Papers of the Week

Recent survey data suggest that a high proportion of patients with Tourette syndrome (TS) experience pain, yet pain features in TS have not been previously investigated in a systematic manner. This article reviews the current understanding and impact of pain in TS as well as identifies possible areas for emphasis for future research on pain in TS. Using a comprehensive search strategy in two relevant research databases (PubMed and Scopus), we searched for relevant peer-reviewed, primary research articles, and review articles. Search terms used were Tourette syndrome, tic disorder, pain, pain management, sensory, and sensory gating. A total of 116 pertinent articles were identified. Pain is reported by 47%-60% of individuals with TS and may relate to different aspects of tic phenomenology or other causes. Pain is more prevalent among TS patients than in the general population and negatively impacts quality of life. To standardize future research efforts, we propose the following classification: tic-related immediate pain, tic-related delayed injury/pain, suppression-related pain, premonitory urge-related pain, and associated primary pain syndromes. Altered sensory gating and interoceptive processing abnormalities are possible mechanisms contributing to pain in TS but warrant further study. Despite pain prevalence, most TS clinical rating scales and outcome measures used in therapeutic studies do not incorporate sufficient information regarding pain. Therapies known to improve pain in non-TS conditions that are also reported to improve tics have not been investigated for their effects on pain among TS patients. TS can be associated with a chronic pain syndrome that negatively affects quality of life. Future research using a systematic framework is needed to better understand pain cause(s) and prevalence, develop appropriate assessment methods, establish outcome measures, and understand mechanisms of pain in TS. Such investigations are likely to lead to therapeutic options for this troublesome symptom.