PANDAS and PANS: Clinical, Neuropsychological, and Biological Characterization of a Monocentric Series of Patients and Proposal for a Diagnostic Protocol.

Objectives: Whether PANS (pediatric acute-onset neuropsychiatric syndrome) and PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection) represent true clinical entities is debated and data for a characteristic phenotype are still controversial. In this study, we aim to characterize clinical, neuropsychological, and biochemical aspects in a sample of PANS and PANDAS patients. Methods: Patients fulfilling a clinical diagnosis of PANS or PANDAS from 2014 to 2017 were enrolled. Neurological and psychiatric examination and biochemical and instrumental assessment results were collected. A neuropsychological battery was administered. For comparison purposes, a control group of patients with Sydenham's chorea (SC) was evaluated. Descriptive and comparative statistical analyses were performed. Results: Seven subjects received a diagnosis of PANS, 12 of PANDAS, and 11 of SC. Clinical presentation of PANS children showed statistically significant differences compared with both PANDAS and SC, in particular, with the presence of obsessive symptoms, behavioral regression, and somatic symptoms in the first group. Moreover, all PANS patients showed some neuropsychological deficits in visual-motor abilities, short- and long-term memory, and processing speed. Conclusions: Our experience confirms that patients with PANS had a complex clinical presentation and a compromised neuropsychological profile with respect to patients with PANDAS or SC. However, the absence of biological markers or instrumental alterations made the diagnosis of the two entities, PANS and PANDAS, a matter of exclusion. For these reasons, we propose a pilot diagnostic protocol that (when applied in a prospective manner) will allow comparison with similar childhood-onset neuropsychiatric disorders, such as obsessive-compulsive or tic disorders, and efficacy evaluation of different therapeutic approaches.