Outcomes of functional tics in adolescents: a single-centre tertiary study.

Abstract

Objective: To investigate the prognosis and co-occurring disorders, including functional neurological symptoms, in adolescents diagnosed with functional tic-like behaviour (FTLB).

Design: This was a single-centre tertiary study in the UK. A structured clinical interview was administered to 43 parents or carers of adolescents assessed with FTLB at their previous outpatient clinic appointment. Data collected included demographic variables, co-occurring psychiatric and neurodevelopmental diagnoses and additional functional neurological symptoms.

Setting: A tertiary UK paediatric tics and neurodevelopmental movement disorder service.

Patients: adolescents diagnosed with FTLB during the COVID-19 pandemic.

Outcome measures: the primary outcome was whether FTLB had resolved, improved, remained constant or worsened. Secondary outcomes were Children's Global Assessment Scale scores, impact on school attendance and parent or carer work absence.

Results: Patient demographics support the European Society for the Study of Tourette Syndrome diagnostic criteria for FTLB, with a 100% female sex bias, adolescent onset and high levels of co-occurring disorders. Anxiety disorders were especially common (70%), as were other functional neurological symptoms. While the majority (65%) of parents reported that the young people had resolution or improvement in the severity of FTLB symptoms at follow-up, a significant minority (16%) saw no change and a fifth reported worsening symptoms.

Conclusions: FTLB show high co-occurrence with psychiatric and neurodevelopmental disorders, along with other functional neurological symptoms. In this study, the prognosis was poor for a fifth of patients diagnosed with FTLB.