Phenomenology
Sex differences
Baizabal-Carvalho and Jankovic compared phenomenology of tics and comorbidities in males and females with GTS
(Baizabal-Carvallo 2022a). Males represented 77.6% of the cohort comprising 201 GTS patients. No differences regarding frequency, distribution and complexity of tics were detected. Males with GTS had higher frequency of ADHD. In children with GTS, males not only had higher rates of ADHD than females, but also had higher frequency of complex motor tics and earlier age at onset than females. These differences were not detected in adults with GTS, since tic complexity increased in females with aging.
Males and females with tics were also compared as part of the EMTICS study
(Garcia-Delgar 2022). Males had more severe symptoms than females, except for emotional problems. There was also a statistically significant interaction between sex and age on the severity of tics and compulsions, with females showing higher symptom severity with increasing age than males.
Group from the University of Calgary examined clinical phenomenology in males and females with tics based on the Pediatric Tic Registry
(Girgis 2022). When comparing both groups, females had more severe motor tics and had higher global severity on the YGTSS. While males were more frequently diagnosed with ADHD, females had significantly higher scores on the Children's Depression Inventory.
Types of tics
Video-recordings of 156 patients with GTS were assessed for tic duration in the intent to distinguish between dystonic and tonic tics
(Baizabal-Carvallo 2022a). Dystonic tics lasted longer than tonic tics. Furthermore, patients with dystonic tics characterized by older age of onset, older age at evaluation, greater tic severity, more complex tics, and increased risk for being considered for deep brain stimulation (DBS) than patients with tonic tics.
The same group of authors evaluated clinical phenomenology and correlations of oculogyric tics
(Baizabal-Carvallo 2022). In order to examine this clinical problem, the authors reviewed video-recordings and clinical history of 201 patients with tics. Oculogyric tics were found in 22.4% of patients. When it comes to phenomenology of simple oculogyric tics, the most common manifestation was transient upward gaze, while eye-closure followed by upward and lateral deviations was the most frequent complex oculogyric tic. Patients with oculogyric tics were younger and had higher frequency of cranial tics. No differences in tic severity, the profile of psychiatric comorbidities and the use of antipsychotics were found.
Treatment refractory tics
(Li 2022) reported about children with refractory GTS and have found that pediatric refractory GTS is characterized by earlier age of onset, longer disease duration, lower IQ, higher prevalence of PU and higher prevalence of psychiatric comorbidities.
Functional tic-like behaviors
Fremer et al. (2022) reported about 32 patients with functional tic-like behaviors provoked by social media, including both operationalized psychiatric diagnosis and a psychodynamic focus. Symptoms typically started abruptly at the mean age of 19 years and were gradually deteriorating. In all patients, timely-related psychological stressors, unconscious intrapsychic conflicts, and/or structural deficits were identified. Nearly all patients (94%) suffered from further psychiatric symptoms. The authors concluded that pre-existing abnormalities in social behavior and psychiatric symptoms, but also GTS in combination with timely-related psychological stressors, unconscious intrapsychic conflicts, and structural deficits predispose to development of these symptoms.
(Zea 2022) evaluated tic phenomenology in videos posted on TikTok. Most videos showed coprophenomena, often with unusual characteristics. Frequently, videos depicted aggression, throwing objects, self-injurious behaviors and repetition of long phrases. These videos were later assessed by independent blinded tic experts who concluded that GTS potrayals on highly viewed TikTok videos are not representative or typical for GTS.
(Han 2022) reported the prevalence and clinical characteristics of children with functional tic-like behaviors detected during the COVID-19 pandemic based on the analysis from the single center. There was a significant increase in the percentage of functional tic-like behaviors in 2020 and 2021. In line with other studies, main differences between patients with functional tics characterized by several distinguishing features: predominance of females, later age of onset and higher rates of anxiety and depression. Patients with FTB also characterized with more frequent presence of coprolalia-like behaviors, complex phrases, self-injurious behaviors, higher rates of hospitalizations and school absenteeism.
Arbuckle et al. (2022) presented new data regarding functional tics based on the sample from the Washington University of Saint Louis. Symptoms that best distinguished the groups included movements or vocalizations that were dramatically worse in the presence of others,
vs. alone, coprophenomena at initial presentation, symptoms that dramatically and persistently disrupt intended actions or communications, and "tic attacks."
Trau et al. (2022) review charts of 198 patients with FTB and proposed diagnostic criteria to separate individuals with tics from those with newly diagnosed FTB, and those with a past typical presentation complicated by a fulminant worsening. Only the presence of rostrocaudal progression and higher rates of OCS were significantly different between patients with new-onset FTB and those with functional worsening of a previous tic disorder. Results also showed that age at tic onset was not a contributing factor for group differentiation. Many patients with FTB were not exposed to videos depicting tics on social media.
(Howlett 2022) investigated the prognosis of functional tic-like behaviors in 20 adolescents and 9 adults. Overall, the authors have shown in this prospective study that adolescents have a better prognosis than adults with FTB. As the most effective therapeutic approach treatment of comorbidities with SSRI and CBT was proposed.
Comorbidities
Eating habits
Food difficulties, among others greater food responsiveness and emotional overeating, were shown to be more common in children with TS than previously reported
(Smith 2022).
Pain and tics
The experience of tic-related pain and use of pain management was assessed in an online survey answered by 188 adults with self-reported tics
(Taylor 2022). Tic-related pain was shown to have a significant physical and psychological impact and is important to be addressed in the long-term management of tic disorders. Similar study was conducted in Poland
(Małek 2022), but this time it was carried out in pediatric population. The authors included 40 children with GTS and 57 parents of children with GTS, as they wanted to collect information about perspective of children and parents on this topic. For assessment of tics the authors used the YGTSS, while pain severity, localization and coping strategies were assessed with the Pediatric Pain Questionnaire, and Pediatric Pain Coping Inventory which was administered both to children and their parents. Pain was reported by 60% of children with GTS and 72% of parents confirmed that their children can suffer from pain. The most common localizations of pain were cervical region, throat, shoulder, ocular region, and joints. Contrary to expected, no correlation has been found between tic severity and pain. Consistency between the declarations of children and their parents in coping with pain was observed.
Sleeping disorders
Ricketts et al.
(Ricketts 2022) published an important article about sleep disorders and the use of sleep medication, nightime tics and pattern of sleep in patients with tics. In this study, 125 adults with tics were included. The participants filled out an internet survey in which they rated sleep history, sleep chronotype as well as the severity of tics and psychiatric comorbidities. The most frequently reported sleep-related disorders in population of patients with tics were bruxism, insomnia and tic-related difficulty falling asleep. Sleep problems correlated with impairment, OCS as well as emotional regulation problems. Interestingly enough, eveningness related to tic severity. Therefore, the authors concluded that interventions to advance chronotype may help with tic improvement.
The same group of authors examined another aspect of sleep disorders in the group of patients with tics
(Ricketts 2022). In this study 114 children with GTS were included and the authors compared those who have sleep disorders (n=32) with those who have no problems with sleep (n=82). Children with GTS and sleep disorder were from households with lower parental education and were at the higher risk of poverty. They also were more frequently diagnosed with comorbidities such as OCD, ODD, ADHD and autism and were prescribed more frequently anti-tic medication. In line with these findings, children with TS and sleep disorder had more severe tics, tic-related impairment and more severe ADHD symptoms.
A case-control study including 271 children with tic disorder and 271 controls revealed that children with tics had increased risks for sleep disturbances as measured with Children´s Sleep Habits Questionnaire
(Mi 2022). Sleep disturbances included, among others, bed time resistance, sleep onset delay, sleep anxiety, night waking, and daytime sleepiness. The presence of comorbid ADHD increased the risk for sleep disturbances.
(Jiménez-Jiménez 2022) published results of the register-based cohort study to estimate the prevalence of insomnia in patients with tics in Sweden. Individuals with tics had a prevalence of insomnia of 32.16% in comparison to 13.70% in the general population and this difference was statistically significant. Importantly, this association was independent from somatic disorders, familial factors or psychiatric comorbidities, although familial factors, neurodevelopmental comorbidities, and ADHD/ADHD medication may explain part of the association.
Other comorbidities
Nail biting (onychophagia) is very common in unselected children but has also been included in descriptions of complex tics. A report from Taiwan examines prevalence of nail biting in over 2000 children, including 765 with a primary tic disorder, finding that nail biting is very common in TS (56.6%) and provisional tic disorder (27.4%)—much more common than in controls (15.0%)—and begins prior to onset of definite tics
(Hsueh 2022).
(Cui 2022) reported about emotional and behavioral profile of children with GTS in China and compare this profile with sex-matched health controls, ADHD, OCD and depression groups. To assess for behavioral and emotional problems in all groups the Child Behavior Checklist (CBCL) was implemented. No association between the eight factors of the CBCL and motor tics, vocal tics or tic severity assessed by the YGTSS was found. Nevertheless, there was a positive association between the impairment scale of the YGTSS and thought problems as well as rule-breaking behavior as assessed by the YGTSS. Contrary to expected, children with GTS showed similar profile of CBCL to the children with depression, but not ADHD and OCD.
(Tessier 2022) compared design fluency profile of children with GTS with matched healthy controls. As a result, they have shown that children with GTS do not show general executive dysfunction in comparison to their peers.
A large Swedish cohort study with more than 13 million individuals and almost 7,800 individuals with TS or chronic tic disorders (CTD), it was found that persons with TS or CTD did have an increased risk of experiencing any violent assault and violent and nonviolent crime convictions
(Mataix-Cols 2022). The presence of comorbid ADHD and substance use disorders increased this risk.
(Baizabal-Carvallo 2022b) published a study about self-injurious behaviors in GTS. The authors included 201 patients with GTS and 34 (16.9%) of them had comorbid SIB. Majority of patients experienced self-inflicted damage (11.4%), while only 3.5% of participants also experienced aggression towards the others and only 2% had what the authors denominated as tic-related SIB. In this study, the authors compared in detail the distribution of different tics in patient with SIB and without in univariable model and concluded that individuals with SIB are more inclined to have tics involving shoulder, trunk, arm, as well as dystonic tics; complex motor tics, copropraxia, complex phonic tics, higher number of phonic tics, coprolalia and OCD. In multivariable analysis SIB was found to be associated with complex motor tics, OCS and greater tic severity. Interestingly enough, patients with SIB have also been selected more frequently for the DBS procedure.
(Vermilion 2022) compared responses on the Youth Risk Behavior Surveillance System (YRBS) in youth with TS with healthy controls and did not show any differences between these groups regarding the profile of risky behaviors.
(Isaacs 2022) compared sensory over-responsivity (SOR) in patients with OCD and tics. SOR was found to be equally frequent in patients with tics and OCD. Across different disorders, SOR has been found to be independently associated with both OCS and ADHD suggesting transdiagnostic nature of this symptom.