Clinical presentation of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections in research and community settings

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.

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.

Case report: Diagnosis and intervention of a non-24-h sleep-wake disorder in a sighted child with a psychiatric disorder

Circadian rhythm sleep-wake disorders (CRSWD) are sleep dysfunctions related to circadian functioning. They are characterized by symptoms of insomnia or excessive sleepiness that occur because the intrinsic circadian pacemaker is not entrained to a 24-h light/dark cycle. Affected individuals with a free-running disorder or hypernycthemeral syndrome (N24SWD) have a longer sleep-wake cycle that produces a sleep pattern that typically delays each day. The disorder is seen in 70% of blind people, and among people with healthy vision, it is a rare pathology. Among sighted cases, 80% are young men and 28% have a psychiatric disorder. The patient was a 14-year-old boy with a psychiatric pathology diagnosed with a PANDAS syndrome (pediatric autoimmune neuropsychiatric disorders associated with streptococci), a sudden acute and debilitating onset of intense anxiety and mood lability accompanied by obsessive compulsive-like issues and/or tics, in association with a streptococcal A infection that occurs immediately prior to the symptoms. As a comorbidity, he exhibited severe insomnia due to an irregular sleep pattern that strongly delayed his sleep schedule day to day. It affected his daily routines, as he was not going to school, and aggravated, furthermore, the psychiatric symptoms. He was referred for sleep consultation, where the case was explored by ambulatory circadian monitoring (ACM) using the novel system Kronowise® (Chronolab, University of Murcia) and diagnosed with a non-24-h sleep-wake disorder (N24SWD). The first treatment approach for the patient was focused on improving symptoms during the acute infection and psychiatric symptoms. Additionally, sleep pathology was treated by light therapy and melatonin. After 8 months and different trials, it was possible to establish a treatment to normalize the symptoms and fix his sleep rhythm in a normal schedule as well as to reduce anxious symptoms during the day. The association of PANDAS and N24SWD has not previously been reported in the literature.

Immunological characterization of an Italian PANDAS cohort

This cross-sectional study aimed to contribute to the definition of Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) pathophysiology. An extensive immunological assessment has been conducted to investigate both immune defects, potentially leading to recurrent Group A β-hemolytic Streptococcus (GABHS) infections, and immune dysregulation responsible for a systemic inflammatory state. Twenty-six PANDAS patients with relapsing-remitting course of disease and 11 controls with recurrent pharyngotonsillitis were enrolled. Each subject underwent a detailed phenotypic and immunological assessment including cytokine profile. A possible correlation of immunological parameters with clinical-anamnestic data was analyzed. No inborn errors of immunity were detected in either group, using first level immunological assessments. However, a trend toward higher TNF-alpha and IL-17 levels, and lower C3 levels, was detected in the PANDAS patients compared to the control group. Maternal autoimmune diseases were described in 53.3% of PANDAS patients and neuropsychiatric symptoms other than OCD and tics were detected in 76.9% patients. ASO titer did not differ significantly between the two groups. A possible correlation between enduring inflammation (elevated serum TNF-α and IL-17) and the persistence of neuropsychiatric symptoms in PANDAS patients beyond infectious episodes needs to be addressed. Further studies with larger cohorts would be pivotal to better define the role of TNF-α and IL-17 in PANDAS pathophysiology.

An updated review of pediatric autoimmune neuropsychiatric disorders associated with Streptococcus/pediatric acute-onset neuropsychiatric syndrome, also known as idiopathic autoimmune encephalitis: What the allergist should know

BACKGROUND

Pediatric acute-onset neuropsychiatric syndrome, further subcategorized as pediatric autoimmune neuropsychiatric disorders associated with streptococcus, is a form of idiopathic autoimmune encephalitis (IAE). Poststreptococcal autoimmunity seen in Idiopathic autoimmune encephalitis manifests as various neuropsychiatric symptoms such as obsessive rituals, tics, anxiety, depression, and many others. Idiopathic autoimmune encephalitis has clinically heterogeneous phenotypes that make accurate diagnosing difficult, although diagnostic testing such as the Cunningham Panel increases the likelihood of finding effective treatments. Current recommended treatments include psychiatric medication, behavioral intervention, antibiotics, anti-inflammatory therapy, and immunomodulating therapy.

OBJECTIVE

To provide an updated review on the diagnosis, management, and treatment of pediatric autoimmune neuropsychiatric disorder associated with streptococcus and pediatric autoimmune neuropsychiatric syndrome, also referred to as IAE.

RESULTS

Information from 47 sources was used to outline current knowledge of IAE pathophysiology, clinical manifestations, and epidemiology, and to outline diagnostic recommendations and current treatment guidelines. Gaps in knowledge, in addition to current controversy, were also outlined to provide a thorough background of this condition and future needs for IAE research.

CONCLUSION

Owing to the complexity and variability in ways patients with IAE may present to the allergist/immunologist office, an interdisciplinary approach is imperative to provide patients with the best medical care. Still, more research is needed to further elucidate the mechanism(s) and optimal treatment algorithm for IAE to facilitate broader recognition and acceptance of this condition by the medical community.

Implication of microbiota gut-brain axis in the manifestation of obsessive-compulsive disorder: Preclinical and clinical evidence

Recent research has highlighted the key role of gut microbiota in the development of psychiatric disorders. The adverse impact of stress, anxiety, and depression has been well documented on the commensal gut microflora. Thus, therapeutic benefits of gut microbiota-based interventions may not be avoided in central nervous system (CNS) disorders. In this review, we outline the current state of knowledge of gut microbiota with respect to obsessive-compulsive disorder (OCD). We discuss how OCD-generated changes corresponding to the key neurotransmitters, hypothalamic-pituitary-adrenal axis, and immunological and inflammatory pathways are connected with the modifications of the microbiota-gut-brain axis. Notably, administration of few probiotics such as Lactobacillus rhamnosus (ATCC 53103), Lactobacillus helveticus R0052, Bifidobacterium longum R0175, Saccharomyces boulardii, and Lactobacillus casei Shirota imparted positive effects in the management of OCD symptoms. Taken together, we suggest that the gut microbiota-directed therapeutics may open new treatment approaches for the management of OCD.

Clinicopathologic Characteristics of PANDAS in a Young Adult: A Case Report

Pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS) is an acute onset or exacerbation of neuropsychiatric symptoms following a group A streptococcus infection. It is believed to be a result of autoimmune response to streptococcal infection, but there is insufficient evidence to fully support this theory. Although this disease is primarily thought to be a disease of childhood, it is reported to occur also in adults. PANDAS is a well-defined clinical entity, but the neuropathology of this condition has not been established yet. We describe the clinical course of a 26-year-old female diagnosed with PANDAS. She committed suicide and her brain was biobanked for further studies. We examined the banked tissue and performed special stains, immunohistochemical, and immunofluorescence analyses to characterize the neuropathology of this condition. Histology of the temporal lobes, hippocampus, and basal ganglia shows mild gliosis and Alzheimer's type II astrocytes. Acute hypoxic ischemic changes were noted in hippocampus CA1 and CA2 areas. Immunostaining shows increased parenchymal/perivascular GFAP staining and many vessels with mild increases in CD3-, CD4-, and CD25-stained lymphocytes in the basal ganglia. The findings suggest that CD4- and CD25-positive T cells might have an important role in understanding the neuroinflammation and pathogenesis of this condition. The case represents the first neuropathological evaluation report for PANDAS.

Symptom flares after COVID-19 infection versus vaccination among youth with PANS/PANDAS

Background: Flares of autoimmune conditions can happen after coronavirus disease 2019 (COVID-19) infection and after COVID-19 vaccines. Patients and clinicians confront difficult decisions about vaccine safety when considering efforts to balance the risks of disease exacerbation after vaccines versus the protection that vaccines offer to potential serious life-threatening complications of COVID-19 infection. Objective: To examine symptom flares after COVID-19 infection and vaccines in the case of a form of autoimmune encephalitis that primarily affects children and young adults (pediatric acute-onset neuropsychiatric syndrome [PANS] / pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections [PANDAS]). Method: A cross-sectional study that used a survey distributed through PANS/PANDAS groups, organizations, and clinics. Results: Surveys were completed by 496 parents and/or caregivers of children with PANS/PANDAS. Among the children reported to have had a COVID-19 infection (n = 178), 43% reported severe flares of PANS/PANDAS symptoms, 23% reported mild flares, and 30% reported no symptom flares. Among those who had received COVID-19 vaccines (n = 181), 65% observed no changes in PANS/PANDAS symptoms after the vaccine, 19% reported mild flares, and 15% reported severe flares. Paired sample t-tests showed that, after COVID-19 infections, children with PANS/PANDAS were significantly more likely to experience a severe symptom flare than a mild flare or no change in symptoms. In contrast, after receiving COVID-19 vaccines, children were significantly more likely to experience no change in PANS/PANDAS symptoms than to endure a mild or severe symptom flare. In addition, children who recovered from PANS/PANDAS were significantly more likely to have no symptom change versus children who were managing the condition, both after COVID-19 infection (92% versus 25%) and vaccine receipt (100% versus 66%). Conclusion: These results support COVID-19 vaccination for most individuals with PANS/PANDAS given that the frequencies of symptom flares and setbacks after COVID-19 infection were significantly higher than after the COVID-19 vaccine. Nonetheless, further studies are needed to fully assess the risk-benefit balance and to provide a more individualized approach to disease prevention in people with immune vulnerabilities.

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.

Distinct Th17 effector cytokines differentially promote microglial and blood-brain barrier inflammatory responses during post-infectious encephalitis

Group A Streptococcus (GAS) infections can cause neuropsychiatric sequelae in children due to post-infectious encephalitis. Multiple GAS infections induce migration of Th17 lymphocytes from the nose into the brain, which are critical for microglial activation, blood-brain barrier (BBB) and neural circuit impairment in a mouse disease model. How endothelial cells (ECs) and microglia respond to GAS infections, and which Th17-derived cytokines are essential for these responses are unknown. Using single-cell RNA sequencing and spatial transcriptomics, we found that ECs downregulate BBB genes and microglia upregulate interferon-response, chemokine and antigen-presentation genes after GAS infections. Several microglial-derived chemokines were elevated in patient sera. Administration of a neutralizing antibody against interleukin-17A (IL-17A), but not ablation of granulocyte-macrophage colony-stimulating factor (GM-CSF) in T cells, partially rescued BBB dysfunction and microglial expression of chemokine genes. Thus, IL-17A is critical for neuropsychiatric sequelae of GAS infections and may be targeted to treat these disorders.

Steroid treatment response to post SARS-CoV-2 PANS symptoms: Case series

Background

Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by a wide spectrum of symptoms, including the onset of obsessive-compulsive disorder and/or severely restricted food intake, associated with emotional symptoms, behavioral symptoms, developmental regression, and somatic symptoms. Among the possible triggering agents, infectious agents have been extensively explored. More recently, sporadic case reports describe a possible association between PANS and SARS-CoV-2 infection but data on clinical presentation and treatment are still scarce.

Methods

We describe a case series (10 children) with acute onset or relapse of PANS symptoms after SARS-CoV-2 infection. Standardized measures (CBCL, CPRS, C-GAS, CGI-S, Y-BOCS, PANSS, and YGTSS) were used to describe the clinical picture. The efficacy of a pulse treatment with steroids for three consecutive months was assessed.

Results

Our data suggest that the clinical presentation of the COVID-19-triggered PANS is largely similar to that reported in typical PANS, including acute onset, with OCD and/or eating disorders, and associated symptoms. Our data suggest that treatment with corticosteroids may be beneficial for both global clinical severity and global functioning. No serious adverse effects were observed. Both OCD symptoms and tics consistently improved. Among psychiatric symptoms, affective and oppositional symptoms appeared more sensitive to the steroid treatment than the other symptoms.

Conclusion

Our study confirms that COVID-19 infection in children and adolescents could trigger acute-onset neuropsychiatric symptoms. Thus, in children and adolescents with COVID-19, a specific neuropsychiatric follow-up should be routinely included. Even if a small sample size and a follow-up with only two points (baseline and endpoint, after 8 weeks) limit the conclusions, it seems that steroid treatment in the acute phase may be beneficial and well tolerated.

Obsessive-Compulsive Disorder, PANDAS, and Tourette Syndrome: Immuno-inflammatory Disorders

In the last years, much focus has been given to the possible role of inflammatory and immunologic alterations in the pathophysiology of obsessive-compulsive disorder (OCD) and some related conditions, such as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) and Tourette syndrome (TS). Although the matter is intriguing, the available data are still controversial and/or limited. Therefore, the aim of this chapter was at reviewing and commenting on the literature on possible dysfunctions of inflammatory and immune system processes in OCD, PANDAS, and TS.This narrative review was carried out through searching PubMed and Google Scholar for English language papers from January 1985 to December 31, 2021.The data gathered up to now would suggest that the mechanisms involved might be heterogeneous according to the age of the patients and the disorder examined. Indeed, PANDAS seem more related to infections triggering autoimmunity not necessarily following group A beta-hemolytic streptococcal (GABHS) infection, as supposed in the past. Autoimmunity seems also important in TS, if coupled with an individual vulnerability that can be genetic and/or environmental. The data in adult OCD, albeit scattered and sometimes obtained in small samples of patients, would indicate that immune system and inflammatory processes are involved in the pathophysiology of the disorder. However, it is still unclear to conclude whether they are primary or secondary phenomena.In conclusion, taken together, the current findings pave that way towards novel and promising domains to explore the pathophysiology of OCD and related disorders, as well towards the development of innovative therapeutic strategy beyond current pharmacological paradigms.

Microbiome in Anxiety and Other Psychiatric Disorders

Initial studies suggested that the fluctuations in the quantity, variety, and composition of the gut microbiota can significantly affect disease processes. This change in the gut microbiota causing negative health benefits was coined dysbiosis. Initial research focused on gastrointestinal illnesses. However, the gut microbiome was found to affect more than just gastrointestinal diseases. Numerous studies have proven that the gut microbiome can influence neuropsychiatric diseases such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis.

Group Psychotherapy for Parents of Youth with Pediatric Acute-Onset Neuropsychiatric Syndrome

Parents of children with diagnoses of Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infections (PANDAS) may experience significant psychological distress related to their child's severe and relapsing illness and challenges with the traumatic nature of its treatment. No manualized or studied psychological interventions specifically for parents of youth with PANS have existed prior to this study. In this pilot study, we assessed the feasibility, satisfaction, and treatment fidelity of a brief 9-session group therapy intervention for parents based on principles of trauma-focused cognitive behavior therapy (CBT). We hypothesized that, if initially elevated, symptoms of depression, anxiety, and trauma would decrease and participants' utilization of positive coping mechanisms would increase post-intervention. We adapted an existing evidence-based group intervention developed for parents of children with premature infants to target sources of stress and coping in parents of children with PANS. Ten parents participated in the study. The 9-session intervention used a combination of techniques that included cognitive restructuring, coping skills, self-care, and a trauma narrative to address psychological stress, trust, grief, and unwanted emotions. Outcome measures included parental symptoms of anxiety, depression, and posttraumatic stress disorder (PTSD), as well as rating of parental satisfaction with the intervention. The treatment was feasible and deliverable with high fidelity. The intervention was rated as useful and satisfactory by parents (overall average usefulness of 4.54 and satisfaction of 4.71 out of 5.0). Elevated symptoms of PTSD and depression decreased with large effect sizes (Cohen's d = 1.42 and Cohen's d = 1.38, respectively). Participating parents demonstrated significantly more active coping and acceptance behaviors and stances. A brief 9-session group therapy intervention based on principles of trauma-focused CBT was found to be effective in reducing symptoms of psychological distress in parents of children with PANS.

1H-NMR-Based Metabolomics in Autism Spectrum Disorder and Pediatric Acute-Onset Neuropsychiatric Syndrome

We recently described a unique plasma metabolite profile in subjects with pediatric acute-onset neuropsychiatric syndrome (PANS), suggesting pathogenic models involving specific patterns of neurotransmission, neuroinflammation, and oxidative stress. Here, we extend the analysis to a group of patients with autism spectrum disorder (ASD), as a consensus has recently emerged around its immune-mediated pathophysiology with a widespread involvement of brain networks. This observational case-control study enrolled patients referred for PANS and ASD from June 2019 to May 2020, as well as neurotypical age and gender-matched control subjects. Thirty-four PANS outpatients, fifteen ASD outpatients, and twenty-five neurotypical subjects underwent physical and neuropsychiatric evaluations, alongside serum metabolomic analysis with 1H-NMR. In supervised models, the metabolomic profile of ASD was significantly different from controls (p = 0.0001), with skewed concentrations of asparagine, aspartate, betaine, glycine, lactate, glucose, and pyruvate. Metabolomic separation was also observed between PANS and ASD subjects (p = 0.02), with differences in the concentrations of arginine, aspartate, betaine, choline, creatine phosphate, glycine, pyruvate, and tryptophan. We confirmed a unique serum metabolomic profile of PANS compared with both ASD and neurotypical subjects, distinguishing PANS as a pathophysiological entity per se. Tryptophan and glycine appear as neuroinflammatory fingerprints of PANS and ASD, respectively. In particular, a reduction in glycine would primarily affect NMDA-R excitatory tone, overall impairing downstream glutamatergic, dopaminergic, and GABAergic transmissions. Nonetheless, we found metabolomic similarities between PANS and ASD that suggest a putative role of N-methyl-D-aspartate receptor (NMDA-R) dysfunction in both disorders. Metabolomics-based approaches could contribute to the identification of novel ASD and PANS biomarkers.

Bowel and Bladder Dysfunction Is Associated with Psychiatric Comorbidities and Functional Impairment in Pediatric Obsessive-Compulsive Disorder

Objective: Neuropsychiatric disorders are common in children with bowel and bladder dysfunction (BBD), a syndrome associated with urinary frequency, urgency, holding, incontinence, and constipation. We evaluated BBD symptom severity in children and youth attending a tertiary care obsessive-compulsive disorder (OCD) clinic. Methods: Consecutive patients attending initial OCD assessments between 2016 and 2020 were invited to participate in a registry study. Diagnosis of OCD and comorbidities was established by structured clinical interview. OCD severity and impact were assessed with the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) and the Child Obsessive Compulsive Impact Scale (COIS-R; self-report), respectively. BBD symptoms were quantified with the Vancouver Symptom Score (VSS), a validated self-report measure. Results: One hundred twelve participants completed the VSS (mean age 13.5 ± 3.3, range 7-20). Based on a cutoff score of 11 corresponding to pediatric urologist-diagnosed BBD, 30.4% of participants screened positive, including more females than males (39.3% vs. 21.4%; p = 0.04). Daytime urinary incontinence was present in a greater proportion of participants with OCD forbidden thoughts (34.8% vs. 8.2%, p = 0.002), major depressive disorder (MDD; 38.5% vs. 6.8%, p = 0.001), and somatization disorder (60% vs. 9%, p = 0.001) compared with those without. A regression model including CY-BOCS, COIS-R, psychiatric comorbidities, medications, age, and gender explained 52.2% of the variance in VSS; COIS-R, tic disorder, and MDD were significant predictors. Conclusion: BBD symptoms are common and associated with high OCD-related impairment and psychiatric comorbidities. Standardized assessment may facilitate identification of BBD symptoms in this population and is critical to mitigating long-term physical and mental health impacts. Further studies are required to assess the relationship between BBD and OCD treatment outcomes.

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.

Cognitive, Graphomotor, and Psychosocial Challenges in Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS)

OBJECTIVES

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) is characterized by the sudden onset of obsessive-compulsive disorder (OCD) and other neurobehavioral symptoms following group A streptococcal infection. The cardinal neuropsychiatric symptoms are believed to reflect an aberrant autoimmune or inflammatory response that may selectively disrupt basal ganglia function. The investigators examined whether neuropsychological skills associated with frontostriatal networks (executive functions and motor skills) are affected in patients with PANDAS following resolution of acute symptoms and the degree to which there are persistent social, emotional, and academic difficulties.

METHODS

Twenty-seven patients ages 6-14 years (mean age=9.63 years [SD=1.78]; male, N=22) completed neuropsychological testing as part of routine clinical care. Performances on measures of intellectual ability, executive function, motor skills, and academic skills are reported, as well as parent-reported emotional, behavioral, and social skills.

RESULTS

On neuropsychological measures, patients exhibited average intellectual functioning with relative and mild difficulties in skills supporting cognitive efficiency, including attentional regulation, inhibitory control, and processing speed. Dexterity was normal but graphomotor skills were reduced. Core reading, math, and writing skills were within expectations, but reading and math fluency were reduced, and the majority of patients received special education services or accommodations. Parents reported high levels of concern about anxiety, depression, inattention, hyperactivity, and social skills.

CONCLUSIONS

These findings indicated relative difficulties with aspects of executive and motor functions. Although evaluations were performed following the resolution of acute symptoms, ongoing and significant academic difficulties and emotional, behavioral, and social concerns were targets for clinical intervention and support.

Neuropsychiatric Disorders in Pediatric Long COVID-19: A Case Series

Few data are available regarding the incidence and the evolution of neuropsychiatric manifestations in children with a history of COVID-19. We herein report five consequent cases of pediatric patients with psychiatric and neurological symptoms of long COVID-19. All patients, mainly males, reported asymptomatic-to-mild COVID-19 and underwent home self-isolation. Abnormal movements, anxiety, and emotional dysregulation were the most recurrent symptoms observed from a few weeks to months after the resolution of the acute infection. A later onset was observed in younger patients. Blood tests and brain imaging resulted in negative results in all subjects; pharmacological and cognitive behavioral therapy was set. A multifactorial etiology could be hypothesized in these cases, as a result of a complex interplay between systemic and brain inflammation and environmental stress in vulnerable individuals. Longer follow-up is required to observe the evolution of neuropsychiatric manifestation in the present cohort and other young patients with previous SARS-CoV-2 infection.

Neuroinflammation in a Rat Model of Tourette Syndrome

Objective

Tourette syndrome (TS) is a group of childhood-onset chronic neuropsychiatric disorders characterized by tics, i.e., repetitive, sudden, and involuntary movements or vocalizations, which is often associated with various psychopathological and/or behavioral comorbidities, including attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, depression, and sleep disorders and have a worse prognosis. The mechanism of TS is still not clear. The relationship between immune activation, neuroinflammation, and neuropsychiatric disorders has attracted much attention in the past two decades. To explore the underlying mechanism in TS, the relationship between neuroinflammation and behavioral alterations in TS rats was investigated in this study.

Methods

A total of 36 Sprague-Dawley male rats were divided into three groups randomly as follows: the TS, control (CON), and drug intervention groups. The TS rat group was treated with haloperidol (Hal) (the TS + Hal group). The TS rat model was established using 3,3-iminodipropionitrile (IDPN), which is a well-known animal model of TS. The behavioral syndromes, brain tissue cytokines, like interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), and microglial activation of the three groups were assessed.

Results

The behavioral scores of rats in the TS group and the TS + Hal group were higher than those in the CON group (P < 0.05), but the scores of behavioral tests in the TS + Hal group were lower than those in the TS group (P < 0.05). The levels of IL-6 and TNF-α in the rat brain tissue were significantly higher in the TS group than in the CON group (P < 0.05), while no significant differences were found between the CON group and the TS + Hal group (P > 0.05). The microglia was significantly activated in the TS group and slightly activated in the TS + Hal group, which was considerably less than that in the TS group.

Conclusion

The IDPN-induced TS rats had significant neuroinflammation in the brain, and the interaction between dopamine (DA) dysregulation and immune dysfunction may play a vital role in the pathogenic mechanisms of TS.

The Clinical Profile of Cat-Scratch Disease’s Neuro-Ophthalmological Effects

Cat-scratch disease is an illness caused by Bartonella henselae that occurs as a result of contact with an infected kitten or dog, such as a bite or scratch. It is more prevalent in children and young adults, as well as immunocompromised individuals. There are limited publications examining the features of CSD in patients. As such, the purpose of this research was to assess the clinical neuro-ophthalmological consequences of CSD reported in the literature. Among the ophthalmologic disorders caused by cat-scratch disease in humans, Parinaud oculoglandular syndrome, uveitis, vitritis, retinitis, retinochoroiditis and optic neuritis are the most prevalent. The neurological disorders caused by cat-scratch disease in humans include encephalopathy, transverse myelitis, radiculitis, and cerebellar ataxia. The current review addresses the neuro-ophthalmological clinical manifestations of cat-scratch disease, as described in papers published over the last four decades (1980–2022). All the data gathered were obtained from PubMed, Medline and Google Scholar. The current descriptive review summarizes the most-often-encountered clinical symptomatology in instances of cat-scratch disease with neurological and ocular invasion. Thus, the purpose of this review is to increase knowledge of cat-scratch disease’s neuro-ophthalmological manifestations.

The Role of Pediatric Rheumatologists in Autoimmune Brain Disease

The spectrum of autoimmune and inflammatory brain diseases continues to evolve with medical advances facilitating both the detection of inflammation of the central nervous system and the discovery of novel disease mechanisms. The clinical overlap of these disorders with primary rheumatic diseases and the efficacy of immunotherapy have led to strong partnerships between pediatric rheumatologists, neurologists, psychiatrists, and other providers in the care of children with these conditions. Early diagnosis and initiation of targeted therapy improve clinical outcomes, highlighting the importance of interdisciplinary collaborative care.

Systematic review and meta-analysis identify significant relationships between clinical anxiety and lower urinary tract symptoms

BACKGROUND

Lower urinary tract symptoms (LUTS), such as voiding symptoms, overactive bladder, and interstitial cystitis, and anxiety disorders are often comorbid conditions in patients. However, the existing evidence regarding the rates and nature of the co-occurrence of these conditions has not been systematically evaluated. The aim of this study was to examine these relationships.

METHODS

We conducted a systematic review and meta-analysis to examine the relationship between LUTS and anxiety. We searched for articles published from January 1990 to July 2019 in PubMed, CENTRAL, PsycINFO, and Google Scholar. Outcomes were anxiety-related disorders and symptoms (clinically significant anxiety) and LUTS. We performed random-effects meta-analyses, inspected funnel plots, and applied the Egger's test to evaluate publication bias. We followed PRISMA guidelines and recorded our protocol on PROSPERO (ID = CRD42019118607).

RESULTS

We identified 814 articles, of which 94 fulfilled inclusion criteria, and 23 had sufficient data for meta-analysis. The odds ratio (OR) for clinically significant anxiety among individuals with LUTS was 2.87 (95% CI: 2.38,3.46, p < .001). The OR for LUTS among individuals with clinically significant anxiety was 2.87 (95% CI: 1.07,7.74, p < .001), although very few studies examined this relationship. A large value of I² index suggests high heterogeneity between studies.

CONCLUSION

The results demonstrate a significant association between clinically significant anxiety and LUTS in both females and males. There were limited studies on younger individuals and on individuals ascertained for clinically significant anxiety, which should motivate further study in these areas. Understanding the co-occurrence of these conditions will lead to better prevention and interventions to ameliorate the progression of the symptoms and improve the quality of life. A thorough assessment of anxiety may provide more optimal care for LUTS patients.

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).

Metabolomic Characterization of Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS)

Introduction

PANS is a controversial clinical entity, consisting of a complex constellation of psychiatric symptoms, adventitious changes, and expression of various serological alterations, likely sustained by an autoimmune/inflammatory disease. Detection of novel biomarkers of PANS is highly desirable for both diagnostic and therapeutic management of affected patients. Analysis of metabolites has proven useful in detecting biomarkers for other neuroimmune-psychiatric diseases. Here, we utilize the metabolomics approach to determine whether it is possible to define a specific metabolic pattern in patients affected by PANS compared to healthy subjects.

Design

This observational case-control study tested consecutive patients referred for PANS between June 2019 to May 2020. A PANS diagnosis was confirmed according to the PANS working criteria (National Institute of Mental Health [NIMH], 2010). Healthy age and sex-matched subjects were recruited as controls.

Methods

Thirty-four outpatients referred for PANS (mean age 9.5 years; SD 2.9, 71% male) and 25 neurotypical subjects matched for age and gender, were subjected to metabolite analysis. Serum samples were obtained from each participant and were analyzed using Nuclear Magnetic Resonance (NMR) spectroscopy. Subsequently, multivariate and univariate statistical analyses and Receiver Operator Curves (ROC) were performed.

Results

Separation of the samples, in line with the presence of PANS diagnosis, was observed by applying a supervised model (R²X = 0.44, R²Y = 0.54, Q² = 0.44, p-value < 0.0001). The significantly altered variables were 2-Hydroxybutyrate, glycine, glutamine, histidine, tryptophan. Pathway analysis indicated that phenylalanine, tyrosine, and tryptophan metabolism, as well as glutamine and glutamate metabolism, exhibited the largest deviations from neurotypical controls.

Conclusion

We found a unique plasma metabolic profile in PANS patients, significantly differing from that of healthy children, that suggests the involvement of specific patterns of neurotransmission (tryptophan, glycine, histamine/histidine) as well as a more general state of neuroinflammation and oxidative stress (glutamine, 2-Hydroxybutyrate, and tryptophan-kynurenine pathway) in the disorder. This metabolomics study offers new insights into biological mechanisms underpinning the disorder and supports research of other potential biomarkers implicated in PANS.

Knowledge and competency standards for specialized cognitive behavior therapy for pediatric obsessive-compulsive disorder

Although exposure-based cognitive behavior therapy (CBT) and pharmacotherapy have demonstrated efficacy for obsessive-compulsive disorder (OCD), the lack of clinicians effectively trained in these treatments significantly limit effective intervention options for affected youth. This is very unfortunate since child onset is reported by 50% of adults with OCD. To ameliorate this serious global issue the 14 nation International Obsessive-Compulsive Disorders Accreditation Task Force (ATF) of The Canadian Institute for Obsessive Compulsive Disorders (CIOCD) has developed knowledge and competency standards recommended for specialized treatments for OCD through the lifespan. Currently available guidelines are considered by experts to be essential but insufficient because there are not enough clinicians with requisite knowledge and competencies to effectively treat OCD. This manuscript presents knowledge and competency standards recommended for specialized cognitive behavior therapy (CBT) for pediatric OCD, derived from comprehensive literature review and expert synthesis. In addition to standards covering the elements of individual CBT-based assessment and treatment, family and school interventions are addressed given the critical role these domains play in the psychosocial development of youths. The ATF standards presented in these phase two papers will be foundational to the upcoming development of certification (individuals) and accreditation (sites) for specialized treatments in OCD through the lifespan.

Case Report: PANDAS and Persistent Lyme Disease With Neuropsychiatric Symptoms: Treatment, Resolution, and Recovery

This case report describes the diagnosis and treatment of a pre-pubertal (onset at age 7) Caucasian female with serological evidence of Lyme disease accompanied by multiple neuropsychiatric symptoms 6 months following a vacation in a tick endemic area of the United States. Prior to the diagnosis of Lyme disease, the patient also met the clinical diagnostic criteria for PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Strep), with serological evidence of three distinct episodes of streptococcal pharyngitis. All three episodes of strep occurred during the 6-months interval between suspected Lyme disease exposure and the onset of multiple neuropsychiatric symptoms. Her sometimes incapacitating symptoms followed a relapsing and remitting course that impacted her personal, family, social, and academic domains. Over a span of 31 consecutive months of treatment with various antimicrobials and three courses of intravenous immunoglobulins (IVIg) she experienced complete remission and remains symptom free at the time of this publication. Written permission was obtained from the minor patient's mother allowing the submission and publication of this case study.

Psychiatric autoimmune conditions in children and adolescents: Is catatonia a severity marker?

OBJECTIVES

Patients with autoimmune encephalitis (AE) are likely to exhibit an acute onset of severe psychiatric features, including psychosis and/or catatonia. Based on the high prevalence of catatonia in AE and our clinical experience, we hypothesized that catatonia might be a marker of severity requiring more aggressive treatment approaches.

METHODS

To reach a sufficient number of cases with brain-autoimmune conditions, we pooled two samples (N = 58): the first from the French National Network of Rare Psychiatric diseases and the second from the largest Italian neuro-pediatrics center for encephalopathies. Autoimmune conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. We retrospectively compared patients with and without catatonia for psychiatric and non-psychiatric clinical features, biological and imaging assessments, type of immunotherapy used and outcomes.

RESULTS

The sample included 25 patients (43%) with catatonia and 33 (57%) without catatonia. Forty-two patients (72.4%) had a definite AE (including 27 anti-NMDA receptor encephalitis) and 16 (27.6%) suspected autoimmune encephalitis. Patients with catatonia showed significantly more psychotic features [18 (72%) vs 9 (27.3%), p < 0.001)] and more movement disorders [25 (100%) vs 20 (60.6%), p < 0.001] than patients without catatonia. First line (corticoids, immunoglobulin and plasma exchanges) and second line (e.g., rituximab) therapies were more effective in patients with catatonia, with 24 (96%) vs 22 (66.7%) (p = 0.006) and 17 (68%) vs 9 (27.3%) (p = 0.002), respectively. However, those with catatonia received more combinations of first and second line treatments and had more relapses during outcomes.

CONCLUSION

Despite its exploratory design, the study supports the idea that autoimmune catatonia may be a marker of severity and morbidity in terms of initial presentation and relapses, requiring the need for early and aggressive treatment.

Breastfeeding in Pediatric Acute-Onset Neuropsychiatric Syndrome: An Italian Observational Study

Objective: Pediatric acute-onset neuropsychiatric syndrome (PANS) is a condition defined by sudden onset of obsessive-compulsive symptoms and/or severe eating restrictions, along with at least two other cognitive, behavioral, or neurological symptoms. Its pathogenesis is unknown but it seems triggered by infections, metabolic disturbances, and other inflammatory reactions. PANS represents a neurodevelopmental problem and infant feeding can play a role. Breast milk is the ideal food for infants and influences children's brain, cognitive, and socio-emotional development. Methods: We enrolled 52 children diagnosed with PANS. We interviewed their parents in order to investigate perinatal history, infant feeding, neurologic development, and confounding factors like socio-economic status and region of origin. We subgrouped PANS patients into three subsets: those who only received human milk (HMO), those who only received infant formula, and those who received mixed feeding. Results: The cohort is composed of 78.9% males, with a median age of 11 years (range 7-17). We found some neurodevelopmental problems (13.5%): walking disorders, ASD, ADHD, oppositional attitude, and delayed psychomotor development. We found scholar performance deficits (25%), including language problems like dysgraphia, dyslexia, and dyscalculia. The achievement of some milestones in the development of the infant is affected in 73.1% of cases. Breastfeeding is not homogeneously practiced in Italy because of social, economic, and cultural phenomena. The richest and the poorest families (100%) in the sample choose breastfeeding, probably with a different approach and for different reasons (awareness or need). In the group of PANS patients fed with HMO, compared to the rest of the patients, we registered fewer cases of growth problems (0 vs. 12.9%; p = 0.14), school performance problems or the need for school support (19.1% vs. 29%; p = 0.42), and a delay in the age of babbling/speaking (range 4-20 vs. 7-36 months; p = 0.066). Conclusion: This is the first study that investigates the role of breastfeeding in the development of PANS. Promoting breastfeeding is important in the general population and also in PANS patients because it has an important social and global health impact, also during adult life. Further studies with a bigger population are needed to investigate the mechanisms underlying PANS and the role that breastfeeding may play in their short- and long-term neurodevelopment.

Discovering prescription patterns in pediatric acute-onset neuropsychiatric syndrome patients

OBJECTIVE

Pediatric acute-onset neuropsychiatric syndrome (PANS) is a complex neuropsychiatric syndrome characterized by an abrupt onset of obsessive-compulsive symptoms and/or severe eating restrictions, along with at least two concomitant debilitating cognitive, behavioral, or neurological symptoms. A wide range of pharmacological interventions along with behavioral and environmental modifications, and psychotherapies have been adopted to treat symptoms and underlying etiologies. Our goal was to develop a data-driven approach to identify treatment patterns in this cohort.

MATERIALS AND METHODS

In this cohort study, we extracted medical prescription histories from electronic health records. We developed a modified dynamic programming approach to perform global alignment of those medication histories. Our approach is unique since it considers time gaps in prescription patterns as part of the similarity strategy.

RESULTS

This study included 43 consecutive new-onset pre-pubertal patients who had at least 3 clinic visits. Our algorithm identified six clusters with distinct medication usage history which may represent clinician's practice of treating PANS of different severities and etiologies i.e., two most severe groups requiring high dose intravenous steroids; two arthritic or inflammatory groups requiring prolonged nonsteroidal anti-inflammatory drug (NSAID); and two mild relapsing/remitting group treated with a short course of NSAID. The psychometric scores as outcomes in each cluster generally improved within the first two years.

DISCUSSION AND CONCLUSION

Our algorithm shows potential to improve our knowledge of treatment patterns in the PANS cohort, while helping clinicians understand how patients respond to a combination of drugs.

PANS/PANDAS: Clinical Experience in IVIG Treatment and State of the Art in Rehabilitation Approaches

Pediatric acute-onset neuropsychiatric syndrome (PANS) is a condition characterized by the abrupt, dramatic onset of obsessive–compulsive disorder (OCD) or eating restriction accompanied by equally abrupt and severe comorbid neuropsychiatric symptoms. PANDAS (pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection) is a heterogeneous syndrome identified as post-Streptococcus pyogenes infection (β-hemolytic Streptococcus group A) complications regarding the central nervous system with specific involvement of neuropsychiatric and behavioral skills. In the first part of our study, we share our experience in the treatment of a group of extreme-grade (according to CY-BOCS severity scale) symptomatic patients with intravenous immunoglobulin (IVIG), following the most recent studies regarding the dosage of the drug. Our contribution is to share our experience made on a sample of 55 patients all in the highest level of a severity grade. In the second part of our study, we also analyze the literature on PANS/PANDAS rehabilitation therapy, since in the literature there is no discussion of union and comparison on this method. Objective: This study aims to evaluate the clinical features of the patients observed from different Italian cohorts, with the attempt at evaluating clinical response to IVIG treatment in children with an extreme severity grade of PANS/PANDAS disease. Furthermore, after having analyzed the literature, we propose rehabilitation therapy as an added value to the pharmacological treatment. Materials and Methods: A total of 55 patients with a diagnosis of PANS/PANDAS, who belonged to an extreme grade of disease, were enrolled. All patients were administered with IVIG treatment at 2 g/kg per day for two consecutive days. Results: From our study, a noticeable improvement (until complete remission) of symptoms was evident for at least one year in 47 out of 55 (85%) observed children, while 11 out of these 43 (25%) showed an evident symptoms remission in a single attempt and the remaining 32 (75%) required a second administration to notice a lasting symptomatic improvement.

The Challenge of Assessing Mild Neuroinflammation in Severe Mental Disorders

Recent psychoneuroimmunology research has provided new insight into the etiology and pathogenesis of severe mental disorders (SMDs). The mild encephalitis (ME) hypothesis was developed with the example of human Borna disease virus infection years ago and proposed, that a subgroup SMD patients, mainly from the broad schizophrenic and affective spectrum, could suffer from mild neuroinflammation, which remained undetected because hard to diagnose with available diagnostic methods. Recently, in neurology an emerging new subgroup of autoimmune encephalitis (AE) cases suffering from various neurological syndromes was described in context with the discovery of an emerging list of Central Nervous System (CNS) autoantibodies. Similarly in psychiatry, consensus criteria of autoimmune psychosis (AP) were developed for patients presenting with CNS autoantibodies together with isolated psychiatric symptoms and paraclinical findings of (mild) neuroinflammation, which in fact match also the previously proposed ME criteria. Nevertheless, identifying mild neuroinflammation in vivo in the individual SMD case remains still a major clinical challenge and the possibility that further cases of ME remain still under diagnosed appears an plausible possibility. In this paper a critical review of recent developments and remaining challenges in the research and clinical diagnosis of mild neuroinflammation in SMDs and in general and in transdisciplinary perspective to psycho-neuro-immunology and neuropsychiatry is given. Present nosological classifications of neuroinflammatory disorders are reconsidered with regard to findings from experimental and clinical research. A refined grading list of clinical states including "classical" encephalitis, AE, AP/ME,and newly proposed terms like parainflammation, stress-induced parainflammation and neuroprogression, and their respective relation to neurodegeneration is presented, which may be useful for further research on the possible causative role of mild neuroinflammation in SMDs. Beyond, an etiology-focused subclassification of ME subtypes, like autoimmune ME or infectious ME, appears to be required for differential diagnosis and individualized treatment. The present status of the clinical diagnosis of mild neuroinflammatory mechanisms involved in SMDs is outlined with the example of actual diagnosis and therapy in AP. Ideas for future research to unravel the contribution of mild neuroinflammation in the causality of SMDs and the difficulties expected to come to novel immune modulatory, anti-infectious or anti-inflammatory therapeutic principles in the sense of precision medicine are discussed.

CE: PANDAS: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infection

If undiagnosed and untreated, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) can suddenly and drastically disrupt the lives of previously healthy children and their families. The key to prompt diagnosis of PANDAS and its appropriate treatment is provider awareness that streptococcal infection may present with neuropsychiatric symptoms. The authors discuss the signs and symptoms that characterize PANDAS, as well as its presumed pathogenesis, and illustrate, through a composite case history, a symptom presentation, diagnostic journey, treatment course, and recovery that is representative of many PANDAS cases.

The Efficacy of Fecal Microbiota Transplantation for Children With Tourette Syndrome: A Preliminary Study

Therapies for Tourette syndrome (TS) are insufficient, and novel therapies are needed. Fecal microbiota transplantation (FMT) has been a potential therapy for several neurological diseases. Here, we report a preliminary study to investigate the effects of FMT on patients with TS. Five patients with TS received a single administration of FMT via endoscopy. Tic symptoms were assessed by Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS) and adverse effects were recorded at week 8 following FMT. Lipopolysaccharide (LPS) levels and 14 cytokines levels were measured. The microbiota profile in feces were analyzed by shotgun metagenomics. Four patients (4/5) responded positively to FMT (YGTSS-TTS reduction rate >25%) at week 8 with high safety. The levels of LPS and cytokines varied after FMT. FMT shifted the composition of the gut microbiota in patients close to that of the donor and continuously changed the abundance of Bacteroides coprocola, Dialister succinatiphilus and Bacteroides vulgatus. The restoration of B.coprocola was correlated with the improvement in tic symptoms (Spearman R = -0.900, P = 0.037). In conclusion, FMT was indicated a potential effective and safe alternative for patients with TS. However, larger clinical trials are needed to confirm the influence of microbiota in TS. Trial Registration: chictr.org.cn Identifier: ChiCTR-IIR-17011871, URL: http://www.chictr.org.cn/showproj.aspx?proj=19941.

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.

Obsessive-Compulsive Disorder

PURPOSE OF REVIEW

This article reviews current knowledge regarding diagnosis, pathophysiology, and treatment trends in obsessive-compulsive disorder (OCD), a severe, underrecognized, and chronic condition frequently encountered in neurologic practice.

RECENT FINDINGS

With a lifetime prevalence estimated at 2.5%, OCD is a common condition that can also present comorbidly with neurologic disease. The core symptoms of OCD are obsessions and compulsions. Obsessions are intrusive repetitive thoughts, urges, images, or impulses that trigger anxiety and that the individual is not able to suppress. Compulsions are repetitive behaviors or mental acts occurring in response to an obsession with the intention of reducing the distress caused by obsessions. Neuroimaging, neuropsychological, and pharmacologic studies suggest that the expression of OCD symptoms is associated with dysfunction in a cortico-striato-thalamo-cortical circuit. Evidence-based treatments for OCD comprise pharmacotherapy and cognitive-behavioral therapy. Selective serotonin reuptake inhibitors (SSRIs) are the first-line drugs recommended for OCD, but significant differences exist in their use for OCD compared to their use for other mood and anxiety conditions, including the need for higher dosage, longer trials necessitated by a longer lag for therapeutic response, and typically lower response rates. Cognitive-behavioral therapy, based on the principles of exposure and response prevention, shows results superior to pharmacologic treatments with lower relapse rates on long-term follow-up and thus should be considered in the treatment plan of every patient with OCD.

SUMMARY

OCD and obsessive-compulsive symptoms are frequently encountered in the neurologic clinic setting and require a high index of suspicion to effectively screen for them and an illness-specific therapeutic approach.

Eye movement desensitisation and reprocessing (EMDR) treatment associated with parent management training (PMT) for the acute symptoms in a patient with PANDAS syndrome: a case report

Background

The purpose of this report was to present the results of eye movement desensitisation and reprocessing (EMDR) therapy associated with parent management training (PMT) in a child with paediatric autoimmune neuropsychiatric disorder associated with streptococcus (PANDAS), who had previously only been treated with pharmacological treatment.

Case presentation

The case concerns an 11-year-old boy who presented with simple and complex vocal tics, motor tics, obsessive-compulsive traits and irritability from the age of 6 years, in addition to a positive result for streptococcal infection. The course of symptoms followed a relapsing-remitting trend with acute phases that were contingent on the infectious episodes.

Conclusions

Following eight sessions of EMDR, preceded by training sessions with the parents, the child showed a significant reduction in symptoms and disappearance of the exacerbation. These results indicate the possibility of improving the treatment outcomes of patients with PANDAS by a combined approach using both antibiotic and EMDR therapies.

Bartonella henselae Bloodstream Infection in a Boy With Pediatric Acute-Onset Neuropsychiatric Syndrome

Background:

With the advent of more sensitive culture and molecular diagnostic testing modalities, Bartonella spp. infections have been documented in blood and/or cerebrospinal fluid specimens from patients with diverse neurological symptoms. Pediatric acute-onset neuropsychiatric syndrome (PANS) is characterized by an unusually abrupt onset of cognitive, behavioral, or neurological symptoms. Between October 2015 and January 2017, a 14-year-old boy underwent evaluation by multiple specialists for sudden-onset psychotic behavior (hallucinations, delusions, suicidal and homicidal ideation).

Methods:

In March 2017, Bartonella spp. serology (indirect fluorescent antibody assays) and polymerase chain reaction (PCR) amplification, DNA sequencing, and Bartonella enrichment blood culture were used on a research basis to assess Bartonella spp. exposure and bloodstream infection, respectively. PCR assays targeting other vector-borne infections were performed to assess potential co-infections.

Results:

For 18 months, the boy remained psychotic despite 4 hospitalizations, therapeutic trials involving multiple psychiatric medication combinations, and immunosuppressive treatment for autoimmune encephalitis. Neurobartonellosis was diagnosed after cutaneous lesions developed. Subsequently, despite nearly 2 consecutive months of doxycycline administration, Bartonella henselae DNA was PCR amplified and sequenced from the patient’s blood, and from Bartonella alphaproteobacteria growth medium enrichment blood cultures. B henselae serology was negative. During treatment with combination antimicrobial chemotherapy, he experienced a gradual progressive decrease in neuropsychiatric symptoms, cessation of psychiatric drugs, resolution of Bartonella-associated cutaneous lesions, and a return to all pre-illness activities.

Conclusions:

This case report suggests that B henselae bloodstream infection may contribute to progressive, recalcitrant neuropsychiatric symptoms consistent with PANS in a subset of patients.

Why chronic cough in children is different

Recently, there have been robust changes in our knowledge of the neurophysiology of cough and novel clinical etiologies. Specifically, cough hypersensitivity in adults and protracted bacterial bronchitis (PBB) in children have been increasingly investigated, and differences between chronic cough in children and adults have been widely reported. In young children, postinfectious cough, bronchiectasis, airway malacia, PBB, and asthma appear to be the main causes of cough; however, by adolescence, the causes of cough are more likely to become those common in adults, namely, gastroesophageal reflux, asthma, and upper airway syndrome. These differences are attributed to changes in various characteristics of the respiratory tract, immune system, and nervous system between children and adults. New knowledge about the neural aspects of cough has revealed a complex network of pathways that initiate cough. The effect of inflammation on cough neural processing occurs at multiple peripheral and central sites within the nervous system. Evidence exists that direct or indirect neuroimmune interaction induces a complex response, which can be altered by mediators released by the sensory or parasympathetic neurons and vice versa. During childhood, the respiratory tract and the nervous system undergo a series of anatomical and physiological maturation processes that produce the cough neural circuits. Alterations provoked by various pathological processes, noxious agents, infection, and inflammation during the developmental period can lead to persistent or irreversible modifications, which may explain why many adult patients, in addition to expressing high cough sensitivity, remain refractive to disease-specific therapies.

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

BACKGROUND

Paediatric acute-onset neuropsychiatric syndrome (PANS) is a newly defined symptom-based condition that mainly occurs in children and adolescents. Few studies have described the clinical characteristics of the syndrome.

METHODS

We clinically assessed and reviewed the medical histories of children and adolescents (aged 4-14 years) with suspected PANS who were referred to a specialist clinic in Gothenburg, Sweden, by local paediatricians and child psychiatrists. We scored severity of symptoms and impairment retrospectively for the timepoint with the most severe symptoms using the PANS scale.

FINDINGS

Of 41 patients (37 referred and four visited upon parents' request), 23 (ten girls and 13 boys) met PANS diagnostic criteria. Mean age at PANS onset was 8·5 years (SD 3·37). 11 (48%) patients had a family history of developmental or neuropsychiatric disorders in a first-degree relative and 11 (48%) had a family history of autoimmune or inflammatory diseases in a first-degree relative. 17 (74%) patients had been previously diagnosed with a developmental disorder (n=5) or had symptoms indicative of developmental problems (n=12). A verified or suspected infection was temporally related to PANS onset in all patients; the infection was bacterial in ten (43%) patients (eight had streptococcal infection and two an infection caused by other bacteria) and viral in 13 (57%) patients. All patients had a relapsing-remitting course of illness. The mean PANS scale symptom score was 46 (SD 3·67) and the mean impairment score was 45 (2·74). Antibiotic treatment was reported as beneficial by the parents of 12 (63%) of the 19 children who received antibiotics.

INTERPRETATION

Our PANS cohort had severe, acute-onset, complex neuropsychiatric symptoms, a relapsing-remitting symptom course, and possible infectious triggers. Further research into the cause of, and appropriate treatment for, PANS is warranted.

FUNDING

Swedish Brain Foundation.

European Multicentre Tics in Children Studies (EMTICS): protocol for two cohort studies to assess risk factors for tic onset and exacerbation in children and adolescents

Genetic predisposition, autoimmunity and environmental factors [e.g. pre- and perinatal difficulties, Group A Streptococcal (GAS) and other infections, stress-inducing events] might interact to create a neurobiological vulnerability to the development of tics and associated behaviours. However, the existing evidence for this relies primarily on small prospective or larger retrospective population-based studies, and is therefore still inconclusive. This article describes the design and methodology of the EMTICS study, a longitudinal observational European multicentre study involving 16 clinical centres, with the following objectives: (1) to investigate the association of environmental factors (GAS exposure and psychosocial stress, primarily) with the onset and course of tics and/or obsessive-compulsive symptoms through the prospective observation of at-risk individuals (ONSET cohort: 260 children aged 3-10 years who are tic-free at study entry and have a first-degree relative with a chronic tic disorder) and affected individuals (COURSE cohort: 715 youth aged 3-16 years with a tic disorder); (2) to characterise the immune response to microbial antigens and the host's immune response regulation in association with onset and exacerbations of tics; (3) to increase knowledge of the human gene pathways influencing the pathogenesis of tic disorders; and (4) to develop prediction models for the risk of onset and exacerbations of tic disorders. The EMTICS study is, to our knowledge, the largest prospective cohort assessment of the contribution of different genetic and environmental factors to the risk of developing tics in putatively predisposed individuals and to the risk of exacerbating tics in young individuals with chronic tic disorders.

PANDAS/PANS in childhood: Controversies and evidence

Since first defined in 1998, paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) and its later, broader iteration, paediatric acute-onset neuropsychiatric syndrome (PANS), have garnered significant attention and controversy. The role of streptococcal infection in children with explosive onset obsessive-compulsive disorder and new onset tics, the natural history of this entity, and the role of symptomatic and disease-modifying therapies, including antibiotics, immunotherapy, and psychoactive drugs, are all issues that have yet to be definitively addressed. While definitive proof of the autoimmune hypothesis of PANDAS is lacking, given the heightened attention to this entity and apparent rise in use of this diagnostic category, addressing questions around diagnosis, treatment, and etiology is imperative. In this paper, we review current working definitions of PANDAS/PANS, discuss published evidence for interventions related to this entity, and propose a clinical approach to children presenting with acute symptoms satisfying criteria for PANDAS/PANS.

Continued Presence of Period Limb Movements During REM Sleep in Patients With Chronic Static Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS)

STUDY OBJECTIVES

A major component of pediatric acute-onset neuropsychiatric syndrome (PANS) is disruption of sleep. These disturbances have been reported in the acute phase of diagnosis but it is unknown if these sleep disruptions persist, especially in patients with chronic static symptoms. This retrospective chart review sought to review polysomnography (PSG) tests of patients in whom PANS has been clinically diagnosed in order to assess sleep architecture, periodic limb movements, and presence of rapid eye movement (REM) sleep without atonia (RSWA) after a chronic static course of symptoms, which were refractory to immunomodulatory interventions.

METHODS

Patients were retrospectively identified through the PANS clinic at our institution and had to have fully completed a PSG study and be younger than 18 years. PSG with video were reviewed and scored based on established criteria.

RESULTS

We identified 9 patients who met inclusion criteria. The median time from presentation to PSG was 4 years. This study identified PSG-measured periodic limb movement index (PLMI) > 5 events/h in REM sleep in 7 of 9 patients. Two patients with elevated PLMI also demonstrated RSWA, although neither fit a clinical diagnosis of REM sleep behavior disorder. This cohort also demonstrated increased onset of REM sleep (median 134 minutes), insomnia (median total sleep time of 389 minutes), and decreased sleep efficiency (77%).

CONCLUSIONS

This study identifies continued sleep disturbances in patients with refractory PANS symptoms several years after diagnosis and treatment. Continued sleep disturbances after presentation and treatment in patients with chronic static PANS may be a contributing factor in prolonged symptomatology of this disease process.

Longitudinal outcomes of children with pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS)

Little is known about the natural history of children with pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS). This study prospectively followed 33 children with PANDAS for up to 4.8 years (mean 3.3 ± 0.7 years) after enrollment in a 24-week randomized, double-blind, placebo-controlled trial of intravenous immunoglobulin (IVIG) (N = 35). Fourteen of eighteen children randomized to placebo received open label IVIG 6 weeks after the blinded infusion, so follow-up results reported below largely reflect outcomes in a population of children who received at least one dose of IVIG. Telephone interviews with the parents of participants found that at the time of phone follow-up, 29 (88%) were not experiencing clinically significant obsessive-compulsive symptoms. During the interim period (6-57 months after entering the clinical trial), 24 (72%) had experienced at least one exacerbation of PANDAS symptoms, with a median of one exacerbation per child (range 1-12; interquartile range 0-3). A variety of treatment modalities, including antibiotics, IVIG, psychiatric medications, cognitive behavioral therapy, and others, were used to treat these exacerbations, and were often used in combination. The outcomes of this cohort are better than those previously reported for childhood-onset OCD, which may support conceptualization of PANDAS as a subacute illness similar to Sydenham chorea. However, some children developed a chronic course of illness, highlighting the need for research that identifies specific symptoms or biomarkers that can be used to predict the longitudinal course of symptoms in PANDAS.

Cross-Sectional Evaluation of Plasma Vitamin D Levels in a Large Cohort of Italian Patients with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections

BACKGROUND

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) are immune-mediated diseases characterized by obsessive-compulsive symptoms and/or tics triggered by group A Streptococcus infections. Despite the well-known action of 25-hydroxyvitamin D [25(OH)D] on different conditions driven by systemic inflammation, there are no data about the 25(OH)D status in patients with PANDAS.

AIMS

To evaluate plasma 25(OH)D levels in a large cohort of children and adolescents with PANDAS and comparing the results with healthy controls.

METHODS

We have evaluated plasma 25(OH)D levels in 179 Italian patients with PANDAS (49 females, 130 males, mean age at diagnosis: 101.4 ± 30.1 months) and in an age-, gender-, and body mass index-matched control group of 224 healthy subjects.

RESULTS

Patients with PANDAS have shown more frequently reduced 25(OH)D levels (<30 ng/mL) in comparison with controls (94.6% vs. 82.5%, p = 0.0007). Patients with PANDAS had also lower levels of 25(OH)D than controls (20.4 ± 6.9 ng/mL vs. 24.8 ± 7.3 ng/mL, p < 0.0001). This difference was observed during both winter (13.7 ± 3.25 ng/mL vs. 21.4 ± 5.9 ng/mL, p < 0.0001) and summer (21.8 ± 6.5 ng/mL vs. 32.5 ± 8.7 ng/mL, p < 0.0001). Notably, serum 25(OH)D levels correlated with both number of streptococcal (strep) infections before diagnosis of PANDAS (p < 0.005) and with infection recurrence (p < 0.005).

CONCLUSIONS

PANDAS patients have reduced 25(OH)D levels, which appear related to streptococcal infections and the probability of recurrence. Further long-term studies with higher number of patients are needed to investigate and confirm this relationship.

Open-label pilot for treatment targeting gut dysbiosis in myalgic encephalomyelitis/chronic fatigue syndrome: neuropsychological symptoms and sex comparisons

BACKGROUND

Preliminary evidence suggests that the enteric microbiota may play a role in the expression of neurological symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Overlapping symptoms with the acute presentation of D-lactic acidosis has prompted the use of antibiotic treatment to target the overgrowth of species within the Streptococcus genus found in commensal enteric microbiota as a possible treatment for neurological symptoms in ME/CFS.

METHODS

An open-label, repeated measures design was used to examine treatment efficacy and enable sex comparisons. Participants included 44 adult ME/CFS patients (27 females) from one specialist medical clinic with Streptococcus viable counts above 3.00 × 105 cfu/g (wet weight of faeces) and with a count greater than 5% of the total count of aerobic microorganisms. The 4-week treatment protocol included alternate weeks of Erythromycin (400 mg of erythromycin as ethyl succinate salt) twice daily and probiotic (D-lactate free multistrain probiotic, 5 × 1010 cfu twice daily). 2 × 2 repeated measures ANOVAs were used to assess sex-time interactions and effects across pre- and post-intervention for microbial, lactate and clinical outcomes. Ancillary non-parametric correlations were conducted to examine interactions between change in microbiota and clinical outcomes.

RESULTS

Large treatment effects were observed for the intention-to-treat sample with a reduction in Streptococcus viable count and improvement on several clinical outcomes including total symptoms, some sleep (less awakenings, greater efficiency and quality) and cognitive symptoms (attention, processing speed, cognitive flexibility, story memory and verbal fluency). Mood, fatigue and urine D:L lactate ratio remained similar across time. Ancillary results infer that shifts in microbiota were associated with more of the variance in clinical changes for males compared with females.

CONCLUSIONS

Results support the notion that specific microorganisms interact with some ME/CFS symptoms and offer promise for the therapeutic potential of targeting gut dysbiosis in this population. Streptococcus spp. are not the primary or sole producers of D-lactate. Further investigation of lactate concentrations are needed to elucidate any role of D-lactate in this population. Concurrent microbial shifts that may be associated with clinical improvement (i.e., increased Bacteroides and Bifidobacterium or decreased Clostridium in males) invite enquiry into alternative strategies for individualised treatment. Trial Registration Australian and New Zealand Clinical Trial Registry (ACTRN12614001077651) 9th October 2014. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366933&isReview=true.

Psychoneuroimmunology of mental disorders

The immune system is a key element in the organism's defence system and participates in the maintenance of homeostasis. There is growing interest in the aetiopathogenic and prognostic implications of the immune system in mental disorders, as previous studies suggest the existence of a dysregulation of the immune response and a pro-inflammatory state in patients with mental disorders, as well as an increased prevalence of neuropsychiatric symptoms in patients suffering from autoimmune diseases or receiving immune treatments. This study aims to conduct a narrative review of the scientific literature on the role of Psychoneuroimmunology in mental disorders, with special focus on diagnostic, prognostic and therapeutic issues. The development of this body of knowledge may bring in the future important advances in the vulnerability, aetiopathogenic mechanisms, diagnosis and treatment of some mental disorders.