Tourette syndrome research highlights from 2020 [version 2; peer review: 2 approved]

We present here research from 2020 relevant to Tourette syndrome (TS). The authors briefly summarize a few reports they consider most important or interesting. in TS, which may contribute to the perception of some people with TS that tics are fully involuntary. Rage attacks in TS were examined using structural and functional MRI network methods in 55 patients with TS, 47% of whom had intermittent explosive outbursts (IEOs) (Atkinson-Clement et al . 2020c). The group with IEOs (TS+IEO) was compared to the remaining (TS (cid:1) IEO) group, and showed increased fractional anisotropy in the right SMA and right hippocampus, and decreased mean diffusivity in the left OFC. Those three regions were used as seeds for resting state fcMRI. The TS+IEO group showed lower connectivity within a sensorimotor cortical-basal ganglia network, and altered connectivity among OFC, amygdala, and hippocampus. These results suggest that IEOs are associated in TS with disrupted white matter and associated functional connectivity in circuits related to action selection, emotion regulation, impulse control, and aggression. palmitoyl ethanolamide (PEA), and arachidonic acid (AA). The key results were that “ CSF AEA (p = 0.0018), 2-AG (p = 0.0003), PEA (p = 0.02), and AA (p < 0.0001) were significantly increased in TS compared with controls, ” and that “ levels of 2-AG correlated with the severity of comorbid ADHD (p < 0.01). ” The authors note these differences could relate to compensation for chronic tics, or may be causative. associating movement inhibition with 8-14 Hz activity in motor cortex. The rhythmic 12 Hz peripheral stimulation of the median nerve evoked synchronous contralateral EEG activity over primary sensorimotor cortex, arrhythmic stimulation at the same mean rate did not. As hypoth-esized, median nerve stimulation (MNS) at 12 Hz created small but statistically significant effects on initiation of voluntary movements. this stimulation did not meaningfully impair concentration, suggesting that the effect did not operate through simple distraction. tested 10 Hz MNS in 19 TS patients, and video ratings significant reduction in tic number and severity during 1-minute stimulation epochs vs 1-minute no-stimulation epochs. during MNS in some This manuscript presents a scoping review of the published literature on the topic of Tourette Syndrome (TS) during 2020. The search is not designed to be exhaustive (e.g., only one database is exploded) and the highlighted articles, presented in narrative form, have been selected based on the subjective judgement of the authors. This, however, works very well as a text-book summary for those in and outside the field of TS, turning it into a compulsory yearly read. I commend and congratulate the authors for doing this for yet another consecutive year. My only minor criticism (or rather a wish) this 2020 review could have appeared earlier. I sincerely appreciate the effort and time behind this manuscript, but the more than 1 year lapse between the review content and the current date makes some (not all) sections appear outdated when I read them now (e.g., functional tics in relation to the Covid-19 pandemic, and some of the treatment parts). On the other hand, some time lag is to expected, it is to see the quick development of the field.