Pediatric early-onset neuropsychiatric obsessive compulsive disorders.

At the time of this writing, most pediatricians or child psychiatrists will probably have treated a child with early acute-onset obsessive compulsive disorder (OCD) behaviors due to the pediatric autoimmune neuropsychiatric disorder associated with Group A beta-hemolytic streptococcus, abbreviated PANDAS, described more than two decades ago; or Tourette syndrome, incorporating motor and vocal tics, described more than a century ago. One typically self-limited post-infectious OCD resulting from exposure to other putative microbial disease triggers defines PANS, abbreviating pediatric autoimmune neuropsychiatric syndrome. Tourette syndrome, PANDAS and PANS share overlapping neuroimaging features of hypometabolism of the medial temporal lobe and hippocampus on brain 18Fluorodeoxyglucose positron emission tomography fused to magnetic resonance imaging (PET/MRI) consistent with involvement of common central nervous system (CNS) pathways for the shared clinical expression of OCD. The field of pediatric neuropsychiatric disorders manifesting OCD behaviors is at a crossroads commensurate with recent advances in the neurobiology of the medial temporal area, with its wide-ranging connectivity and cortical cross-talk, and CNS immune responsiveness through resident microglia. This review advances the field of pediatric neuropsychiatric disorders and in particular PANS, by providing insights through clinical vignettes and descriptive clinical and neuroimaging correlations from the author's file. Neuroscience collaborations with child psychiatry and infectious disease practitioners are needed to design clinical trials with the necessary rigor to provide meaningful insights into the rational clinical management of PANS with the aim of developing evidence-based guidelines for the clinical management of early, abrupt-onset childhood OCD to avert potentially life-long neuropsychological struggles.