Cognitive and motor event-related potentials in Tourette syndrome and tic disorders: A systematic review

Abstract

Objectives: Tourette syndrome (TS) patients face various cognitive and motor impairments. Event-related potentials (ERP) constitute an effective way to investigate the neural correlates of those functional impairments. Various components have been assessed among TS patients, with a wide variety of paradigms. This systematic review aimed to evaluate the portrait of ERP components in TS patients, and to understand the factors leading to discrepancies across studies.

Methods: A literature search was performed in Embase, PsycINFO, Pubmed, and Web of Science, to identify studies that conducted ERP experiments among TS patients. Of the 372 unique records identified, 47 met inclusion criteria and were included in our systematic review.

Results: Various ERP particularities were reported among included studies. Many discrepancies exist, but impairments in motor-related potentials and contingent negative variation seem constant across studies. Divergent findings point toward a possibly reduced P3b during oddball tasks.

Conclusions: ERPs offer an insightful investigation into the cognitive and motor functions of TS patients. Future studies should always control for confounding factors such as comorbidity, age, or medication status.

Significance: This is the first systematic review of ERP in TS patients. Motor-related and slow cortical potentials could constitute electrophysiological markers of TS.

Keywords: Cognition; Electrophysiology; Event-related potentials; Motor potentials; Tic disorders; Tourette syndrome.