Neuroimaging studies

Polyanska and colleagues provide a meta-analysis of task-based neuroimaging reports in TS \citep{28831377}.
Elevated TSPO in OCD \citep{28636705}.
Adults with TS show some impairment in lateralized sequential finger tapping movements, and this impairment was compared to fractional anisotropy of M1-M1 and SMA-SMA white matter tracts \citep{28708864}
Another study in which machine learning was applied to functional connectivity fMRI data \citep{28478510}.

Pharmacological studies

A study in unmedicated TS patients versus those taking the dopamine D2-like partial agonist aripiprazole show that this medication may impair learning from outcomes not chosen \citep{28740149}.
\citep*{28734459} review evidence and propose a theory of how tonic and phasic dopamine release may contribute to development and expression of tics.

Clinical and neuropsychological studies

The Montréal group published a review of neuropsychological studies of TS \citep{28820427}. A study using the alternating serial reaction time task found no impairment of procedural learning in TS or ADHD \citep{28710940}. This result is surprising, given that habit learning on a "weather prediction" task is slower in TS \citep{11931939,15583117}, but may indicate that the two tasks engage different learning systems, a conclusion supported by the generally normal cognitive function in TS.
[I want to read this "perspective article": stereotypies in terms of sensorimotor integration \citep{Shafer_2017}.]

Treatment

A group of international experts provided a status report and recommendations for using brain imaging for the rational development of novel psychopharmacological interventions \citep{28031269}

Psychological interventions

Predictors of response to CBIT \citep{28202705}.
O'Connor and colleagues published a book describing their combined psychotherapeutic approach to tics \citep{OConnor2017book}.
Internet-based, therapist-guided behavior therapy for tics: BiP-TIC project, discussed here.

Medication

Initial results from the first randomized, controlled trial (RCT) with a dopamine D1 receptor antagonist in pediatric TS were released by the sponsor in January, 2017 \citep{chipkin:2017}. These new results supported the positive results from a pilot study in adults with TS \citep{24434529}, and suggest a novel treatment mechanism for tics. 
In April, the US FDA approved the presynaptic dopamine depleting agent valbenazine (Ingrezza®) for treatment of tardive dyskinesia \citep{NBI:pressrelease}. Tourette syndrome is a likely off-label use for the drug, as the company has been conducting studies in children and adults with TS (ClinicalTrials.gov). The FDA designated valbenazine an orphan drug for pediatric patients with TS \citep{syndrome}. Another VMAT–2 inhibitor, tetrabenazine, has been used for some time in the treatment of TS \citep{4281483,4613321,27819145}, and a related compound, deutetrabenazine \citep{28387387}, showed initial positive results in TS \citep{27917309}; the FDA approved it for treatment of tardive dyskinesia in August \citep{Austedo:approval}
Cannabinoids for TS: a brief review
The results of a RCT of aripiprazole for TS in children finally appeared \citep{28686474}. The drug was clearly effective and was quite well tolerated. The placebo response rate (for the Clinical Global Impression scale), though half the response in the treatment groups, was surprisingly high (38%). A small (N=34) RCT of guanfacine showed no meaningful difference in effects on tic ratings or clinical impressions of improvement between the drug and placebo groups \citep{28723227a}. This result is important and surprising, given that adrenergic α2 agonists have been seen as first-line treatment for TS, especially in TS patients with ADHD \citep{26786936}.  Both these studies show how important RCTs are to clinical care in TS. Speaking of RCTs and guanfacine, a press release reported that extended-release guanfacine showed superiority to placebo in adults with ADHD (discussed here). The importance of this report comes primarily from the scarcer data on ADHD treatments in adults vs. children. 
\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."
Michael Okun and colleagues show proof of principle that triggered rather than continuous DBS may be helpful \citep{28960154}. A patient was treated with DBS in the centromedian-parafascicular (CmPf) thalamus region bilaterally, and DBS was controlled by a 5- to 15-Hz signal there. Response was similar to that obtained with continuous DBS, and the battery usage was over 60% lower.  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}. A subthalamic nucleus (STN) DBS study in OCD reminds us that DBS can cause side effects; STN stimulation at higher voltages caused chorea-ballismus \citep{28532905}.