Another case report that adds another variant of malignant TS in the form of closed head trauma due to head banging in a 15 year old, with important sequelae, underlining the need for rapid and aggressive tic management in some patients \cite{Fasano2018}
\citet*{29636375} discusses cases on the borders of TS, such as tic disorder beginning in adulthood and the question of functional (conversion) tics.
Four men with TS, ADHD and heroin dependence were described \citep{30395551}. All of them noted improvement in tics when using heroin.
Creativity on the Creative Thinking ASK Test  was higher in TS than in Parkinson disease \citep{28698486}

Etiology

Genetics

Tying genetics of TS to genetics of brain volumes \citep{Mufford_2018}
Polygenic risk scores from a GWAS validated in the Avon Longitudinal Study \citep{30424865}
Genetic overlap of OCD and ADHD subtypes with Tourette syndrome \citep{28651666}
"First Risk Genes for ADHD Discovered\citep{30478444}

Epigenetics

Environmental risk factors

Brander et al, Mol Psychiatry 2018

Pathophysiology

Animal models

"Aripiprazole selectively reduces motor tics in a young animal model for Tourette's syndrome and comorbid attention deficit and hyperactivity disorder" \cite{29487562}.
\citep{Nespoli2018} found that dopaminergic imbalance in the dorsal striatum induced a Tourette's-like phenotype in a rodent model.  Administration of quinpirole, a selective D2/D3 receptor agonist, in juvenile rats with lesions to striatal projection neurons produced both simple and complex tics in the neck, limbs, and mouth.  A modified YGTSS was created to comprehensively score tic-like movements based on frequency, complexity, and severity of impairment.  Immunohistochemical analyses revealed significantly decreased D1 receptor RNA expression at the lesion site, consistent with the decreased striatal D1 receptor expression seen in a human post-mortem study of Tourette's \citep{Lennington2016}.  The dopaminergic imbalance induced by decreased striatal D1 receptor activity, coupled with increased D2 receptor activity, may give insight into the pathophysiology of Tourette's syndrome.  

Pathological studies

Electrophysiology

Eight awake TS patients undergoing DBS electrode implantation had recordings of individual cells of the external and internal globus pallidus (GP) \citep{28556479}. Some cells in each division of the GP showed transient changes in firing rates associated with tics.

Neuroimaging studies

WM microstructure \cite{Sigurdsson2018}
7T spectroscopy \cite{Mahone2018}
Tic suppression, blink suppression \citep{30268027}  

Pharmacological studies

\citet{Maia_2018} elaborate on their theory of how dopamine may relate to tics in TS. 
\citet{30072700} provide a meta-analysis of PET and SPECT studies in TS measuring the dopamine transporter (DAT) or D2-like dopamine receptors.

Clinical and neuropsychological studies

A research consortium in Germany has recently proposed that tics may correspond to altered perception-action binding \cite{Beste2018}. Here comes a first experimental demonstration in 35 adolescents with TS and 39 healthy controls using a Go/no-go task and subsequent EEG analysis, providing support for the idea that stimulus-action binding is stronger in patients with TS, and that "unbinding" may thus represent a useful therapeutic venue \cite{Petruo2018}.
On motor inhibition: \citep{30485912}
Implicit sequence learning (Shephard 2018)
Adaptive functioning mostly driven by executive function, including ADHD symptoms and PIQ. DOI 10.1136/goshabs.75

Other

Inhibition in children with OCD and TS \cite{Mancini2018}
Executive control in TS and tic reduction \cite{Yaniv2018}
 

Treatment

 

Psychological interventions

Major study, preliminary results, https://psyarxiv.com/dp3qz
Group-based psychotherapeutic interventions for tics bear the promise of reduced costs and easier access to appropriate care. One recent paper has investigated the long term effects of this approach on tic severity, quality of life and school attendance in 28 children with TS 12 months after completing HRT training or education (a follow up to the 2016 study, \cite{Yates2016}), both showing positive effects in the long run but apparently without significant differences between both groups \cite{Dabrowski2018}
A Scandinavian study investigated a combined ERP / HRT protocol comparing group with individual sessions (n=27 per group, n=54 total). The efficacy on decreasing tic severity was similar in both treatment arms \citep{Nissen2018}
Traditionally, ERP sessions (as compared to HRT / CBIT) were supposed to last for two hours, making them more difficult and expensive. In this study, session duration was shortened to one hour and shorter exposure was as effective, if not more, than the classic format \citep{van2018}.
Final publication of this clinical trial:  Seragni G, Chiappedi M, Bettinardi B, Zibordi F, Colombo T, Reina C, Angelini L: Habit Reversal Training in children and adolescents with chronic tic disorders: an Italian randomized, single blind, pilot study. Minerva Pediatr 70(1):5-11, 2018. Link to full text
 

Medication

Swedish treatment registries were searched to identify patterns of medication prescribing for almost 7000 patients with TS/CTD from 2005–2013 \citep{29870273}. Among other interesting findings, ADHD drugs, antidepressants, and hypnotics/sedatives were all prescribed more often than antipsychotics.
A first direct comparison of pharmacotherapy with behavioral therapy in children and adolescents with TS / CTD  \cite{Rizzo2018}. Both approaches were effective in reducing tics and improving quality of life; however, only pharmacotherapy was effective in reducing OC symptoms. 
The D1 receptor antagonist ecopipam was compared to placebo in a double-blind, crossover, randomized controlled trial (RCT) in children and adolescents with TS \citep{chipkin2017}\citep{chipkin2018}. YGTSS total tic score (TTS) declined significantly more with the active drug. 
 

Neurosurgery

Efficacy and Safety of Deep Brain Stimulation in Tourette Syndrome: The International Tourette Syndrome Deep Brain Stimulation Public Database and Registry \citep{Martinez_Ramirez_2018}. This report summarizes information on 185 Tourette patients from 10 countries. Mean improvement in total YGTSS score was 40% at 6 months after vs. before surgery, and 45% at 12 months. The difference between stimulation sites (CM-Pf, anterior GPi, posterior GPi) was not statistically significant. About a third of patients had side effects, mostly related to stimulation not surgery.
\citet{Smeets2018} discuss ethical considerations regarding DBS in TS patients under the age of 18. \citet{Canaz2018} also offer their experience in two pediatric TS patients who underwent DBS.
Butson and colleagues, 3D analysis of DBS results (poster)