Rapid Onset Functional Tic-Like Disorder Outbreak: A Challenging Differential Diagnosis in the COVID-19 Pandemic.

During the COVID-19 pandemic, several countries have observed an unexpected increase in the number of adolescents and young adults presenting with rapid onset functional tic-like behaviours after being exposed to social media content of others displaying a similar pattern of functional tics. Many of these patients have been referred to Movement Disorders Clinics with misdiagnoses of late-onset refractory Tourette Syndrome after failing different pharmacological treatments for tics. Tourette Syndrome is a well-known condition with clear clinical diagnostic criteria and which presents with the insidious onset of simple motor and phonic tics in a rostro-caudal evolution starting in early childhood. Clinical and demographic aspects can differentiate rapid onset functional tic-like behaviours from Tourette Syndrome, including the former having abrupt and explosive presentation of severe symptoms, later age of onset, female gender predominance, lack of suppressibility, comorbid anxiety and depression, atypical premonitory urge and history of exposure to social media content displaying tic-like behaviours. This new presentation of a functional neurological disorder may be explained in part by the relationship between social media exposure to tic-like behaviours, and maladaptive response to anxiety caused by life stressors (e.g. COVID-19 pandemic), especially in young individuals. Rapid onset functional tic-like behaviours may be considered a spreading neuropsychiatric disorder that is potentially fostered by the psychosocial impact caused by the COVID-19 pandemic.