Evaluation of a neuropsychiatric disorder: From PANDAS to PANS and CANS

Abstract

PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections) syndrome is a disorder that presents itself before adolescence with an abrupt onset of obsessive-compulsive disorder symptoms and/or tics. This disorder is related to Group A streptococcal (GAS) infection with neurological findings, such as motor hyperactivity and choreiform movements. The progress of the disorder may be described as wax-and-waning apart from abrupt onset and this remitting and relapsing course is associated with exacerbating infections, according to the creators of PANDAS syndrome. The ruling out of rheumatoid fever and Sydenham's chorea is necessary for making a proper diagnosis. Since the recognition of this syndrome, clinicians have encountered many children who did not fulfill all 5 criteria for PANDAS classification, which must be met for diagnosis. Since literature findings show a lack or absence of strong evidence for a major role of GAS, the newly-defined categories PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) and CANS (Childhood Acute Neuropsychiatric Syndrome) were created to encompass non- PANDAS patients who "almost meet" the criteria. PANS and CANS include significant psychiatric symptoms that associate with abrupt onset of OCD symptoms and/or tics but do not require identification of any infection agents, immune dysfunctions, or environmental precipitants. In this paper, we aimed to discuss the diagnosis of PANS/CANS on the basis of a case in which the patient developed an abrupt onset of anxiety, obsessions, and vocal tics following an infection. The progress of PANDAS classification criteria and the diagnosis category whereby patients 'almost meet' the criteria for PANDAS diagnosis are discussed.