The PANDAS Controversy: Why (and How) Is It Still Unsettled?

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.

Plasmapheresis, Rituximab, and Ceftriaxone Provided Lasting Improvement for a 27-Year-Old Adult Male with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS)

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) is a specific autoimmune response to group-A streptococcal (GAS) infections in children and adolescents with a sudden onset of neuropsychiatric disorders including obsessive-compulsive disorder (OCD) or tic-like symptoms. We present a case report of a 27-year-old male patient who had lasting improvement with plasmapheresis, rituximab, and ceftriaxone. Our patient first developed sudden psychosis and confusion after GAS infections at age 17. He had elevated anti-streptolysin O (ASO) titers, negative urine drug screen, no ETOH in blood, normal CBC, normal TSH, normal salicylate, normal acetaminophen, and a normal head CT. The tentative diagnosis of PANDAS was made, and the patient was thereafter treated with antipsychotics, antibiotics, tonsillectomy, and IVIG which resulted in remissions and relapses of his neuropsychiatric symptoms. Once he reached age 27, he received a trial of therapeutic plasma exchange (TPE), rituximab, and ceftriaxone. This eventually resulted in sustained benefit and minimal fluctuations of his clinical symptoms. Our report is noteworthy in three ways.One, he is a 27-year-old adult with PANDAS.Two, he improved after TPE, rituximab, and ceftriaxone. Our literature search yielded minimal data on the use of plasmapheresis for nonteenage adults with PANDAS. Three, he had unusual symptoms of PANDAS, as the typical OCD and/or tic-like symptoms were not observed.

Alterations in the Nervous System and Gut Microbiota after β-Hemolytic Streptococcus Group A Infection-Characteristics and Diagnostic Criteria of PANDAS Recognition

The objective of this paper is to review and summarize conclusions from the available literature regarding Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). The authors have independently reviewed articles from 1977 onwards, primarily focusing on the etiopathology, symptoms, differentiation between similar psychiatric conditions, immunological reactions, alterations in the nervous system and gut microbiota, genetics, and the available treatment for PANDAS. Recent research indicates that PANDAS patients show noticeable alterations within the structures of the central nervous system, including caudate, putamen, globus pallidus, and striatum, as well as bilateral and lentiform nuclei. Likewise, the presence of autoantibodies that interact with basal ganglia was observed in PANDAS patients. Several studies also suggest a relationship between the presence of obsessive-compulsive disorders like PANDAS and alterations to the gut microbiota. Further, genetic predispositions-including variations in the MBL gene and TNF-α-seem to be relevant regarding PANDAS syndrome. Even though the literature is still scarce, the authors have attempted to provide a thorough insight into the PANDAS syndrome, bearing in mind the diagnostic difficulties of this condition.

Neuropsychiatric symptoms following sore throat in a young boy

A previously healthy 6-year-old boy was referred to us by his primary provider, with a history of sudden onset behavioural abnormalities including irritability, sleep disturbance and anxiety. Physical examination revealed no significant findings; further analyses were not suggestive of meningitis, encephalitis, metabolic abnormalities, toxicity or any other obvious cause. On rechecking the patient's history, an episode of throat pain 1 week prior to the symptom onset was noted. Therefore, the possibility of paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) was considered. The antistreptolysin O titre was high (1078 IU/mL), and it increased to 1194 IU/mL 4 weeks later, leading to a diagnosis of PANDAS. He was started on ampicillin and administered one dose of intravenous immunoglobulin. His abnormal behaviours subsided and he returned to a normal state within 48 hours of treatment. This report aims to provide insights into the symptomology and diagnosis of PANDAS in children.

Prevalence of Acute-Onset Subtypes in Pediatric Obsessive-Compulsive Disorder

BACKGROUND

Pediatric obsessive-compulsive disorder (OCD) is a common, debilitating illness. When childhood OCD symptom onset is described as acute and severe, diagnostic criteria for pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) and pediatric acute-onset neuropsychiatric syndrome (PANS) should be considered. However, the frequency and differentiating features of these putative syndromes within pediatric OCD remain poorly understood.

OBJECTIVES

To determine the prevalence and characteristics of those meeting PANDAS and/or PANS criteria within pediatric OCD, as determined by parent report and clinician interview.

METHODS

Consecutive youth presenting to a subspecialty pediatric OCD clinic were rigorously assessed through the Anxiety Disorders Interview Schedule for DSM-IV, the Children's Yale-Brown Obsessive-Compulsive Scale, and through self- and parent-report measures, including a medical questionnaire. Strict diagnostic criteria for PANDAS and PANS were applied to determine prevalence rates, and comparative analyses were performed between subgroups.

RESULTS

Among 136 youth with a lifetime OCD diagnosis, 5% (n = 7; 95% adjusted Wald interval: 1%-10%) met proposed criteria for PANDAS and/or PANS, of whom two met PANDAS criteria, four met PANS criteria, and one met criteria for both. Those in the PANDAS/PANS subgroup were more likely to have autoimmune illness, less likely to report symmetry factor symptoms, and had greater OCD-related family impairment during their worst OCD episode.

CONCLUSION

A small yet significant percentage of pediatric OCD outpatients met criteria for PANDAS and/or PANS, justifying routine screening and attention to related characteristics during assessment and management. Longitudinal studies of these putative subtypes are warranted.