Tics and functional tic-like movements: Can we tell them apart?

Area of Science:

• Neurology
• Movement Disorders
• Clinical Neuroscience

Background:

• Tics and functional tic-like movements are distinct but phenotypically similar movement disorders.
• Their overlap in kinematics and muscle synergies complicates clinical differentiation.
• Misdiagnosis can occur due to historical diagnostic challenges and the potential coexistence of both conditions.

Purpose of the Study:

• To review the literature on tics and functional tic-like movements.
• To highlight the difficulties in clinically distinguishing these two motor phenomena.
• To explore pathophysiologic similarities and differences, and discuss treatment implications.

Main Methods:

• Literature review of existing studies on tics and functional tic-like movements.
• Analysis of phenomenological, pathophysiologic, and treatment characteristics.
• Discussion of diagnostic challenges and implications.

Main Results:

• Significant phenomenological overlap exists between tics and functional tic-like movements, leading to diagnostic challenges.
• Both phenomena involve action monitoring, attentional allocation, and behavioral reinforcement.
• Current behavioral treatments show overlap, but diagnostic mislabeling necessitates tailored approaches.

Conclusions:

• Accurate differentiation between tics and functional tic-like movements remains a clinical challenge.
• Understanding shared pathophysiologic mechanisms is key for developing next-generation phenotyping and neurobiology-driven treatments.
• Tailoring behavioral interventions and guiding decisions for invasive treatments requires precise phenotyping.