We've all been wrong about provisional tic disorder.

BACKGROUND: Provisional Tic Disorder (PTD) is common in childhood. The received wisdom among clinicians is that PTD is short-lived and mild, with at most a few tics, and rarely includes complex tics, premonitory phenomena or comorbid illnesses. However, such conclusions come from clinical experience, with biased ascertainment and limited follow-up. METHODS: Prospective study of 89 children with tics starting 0-9 months ago (median 4 months), fewer than half from clinical sources. Follow-up at 12 (± 24, 36, 48) months after the first tic. RESULTS: At study entry, many children had ADHD (39), an anxiety disorder (27), OCD (9) or enuresis (17). All had at least two current tics, with a mean total since onset of 6.9 motor and 2.0 phonic tics. Forty-one had experienced a complex tic, and 69 could suppress some tics. Tics were clinically meaningful: 64 had tics severe enough for a clinical trial, and 76 families sought medical attention for the tics. At 12 months, 79 returned, and 78 still had tics. Of these, 29 manifested no tics during history and extended examination, but only via audio-visual monitoring when the child was seated alone. Only 12/70 now had plans to see a doctor for tics. Most who returned at 2-4 years still had tics known to the child and family, but medical impact was low. CONCLUSIONS: Our results do not contradict previous data, but overturn clinical lore. The data strongly argue against the longstanding but arbitrary tradition of separating tic disorders into recent-onset versus chronic.

Causal network localization of brain stimulation targets for trait anxiety.

Transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) can treat some neuropsychiatric disorders, but there is no consensus approach for identifying new targets. We localized causal circuit-based targets for anxiety that converged across multiple natural experiments. Lesions (n=451) and TMS sites (n=111) that modify anxiety mapped to a common normative brain circuit (r=0.68, p=0.01). In an independent dataset (n=300), individualized TMS site connectivity to this circuit predicted anxiety change (p=0.02). Subthalamic DBS sites overlapping the circuit caused more anxiety (n=74, p=0.006), thus demonstrating a network-level effect, as the circuit was derived without any subthalamic sites. The circuit was specific to trait versus state anxiety in datasets that measured both (p=0.003). Broadly, this illustrates a pathway for discovering novel circuit-based targets across neuropsychiatric disorders.

Brain Imaging in Routine Psychiatric Practice.

Technologies in the 21st century provide increasingly detailed and accurate maps of brain structure and function. So why don't psychiatrists order brain imaging on all our patients? Here we briefly review major neuroimaging methods and some of their findings in psychiatry. As clinicians and neuroimaging researchers, we are eager to bring brain imaging into daily clinical practice. However, to be clinically useful, any test in medicine must demonstrate adequate test statistics, and show proven benefits that outweigh its risks and costs. In 2024, beyond certain limited circumstances, we have no imaging tests that can meet those standards to provide diagnosis or guide treatment. This cold fact explains why for most psychiatric patients, neuroimaging is not currently recommended by professional organizations or the National Institute of Mental Health.

Tourette syndrome research highlights from 2022.

This is the ninth yearly article in the Tourette Syndrome Research Highlights series, summarizing selected research reports from 2022 relevant to Tourette syndrome. The authors briefly summarize reports they consider most important or interesting.

Study protocol: A cross-sectional survey of clinicians to identify barriers to clinical practice guideline implementation in the assessment and treatment of persistent tic disorders.

INTRODUCTION: Eight members of the International Parkinson's Disease and Movement Disorders Society Tic and Tourette Syndrome Study Group formed a subcommittee to discuss further barriers to practice guideline implementation. Based on expert opinion and literature review, the consensus was that practice variations continue to be quite broad and that many barriers in different clinical settings might negatively influence the adoption of the American Academy of Neurology and the European Society for the Study of Tourette Syndrome published guidelines. OBJECTIVES: 1) To identify how clinical practices diverge from the existing American Academy of Neurology and European Society for the Study of Tourette Syndrome guidelines, and 2) to identify categories of barriers leading to these clinical care gaps. METHODS AND ANALYSIS: This article presents the methodology of a planned cross-sectional survey amongst healthcare professionals routinely involved in the clinical care of patients with persistent tic disorders, aimed at 1) identifying how practices diverge from the published guidelines; and 2) identifying categories of barriers leading to these clinical care gaps. Purposeful sampling methods are used to identify and recruit critical persistent tic disorders stakeholders. The analysis will use descriptive statistics.

Early-Life and Family Risk Factors for Tic Disorder Persistence into Adulthood.

BACKGROUND: Many children with tic disorders outgrow their tics, but little is known about the proportion of individuals who will continue to require specialist services in adulthood and which variables are associated with tic persistence. OBJECTIVES: The aims were to estimate the proportion of individuals first diagnosed with tic disorders in childhood who continued to receive tic disorder diagnoses after age 18 years and to identify risk factors for persistence. METHODS: In this Swedish nationwide cohort study including 3761 individuals diagnosed with tic disorders in childhood, we calculated the proportion of individuals whose diagnoses persisted into adulthood. Minimally adjusted logistic regression models examined the associations between sociodemographic, clinical, and family variables and tic disorder persistence. A multivariable model was then fitted, including only variables that were statistically significant in the minimally adjusted models. RESULTS: Seven hundred and fifty-four (20%) children with tic disorders received a diagnosis of a chronic tic disorder in adulthood. Psychiatric comorbidity in childhood (particularly attention-deficit hyperactivity disorder, obsessive-compulsive disorder, pervasive developmental disorders, and anxiety disorders) and psychiatric disorders in first-degree relatives (particularly tic and anxiety disorders) were the strongest risk factors for persistence. We did not observe statistically significant associations with socioeconomic variables, perinatal complications, comorbid autoimmune diseases, or family history of autoimmune diseases. All statistically significant variables combined explained approximately 10% of the variance in tic disorder persistence (P < 0.0001). CONCLUSIONS: Childhood psychiatric comorbidities and family history of psychiatric disorders were the strongest risk factors associated with tic disorder persistence into adulthood. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Median Nerve Stimulation for Treatment of Tics: Randomized, Controlled, Crossover Trial.

A prior study showed that rhythmic, but not arrhythmic, 12 Hz stimulation of the median nerve (MNS) entrained the sensorimotor cortex EEG signal and found that 10 Hz MNS improved tics in Tourette syndrome (TS). However, no control condition was tested, and stimulation blocks lasted only 1 min. We set out to replicate the TS results and to test whether tic improvement occurs by the proposed cortical entrainment mechanism. Preregistration was completed at ClinicalTrials.gov, under number NCT04731714. Thirty-two people with TS, age 15-64, completed two study visits with repeated MNS on and off blocks in random order, one visit for rhythmic and one for arrhythmic MNS. Subjects and staff were blind to order; a video rater was additionally blind to stimulation and to the order of visits and blocks. Rhythmic MNS at 10 Hz improved tics. Both rhythmic and arrhythmic 12 Hz MNS improved tic frequency, intensity, and urges, but the two treatments did not differ significantly. Participant masking was effective, and there was no carryover effect. Several participants described a dramatic benefit. Discomfort was minimal. There was no evidence that the MNS benefit persisted after stimulation ended. These results replicate the tic benefit from MNS but show that the EEG entrainment hypothesis cannot explain that benefit. Another electrophysiological mechanism may explain the benefit; alternatively, these data do not exclude a placebo effect.

Median Nerve Stimulation for Treatment of Tics: A 4-Week Open Trial with Ecological Momentary Assessment.

Median nerve stimulation (MNS) at 10-12 Hz was recently proposed as a treatment for Tourette syndrome and other chronic tic disorders (TS/CTD). We report on 31 participants ages 15-64 with TS/CTD in an open-label, comparative (within-group, several time points) study of MNS (ClinicalTrials.gov registration number NCT05016765). Participants were recruited from completers of a randomized controlled trial (RCT) of MNS and were given a transcutaneous electrical nerve stimulation (TENS) unit to use as desired for 12 Hz MNS for 4 weeks. Participants were instructed to complete surveys regarding tic symptoms and stimulation discomfort before and after stimulation, as well as twice daily when randomly prompted by text message. Participants also completed an extensive final survey. Twenty-seven participants completed the study. Median device use was 1.5 days per week and 50 min per day used. Tic frequency improved during MNS (mean improvement: 1.0 on a 0-5 scale, p < 0.001), as did tic intensity (mean improvement: 0.9, p < 0.001). Mean discomfort was mild (1.2 on a 3-point scale). In total, 21 participants (78%) planned to continue using the device. Participants' results in this study did not correlate significantly with their results in the blinded RCT. We found MNS to improve tic frequency and intensity with minimal side effects.

Peripheral nerve induction of inhibitory brain circuits to treat Tourette syndrome: A randomized crossover trial.

A prior study showed that rhythmic, but not arrhythmic, 12 Hz stimulation of the median nerve (MNS) entrained sensorimotor cortex EEG signal, and found that 10 Hz MNS improved tics in Tourette syndrome (TS). However, no control condition was tested and stimulation blocks lasted only 1 minute. We set out to replicate the TS results and to test whether tic improvement occurs by the proposed cortical entrainment mechanism. Thirty-two people with TS, age 15-64, completed two study visits with repeated MNS on and off blocks in random order, one visit for rhythmic and one for arrhythmic MNS. Subjects and staff were blind to order; a video rater was additionally blind to stimulation and to order of visits and blocks. Rhythmic MNS at 10 Hz improved tics. Both rhythmic and arrhythmic 12 Hz MNS improved tic frequency, intensity and urges without significant difference. Participant masking was effective and there was no carryover effect. Several participants described dramatic benefit. Discomfort was minimal. MNS benefit did not persist after the end of stimulation. These results replicate the tic benefit from MNS, but show that the EEG entrainment hypothesis cannot explain that benefit. Another electrophysiological mechanism may explain benefit; alternatively, these data do not exclude a placebo effect. Registration: ClinicalTrials.gov , NCT04731714 .

Biomass carbon stocks and stock changes in managed hedgerows.

Landscape features, such as hedgerows, can play a role in enhancing terrestrial carbon (C) sinks, especially in North-western Europe, where they form a large part of the agricultural landscape. To date, there are few studies relating aerial imagery to ground-truthed biomass measurements and relating changes in biomass to hedgerow management. This study sought to develop relationships between measured biomass of hedgerows and digital elevation model (DEM) data from drones and aircraft. Furthermore, changes in hedgerow above-ground and below-ground biomass stocks were assessed using a systematic grid sample, DEM data and developed volume-biomass regression models. The developed inventory framework was then applied to a pilot study area of 419,701 ha in Ireland. Robust relationships were developed relating DEM data to volume and above-ground biomass. Model equations were also developed linking above-ground and below-ground biomass. However, these were less robust due to the confounding impacts of hedgerow management intensity, hedgerow type and dominant species. Above-ground biomass density was linearly correlated with hedge volume. Wider, less intensively managed, irregular hedges exhibit a higher biomass stocks per km, when compared to regular, more intensively managed hedgerows. When the models were extrapolated to the county level, hedgerow biomass C pools for Co Wexford and Waterford are suggested to be a net emission of -0.3 tC ha-1 year-1 due to hedgerow removals and management. Flailing or coppicing of hedgerows, in particular irregular profile hedgerows, had the largest impact on the biomass C balance in the pilot study area. Re-introduction of traditional management practices such as layering and increasing the allowable hedgerow width in areas qualifying for farm payments could be considered with the aim of increasing the maximum sink potential of established hedgerows.

TikTok Tourette's: Are We Witnessing a Rise in Functional Tic-Like Behavior Driven by Adolescent Social Media Use?

Perceptions of Tourette syndrome (TS) and tic disorders are often driven by social media. During the COVID-19 pandemic, social media consumption greatly increased, particularly in the adolescent population. In parallel with increased social media consumption, there has also been an increase in tic severity and functional tic-like behavior (FTLB). Given that many of the tic videos posted on social media are misleading, perpetuate false beliefs about TS, or reinforce tic-like behaviors, there is increasing concern that these videos are driving the rapid increase in FTLBs. Several studies have reviewed newly presenting cases of FTLB and have found shared characteristics, including that a higher proportion of affected individuals are female, there is a low proportion with a history of childhood or family tics, and symptom onset is typically acute and develops in the teenage years. In addition, the quality of the tics seen in association with FTLB mirrors many of the tics seen on popular social media channels, with higher rates of coprophenomena, tic attacks, and involvement of the trunk and extremities than is seen with typical tics. FTLBs are likely a specific subgroup of functional tics largely influenced by the portrayal of and growing popularity of functional tics posted on social media during the COVID-19 pandemic. However, several factors, including increased anxiety, social isolation, and social media use in general during the pandemic are likely also contributing factors to the surge of FTLBs seen recently. In this era of increased social media consumption, it will become increasingly important for clinicians to educate patients about where and how medical information is spread, to ensure the best possible diagnosis, treatment, and outcomes for patients.

Low-Dose Augmentation With Buprenorphine for Treatment-Resistant Depression: A Multisite Randomized Controlled Trial With Multimodal Assessment of Target Engagement.

Background: The experimental therapeutics approach that combines a placebo-controlled clinical trial with translational neuroscience methods can provide a better understanding of both the clinical and physiological effects of pharmacotherapy. We aimed to test the efficacy and tolerability of low-dose augmentation with buprenorphine (BPN) for treatment-resistant depression, combined with multimodal assessment of target engagement. Methods: In this multisite randomized clinical trial, 85 participants ≥50 years of age with a major depressive episode that had not responded to venlafaxine extended release were randomized to augmentation with BPN or placebo for 8 weeks. The primary outcome measure was the Montgomery-Åsberg Depression Rating Scale. In addition, three linked experiments were conducted to test target engagement: 1) functional magnetic resonance imaging using the monetary incentive delay task, 2) brain positron emission tomography of healthy participants using a novel kappa opioid receptor antagonist tracer [11C]LY2795050, and 3) transcranial magnetic stimulation measure of cortical transmission after daily BPN administration. Results: The mean ± SD dosage of BPN was 0.59 ± 0.33 mg/day. There were no significant differences between the BPN and placebo groups in Montgomery-Åsberg Depression Rating Scale changes over time or adverse effects. BPN administration had minimal effects on functional magnetic resonance imaging blood oxygen level-dependent responses in regions involved in reward anticipation and response, no significant displacement of kappa opioid receptor radioligand in positron emission tomography imaging, and no significant changes in transcranial magnetic stimulation measures of inhibitory and excitatory cortical transmission. Conclusions: Our findings suggest a lack of clinical effect of low-dose BPN augmentation and lack of target engagement with this dosage and physiological probes.

Tourette syndrome research highlights from 2021.

We summarize selected research reports from 2021 relevant to Tourette syndrome that the authors consider most important or interesting. The authors welcome article suggestions and thoughtful feedback from readers.

Diagnosis and Management of Functional Tic-Like Phenomena.

Over the past 3 years, a global phenomenon has emerged characterized by the sudden onset and frequently rapid escalation of tics and tic-like movements and phonations. These symptoms have occurred not only in youth known to have tics or Tourette syndrome (TS), but also, and more notably, in youth with no prior history of tics. The Tourette Association of America (TAA) convened an international, multidisciplinary working group to better understand this apparent presentation of functional neurological disorder (FND) and its relationship to TS. Here, we review and summarize the literature relevant to distinguish the two, with recommendations to clinicians for diagnosis and management. Finally, we highlight areas for future emphasis and research.

Why Tic Severity Changes from Then to Now and from Here to There.

Much of the research regarding Tourette's syndrome (TS) has focused on why certain individuals develop tics while others do not. However, a separate line of research focuses on the momentary influences that cause tics to increase or decrease in patients who are already known to have TS or another chronic tic disorder (CTD). Environmental and internal variables such as fatigue, anxiety, and certain types of thoughts all have been shown to worsen tic severity and may even overcome the positive effects of treatment. Other influences such as stress, distraction, and being observed have had mixed effects in the various studies that have examined them. Still, other variables such as social media exposure and dietary habits have received only minimal research attention and would benefit from additional study. Understanding the impact of these environmental and internal influences provides an opportunity to improve behavioral treatments for TS/CTD and to improve the lives of those living with these conditions. This review will examine the current literature on how these moment-to-moment influences impact tic expression in those with TS/CTD.

Tourette syndrome research highlights from 2020.

We present here research from 2020 relevant to Tourette syndrome (TS). The authors briefly summarize a few reports they consider most important or interesting.

Fractality of tics as a quantitative assessment tool for Tourette syndrome.

Tics manifest as brief, purposeless and unintentional movements or noises that, for many individuals, can be suppressed temporarily with effort. Previous work has hypothesized that the chaotic temporal nature of tics could possess an inherent fractality, that is, have neighbour-to-neighbour correlation at all levels of timescale. However, demonstrating this phenomenon has eluded researchers for more than two decades, primarily because of the challenges associated with estimating the scale-invariant, power law exponent-called the fractal dimension Df-from fractional Brownian noise. Here, we confirm this hypothesis and establish the fractality of tics by examining two tic time series datasets collected 6-12 months apart in children with tics, using random walk models and directional statistics. We find that Df is correlated with tic severity as measured by the YGTTS total tic score, and that Df is a sensitive parameter in examining the effect of several tic suppression conditions on the tic time series. Our findings pave the way for using the fractal nature of tics as a robust quantitative tool for estimating tic severity and treatment effectiveness, as well as a possible marker for differentiating typical from functional tics.

Functional tic-like presentations differ strikingly from Provisional Tic Disorder.

Background: Recent years have seen a dramatic increase in new "tic" cases in teens and young adults. These individuals often present with fulminant onset of symptoms not commonly seen in Tourette syndrome (TS) and are often diagnosed with Functional Neurological Symptom Disorder (FND-tic). However, some authors have questioned whether this illness truly differs from typical Provisional Tic Disorder (PTD) and TS. Previous studies have compared FND-tic, usually a few months after symptom onset, to patients with TS, usually years after symptom onset. We sought to test whether the presenting symptoms of FND-tic differ substantially from those in patients at a similar duration of symptoms who are later diagnosed with TS. Methods: This comparative study examines clinical features summarized from published reports of FND-tic with novel data from a longitudinal study of PTD. This study came from a referral center for TS and tic disorders and included 89 children with tics whose first tic occurred a median of 3.6 months earlier, nearly all of whom were diagnosed with a chronic tic disorder at follow-up. Specifically, we examine clinical features identified in a recent literature review as supporting a diagnosis of FND-tic, including symptom characteristics, course, severity and comorbidity. Results: Several clinical features dramatically distinguish the patients diagnosed with FND-tic from those diagnosed with typical PTD. For example, coprophenomena are reported at or shortly after symptom onset in over half of FND-tic patients, whereas even several months after onset, coprophenomena had occurred in only 1 of 89 children with PTD. Six clinical features each have a positive predictive value over 90% for FND-tic diagnosis if prior probability is 50%. Conclusions: These new data provide strong evidence supporting the diagnostic validity of FND-tic as distinct from TS.

Incidence of Venous Thromboembolism following Knee Arthroscopy: Effectiveness of a Risk-Based Stratified Chemoprophylaxis Protocol.

The incidence of symptomatic venous thromboembolism (VTE) has been reported in up to 10.9% of patients undergoing knee arthroscopy without chemoprohylaxis. The purpose of this study was to evaluate the effectiveness of a chemoprophylaxis protocol in patients undergoing knee arthroscopy. A retrospective review of prospectively enrolled patients in a new institutional VTE prophylaxis protocol identified all patients undergoing knee arthroscopy during a 5-year period. This risk-based chemoprophylaxis protocol was instituted based on the Caprini model: patients at more than minimal risk were prescribed enoxaparin 40 mg daily for 3 weeks, while all others were instructed to take aspirin 325 mg twice daily. The primary outcome measure was incidence of VTE within 60 days postoperatively. Demographic characteristics and other risk factors for VTE were also recorded, as well as any postoperative complications. Among the 1,276 knee arthroscopies, there were 26 VTE events (2.0%), including 23 with deep vein thrombosis (DVT), two pulmonary emboli (PE), and one patient with both DVT and PE. There were no deaths or complications requiring hospitalization or reoperation. The VTE diagnosis occurred at, on average, 9 days postoperatively. Patients in the high-risk group treated with enoxaparin had a lower VTE incidence (1.49%) than those instructed to take aspirin (2.0%); p = 0.75. Those undergoing an anterior cruciate ligament (ACL) reconstruction had the highest VTE incidence (2.87%). This study found that a chemoprophylaxis protocol with preferential use of aspirin or low-molecular weight heparin based on risk factors reduced the VTE incidence below to 2.0%, which is lower than most historical controls.