINION

Although data from existing animal models are consistent with an important role for anti-neuronal antibodies in PANS triggered by GAS infection, we lack models for identifying pathophysiological mechanisms of PANS associated with other infectious and non-infectious triggers. The authors propose a strategy for developing such models that incorporates known vulnerability and triggering factors for PANS into the modeling process. This novel strategy should expand our understanding of the pathophysiology of PANS, as well as facilitate the development of new pharmacological treatments for PANS and related syndromes.

Paediatric Acute onset Neuropsychiatric Syndrome: Exploratory study finds no evidence of HLA class II association but high rate of autoimmunity in first-degree relatives

AIM

Paediatric acute-onset neuropsychiatric syndrome (PANS) is defined by an acute onset of obsessive-compulsive disorder and/or eating restrictions and at least two other severe neuropsychiatric symptoms. The condition is suspected to have an immune-mediated pathophysiology, but reliable biomarkers have not been identified.

METHODS

We hypothesised that PANS, like narcolepsy, might have a human leucocyte antigen (HLA) association, as found in 95% of children developing narcolepsy after H1N1 immunisation. Low resolution genotyping of the MHC class II antigens HLA-DRB1 and HLA-DQB1 was performed using two different PCR-based methods. In addition, parents were interviewed regarding a detailed family history of autoimmune diseases in first-degree relatives. A total of 18 children, aged 5-14 (mean 8.2) years at onset of PANS met symptom criteria.

RESULTS

No evident association between PANS and the specific HLA alleles examined was observed. In first-degree relatives of 10 of the 18 children, an autoimmune disease had been diagnosed, and three of the 18 children themselves had an autoimmune disease.

CONCLUSION

No HLA allele association such as seen in children with narcolepsy after H1N1 immunisation could be confirmed in this group of children with PANS. However, more than half the group had a first-degree relative with a diagnosed autoimmune disease.

Immunological causes of obsessive-compulsive disorder: is it time for the concept of an "autoimmune OCD" subtype?

Obsessive-compulsive disorder (OCD) is a highly disabling mental illness that can be divided into frequent primary and rarer organic secondary forms. Its association with secondary autoimmune triggers was introduced through the discovery of Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infection (PANDAS) and Pediatric Acute onset Neuropsychiatric Syndrome (PANS). Autoimmune encephalitis and systemic autoimmune diseases or other autoimmune brain diseases, such as multiple sclerosis, have also been reported to sometimes present with obsessive-compulsive symptoms (OCS). Subgroups of patients with OCD show elevated proinflammatory cytokines and autoantibodies against targets that include the basal ganglia. In this conceptual review paper, the clinical manifestations, pathophysiological considerations, diagnostic investigations, and treatment approaches of immune-related secondary OCD are summarized. The novel concept of "autoimmune OCD" is proposed for a small subgroup of OCD patients, and clinical signs based on the PANDAS/PANS criteria and from recent experience with autoimmune encephalitis and autoimmune psychosis are suggested. Red flag signs for "autoimmune OCD" could include (sub)acute onset, unusual age of onset, atypical presentation of OCS with neuropsychiatric features (e.g., disproportionate cognitive deficits) or accompanying neurological symptoms (e.g., movement disorders), autonomic dysfunction, treatment resistance, associations of symptom onset with infections such as group A streptococcus, comorbid autoimmune diseases or malignancies. Clinical investigations may also reveal alterations such as increased levels of anti-basal ganglia or dopamine receptor antibodies or inflammatory changes in the basal ganglia in neuroimaging. Based on these red flag signs, the criteria for a possible, probable, and definite autoimmune OCD subtype are proposed.

No neurochemical evidence of neuronal injury or glial activation in children with Paediatric Acute-onset Neuropsychiatric Syndrome. An explorative pilot study

Objective: Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) is characterised by an acute onset of obsessive compulsive disorder, combined with at least two other neuropsychiatric symptoms with acute onset. Diagnostic criteria also require that no specific medical aetiology is identified. Although there are no verified aetiological biomarkers, PANS is assumed to be a neuroinflammatory disorder with a possible autoimmune aetiology. Neurochemical markers such as neurofilament light (NfL, a neuronal injury marker) and glial fibrillary acidic protein (GFAP, an astrocytic activation marker) have not been published for this patient group.Method: Blood samples from 17 children meeting diagnostic criteria for PANS, after assessment at a child neuropsychiatry clinic were analysed for serum concentrations of NfL and GFAP. Ten age-matched children without any neurological or psychiatric disorder served as a comparison group.Results: No difference was found in mean NfL and mean GFAP serum concentrations between children with PANS and controls.Conclusion: Neuronal injury and astrocyte activation do not seem to be a major event in PANS. The study group was small, and even if findings may be reassuring for parents and patients, they should be interpreted with caution and verified in larger cohorts and possibly with other markers in both serum and CSF.

Measuring clinical outcomes in children with pediatric acute-onset neuropsychiatric syndrome: data from a 2-5 year follow-up study

BACKGROUND

It is unclear how to best measure the complex symptom presentation of pediatric acute-onset neuropsychiatric syndrome (PANS).

METHODS

Well-characterized participants of a 2-5 year follow-up study (n = 34; 56% male) underwent clinical evaluations and completed scales assessing global symptom severity, functional impairment and specific psychiatric symptoms. We explored inter-correlations between the measures and used intraclass correlation coefficients to evaluate the agreement between clinician-, parent- and child ratings of the same constructs.

RESULTS

Ratings on symptom-specific measures varied largely between participants. Agreement between informants was excellent on functional scales, fair-to-moderate on global severity scales and mixed on symptom-specific scales. Clinician-rated global and functional measures had stronger inter-correlations with parent- and child-rated functional measures than with symptom-specific measures.

CONCLUSIONS

General instruments assessing global severity and functioning are well suited for the assessment and follow-up of PANS, but should be complemented by symptom-specific scales representative of core symptoms.

Anti-inflammatory, antibacterial and immunomodulatory treatment in children with symptoms corresponding to the research condition PANS (Pediatric Acute-onset Neuropsychiatric Syndrome): A systematic review

OBJECTIVE

To assess effects of treatment against a hypothesized neuroinflammation in children with symptoms corresponding to the research condition Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) which is not included in current diagnostic systems.

METHODS

Systematic literature searches were performed (1998 to June 2020) in PubMed, Embase, the Cochrane Library, CINAHL, PsycInfo, and HTA databases. Inclusion criteria: patients (P) were children (<18 years) with PANS; intervention (I)/comparison (C) was use of, versus no use of, anti-inflammatory, antibacterial or immunomodulating treatments; outcomes (O) were health-related quality of life (HRQL), level of functioning, symptom change, and complications.

RESULTS

Four randomised controlled trials (RCTs) and three non-RCTs, including 23 to 98 patients, fulfilled the PICO. HRQL was not investigated in any study. Regarding level of functioning, two RCTs investigated antibiotics (penicillin V, azithromycin) and one RCT investigated immunomodulating treatments (intravenous immunoglobulins (IVIG), plasma exchange). Regarding symptoms, two non-RCTs investigated anti-inflammatory treatment (cyclooxygenase (COX) inhibitors, corticosteroids), two RCTs and one non-RCT investigated antibiotics (penicillin V, azithromycin), and two RCTs investigated immunomodulating treatments (IVIG, plasma exchange). Complications, reported in five studies, were consistent with those listed in the summary of products characteristics (SPC). All studies were assessed to have some or major problems regarding directness, the absence of an established diagnosis contributing to clinical diversity in the studied populations. All studies were assessed to have major risk of bias, including selection and detection biases. Due to clinical and methodological diversity, meta-analyses were not performed.

CONCLUSION

This systematic review reveals very low certainty of evidence of beneficial effects, and moderate certainty of evidence of adverse effects, of anti-inflammatory, antibacterial or immunomodulating treatments in patients with symptoms corresponding to the research condition PANS. Available evidence neither supports nor excludes potential beneficial effects, but supports that such treatment can result in adverse effects.

REGISTRATION

PROSPERO (CRD42020155714).

Hypoferritinemia and iron deficiency in youth with pediatric acute-onset neuropsychiatric syndrome

BACKGROUND

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt debilitating psychiatric illness. We anecdotally observed hypoferritinemia and iron deficiency in a subset of patients with PANS, prompting this study.

METHODS

In this IRB-approved prospective cohort study, we included patients seen at the Stanford PANS Clinic who met study criteria. The prevalence of hypoferritinemia (using cut-offs of 7 ng/ml in children ≤ 15 years and 18 ng/ml in adolescents > 15 years) and iron deficiency was estimated. Differences in patients with and without hypoferritinemia during PANS flare were explored.

RESULTS

Seventy-nine subjects (mean age of PANS onset of 8.7 years) met study criteria. Hypoferritinemia was observed in 27% and three quarters occurred during a PANS flare. Compared to patients without hypoferritinemia during PANS flare, patients with hypoferritinemia had worse global impairment, more comorbid inflammatory diseases, and exhibited a chronic course of PANS illness. The estimated prevalence of iron deficiency was 3-8% in the PANS cohort, 1.4-2.0-fold higher than in the age- and sex-matched U.S.

POPULATION

More stringent ferritin level cut-offs than the comparison CDC dataset were used.

CONCLUSION

Hypoferritinemia and iron deficiency appear to be more common in PANS patients. More research is needed to confirm and understand this association.

IMPACT

Our study suggests hypoferritinemia and iron deficiency are more common in patients with pediatric acute-onset neuropsychiatric syndrome (PANS) than in the sex- and age-matched US population. Hypoferritinemia was commonly observed during a disease flare but not associated with dietary or demographic factors. In patients with PANS and iron deficiency, clinicians should consider possibility of inflammation as the cause especially if iron deficiency cannot be explained by diet and blood loss. Future research should include larger cohorts to corroborate our study findings and consider examining the iron dynamics on MRI brain imaging in order to better understand the pathophysiology of PANS.

Diagnostic Approach to Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS): A Narrative Review of Literature Data

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) are clinical conditions characterized by the sudden onset of obsessive-compulsive disorder and/or tics, often accompanied by other behavioral symptoms in a group of children with streptococcal infection. PANDAS-related disorders, including pediatric acute-onset neuropsychiatric syndrome (PANS), childhood acute neuropsychiatric symptoms (CANS), and pediatric infection triggered autoimmune neuropsychiatric disorders (PITANDs), have also been described. Since first defined in 1998, PANDAS has been considered a controversial diagnosis. A comprehensive review of the literature was performed on PubMed and Scopus databases, searching for diagnostic criteria and diagnostic procedures of PANDAS and related disorders. We propose a test panel to support clinicians in the workout of PANDAS/PANS patients establishing an appropriate treatment. However, further studies are needed to improve our knowledge on these acute-onset neuropsychiatric conditions.

Association of Pediatric Acute-Onset Neuropsychiatric Syndrome With Microstructural Differences in Brain Regions Detected via Diffusion-Weighted Magnetic Resonance Imaging

IMPORTANCE

Epidemiological studies indicate a link between obsessive-compulsive disorder and infections, particularly streptococcal pharyngitis. Pediatric acute-onset neuropsychiatric syndrome (PANS) manifests suddenly with obsessions, compulsions, and other behavioral disturbances, often after an infectious trigger. The current working model suggests a unifying inflammatory process involving the central nervous system, particularly the basal ganglia.

OBJECTIVE

To investigate whether diffusion-weighted magnetic resonance imaging (DWI) detects microstructural abnormalities across the brain regions of children with PANS.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study performed at a single-center, multidisciplinary clinic in the United States focusing on the evaluation and treatment of children with PANS. Sixty consecutive patients who underwent 3 Tesla (T) magnetic resonance imaging (MRI) before immunomodulation from September 3, 2012, to March 30, 2018, were retrospectively reviewed for study inclusion. Six patients were excluded by blinded investigators because of imaging or motion artifacts, 3 patients for major pathologies, and 17 patients for suboptimal atlas image registration. In total, 34 patients with PANS before initiation of treatment were compared with 64 pediatric control participants.

MAIN OUTCOMES AND MEASURES

Using atlas-based MRI analysis, regional brain volume, diffusion, and cerebral blood flow were measured in the cerebral white matter, cerebral cortex, thalamus, caudate, putamen, pallidum, hippocampus, amygdala, nucleus accumbens, and brainstem. An age and sex-controlled multivariable analysis of covariance was used to compare patients with control participants.

RESULTS

This study compared 34 patients with PANS (median age, 154 months; age range, 55-251 months; 17 girls and 17 boys) and 64 pediatric control participants (median age, 139 months; age range, 48-213 months); 41 girls and 23 boys). Multivariable analysis demonstrated a statistically significant difference in MRI parameters between patients with PANS and control participants (F21,74 = 6.91; P < .001; partial η2 = 0.662). All assessed brain regions had statistically significantly increased median diffusivity compared with 64 control participants. Specifically, the deep gray matter (eg, the thalamus, basal ganglia, and amygdala) demonstrated the most profound increases in diffusivity consistent with the cardinal clinical symptoms of obsessions, compulsions, emotional dysregulation, and sleep disturbances. No statistically significant differences were found regarding volume and cerebral blood flow.

CONCLUSIONS AND RELEVANCE

This study identifies cerebral microstructural differences in children with PANS in multiple brain structures, including the deep gray matter structures (eg, the thalamus, basal ganglia, and amygdala). Further study of MRI is warranted in prospective, clinical trials as a potential quantitative method for assessing patients under evaluation for PANS.