. Each participant received a vaporized single 0.25 g dose of Δ9-tetrahydrocannabinol (THC) 10%, THC/cannabidiol (CBD) 9%/9%, CBD 13%, and placebo at 2-week intervals. There were no statistically significant differences in tic severity for any of the cannabis-based medicine in primary outcome, but THC 10% was significantly better than placebo on the secondary outcome measures.
Neurosurgery
A very elegant study by Ganos et al. \citep{Ganos_2022}offers new insights regarding our knowledge of tic network and the effects of deep brain stimulation (DBS). They studied 22 patients with secondary tics caused by various types of brain lesions and employed lesion network mapping to identify a common neural network implicated in tics generation. They found that despite their very varied brain locations, tic-inducing lesions mapped to a common network encompassing the insular cortices, the cingulate gyrus, the striatum, the globus pallidus internus (GPi) and the cerebellum. The connectivity of the anterior striatum was significantly associated with tics compared to lesions inducing other types of movement disorders. They then collected data from 30 patients with GTS who had undergone thalamic or pallidal neurostimulation and found that the overlap between the site of neurostimulation and the lesion network map was predictive of tic improvement.