Changes in the stool and oropharyngeal microbiome in obsessive-compulsive disorder.

Although the etiology of obsessive-compulsive disorder (OCD) is largely unknown, it is accepted that OCD is a complex disorder. There is a known bi-directional interaction between the gut microbiome and brain activity. Several authors have reported associations between changes in gut microbiota and neuropsychiatric disorders, including depression or autism. Furthermore, a pediatric-onset neuropsychiatric OCD-related syndrome occurs after streptococcal infection, which might indicate that exposure to certain microbes could be involved in OCD susceptibility. However, only one study has investigated the microbiome of OCD patients to date. We performed 16S ribosomal RNA gene-based metagenomic sequencing to analyze the stool and oropharyngeal microbiome composition of 32 OCD cases and 32 age and gender matched controls. We estimated different α- and ß-diversity measures and performed LEfSe and Wilcoxon tests to assess differences in bacterial distribution. OCD stool samples showed a trend towards lower bacterial α-diversity, as well as an increase of the relative abundance of Rikenellaceae, particularly of the genus Alistipes, and lower relative abundance of Prevotellaceae, and two genera within the Lachnospiraceae: Agathobacer and Coprococcus. However, we did not observe a different Bacteroidetes to Firmicutes ratio between OCD cases and controls. Analysis of the oropharyngeal microbiome composition showed a lower Fusobacteria to Actinobacteria ratio in OCD cases. In conclusion, we observed an imbalance in the gut and oropharyngeal microbiomes of OCD cases, including, in stool, an increase of bacteria from the Rikenellaceae family, associated with gut inflammation, and a decrease of bacteria from the Coprococcus genus, associated with DOPAC synthesis.

The Effect of Lactobacillus casei Consumption in Improvement of Obsessive-Compulsive Disorder: an Animal Study.

Obsessive-compulsive disorder (OCD) is an important neuropsychiatric disorder worldwide. Common treatments of OCD include serotonergic antidepressants, which can cause potentially serious side effects. We assessed the effects of Lactobacillus casei (L. casei) Shirota consumption in an animal model of OCD. OCD-like symptoms were induced in rats by the chronic injection of the D2/D3 dopamine agonist quinpirole hydrochloride. Rats were classified into five groups of 6 rats. Four groups were injected chronically with quinpirole (0.5 mg/kg, twice weekly for 5 weeks). They were fed with L. casei Shirota (109 CF/g, daily for 4 weeks) (group 1), fluoxetine (10 mg/kg, daily for 4 weeks) (group 2), combination of L. casei Shirota and fluoxetine (group 3), and normal saline (positive control group). The last group did not receive dopamine agonist and was only injected with saline (negative control group). Expression levels of brain-derived neurotrophic factor (Bdnf), solute carrier family 6 member 4 (Slc6a4), and 5-hydroxytryptamine receptor type 2A (Htr2a) were assessed in orbitofrontal cortex tissues of all rats. Behavioral tests showed improvement of OCD signs in rats treated with L. casei Shirota, fluoxetine, and a combination of drugs. Quantitative PCR analysis showed a remarkable decrease in the expression of Bdnf and an increase in the expression of Htr2a in quinpirole-treated rats. After treatment with L. casei Shirota and fluoxetine, the expression level of Bdnf was increased remarkably, whereas Htr2a expression was decreased. The current study showed the effectiveness of L. casei Shirota in the treatment of OCD in a rat model. The beneficial effects of this probiotic are possibly exerted through the modulation of serotonin-related genes expression.

Pediatric Acute-onset Neuropsychiatric Syndrome and Mycoplasma Pneumoniae Infection: A Case Report Analysis with a Metabolomics Approach.

Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) is a clinical condition characterized by a sudden and dramatic obsessive-compulsive disorder with a suggested post-infectious immune-mediated etiology. This condition is accompanied by an extensive series of relatively serious neuropsychiatric symptoms. The diagnosis of PANS is made by "exclusion", as the individual PANS symptoms overlap with a multiplicity of psychiatric disorders with the onset in childhood. A number of researchers accumulated evidence to support the hypothesis that PANS was closely associated with a number of infections. In the last decade, metabolomics played an essential role in improving the knowledge of complex biological systems and identifying potential new biomarkers as indicators of pathological progressions or pharmacologic responses to therapy. The metabolome is considered the most predictive phenotype, capable of recognizing epigenetic differences, reflecting more closely the clinical reality at any given moment and thus providing extremely dynamic data. In the present work, the most recent hypothesis and suggested mechanisms of this condition are reviewed and the case of a 10 - year-old girl with PANS is described, before and after clarithromycin treatment. The main results of this case report are discussed from a metabolomics point of view. The alteration of several metabolic pathways concerning the microbial activity highlights the possible role of the microbiome in the development of PANS. Furthermore, different metabolic perturbations at the level of protein biosynthesis, energy and amino acid metabolisms are observed and discussed. Based on our observations, it is believed that metabolomics is a promising technology to unravel the mysteries of PANS in the near future.

Clinical-Serological Characterization and Treatment Outcome of a Large Cohort of Italian Children with Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection and Pediatric Acute Neuropsychiatric Syndrome.

Objective: Pediatric autoimmune neuropsychiatric disorder associated with Streptococcus pyogenes infection (PANDAS) and pediatric acute-onset neuropsychiatric syndrome (PANS) are emerging immune-mediated encephalopathies characterized by sudden onset of seemingly inexplicable complex neuropsychiatric symptoms, including obsessions, compulsions, and heterogeneous tics, which occur in children. Main goal of this study was to report our experience in a large cohort of Italian children affected by either PANDAS or PANS and treated long term with an antibiotic regimen similar to that used for acute rheumatic fever. Patients and Methods: The clinical charts of a cohort of 371 consecutive Italian children, 345 with PANDAS (93.0%) and 26 with PANS (7.0%), were retrospectively evaluated. Antistreptococcal, antinuclear antibodies, and serologic evaluation for a group of common autoantibodies and microbial agents were also assessed. A strict differential diagnosis with other autoimmune diseases displaying neuropsychiatric manifestations was performed. Results: Antistreptolysin O and anti-DNase B antibody titers were tested and were positive in all PANDAS subjects, but negative in PANS. Anti-Mycoplasma pneumoniae antibodies and anti-Epstein-Barr virus Nuclear Antigen antibodies were found positive in 11 (42.3%) and 5 (19.2%) patients with PANS, respectively. Among PANDAS cases, a clear streptococcal infection was clinically evident at the onset of neurological symptoms in only 74 patients (21.4%), whereas the relationship with Streptococcus pyogenes was confirmed by serologic tests in the other 271 (78.6%). All patients fulfilling the diagnostic criteria for PANDAS (n = 345) received amoxicillin/clavulanic acid for 10-21 days at diagnosis, while those who were diagnosed with PANS (n = 26) received treatment according to the causative agent. Thereafter, all PANDAS/PANS patients received prophylaxis with benzathine benzylpenicillin for an overall period of at least 5 years to prevent subsequent potential streptococcal infections. To date, 75.0% of PANDAS patients (n = 258) have shown an improvement of neurologic symptoms, mainly observed within 3-5 months of treatment for PANDAS cases, while 88.4% of PANS patients (n = 23) have improved after 6-12 months. Infection-related relapses of neurologic manifestations were observed in both PANDAS and PANS patients (n = 167 out of 371; 45% of the total cohort) in the long term. Conclusions: Our study has confirmed the usefulness of the preliminary diagnostic criteria for PANDAS and PANS, revealing also the importance of early diagnosis to reduce the risk of evolution toward disabling chronic neurologic sequelae. Long-term antibiotic prophylaxis has resulted in a substantial benefit to reduce neurological symptoms for the majority of PANDAS and PANS patients over a 7-year period.

Neonatal corticosterone mitigates autoimmune neuropsychiatric disorders associated with streptococcus in mice.

Increased glucocorticoid concentrations have been shown to favor resilience towards autoimmune phenomena. Here, we addressed whether experimentally induced elevations in circulating glucocorticoids mitigate the abnormalities exhibited by an experimental model of Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS). This is a pathogenic hypothesis linking repeated exposures to Group-A-beta-hemolytic streptococcus (GAS), autoantibodies targeting selected brain nuclei and neurobehavioral abnormalities. To persistently elevate glucocorticoid concentrations, we supplemented lactating SJL/J mice with corticosterone (CORT; 80 mg/L) in the drinking water. Starting in adolescence (postnatal day 28), developing offspring were exposed to four injections - at bi-weekly intervals - of a GAS homogenate and tested for behavioral, immunological, neurochemical and molecular alterations. GAS mice showed increased perseverative behavior, impaired sensorimotor gating, reduced reactivity to a serotonergic agonist and inflammatory infiltrates in the anterior diencephalon. Neonatal CORT persistently increased circulating glucocorticoids concentrations and counteracted these alterations. Additionally, neonatal CORT increased peripheral and CNS concentrations of the anti-inflammatory cytokine IL-9. Further, upstream regulator analysis of differentially expressed genes in the striatum showed that the regulatory effect of estradiol is inhibited in GAS-treated mice and activated in GAS-treated mice exposed to CORT. These data support the hypothesis that elevations in glucocorticoids may promote central immunomodulatory processes.

Association of Streptococcal Throat Infection With Mental Disorders: Testing Key Aspects of the PANDAS Hypothesis in a Nationwide Study.

Importance: Streptococcal infection has been linked with the development of obsessive-compulsive disorder (OCD) and tic disorders, a concept termed pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). However, previous studies of this association have been small, and the results have been conflicting. Objective: To investigate the risk of mental disorders, specifically OCD and tic disorders, after a streptococcal throat infection. Design, Setting, and Participants: A population-based cohort study was conducted using data from the nationwide Danish registers from January 1, 1996, to December 31, 2013, with up to 17 years of follow-up. The Danish National Health Service Register provided information on individuals with the registration of a streptococcal test. Data analysis was conducted from January 1, 2016, to February 28, 2017. Main Outcomes and Measures: Individuals were followed up in the nationwide Psychiatric Central Register for a diagnosis of any mental disorder, OCD, or tic disorders. Incidence rate ratios (IRRs) were calculated by Poisson regression analysis. Results: Of the 1 067 743 children (<18 years of age) included in the study (519 821 girls and 547 922 boys), 638 265 received a streptococcal test, 349 982 of whom had positive test results at least once. Individuals with a positive streptococcal test result had an increased risk of any mental disorder (n = 15 408; IRR, 1.18; 95% CI, 1.15-1.21; P < .001), particularly of OCD (n = 556; IRR, 1.51; 95% CI, 1.28-1.77; P < .001) and tic disorders (n = 993; IRR, 1.35; 95% CI, 1.21-1.50; P < .001), compared with individuals without a streptococcal test. Furthermore, the risk of any mental disorder and OCD was more elevated after a streptococcal throat infection than after a nonstreptococcal infection. Nonetheless, individuals with a nonstreptococcal throat infection also had an increased risk of any mental disorder (n = 11 315; IRR, 1.08; 95% CI, 1.06-1.11; P < .001), OCD (n = 316; IRR, 1.28; 95% CI, 1.07-1.53; P = .006), and tic disorders (n = 662; IRR, 1.25; 95% CI, 1.12-1.41; P < .001). Conclusions and Relevance: This large-scale study investigating key aspects of the PANDAS hypothesis found that individuals with a streptococcal throat infection had elevated risks of mental disorders, particularly OCD and tic disorders. However, nonstreptococcal throat infection was also associated with increased risks, although less than streptococcal infections for OCD and any mental disorder, which could also support important elements of the diagnostic concept of pediatric acute-onset neuropsychiatric syndrome.

Can gut microbes play a role in mental disorders and their treatment?

The gut microbes, collectively called microbiota, are linked to the brain through a bidirectional system that involves the vagus nerve, the immune system, and various neurotransmitters. Stress response, memory functions, social behavior, and mood are modulated by microbiota. Furthermore, microbiota play a role in the development of the central nervous system. These features, established largely in rodent studies, have informed hypotheses about the role of microbiota in human psychiatric disorders. Microbiota affect phenomena that are known to be parts of the depression phenotype, such as exaggerated response to stress and inflammatory features. Furthermore, the role of microbiota in neurodevelopment and in the modulation of social behavior suggests the possibility of its role in autism spectrum disorder and in schizophrenia. If altered, microbiota play a role in psychiatric disorders, then efforts to normalize the gut microbial population by the ingestion of probiotics (live bacteria) could have antidepresssant or antipsychotic effects. Testing such hypotheses in translational human studies is a matter of future research.

"WHAT'S BUGGING THE GUT IN OCD?" A REVIEW OF THE GUT MICROBIOME IN OBSESSIVE-COMPULSIVE DISORDER.

The gut microbiome has become a topic of major interest as of late, with a new focus specifically on psychiatric disorders. Recent studies have revealed that variations in the composition of the gut microbiota may influence anxiety and mood and vice versa. Keeping the concept of this bidirectional "microbiota-gut-brain" axis in mind, this review aims to shed light on how these findings may also be implicated in obsessive-compulsive disorder (OCD); potentially outlining a novel etiological pathway of interest for future research in the field.

Detection of anti-streptococcal, antienolase, and anti-neural antibodies in subjects with early-onset psychiatric disorders.

INTRODUCTION: Infection with group A Streptococcus (StrepA) can cause post-infectious sequelae, including a spectrum of childhood-onset obsessive-compulsive (OCD) and tic disorders with autoimmune origin (PANDAS, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections). Until now, no single immunological test has been designed that unequivocally diagnoses these disorders. In this study, we assessed the detection of serum antibodies against human brain enolase (AE), neural tissue (AN) and Streptococcus (AS) as a laboratory tool for the diagnosis of early-onset psychiatric disorders. METHODOLOGY: Serum antibodies against human brain enolase, total brain proteins, and total proteins from StrepA were detected by ELISA in 37 patients with a presumptive diagnosis of PANDAS and in 12 healthy subjects from Mexico and Cuba. RESULTS: The antibody titers against human brain enolase (AE) and Streptococcal proteins (AS) were higher in patients than in control subjects (t-student, tAE=-2.17, P=0.035; tAS=-2.68, P=0.01, n=12 and 37/group, df=47, significance level 0.05), while the neural antibody titers did not differ between the two groups (P(t)=0.05). The number of subjects (titers> meancontrol + CI95) with simultaneous seropositivity to all three antibodies was higher in the patient group (51.4%) than in the control group (8.3%) group (X2=5.27, P=0.022, df=1, n=49). CONCLUSIONS: The simultaneous detection of all three of these antibodies could provide valuable information for the etiologic diagnosis of individuals with early-onset obsessive-compulsive disorders associated with streptococcal infection and, consequently, for prescribing suitable therapy.

Obsessive-compulsive disorder and gut microbiota dysregulation.

Obsessive-compulsive disorder (OCD) is a debilitating disorder for which the cause is not known and treatment options are modestly beneficial. A hypothesis is presented wherein the root cause of OCD is proposed to be a dysfunction of the gut microbiome constituency resulting in a susceptibility to obsessional thinking. Both stress and antibiotics are proposed as mechanisms by which gut microbiota are altered preceding the onset of OCD symptomology. In this light, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) leading to episodic OCD is explained not by group A beta-hemolytic streptococcal infections, but rather by prophylactic antibiotics that are administered as treatment. Further, stressful life events known to trigger OCD, such as pregnancy, are recast to show the possibility of altering gut microbiota prior to onset of OCD symptoms. Suggested treatment for OCD would be the directed, specie-specific (re)introduction of beneficial bacteria modifying the gut microbiome, thereby ameliorating OCD symptoms. Special considerations should be contemplated when considering efficacy of treatment, particularly the unhealthy coping strategies often observed in patients with chronic OCD that may need addressing in conjunction with microbiome remediation.

Tonsillectomies and adenoidectomies do not prevent the onset of pediatric autoimmune neuropsychiatric disorder associated with group A streptococcus.

BACKGROUND: In children presenting with obsessive compulsive disorder (OCD) and/or tics, especially those with a temporal association with streptococcal pharyngitis (eg, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus), there is speculation about whether tonsillectomy/adenoidectomy might improve the child's neuropsychiatric course. Our objective was to examine whether removal of the tonsils and/or adenoids impacted streptococcal antibody titers, the timing of onset of OCD and/or tics and the clinical severity of these symptoms. METHODS: Study participants (N = 112; average age = 9.2 ± 2.4; 44 women) were recruited as part of a prospective investigation of neuropsychiatric phenomena with temporal association to streptococcal pharyngitis and examined by family history, diagnostic interview, physical examination, medical record review, psychological testing and streptococcal antibodies and divided into surgical or nonsurgical groups. The surgical group consisted of children having previously had a tonsillectomy and/or adenoidectomy (n = 32). The remaining children were categorized as nonsurgical group (n = 76). Measures of OCD and tic severity, streptococcal antibody titers and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus classification were compared between both groups. RESULTS: There were no significant differences as determined by streptococcal antibody titers, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus classification and OCD or tic severity between the surgical and nonsurgical groups. Most participants had surgery before the onset of neuropsychiatric symptoms and surgery did not affect symptomology. CONCLUSIONS: Streptococcal antibodies and neuropsychiatric symptom severity did not differ on the basis of surgical status. From these data, we cannot infer that tonsillectomy and adenoidectomy are likely to impact positively the course of OCD/tics or streptococcal antibody concentrations.

Streptococcal upper respiratory tract infections and exacerbations of tic and obsessive-compulsive symptoms: a prospective longitudinal study.

OBJECTIVE: The objective of this blinded, prospective, longitudinal study was to determine whether new group A ß hemolytic streptococcal (GABHS) infections are temporally associated with exacerbations of tic or obsessive-compulsive (OC) symptoms in children who met published criteria for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). A group of children with Tourette syndrome and/or OC disorder without a PANDAS history served as the comparison (non-PANDAS) group. METHOD: Consecutive clinical ratings of tic and OC symptom severity were obtained for 31 PANDAS subjects and 53 non-PANDAS subjects. Clinical symptoms and laboratory values (throat cultures and streptococcal antibody titers) were evaluated at regular intervals during a 25-month period. Additional testing occurred at the time of any tic or OC symptom exacerbation. New GABHS infections were established by throat swab cultures and/or recent significant rise in streptococcal antibodies. Laboratory personnel were blinded to case or control status, clinical (exacerbation or not) condition, and clinical evaluators were blinded to the laboratory results. RESULTS: No group differences were observed in the number of clinical exacerbations or the number of newly diagnosed GABHS infections. On only six occasions of a total of 51 (12%), a newly diagnosed GABHS infection was followed, within 2 months, by an exacerbation of tic and/or OC symptoms. In every instance, this association occurred in the non-PANDAS group. CONCLUSIONS: This study provides no evidence for a temporal association between GABHS infections and tic/OC symptom exacerbations in children who meet the published PANDAS diagnostic criteria.

Streptococcal infection and exacerbations of childhood tics and obsessive-compulsive symptoms: a prospective blinded cohort study.

OBJECTIVE: If pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections is a unique clinical entity, we hypothesized that children meeting diagnostic criteria would have more clinical exacerbations temporally linked to bona fide group A beta-hemolytic streptococcus infection than matched control subjects (chronic tic and/or obsessive-compulsive disorder with no known temporal relationship to group A beta-hemolytic streptococcus infection). PATIENTS AND METHODS: Subjects included 40 matched pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections case-control pairs who were prospectively evaluated with intensive laboratory testing for group A beta-hemolytic streptococcus and clinical measures for an average of 2 years. Additional testing occurred at the time of any clinical exacerbations or illness. Laboratory personnel were blinded to case or control status and clinical (exacerbation or not) condition. Clinical raters were blinded to the results of laboratory tests. RESULTS: The cases had a higher clinical exacerbation rate and a higher bona fide group A beta-hemolytic streptococcus infection rate than the control group. Only 5 of 64 exacerbations were temporally associated (within 4 weeks) with a group A beta-hemolytic streptococcus infection, and all occurred in cases. The number (5.0) was significantly higher than the number that would be expected by chance alone (1.6). Yet, >/=75% of the clinical exacerbations in cases had no observable temporal relationship to group A beta-hemolytic streptococcus infection. CONCLUSIONS: Patients who fit published criteria for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections seem to represent a subgroup of those with chronic tic disorders and obsessive-compulsive disorder who may be vulnerable to group A beta-hemolytic streptococcus infection as a precipitant of neuropsychiatric symptom exacerbations. Group A beta-hemolytic streptococcus infection is not the only or even the most common antecedent event associated with exacerbations for these patients. Additional intensive studies are needed to determine whether there is clinical or scientific evidence to support separating out subgroups of tic disorder and/or obsessive-compulsive disorder patients based on specific symptom precipitants.

Antineuronal antibodies in a group of children with obsessive-compulsive disorder and Tourette syndrome.

An autoimmune hypothesis has been suggested for early onset obsessive-compulsive disorder and Tourette syndrome. The term: Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) has been proposed as an aetiological subtype of OCD and TS, related to a Group A beta haemolytic streptococcal (GABHS) infection that triggers an autoimmune response. Antineural antibodies have been studied and found in the sera of some patients with these disorders, and they are thought to cross-react with streptococcal and basal ganglia antigens. The present study included 32 prepubertal-onset OCD patients, 21 with TS diagnosis (some of them meeting criteria for PANDAS) and 19 normal children, all aged between 9 and 17 years. Antibodies were assayed by immunohistochemistry and immunoblot. Special attention was paid to the methodology and a high serum dilution was used to minimize non-specific binding. No anti-basal ganglia antibodies were detected by immunohistochemistry in any of the samples. Two proteins, with approximate molecular weights of 86 kDa and 55 kDa, were found in sera from 7 patients. Though the study supports the hypothesis of an autoimmune process underlying OCD or TS in some patients, further research is needed.

PANDAS: uma nova doença? / PANDAS: a new disease?

OBJETIVO: Apresentar as bases diagnósticas e analisar as evidências que têm sido apontadas para a etiopatogenia, tratamento e profilaxia de PANDAS. FONTES DOS DADOS: Revisão de literatura científica através do MEDLINE no período de 1989 a 2006. SíNTESE DOS DADOS: Os critérios diagnósticos para PANDAS foram estabelecidos há quase 10 anos, mas ainda há muita controvérsia sobre a real existência desta nova doença pediátrica. A escolha deste nome para uma nova doença, supostamente de origem pós-estreptocócica, baseia-se no acrônimo de P (pediátrico, porque ocorre em crianças), A (auto-imune), N (neuropsiquiátrico), D (doença), A (associada) e S (Streptococcus). Os tiques e os sintomas obsessivo-compulsivos são as principais manifestações clínicas da doença e surgem após infecções estreptocócicas, provavelmente por mecanismos auto-imunes. Apesar de estes sintomas neuropsiquiátricos serem comuns na coréia reumática, também de etiologia pós-estreptocócica, em PANDAS faltam os movimentos clássicos da coréia e as outras manifestações de febre reumática. As possibilidades de terapia antimicrobiana e imunológica estão sendo pesquisadas e demonstram viabilidade de uso em alguns casos. CONCLUSÕES: Pesquisas ainda são necessárias para responder à pergunta-título. Enquanto isso não ocorre, a identificação de casos de tiques e transtorno obsessivo-compulsivo em crianças deve considerar a possibilidade de PANDAS, buscando a evidência de infecção estreptocócica precedendo os episódios.

OBJECTIVE: To establish the diagnostic criteria for PANDAS and to analyze the existing evidence regarding its etiopathogenesis, treatment and prophylaxis. SOURCES: Review of the scientific literature through a MEDLINE search carried out between 1989 and 2006. SUMMARY OF THE FINDINGS: The diagnostic criteria for PANDAS were established nearly 10 years ago, but a lot of controversy still exists over the actual existence of this new pediatric disease. The name of this new disease, supposedly of poststreptococcal etiology, derives from an acronym that stands for pediatric autoimmune neuropsychiatric disease associated with streptococcal infection. Tics and obsessive-compulsive symptoms are the major clinical signs of the disease, which develop after streptococcal infections, probably through autoimmune mechanisms. Even though these neuropsychiatric symptoms are common in rheumatic chorea, whose etiology is also poststreptococcal, the classic choreiform movements and other symptoms of rheumatic fevers are absent in PANDAS. The use of antimicrobial and immunologic therapy has been investigated and considered feasible in some cases. CONCLUSIONS: Further research is still necessary in order to answer the question posed in the title of this article. In the meantime, the identification of tic disorders and obsessive-compulsive disorders in children should include the possibility of PANDAS, seeking to provide evidence of previous streptococcal infection.

PANDAS: a new disease?

OBJECTIVE: To establish the diagnostic criteria for PANDAS and to analyze the existing evidence regarding its etiopathogenesis, treatment and prophylaxis. SOURCES: Review of the scientific literature through a MEDLINE search carried out between 1989 and 2006. SUMMARY OF THE FINDINGS: The diagnostic criteria for PANDAS were established nearly 10 years ago, but a lot of controversy still exists over the actual existence of this new pediatric disease. The name of this new disease, supposedly of poststreptococcal etiology, derives from an acronym that stands for pediatric autoimmune neuropsychiatric disease associated with streptococcal infection. Tics and obsessive-compulsive symptoms are the major clinical signs of the disease, which develop after streptococcal infections, probably through autoimmune mechanisms. Even though these neuropsychiatric symptoms are common in rheumatic chorea, whose etiology is also poststreptococcal, the classic choreiform movements and other symptoms of rheumatic fevers are absent in PANDAS. The use of antimicrobial and immunologic therapy has been investigated and considered feasible in some cases. CONCLUSIONS: Further research is still necessary in order to answer the question posed in the title of this article. In the meantime, the identification of tic disorders and obsessive-compulsive disorders in children should include the possibility of PANDAS, seeking to provide evidence of previous streptococcal infection.