The spectrum of functional tic-like behaviours: Data from an international registry

Prevalence of mass social media-induced illness presenting with Tourette-like behavior in Germany between 2019 and 2021

Starting in 2019, in Germany the first well documented outbreak of mass sociogenic illness induced by social media (mass social media-induced illness; MSMI) occurred presenting with functional Tourette-like behaviors (FTB). This study aimed to provide first data on the prevalence rate of MSMI-FTB in Germany between 2019 and 2021 in the general population. We conducted a large-scale representative population survey in cooperation with the USUMA market and social research institute. Between August and December 2021, n = 2.509 people (mean age: 49.5 years, range: 16-95 years, n = 1.276 females) were randomly selected, visited in their households, interviewed, and asked to answer for themselves, but also for close family members (n = 6.744). Thus, in total, we received answers for n = 9.253 people. Probable MSMI-FTB was found in n = 33 individuals (mean age at onset: 30.5 years, n = 8 females). Based on strict criteria, the diagnosis of MSMI-FTB was considered highly likely in 16/33 individuals (mean age at onset: 25.6 years, n = 2 females) corresponding to prevalence rates of 0.17% (CIlower = 0.10, CIupper = 0.28) and 0.36% (CIlower = 0.25, CIupper = 0.50), respectively. This is the first large-scale, population representative study investigating the prevalence of MSMI-FTB in the general population in Germany between 2019 and 2021. Based on the prevalence rates found, MSMI-FTB is highly relevant for health economy. Accordingly, we suggest educating healthcare professionals and the general public to avoid misdiagnosis and inefficient treatment.

A Critical Examination of the Clinical Diagnosis of Functional Tic-like Behaviors

BACKGROUND

Since the COVID-19 pandemic, movement disorder clinics have seen an increase in patients with an unusual type of tic-like symptoms: young adults with abrupt onset complex behaviors. It was quickly suspected that these patients suffered from functional neurological symptoms, later named Functional Tic-Like Behaviors (FTLB). Subsequent research on the differential diagnosis between FTLB and tics has been substantial and led to the development of diagnostic checklists.

OBJECTIVES

We conducted a theoretical reappraisal of the FTLB literature to clarify the validity of the concept and its diagnostic implications.

METHODS

This paper addresses several key aspects of the current FTLB literature: circular reasoning, the complications of the FTLB phenomenology and demographics, the impact of FTLB on tic literature at large, and issues with alignment of the FTLB concept with the diagnostic criteria for functional disorders.

RESULTS

The clinical approach to FTLB might involve circular reasoning due to a lack of clinical benchmarks. The FTLB phenomenology and demographics may need more work to ensure a lack of bias and a proper description of this patient group including a clear distinction from tics. The impact of the FTLB discussion on the wider literature needs consideration. The validation of positive signs may help with both these endeavors and pave way to the inclusion of FTLB within psychiatric classification systems. Furthermore, the coexistence of FTLB and tics within the same patient needs to be addressed.

CONCLUSION

More research may be needed to fully establish the diagnosis of FTLB and differentiate it from tics.

Comorbidity rates of autism spectrum disorder and functional neurological disorders: A systematic review, meta-analysis of proportions and qualitative synthesis

LAY ABSTRACT

Autism spectrum disorder (ASD) and functional neurological disorders (FND) are relatively common conditions, and there has been recent interest in the overlap between them. Both conditions share core features of alexithymia, impaired interoception and deficits in attentional focus. To date, relatively little is known about the comorbidity rates between ASD and FND. This is the first meta-analysis and qualitative synthesis on the subject. We found that around 10% of children presenting with functional seizures have a comorbid ASD diagnosis. People with ASD are more likely than the neurotypical population to have functional somatic disorders, and there is also evidence that ASD rates are higher for other FNDs such as functional motor disorders. Since FND comes with risks of unnecessary medical procedures and investigations, it is important to recognize the potential for people with ASD to have an FND comorbidity.

Tourette syndrome research highlights from 2023

In this, the tenth annual update for the F1000Research Tics collection, we summarize research reports from 2023 on Gilles de la Tourette syndrome and other tic disorders. The authors welcome article suggestions and thoughtful feedback from readers.

Validation and assessment of the self-injurious behavior scale for tic disorders (SIBS-T)

Self-injurious behavior (SIB) is a well-known phenomenon in patients with chronic tic disorders (CTD). To investigate prospectively symptomatology of SIB in adults with CTD, we developed and validated the self-injurious behavior scale for tic disorders (SIBS-T). Patients completed the SIBS-T and a variety of assessments for tics and comorbidities. We investigated SIB frequency, internal consistency of the SIBS-T, and carried out an exploratory factor analysis (EFA). We enrolled n = 123 adult patients with CTD. SIB was reported by n = 103 patients (83.7%). The most frequently reported SIB were beating/pushing/throwing and were found in 79.6% of cases. Patients with SIB had significantly higher tic severity measured with the Adult Tic Questionnaire (ATQ) (p = 0.002) as well as higher severity of psychiatric comorbidities such as obsessive-compulsive symptoms (OCS) (p < 0.001,), attention deficit/hyperactivity disorder (ADHD) (p < 0.001,), and anxiety (p = 0.001). In addition, patients with SIB had significantly lower quality of life (p = 0.002). Pearson correlations demonstrated significant associations between SIB and severity of tics (p < 0.001), depression (p = 0.005), ADHD (p = 0.008), and borderline personality traits (p = 0.014). Consequently, higher SIBS-T also correlated with greater impairment of quality of life (p < 0.001). The internal consistency of the SIBS-T was good (α = 0.88). The EFA confirmed a single factor underlying the SIBS-T.

Psychological Factors Associated with Functional Tic-like Behaviours during the COVID-19 Pandemic

Functional tic-like behaviours (FTLB) are a female predominant functional neurological disorder that escalated in incidence during the SARS CoV2 pandemic. This study compared social and adaptive functioning, social media use, pandemic experiences, and psychiatric comorbidities between FTLB (n = 35), Tourette Syndrome (TS) (n = 22), and neurotypical (NT) (n = 25) participants ages 11 to 25 years. The psychiatric comorbidity burden for participants with FTLB was formidable, with frequencies ranging from 1.5 to 10 times higher for major depressive disorder and panic disorder compared to TS and NT participants. Borderline personality disorder (BPD), agoraphobia, social anxiety disorder, and generalized anxiety disorder were also significantly more common in FTLB compared to NT participants. Vulnerable attachment scores, social phobia and social interaction anxiety symptoms were higher in participants with FTLB than NT but not TS. Overall distress tolerance, resilient coping, suggestibility, hours on social media, and exposure to tic and TS content were not significantly different between groups. FTLB participants rated their mental health declined more severely during the pandemic than both TS and NT participants and were more likely to experience trouble sleeping, loneliness, and difficulty affording housing and food than NT participants. Participants with FTLB were significantly more likely to identify as gender minority people than TS and NT, though there were no significant differences based on gender identity in the study variables within the FTLB group. The association and potential pathways explaining how psychiatric disorders may be contributing to FTLB, and why certain groups appear at particular risk are discussed.

Misdiagnosis of functional neurological symptom disorders in paediatrics: Narrative review and relevant case report

Functional neurological symptom disorders (FNSD) pose a common challenge in clinical practice, particularly in pediatric cases where the clinical phenotypes can be intricate and easily confused with structural disturbances. The frequent coexistence of FNSDs with other medical disorders often results in misdiagnosis. In this review, we highlight the distinctions between FNSD and various psychiatric and neurological conditions. Contrary to the misconception that FNSD is a diagnosis of exclusion, we underscore its nature as a diagnosis of inclusion, contingent upon recognizing specific clinical features. However, our focus is on a critical learning point illustrated by the case of a 14-year-old male initially diagnosed with FNSD, but subsequently found to have a rare primary monogenic movement disorder (paroxysmal kinesigenic dyskinesia, PKD). The crucial takeaway from this case is the importance of avoiding an FNSD diagnosis based solely on psychiatric comorbidity and suppressible symptoms. Instead, clinicians should diligently assess for specific features indicative of FNSD, which were absent in this case. This emphasizes the importance of making a diagnosis of inclusion. Extended follow-up and clinical-oriented genetic testing might help identify comorbidities, prevent misdiagnosis, and guide interventions in complex cases, which cannot be simply classified as "functional" solely because other conditions can be excluded.

Testing the specificity of phenomenological criteria for functional tic-like behaviours in youth with Tourette syndrome

BACKGROUND AND PURPOSE

The aim was to test the specificity of phenomenological criteria for functional tic-like behaviours (FTLBs). The European Society for the Study of Tourette Syndrome (ESSTS) criteria for the diagnosis of FTLBs include three major criteria: age at symptom onset ≥12 years, rapid evolution of symptoms and specific phenomenology.

METHODS

Children and adolescents with primary tic disorders have been included in a Registry in Calgary, Canada, since 2017. Using the Yale Global Tic Severity Scale, the proportion of youth with primary tic disorders who met specific phenomenological criteria for FTLBs at first visit was assessed: (1) having ≥1 specific complex motor tic commonly seen in FTLBs, including complex arm/hand movements, self-injurious behaviour, blocking, copropraxia; (2) having ≥1 specific complex phonic tic commonly seen in FTLBs, including saying words, phrases, disinhibited speech, coprolalia; (3) having a greater number of complex tics than simple tics. Children seen for the first time between 2017 and 2019 and between 2021 and 2023 were analysed separately.

RESULTS

Of 156 participants included between 2017 and 2019, high specificity (94.2%) of the age at onset criterion (≥12 years) and of having at least two complex motor behaviours and one complex phonic behaviour at first visit (96.2%) was observed. Some of the complex motor tics had lower specificity. The specificity of the FTLB diagnostic criterion of having more complex tics than simple tics was 89.7%. There was no significant difference in specificity of the criteria for children seen for the first time between 2017 and 2019 and between 2021 and 2023 (n = 149).

CONCLUSION

This information supports the use of the ESSTS criteria for FTLBs in clinical practice.

Symptom Severity and Health Impacts of Functional Tic-Like Behaviors in Youth

BACKGROUND

We performed this study to improve understanding of the relationship between functional tic-like behaviors (FTLBs) and quality of life, loneliness, family functioning, anxiety, depression, and suicidality.

METHOD

This cross-sectional study assessed self-reported quality of life, disability, loneliness, depression, anxiety, family functioning, tic severity, and suicide risk in age- and birth-sex matched youth with FTLBs, Tourette syndrome (TS), and neurotypical controls. We performed specific subanalyses comparing individuals with FTLBs who identified as transgender/gender diverse (TGD) with cisgender individuals.

RESULTS

Eighty-two youth participated (age range 11 to 25, 90% female at birth), including 35 with FTLBs, 22 with TS, and 25 neurotypical controls. A significantly higher proportion of participants with FTLB identified as TGD (15 of 35) than TS (two of 22) and neurotypical control (three of 25) participants. Compared with neurotypical controls, individuals with FTLBs had significantly lower quality of life, greater disability, loneliness, social phobia, anxiety symptoms, depressive symptoms, and suicidality. Compared with individuals with TS, individuals with FTLBs had more school/work absences due to tics, had more depressive symptoms, were more likely to be at high risk for suicidality, and had disability in self-care and life activity domains. There were no significant differences between cisgender and TGD participants with FTLB in any of the domains assessed.

CONCLUSIONS

Youth with FTLB have unique health care needs and associations with anxiety, depression, sex, and gender.

Functional Tic-like Behaviors: From the COVID-19 Pandemic to the Post-Pandemic Era

During the COVID-19 pandemic, there have been multiple reports about an unforeseen surge in adolescents and young adults exhibiting sudden onset functional tic-like behaviors. This phenomenon has been mainly associated with the female gender and occasionally after exposure to social media content featuring similar patterns of functional tic-like behaviors. A significant portion of these individuals have been directed to specialist clinics for movement disorders with initial misdiagnoses of late-onset refractory Tourette syndrome. Distinguishing between rapid onset functional tic-like behaviors and neurodevelopmental tics as part of Tourette syndrome can be challenging; however, the differential diagnosis is facilitated by focusing on specific clinical and demographic factors, which we have explored in a systematic literature review. Compared to neurodevelopmental tics, functional tic-like behaviors typically present with a more abrupt and intense manifestation of symptoms, onset at a later age, higher prevalence among females, inability to suppress tics, coexisting anxiety and depression, and sometimes a history of exposure to social media content portraying tic-like behaviors of a similar nature. This novel manifestation of a functional neurological disorder may thus be viewed as an emerging neuropsychiatric condition potentially triggered/exacerbated by the psychosocial repercussions of the COVID-19 crisis.

Recent advances in understanding the neurobiology of pediatric functional neurological disorder

INTRODUCTION

Functional neurological disorder (FND) is a neuropsychiatric disorder that manifests in a broad array of functional motor, sensory, or cognitive symptoms, which arise from complex interactions between brain, mind, body, and context. Children with FND make up 10%-20% of presentations to neurology services in children's hospitals and up to 20% of adolescents admitted to hospital for the management of intractable seizures.

AREAS COVERED

The current review focuses on the neurobiology of pediatric FND. The authors present an overview of the small but growing body of research pertaining to the biological, emotion-processing, cognitive, mental health, physical health, and social system levels.

EXPERT OPINION

Emerging research suggests that pediatric FND is underpinned by aberrant changes within and between neuron-glial (brain) networks, with a variety of factors - on multiple system levels - contributing to brain network changes. In pediatric practice, adverse childhood experiences (ACEs) are commonly reported, and activation or dysregulation of stress-system components is a frequent finding. Our growing understanding of the neurobiology of pediatric FND has yielded important flow-on effects for assessing and diagnosing FND, for developing targeted treatment interventions, and for improving the treatment outcomes of children and adolescents with FND.

What are the Key Phenomenological Clues to Diagnose Functional Tic-Like Behaviors in the Pandemic Era?

BACKGROUND

Functional tic-like behaviors (FTLBs) can be difficult to distinguish from tics.

OBJECTIVES

To describe the phenomenology of FTLBs in youth and assess the movements and vocalizations most suggestive of the diagnosis.

METHODS

We compared the phenomenology of tics between youth (<20 yr) with FTLBs and with primary tics from our Registry in Calgary, Canada.

RESULTS

Two hundred and thirty-six youths were included: 195 with primary tics (75% males; mean age: 10.8 yr) and 41 with FTLBs (98% females; 16.1 yr). In the bivariate models, FTLBs were most associated with copropraxia (OR = 15.5), saying words (OR = 14.5), coprolalia (OR = 13.1), popping (OR = 11.0), whistling (OR = 9.8), simple head movements (OR = 8.6), and self-injurious behaviors (OR = 6.9). In the multivariable model, FTLBs were still associated with saying words (OR = 13.5) and simple head movements (OR = 6.3). Only 12.2% of youth with FTLBs had throat clearing tics (OR = 0.2).

CONCLUSIONS

This study shall help physicians diagnose youth with FTLBs according to the presence/association of specific movements and vocalizations.

Time is ticking for TikTok tics: A retrospective follow-up study in the post-COVID-19 isolation era

INTRODUCTION

During the COVID-19 pandemic, an influx of adolescents presented worldwide with acute onset of functional tic-like behaviors (FTLBs). Our goal was to evaluate psychosocial factors around onset, to elucidate outcomes after pandemic isolation protocols were lifted, and to examine therapy and medication management.

METHODS

A retrospective review was performed of 56 patients ages 10-18 years with new-onset FTLBs seen at Boston Children's Hospital beginning in March 2020. Demographic factors, medical history, and treatment were evaluated. Patient outcomes were determined retrospectively based on the Clinical Global Impression Improvement (CGI-I) and Severity (CGI-S) scales from follow-up visits. CGI-I scores assessed the progression of FTLBs; CGI-S assessed overall function.

RESULTS

Ninety-six percent of patients were female-assigned at birth with high rates of comorbid anxiety (93%) and depression (71%). Forty-five percent were gender-diverse. Based on scales that assessed FTLBs (CGI-I) and overall functioning (CGI-S), up to 79% of patients improved independent of comorbid diagnosis or treatment. Evidence-based tic-specific treatments were not more effective than other treatments. A subset of patients had improvement in their FTLBs but not in their general functioning and continued to have other psychosomatic presentations.

CONCLUSION

While many patients' FTLBs improved, it is critical to remain alert to patients' overall function and to assess for other functional neurological disorders and mental health concerns. The tendency of FTLBs to improve in this population, independent of treatment, highlights the unique pathophysiology of FTLBs. Future research on contributing psychosocial factors and specific treatment protocols will allow optimal support for these patients.

Premonitory Urge in Patients with Tics and Functional Tic-like Behaviors

BACKGROUND

Premonitory urges (PU) are well described in primary tics, but their frequency and intensity in functional tic-like behaviors (FTLB) are unclear.

OBJECTIVE

To study the experience of PU in patients with FTLB.

METHODS

We compared the results of the premonitory urge for tics scale (PUTS) in adults with tics and FTLB in the University of Calgary Adult Tic Registry.

RESULTS

We included 83 patients with tics and 40 with FTLB. When comparing patients with tics, FTLB with tics and FTLB only, we did not detect significant differences either in the total PUTS score (P = 0.39), or in any of the individual PUTS item sub-scores (P values ranging between 0.11 and 0.99).

CONCLUSIONS

Patients with FTLB report PU at similar frequency and intensity to patients with tics. This finding confirms that PU are not a useful feature to discriminate FTLB from tics.

Functional Tic-Like Behaviors: A Common Comorbidity in Patients with Tourette Syndrome

BACKGROUND

Comorbid functional tic-like behaviors (FTB) have been described only rarely in patients with Tourette syndrome (TS).

OBJECTIVES

We present the first large sample of patients suffering from TS and FTB to raise awareness of this clinical presentation and to guide how to differentiate one from the other.

METHODS

We analyzed clinical data of 71 patients (n = 27 [38.0%] female, mean age: 21.5, range: 11-55) with TS + FTB.

RESULTS

In the majority of patients, FTB started abruptly on average 15 years after tic onset with "treatment-resistant" complex movements and ("coprophenomena-like") vocalizations preceded by timely related psychological stressors. Psychological evaluation revealed evidence for internal conflicts (79%), emotional dysregulation (56%), and maintaining factors (70%). About one third of patients had a positive history for further medically unexplained symptoms. Compared to a large TS sample (n = 1032), patients with TS + FTB were more likely to be female, and presented significantly more common with "coprophenomena-like" symptoms, atypical influential factors, atypical descriptions of premonitory sensations, and higher rates of comorbid obsessive-compulsive disorder and "self-injurious" behavior.

CONCLUSIONS

Based on our data it can be assumed that FTB is a common comorbidity in TS, similar to functional overlay in other movement disorders and epilepsy. Before classifying a patient as suffering from treatment-resistant TS, FTB should be ruled out.

Prospective follow-up study of youth and adults with onset of functional tic-like behaviours during the COVID-19 pandemic

BACKGROUND AND PURPOSE

Very little is known about the long-term prognosis of patients with functional tic-like behaviours (FTLBs). We sought to characterize the trajectory of symptom severity over a 12-month period.

METHODS

Patients with FTLBs were included in our prospective longitudinal child and adult clinical tic disorder registries at the University of Calgary. Patients were prospectively evaluated 6 and 12 months after their first clinical visit. Tic inventories and severity were measured with the Yale Global Tic Severity Scale (YGTSS).

RESULTS

Eighty-three youths and adults with FTLBs were evaluated prospectively until April 2023. Mean YGTSS total tic severity scores were high at baseline, with a mean score of 29.8 points (95% confidence interval [CI] = 27.6-32.1). Fifty-eight participants were reevaluated at 6 months, and 32 participants were reevaluated at 12 months. The YGTSS total tic severity score decreased significantly from the first clinical visit to 6 months (raw mean difference = 8.9 points, 95% CI = 5.1-12.7, p < 0.0001), and from 6 to 12 months (raw mean difference = 6.4 points, 95% CI = 0.8-12.0, p = 0.01). Multivariable linear regression demonstrated that tic severity at initial presentation and the presence of other functional neurological symptoms were associated with higher YGTSS total tic scores at 6 months, whereas younger age at baseline, receiving cognitive behavioural therapy for anxiety and/or depression, and prescription of selective serotonin reuptake inhibitors were associated with lower YGTSS total tic scores at 6 months.

CONCLUSIONS

We observed a meaningful improvement in tic severity scores in youth and adults with FTLBs over a period of 6-12 months.

Integrated cognitive behavioral intervention for functional tics (I-CBiT): case reports and treatment formulation

Introduction

The onset of the COVID-19 pandemic saw a global surge in functional tic-like behaviors (FTLBs). FTLBs are unique from primary tic disorders. They are thought to manifest through a complex interplay between environmental and personal factors, including the stress-arousal system, and are characterized by their sudden and explosive onset. Accordingly, common interventions for tic disorders show limited efficacy in this population. We present an Integrated Cognitive Behavioral Intervention for Functional Tics (I-CBiT) that uses an urge acceptance model to manage tics and related stress and anxiety.

Methods

We describe the treatment outcomes of eight young people presenting with new and sudden onset FTLBs who underwent I-CBiT, which integrates traditional behavioral tic interventions with third-wave cognitive behavioral therapies. All cases completed the three-phase intervention involving core components of psychoeducation, exposure and response prevention with urge acceptance, sensory grounding strategies, and cognitive behavioral intervention targeting the stress-arousal system. Tic severity and impairment were assessed prior to treatment and at completion.

Results

All cases showed a significant reduction in tic severity post I-CBiT and an improvement in overall daily living function. These cases highlight the role of urge acceptance in managing both tic urges and the underlying stress-arousal system to bring about long-term change.

Conclusion

We demonstrated the efficacy of I-CBiT for managing FTLBs. Our findings illustrate the importance of treating underlying stress and anxiety in this population and, therefore, a need for greater interaction between multidisciplinary services in managing FTLBs to comprehensively cover the varied symptom presentations linked to thoughts, emotions, bodily sensations, and stress responses.

Functional Movement Disorder: Assessment and Treatment

Functional movement disorder (FMD) is a common, potentially reversible source of disability in neurology. Over the last two decades, there have been major advances in our understanding of the clinical picture, diagnosis, and management of this condition. Motor presentation is heterogeneous and several non-motor symptoms (e.g., pain, fatigue) are part of the clinical spectrum. The diagnosis should be made by neurologists or neuropsychiatrists based on the presence of positive signs of inconsistency and incongruence with neurological diseases. Promising evidence has accumulated for the efficacy of physiotherapy, psychotherapy, or both in the management of FMD, for a majority of patients.

Illness-Promoting Psychological Processes in Children and Adolescents with Functional Neurological Disorder

Previous studies suggest that subjective distress in children with functional neurological disorder (FND) is associated with stress-system dysregulation and modulates aberrant changes in neural networks. The current study documents illness-promoting psychological processes in 76 children with FND (60 girls and 16 boys, aged 10.00-17.08 years) admitted to the Mind-Body Program. The children completed a comprehensive family assessment and self-report measures, and they worked with the clinical team to identify psychological processes during their inpatient admission. A total of 47 healthy controls (35 girls and 12 boys, aged 8.58-17.92 years) also completed self-report measures, but were not assessed for illness-promoting psychological processes. Children with FND (vs. controls) reported higher levels of subjective distress (total DASS score, t(104.24) = 12.18; p ˂ 0.001) and more adverse childhood experiences across their lifespans (total ELSQ score, t(88.57) = 9.38; p ˂ 0.001). Illness-promoting psychological processes were identified in all children with FND. Most common were the following: chronic worries about schoolwork, friendships, or parental wellbeing (n = 64; 84.2%); attention to symptoms (n = 61; 80.3%); feeling sad (n = 58; 76.3%); experiencing a low sense of control (helplessness) in relation to symptoms (n = 44; 57.9%); pushing difficult thoughts out of mind (n = 44; 57.9%); self-critical rumination (n = 42; 55.3%); negative/catastrophic-symptom expectations (n = 40; 52.6%); avoidance of activities (n = 38; 50%); intrusive thoughts/feelings/memories associated with adverse events (n = 38, 50%); and pushing difficult feelings out of mind (n = 37; 48.7%). In children with FND-disabled enough to be admitted for inpatient treatment-illness-promoting psychological processes are part of the clinical presentation. They contribute to the child's ongoing sense of subjective distress, and if not addressed can maintain the illness process. A range of clinical interventions used to address illness-promoting psychological processes are discussed, along with illustrative vignettes.

Functional tics: Expanding the phenotypes of functional movement disorders?

BACKGROUND AND PURPOSE

Until the outbreak reported during the COVID-19 pandemic, functional tics were considered to be a relatively rare clinical phenotype, as opposed to other functional movement disorders such as functional tremor and dystonia. To better characterize this phenotype, we compared the demographic and clinical characteristics of patients who developed functional tics during the pandemic and those of patients with other functional movement disorders.

METHODS

Data from 110 patients were collected at the same neuropsychiatry centre: 66 consecutive patients who developed functional tics without other functional motor symptoms or neurodevelopmental tics and 44 patients with a mix of functional dystonia, tremor, gait, and myoclonus.

RESULTS

Both groups were characterized by female sex preponderance (70%-80%) and (sub)acute onset of functional symptoms (~80%). However, patients with functional tics had a significantly earlier age at onset of functional symptoms (21 vs. 39 years). Exposure to relevant social media content was reported by almost half of the patients with functional tics, but by none of the patients with other functional movement disorders. Comorbidity profiles were similar, with relatively high rates of anxiety/affective symptoms and other functional neurological symptoms (nonepileptic attacks).

CONCLUSIONS

Patients who developed functional tics during the pandemic represent a phenotypic variant of the wider group of patients with functional movement disorders, associated with younger age at onset and influenced by pandemic-related factors, including increased exposure to specific social media content. Diagnostic protocols and treatment interventions should be tailored to address the specific features of this newly defined phenotype.

Distinguishing functional from primary tics: a study of expert video assessments

BACKGROUND

Reliably applied criteria to differentiate functional from primary tics are lacking. In the absence of biological markers, the development of new diagnostic criteria to assist clinicians is predicated on expert judgement and consensus. This study examines the level of diagnostic agreement of experts in tic disorders using video footage and clinical descriptions.

METHODS

Using a two-part survey, eight experts in the diagnosis and management of tics were first asked to study 24 case videos of adults with primary tics, functional tics or both and to select a corresponding diagnosis. In the second part of the survey, additional clinical information was provided, and the diagnosis was then reconsidered. Inter-rater agreement was measured using Fleiss' kappa. In both study parts, the factors which influenced diagnostic decision-making and overall diagnostic confidence were reviewed.

RESULTS

Based on phenomenology alone, the diagnostic agreement among the expert raters was only fair for the pooled diagnoses (κ=0.21) as well as specifically for functional (κ=0.26) and primary tics (κ=0.24). Additional clinical information increased overall diagnostic agreement to moderate (κ=0.51) for both functional (κ=0.6) and primary tics (κ=0.57). The main factors informing diagnosis were tic semiology, age at tic onset, presence of premonitory urges, tic suppressibility, the temporal latency between tic onset and peak severity, precipitants and tic triggers and changes in the overall phenotypic presentation.

CONCLUSIONS

This study confirmed that in the absence of clinical information, the diagnostic distinction between primary and functional tics is often difficult, even for expert clinicians.

Neurodevelopmental versus functional tics: A controlled study

BACKGROUND

An unprecedented increase in newly developed functional tics, mainly in young females, has been reported during the COVID-19 pandemic. We set out to complement existing case series with the largest controlled study to date on the clinical phenomenology of functional tics versus neurodevelopmental tics.

METHODS

Data from 166 patients were collected at a specialist clinic for tic disorders during a three-year period overlapping with the COVID-19 pandemic (2020-2023). We compared the clinical features of patients who developed functional tics during the COVID-19 pandemic (N = 83) to patients with Tourette syndrome matched for age and gender (N = 83).

RESULTS

Female adolescents and young adults accounted for 86% of the clinical sample of patients with functional tics, who were less likely to report a family history of tic disorders than their matched controls with Tourette syndrome. Co-morbidity profiles were significantly different: anxiety and other functional neurological disorders were more strongly associated with functional tics, whereas attention-deficit and hyperactivity disorder and tic-related obsessive-compulsive behaviors co-occurred more frequently with neurodevelopmental tics. Overall, absence of tic-related obsessive-compulsive behaviors (t = 8.096; p < 0.001) and absence of a family history of tics (t = 5.111; p < 0.001) were the strongest predictors of the diagnosis of functional tics. Compared to neurodevelopmental tics, functional tics were more likely to present acutely/subacutely at a later age (21 versus 7 years), without a clear rostro-caudal progression. Coprophenomena, self-injurious behaviors, and complex clinical manifestations such as blocking tics, throwing tics, and tic attacks, were all over-represented in the functional group.

CONCLUSIONS

Our findings provide robust confirmation of both patient-related variables and tic characteristics contributing to the differential diagnosis between functional tics developed during the pandemic and neurodevelopmental tics reported by patients with Tourette syndrome.

Clarifying the Differences between Patients with Organic Tics and Functional Tic-Like Behaviors

Due to the global increase in the number of patients with Functional Tic-Like Behaviors (FTLB), it has become increasingly important to find reliable differences between this patient group and patients with organic tics (OTs), which can be used in differential diagnosis. The purpose of this retrospective study was to critically examine both established and suggested differences between the patient groups. A total of 53 FTLB patients and 200 OT patients were included. Several findings from the current literature were replicated in this study: Compared to patients with OTs, patients with FTLB had significantly more complex tics, were older at symptom onset, were more likely to be female, and were less likely to have family members with tics. Furthermore, the study also revealed new differences between the groups: Patients with FTLB had significantly more family members with a psychiatric disorder, were more likely to have experienced an adverse psychosocial event immediately before symptom onset, and had significantly fewer simple tics. Finally, this study was unable to replicate the previously found differences in comorbidities between patients with OTs and FTLB. These findings could contribute significantly to the understanding of FTLB's etiology and to improve diagnosis, as including the presence of simple tics and comorbidities in the diagnostic criteria might be discussed in future studies.

Have We Forgotten What Tics Are? A Re-Exploration of Tic Phenomenology in Youth with Primary Tics

Background

The first systematic description of tics in a large sample was in 1978.

Objectives

To assess the phenomenology of tics in youth and investigate how age and sex influence tic phenomenology.

Methods

Children and adolescents with primary tic disorders have been prospectively included in our Registry in Calgary, Canada, since 2017. We examined tic frequency and distribution using the Yale Global Tic Severity Scale, differences between sexes, and changes in tic severity with age and with mental health comorbidities.

Results

A total of 203 children and adolescents with primary tic disorders were included (76.4% males; mean age = 10.7 years, 95% CI = 10.3-11.1). At first assessment, the most common simple motor tics were eye blinking (57%), head jerks/movements (51%), eye movements (48%) and mouth movements (46%); 86% had at least one simple facial tic. The most frequent complex motor tics were tic-related compulsive behaviors (19%). Throat clearing was the most common simple phonic tic (42%); 5% only had coprolalia. Females had higher frequency and intensity of motor tics than males (P = 0.032 and P = 0.006, respectively), associated with greater tic-related impairment (P = 0.045). Age was positively correlated with the Total Tic Severity Score (coefficient 0.54, P = 0.005), along with the number, frequency and intensity of motor tics but not with their complexity. Psychiatric comorbidities were associated with greater tic severity.

Conclusions

Our study suggests that age and sex affect clinical presentation in youth with tics. The phenomenology of tics in our sample was similar to the 1978 description of tics, and contrasts with functional tic-like behaviors.

European Society for the Study of Tourette Syndrome 2022 criteria for clinical diagnosis of functional tic-like behaviours: International consensus from experts in tic disorders

BACKGROUND AND PURPOSE

In 2020, health professionals witnessed a dramatic increase in referrals of young people with rapid onset of severe tic-like behaviours. We assembled a working group to develop criteria for the clinical diagnosis of functional tic-like behaviours (FTLBs) to help neurologists, pediatricians, psychiatrists, and psychologists recognize and diagnose this condition.

METHODS

We used a formal consensus development process, using a multiround, web-based Delphi survey. The survey was based on an in-person discussion at the European Society for the Study of Tourette Syndrome (ESSTS) meeting in Lausanne in June 2022. Members of an invited group with extensive clinical experience working with patients with Tourette syndrome and FTLBs discussed potential clinical criteria for diagnosis of FTLBs. An initial set of criteria were developed based on common clinical experiences and review of the literature on FTLBs and revised through iterative discussions, resulting in the survey items for voting.

RESULTS

In total, 24 members of the working group were invited to participate in the Delphi process. We propose that there are three major criteria and two minor criteria to support the clinical diagnosis of FTLBs. A clinically definite diagnosis of FTLBs can be confirmed by the presence of all three major criteria. A clinically probable diagnosis of FTLBs can be confirmed by the presence of two major criteria and one minor criterion.

CONCLUSIONS

Distinguishing FTLBs from primary tics is important due to the distinct treatment paths required for these two conditions. A limitation of the ESSTS 2022 criteria is that they lack prospective testing of their sensitivity and specificity.

Rapid onset of functional tic-like behaviors among adolescent girls-Minnesota, September-November 2021

Background

On October 15, 2021, the Minnesota Department of Health began investigating a school cluster of students experiencing tic-like behaviors thought to be related to recent COVID-19. The objective of this report is to describe the investigation, key findings, and public health recommendations.

Methods

Affected students and proxies were interviewed with a standardized questionnaire including validated depression and anxiety screens.

Results

Eight students had tic-like behaviors lasting >24 h after initial report with onset during September 26-October 30, 2021. All eight students were females aged 15-17 years. All students either had a history of depression or anxiety or scored as having more than minimal anxiety or depression on validated screens. Four students previously had confirmed COVID-19: the interval between prior COVID-19 and tic symptom onset varied from more than a year prior to tic symptom onset to at the time of tic symptom onset.

Conclusion

The onset of tic-like behaviors at one school in Minnesota appeared to be related more to underlying mental health conditions than recent COVID-19. These findings highlight the need to better understand functional tic-like behaviors and adolescent mental health.

Functional tic-like behaviours during the COVID-19 pandemic: Follow-up over 12 months

BACKGROUND

Functional tics are included in the wide spectrum of functional movement disorders (FMDs). Their distinction from organic tics is challenging because they both phenomenologically present common features. During the COVID-19 pandemic, there has been an increase in functional tic-like behaviours in vulnerable children and adolescents after social media exposure. This study explores the phenomenology and course of a cohort of newly diagnosed functional tic-like behaviors.

METHODS

We analysed clinical data of 243 patients affected by tic disorders collected at outpatient Tourette Clinic, Child and Adolescent Neurology and Psychiatry Unit, Catania University. Among the clinical cohort with functional tic-like behaviors, we evaluated the clinical course of symptoms at follow-up visits after 6 and 12 months.

RESULTS

Among the cohort of 243 patients referred for evaluation at our centre, 11 were diagnosed with functional tic-like behaviours. The majority of participants with functional tic-like behaviours were female with a mean age of 15 years old and presented an explosive symptom's onset. At follow-up visit after 12 months, patients with functional tic-like behaviors showed a significant variation in the severity of tics and anxiety symptoms. Conversely, depressive, and obsessive-compulsive symptoms did not significantly differ during the follow-up.

CONCLUSION

Our data suggest that several characteristics in clinical course and their phenomenology can help clinicians to distinguish functional tic-like behaviours from organic tics. Our results also suggest a better outcome for tics and anxiety symptoms respect on other comorbidities. A prompt diagnosis and management not only of tics but also comorbidities are recommended, as generally conventional pharmacotherapy for tics does not have positive effects on these patients.