Both these studies show how important RCTs are to clinical care in TS.
\citet{Mills_2017} describe a 22-year-old man with schizophrenia who developed tics on olanzapine after tapering risperidone. The authors are appropriately cautious in presenting this as a possible case of secondary tics, but given that many people with tics are unaware of the diagnosis, and the fact that olanzapine on average effectively treats tics, this case is much more likely to represent a previously undiagnosed primary tic disorder than a side effect of olanzapine.

Neurosurgery

A fascinating study demonstrated in mice that interfering electrical "beats" (such as the beats one hears when tuning one instrument to another) can be used to steer neuron activation to focal sites in the brain without surgical electrode implantation \citep{28575667a}. Much work remains to be done to demonstrate feasibility, safety and efficacy in humans, but this potentially could lead to noninvasive, focal brain stimulation. 
An important randomized, controlled trial of anterior GPi (globus pallidus, pars interna) DBS in 16-19 patients with TS was published \citep{28645853}. Surprisingly, at 3 months there was no significant difference in YGTSS scores between active and sham stimulation groups.
A London center reported an analysis of GPi DBS data, looking for the "sweet spot" for DBS for tic improvement \citep{28787721}. They report that "a region within the ventral limbic GPi, specifically on the medial medullary lamina in the pallidum at the level of the AC-PC, was significantly associated with improved tics but not mood or OCB outcome."
A report from the deep brain stimulation (DBS) group in the Netherlands called attention to side effects over the course of treatment in TS patients with thalamic DBS \citep{28102636}.