Research

Bartonella henselae, Babesia odocoilei and Babesia divergens-like MO-1 infection in the brain of a child with seizures, mycotoxin exposure and suspected Rasmussen’s encephalitis
Breitschwerdt EB, Maggi RG, Robveille C, Kingston E. Bartonella henselae, Babesia odocoilei and Babesia divergens-like MO-1 infection in the brain of a child with seizures, mycotoxin exposure and suspected Rasmussen’s encephalitis. J Cent Nerv Syst Dis. 2025 Mar 12;17:11795735251322456. doi: 10.1177/11795735251322456. PMID: 40083671; PMCID: PMC11905044.
  • Despite cat and suspected tick exposure, Bartonella henselae and Borrelia burgdorferi serology remained negative.
  • Neurodiagnostic testing partially supported Rasmussen’s encephalitis; brain biopsy showed astrogliosis.
  • Bartonella henselae DNA was detected in brain tissue cultures.
  • Babesia odocoilei and Babesia divergens-like MO-1 were confirmed in blood and brain tissue from 2022–2023.
  • Infections, compounded by mycotoxin exposure, created a complex clinical case.
Obsessive Compulsive Disorder associated with Autoimmunity in Youth: Clinical Course before and after Rituximab+/- Adjunctive Immunomodulation
Frankovich J, Calaprice D, Ma M, Knight O, Miles K, Manko C, Hernandez JD, Sandberg J, Farhadian B, Xie Y, Silverman M, Madan J, Strand V, Chang K, Thienemann M. Obsessive Compulsive Disorder associated with Autoimmunity in Youth: Clinical Course before and after Rituximab+/- Adjunctive Immunomodulation. Dev Neurosci. 2025 Mar 10:1-26. doi: 10.1159/000544993. Epub ahead of print. PMID: 40064151.
  • Case review (n=23) from Stanford on their use of rituximab for presumed-neuroimmune and severe OCD in youth
  • Some (47.8%) experienced transient increases in psychiatric or joint pain symptoms before signs of improvement. The time frame for signs of improvement was 3-4 months. 
  • 70% achieved full or partial recovery at 1-5 years.
  • Receiving adjunct immunomodulation was associated with a higher likelihood of achieving full or partial recovery compared with those without adjunct immunomodulation
Neuroinflammation and pathways that contribute to Tourette Syndrome

Wu, X., Hao, J., Jiang, K. et al. Neuroinflammation and pathways that contribute to tourette syndrome. Ital J Pediatr 51, 63 (2025). https://doi.org/10.1186/s13052-025-01874-3

  • Tourette Syndrome (TS): A neurodevelopmental disorder characterized by motor and vocal tics, often co-occurring with ADHD, OCD, and other psychological issues.
  • Neurotransmitter Imbalances: TS is traditionally linked to neurotransmitter disruptions, especially within the cortex-striatum-thalamus-cortex circuit, involving dopamine and glutamate.
  • Neuroinflammation: Emerging research shows neuroinflammation, often triggered by infections or allergies, contributes to neurotransmitter imbalances that may induce tics.
  • Infectious Triggers: Streptococcal infections (e.g., PANDAS), viral infections (e.g., enterovirus, COVID-19), and other pathogens (e.g., Chlamydia, Mycoplasma) are linked to TS exacerbation.
  • Immune Mechanisms: Inflammatory responses activate microglia and the peripheral immune system, disrupting neurotransmitter balance and leading to tics.
Fluoxetine promotes IL-10-dependent metabolic defenses to protect from sepsis-induced lethality
Gallant RM, Sanchez KK, Joulia E, Snyder JM, Metallo CM, Ayres JS. Fluoxetine promotes IL-10-dependent metabolic defenses to protect from sepsis-induced lethality. Sci Adv. 2025 Feb 14;11(7):eadu4034. doi: 10.1126/sciadv.adu4034. Epub 2025 Feb 14. PMID: 39951524; PMCID: PMC11827869.
  • SSRIs Overview: Among the most prescribed drugs globally, primarily used to enhance serotonergic signaling in the brain.
  • Beyond the Brain: SSRIs also impact immune and metabolic functions.
  • Infection Protection: Studies show SSRIs, including fluoxetine, protect against infections like sepsis and COVID-19, though mechanisms remain unclear.
  • Key Findings on Fluoxetine:Protection is independent of peripheral serotonin.
    • Increases circulating interleukin-10 (IL-10) levels.
    • IL-10 prevents sepsis-induced hypertriglyceridemia and associated cardiac issues (glucose oxidation impairment, lipid accumulation, ventricular stretch, potential cardiac failure).
  • Therapeutic Potential: Fluoxetine’s “off-target” effects offer a protective immunometabolic mechanism with possible clinical applications.
Frequency and impact of paediatric acute-onset neuropsychiatric syndrome/paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections diagnosis in Canada

Rachel Goren, Ari Bitnun, Asif Doja, Peter J Gill, Ronald M Laxer, Deborah M Levy, Tamara Pringsheim, Paul Sandor, Eluen Ann Yeh, Colin Wilbur, Sefi Kronenberg, Michelle Shouldice, Frequency and impact of paediatric acute-onset neuropsychiatric syndrome/paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections diagnosis in Canada, Paediatrics & Child Health, 2024;, pxae092, https://doi.org/10.1093/pch/pxae092

In a Canadian study, a significant percentage of children diagnosed with PANDAS/PANS had OCD and/or tics, with the majority experiencing at least two neuropsychiatric symptoms, and healthcare utilization was high, including emergency visits and inpatient admissions

  • The Canadian Paediatric Surveillance Program estimated that the prevalence of PANS/PANDAS was 1 in 60,115 (0.0017%) for children ages 3 through 18 years
  • The core diagnostic criteria of OCD, tics, or acute food refusal was absent in 12% of cases with 22% reporting sudden symptom onset
  • Infection was associated with onset or exacerbation in less than 1 out of every 3 cases
  • Most of the population exhibited 2+ neuropsychiatric symptoms with significant health care utilization amongst cases

 

The pattern of childhood infections during and after the COVID-19 pandemic
Nygaard U, Holm M, Rabie H, Rytter M. The pattern of childhood infections during and after the COVID-19 pandemic. Lancet Child Adolesc Health. 2024 Dec;8(12):910-920. doi: 10.1016/S2352-4642(24)00236-0. PMID: 39572124.
  • Initial Decline: Pediatric infections dropped during COVID-19 due to safety measures.
  • Post-Pandemic Surge: Infections rebounded as restrictions eased, with changes in severity, strains, and affected age groups.
  • Key Cause: Immunity debt from reduced exposure, not new variants or resistance.
  • Impact: Unusual symptoms emerged, offering new insights into disease spread and progression.
TIC-TOC: PANDAS syndrome (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection) and psychiatric pathology in children and adolescents

Hilario Blasco-Fontecilla, Victor del Rio-Peña, Ping Wang, Chao Li, Marina Martin-Moratinos, Marcos Bella-Fernández, Trastorno por tics y trastorno obsesivo compulsivo: Trastornos neuropsiquiátricos pediátricos autoinmunes asociados a infecciones por estreptococos (PANDAS) y enfermedades psiquiátricas en niños y adolescentes, Psiquiatría Biológica, Volume 31, Supplement 1, 2024,100554, ISSN 1134-5934,https://doi.org/10.1016/j.psiq.2024.100554.

  • Study Overview: Compared 801 children with and without ASLO positivity (Antistreptolysin O, a marker of past strep infection).
  • ASLO-positive kids are 7x more likely to have tics & OCD.
  • More ER visits and higher trauma/fracture rates.
  • No link to ADHD or academic performance.
IVIG response in pediatric acute-onset neuropsychiatric syndrome correlates with reduction in pro-inflammatory monocytes and neuropsychiatric measures
Melamed, Isaac, et al.“IVIG Response in Pediatric Acute-onset Neuropsychiatric Syndrome Correlates with Reduction in Pro-inflammatory Monocytes and Neuropsychiatric Measures.”Frontiers in Immunology, vol. 15, 2024, p. 1383973, https://doi.org/10.3389/fimmu.2024.1383973. Accessed 3 Oct. 2024.
  • Study aimed to investigate the pro-inflammatory state in PANS patients before and after IVIG treatment.
  • Ten male PANS patients (ages 6–16) received six IVIG infusions over 3 weeks.
  • Blood samples and psychiatric assessments were taken before treatment and at follow-up points (4 and 11 weeks post-treatment).
  • Myeloid cell activation was analyzed using flow cytometry.* Significant improvement in all psychiatric assessments and parent-reported outcomes (CY-BOCS, YGTSS, and PANS rating scales; all p<0.001).
  • Pro-inflammatory monocytes and dendritic cells significantly decreased after IVIG.
  • Reduction in pro-inflammatory monocytes was observed both proportionally and in absolute numbers.
Obsessive Compulsive Disorder and Other Specified Anxiety Disorder in an 8-Year-Old Post-respiratory Infection: A Case Report

Tran, Michael; Amador, Alcides; and Camacho Bermudez, Sofia, “Obsessive Compulsive Disorder and Other Specified Anxiety Disorder in an 8-Year-Old Post-respiratory Infection: A Case Report” (2024). Research Colloquium. 91.https://scholarworks.utrgv.edu/colloquium/2024/posters/91

Conclusions: This case underscores the importance of considering infectious etiologies in the differential diagnosis of sudden-onset psychiatric symptoms in pediatric patients. The positive response to Sertraline and the proposed CBT highlights the potential benefits of a combined pharmacological and therapeutic approach in managing OCD and anxiety disorders. Continued follow-up and treatment adaptation is essential to ensure sustained improvement and quality of life for pediatric patients with similar presentations.

A population-based multigenerational family co-aggregation study of severe infections and obsessive-compulsive disorder

Pol-Fuster J., Fernández de la Cruz L., Beucke J., Hesselmark E., Crowley J.J., de Schipper E., Brikell I., Chang Z., D’Onofrio B.M., Larsson H., Lichtenstein P., Kuja-Halkola, R. & Mataix-Cols D., A population-based multigenerational family co-aggregation study of severe infections and obsessive-compulsive disorder, Biological Psychiatry (2024), doi: https://doi.org/10.1016/ j.biopsych.2024.09.004.

This large population-based study in Sweden investigated the potential link between severe infections and obsessive-compulsive disorder (OCD) through a familial co-aggregation approach. By analyzing data from over 4.9 million individuals born between 1960 and 2008, researchers explored the risk of OCD among relatives of those with severe infections, spanning varying degrees of genetic relatedness. The study found that the risk of OCD increased with closer genetic ties, with monozygotic twins showing the highest correlation. A dose-response relationship between the number of infections and the odds of OCD was also identified. These findings remained robust even after adjusting for comorbid autoimmune disorders and infections in relatives. The results suggest that genetic factors play a significant role in the observed association, pointing to shared genetic susceptibilities between infections and OCD. This supports the idea that genetic pleiotropy—where the same genes influence multiple traits—may contribute to both infection susceptibility and OCD risk. The study highlights the importance of considering both genetic and environmental factors in understanding OCD development.

Reliability and validity of a newly developed PANDAS/PANS questionnaire
Bleibach A, Sørensen CB, Skov L, Christensen KB, Debes NM. Reliability and validity of a newly developed PANDAS/PANS questionnaire. Eur J Paediatr Neurol. 2024 Sep;52:109-130. doi: 10.1016/j.ejpn.2024.07.008. Epub 2024 Jul 15. PMID: 39232358.
The validity and clinical feasibility of the PANDAS/PANS questionnaire were confirmed as an effective tool for screening symptoms, assessing symptom severity, and evaluating comorbidity and daily life impairment in individuals with PANDAS/PANS. These findings can potentially enhance the management of PANDAS/PANS patients in both clinical and research settings.