Neurodevelopmental versus functional tics: A controlled study.

Area of Science:

• Neurology
• Psychiatry
• Epidemiology

Background:

• The COVID-19 pandemic is linked to an increase in new-onset functional tics, particularly among young females.
• Existing case series lack controlled data on the clinical differences between functional and neurodevelopmental tics.

Purpose of the Study:

• To conduct the largest controlled study comparing the clinical phenomenology of functional tics that emerged during the COVID-19 pandemic with neurodevelopmental tics in Tourette syndrome patients.
• To identify distinct clinical features and patient-related variables for differential diagnosis.

Main Methods:

• A comparative study of 166 patients (83 functional tics, 83 Tourette syndrome) treated at a specialist tic disorder clinic between 2020-2023.
• Matched controls (age, gender) were used to compare clinical features, co-morbidities, and family history.

Main Results:

• Functional tics predominantly affected females (86%), with later onset (21 vs. 7 years) and less family history of tics compared to Tourette syndrome.
• Anxiety and functional neurological disorders were more common with functional tics, while ADHD and tic-related OCD were more frequent in Tourette syndrome.
• Absence of tic-related OCD and family history of tics were strong predictors of functional tics. Complex manifestations like tic attacks were over-represented in functional tics.

Conclusions:

• Findings confirm distinct patient-related variables and tic characteristics differentiating pandemic-related functional tics from neurodevelopmental tics.
• This research aids in the differential diagnosis of tic disorders, especially in the context of recent epidemiological shifts.