Epidemiology of Huntington's Disease in Latin America: A Systematic Review and Meta-Analysis.

BACKGROUND: Latin America has played a crucial role in advancing our understanding of Huntington's disease (HD). However, previous global reviews include limited data from Latin America. It is possible that English-based medical search engines may not capture all the relevant studies. METHODS: We searched databases in Spanish, Portuguese, and English. The names of every country in Latin America in English-based search engines were used to ensure we found any study that had molecular ascertainment and provided general epidemiological information or subpopulation data. Additionally, we contacted experts across the region. RESULTS: The search strategy yielded 791 citations; 24 studies met inclusion criteria, representing 12 of 36 countries. The overall pooled prevalence was 0.64 per 100,000 (prediction interval, 0.06-7.22); for cluster regions, it was 54 per 100,000 (95% CI, 34.79-84.92); for juvenile HD, it was 8.7% (prediction interval, 5.12-14.35), and 5.9% (prediction interval, 2.72-13.42) for late-onset HD. The prevalence was higher for Mexico, Peru, and Brazil. However, there were no significant differences between Central America and the Caribbean versus South America. CONCLUSION: The prevalence of HD appears to be similar across Latin America. However, we infer that our findings are underestimates, in part because of limited research and underdiagnosis of HD because of limited access to molecular testing and the availability of neurologists and movement disorders specialists. Future research should focus on identifying pathways to improve access to molecular testing and education and understanding differences among different ancestral groups in Latin America. © 2024 International Parkinson and Movement Disorder Society.

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.

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.

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.

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.

Lifestyle Factors Associated With Frequent Recurrent Headaches in Children and Adolescents: A Canadian Population-Based Study.

BACKGROUND AND OBJECTIVES: Lifestyle behaviors have been postulated to affect headache frequency in youth and are often the primary target of self-management recommendations. Our study aimed to assess the association between various lifestyle factors and frequent recurrent headaches in children and youth. METHODS: Children and adolescents aged 5-17 years were enrolled in a large cross-sectional Canadian population-based health survey, completed on January 31, 2019. Headache frequency was dichotomized into "approximately once/week or less" or ">once/week" (defined as frequent recurrent headaches). The association between frequent headaches and meal schedules, screen exposure, physical activity, chronotype, and frequent substance use/exposure (alcohol, cigarettes, electronic cigarettes, and cannabis) was assessed using both unadjusted logistic regression models and models adjusted for age/sex. Fully adjusted models examined the odds of frequent headaches according to all exposures. Survey design effects were accounted for using bootstrap replicate weighting. RESULTS: There were an estimated nweighted = 4,978,370 eligible participants in the population. The mean age was 10.9 years (95% CI 10.9-11.0); 48.8% were female; 6.1% had frequent headaches. Frequent headaches were associated with older age (odds ratio [OR] = 1.31, 95% CI 1.28-1.34, p < 0.001) and female sex (OR = 2.39, 95% CI 2.08-2.75, p < 0.001). In models adjusted for age/sex, the odds of frequent headaches decreased with meal regularity (adjusted OR [aOR] = 0.90, 95% CI 0.89-0.92, p < 0.001) and increased with later chronotype (aOR = 1.10, 95% CI 1.05-1.15, p < 0.001) and excess screen exposure (≥21 hours vs none in past week: aOR = 2.97, 95% CI 1.53-5.77, p = 0.001); there was no significant association with reported physical activity (aOR = 0.95, 95% CI 0.67-1.34, p = 0.77). In 12- to 17-year-olds, frequent headaches were associated with frequent alcohol use (≥1/wk vs never: aOR = 3.50, 95% CI 2.18-5.62, p < 0.001), binge drinking (≥5 times in past month vs never: aOR = 5.52, 95% CI 2.95-10.32, p < 0.001), smoking cigarettes (daily vs never: aOR = 3.81, 95% CI 1.91-7.62, p < 0.001), using e-cigarettes (daily vs never: aOR = 3.10, 95% CI 2.29-4.20, p < 0.001), and cannabis use (daily vs never: aOR = 3.59, 95% CI 2.0-6.45, p < 0.001). In the entire sample, daily exposure to smoking inside the house was associated with frequent headaches (aOR = 2.00, 95% CI 1.23-3.27, p = 0.005). DISCUSSION: Several lifestyle behaviors were associated with frequent headaches in children and youth, such as meal irregularity, late chronotype, prolonged screen exposure, and frequent substance use/exposure, suggesting that these are potential modifiable risk factors to target in this population.

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.

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.

Tourette syndrome and other tic disorders of childhood.

Tics are repetitive, patterned, and nonrhythmic movements or vocalizations/audible sounds that are misplaced in context. Phenomenology and characteristics of tics (e.g., premonitory urge, suppressibility) differentiate them from compulsions, stereotypies, functional tic-like behaviors, and other types of hyperkinetic movement disorders. With a prevalence of approximately 1% in school-aged boys, Tourette syndrome (TS) is considered a common childhood-onset neurodevelopmental disorder, defined by the combination of at least two motor tics and at least one phonic tic lasting more than 1 year. TS is a highly heritable disorder, with a wide spectrum of severity. In some individuals, tics can cause pain, distress, functional impairment, or stigmatization. About 90% of individuals with TS have at least one mental health comorbidity (attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety/depressive disorders). These comorbidities significantly impact patients' quality of life and must therefore be screened and managed accordingly in this population. Treatment of tics is based on behavioral therapies targeting tics (habit reversal training included in the comprehensive behavioral intervention for tics, and exposure and response prevention for tics), in association with medication if needed (e.g., alpha-2-agonists, second-generation antipsychotics). Deep brain stimulation is considered an experimental option in the most severe, treatment-resistant patients. In adulthood, less than 25% of individuals still have moderate or severe tics.

Association Between Peer Victimization, Gender Diversity, Mental Health, and Recurrent Headaches in Adolescents: A Canadian Population-Based Study.

BACKGROUND AND OBJECTIVES: It is unknown whether bullying and gender diversity are associated with increased headache frequency in adolescents. Our study aimed to assess the association between peer victimization, gender diversity, and frequent recurrent headaches in adolescents, while controlling for age, sex, socioeconomic status, and potential confounders (mood and anxiety disorders, suicidality). METHODS: This was a cross-sectional observational study of adolescents aged 12-17 years using data from a Canadian population-based health survey. Headache frequency was dichotomized into "≤once/wk" or ">once/wk" (i.e., frequent recurrent headaches). Logistic regression was used to quantify the association between frequent peer victimization (overt or relational), gender diversity (female sex at birth + male gender, male sex at birth + female gender, or gender diverse), mood/anxiety disorder, suicidality, and the odds of frequent recurrent headaches. The fully adjusted multivariable logistic regression model included all exposures and was controlled for age, sex, and socioeconomic status. Bootstrap replicate weighting was used to account for survey design effects. RESULTS: There were an estimated 2,268,840 eligible participants (weighted sample size) (mean age = 14.4 years, 48.8% female, 0.5% gender diverse), and 11.2% reported frequent recurrent headaches. Frequent recurrent headaches were associated with older age (odds ratio [OR] = 1.26 per year of age, 95% CI 1.20-1.31), female sex (OR = 2.89, 95% CI 2.47-3.37), and being gender diverse (OR = 3.30, 95% CI 1.64-6.63, adjusted for age/sex). Youth with frequent headaches had higher odds of experiencing both overt and relational bullying compared with peers (OR = 2.69, 95% CI 2.31-3.14, and OR = 3.03, 95% CI 2.58-3.54, adjusted for age/sex). In the fully adjusted model, frequent headaches were no longer associated with gender diversity (OR = 1.53, 95% CI 0.63-3.69) but were still associated with frequent overt and relational peer victimization (OR = 1.82, 95% CI 1.41-2.34, and OR = 1.54, 95% CI 1.17-2.03, respectively), suicidality (OR = 1.83, 95% CI 1.44-2.32), and having a mood or anxiety disorder (OR = 1.50, 95% CI 1.01-2.21, and OR = 1.74, 95% CI 1.24-2.45, respectively). In a model adjusted for age, sex, and mood/anxiety disorders, the risk of suicidality increased incrementally with headache frequency. DISCUSSION: Peer victimization and suicidality may be associated with higher headache frequency in adolescents with headaches, independently of mood and anxiety symptoms. Gender-diverse adolescents may have a higher risk of experiencing frequent headaches when compared with cisgender peers, and this may be explained by associated psychosocial factors (anxiety, depression, suicidality, and peer victimization).

Scoping Review on ADCY5-Related Movement Disorders.

Background: Adenylyl cyclase 5 (ADCY5)-related movement disorder (ADCY5-RMD) is a rare, childhood-onset disease resulting from pathogenic variants in the ADCY5 gene. The clinical features, diagnostic options, natural history, and treatments for this disease are poorly characterized and have never been established through a structured approach. Objective: This scoping review attempts to summarize all available clinical literature on ADCY5-RMD. Methods: Eighty-seven articles were selected for inclusion in this scoping review. The majority of articles identified were case reports or case series. Results: These articles demonstrate that patients with ADCY5-RMD suffer from permanent and/ or paroxysmal hyperkinetic movements. The paroxysmal episodes can be worsened by environmental triggers, in particular the sleep-wake transition phase in the early morning. Occurrence of nocturnal paroxysmal dyskinesias and perioral twitches are highly suggestive of the diagnosis when present. In the majority of patients intellectual capacity is preserved. ADCY5-RMD is considered a non-progressive disorder, with inter-individual variations in evolution with aging. Somatic mosaicism, mode of inheritance and the location of the mutation within the protein can influence phenotype. Conclusions: The current evidence for therapeutic options for ADCY5-RMD is limited: caffeine, benzodiazepines and deep brain stimulation have been consistently reported to be useful in case reports and case series.

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.

Developmental stuttering, physical concomitants associated with stuttering, and Tourette syndrome: A scoping review.

BACKGROUND AND PURPOSE: Developmental stuttering and Tourette syndrome (TS) are common neurodevelopmental disorders. Although disfluencies may co-occur in TS, their type and frequency do not always represent pure stuttering. Conversely, core symptoms of stuttering may be accompanied by physical concomitants (PCs) that can be confused for tics. This scoping review aimed to explore the similarities and differences between stuttering and tics in terms of epidemiology, comorbidities, phenomenology, evolution, physiopathology, and treatment. We also described the nature of PCs in stuttering and disfluencies in TS. METHODS: A literature search on Medline, Embase and PsycInfo was executed in March 2022. From 426 studies screened, 122 were included in the review (a majority being narrative reviews and case reports). RESULTS: TS and stuttering have several epidemiological, phenomenological, comorbidity, and management similarities suggesting shared risk factors and physiopathology (involving the basal ganglia and their connections with speech and motor control cortical regions). PCs in stuttering commonly involve the face (eyelids, jaw/mouth/lip movements) and sometimes the head, trunk and limbs. PCs can be present from early stages of stuttering and vary over time and within individuals. The function of PCs is unknown. Some individuals with TS have a distinct disfluency pattern, composed of a majority of typical disfluencies (mostly between-word disfluencies), and a mix of cluttering-like behaviors, complex phonic tics (e.g. speech-blocking tics, echolalia, palilalia), and rarely, atypical disfluencies. CONCLUSION: Future investigations are warranted to better understand the complex relationships between tics and stuttering and address the management of disfluencies in TS and PCs in stuttering.

Engaging youth and parents in clinical pediatric research: A case-based example.

Background: Youth and parent engagement is a key component of clinical research. There are many ways to actively and meaningfully engage youth and parents as integral members of research teams, for example, through ad-hoc committees, advisory councils, or as co-leads on projects. When youth and parents are actively and meaningfully engaged in research projects, they share knowledge from their lived experiences to improve the quality and relevance of research. Methods: We describe a case-based example of engaging youth and parent research partners when co-designing a questionnaire to assess preferences for pediatric headache treatments, from both a researcher and youth/parent perspective. We also summarize best practices in patient and family engagement from the literature and pertinent guidelines to assist researchers with integrating patient and family engagement into their studies. Results: As researchers, we felt that the integration of a youth and parent engagement plan into our study significantly altered and strengthened questionnaire content validity. We encountered challenges throughout the process and detailed these experiences to help educate others about challenge mitigation and best practices in youth and parent engagement. As youth and parent partners, we felt that engaging in the process of questionnaire development was an exciting and empowering opportunity, and that our feedback was valued and integrated. Conclusions: By sharing our experience, we hope to catalyze thought and discussion around the importance of youth and parent engagement in pediatric research, with the goal of stimulating more appropriate, relevant, and high-quality pediatric research and clinical care in the future.

Transitional Care for Young People with Movement Disorders: Consensus-Based Recommendations from the MDS Task Force on Pediatrics.

Background: The International Parkinson and Movement Disorders Society (MDS) set up a working group on pediatric movement disorders (MDS Task Force on Pediatrics) to generate recommendations to guide the transition process from pediatrics to adult health care systems in patients with childhood-onset movement disorders. Methods: To develop recommendations for transitional care for childhood onset movement disorders, we used a formal consensus development process, using a multi-round, web-based Delphi survey. The Delphi survey was based on the results of the scoping review of the literature and the results of a survey of MDS members on transition practices. Through iterative discussions, we generated the recommendations included in the survey. The MDS Task Force on Pediatrics were the voting members for the Delphi survey. The task force members comprise 23 child and adult neurologists with expertise in the field of movement disorders and from all regions of the world. Results: Fifteen recommendations divided across four different areas were made pertaining to: (1) team composition and structure, (2) planning and readiness, (3) goals of care, and (4) administration and research. All recommendations achieved consensus with a median score of 7 or greater. Conclusion: Recommendations on providing transitional care for patients with childhood onset movement disorders are provided. Nevertheless several challenges remain in the implementation of these recommendations, related to health infrastructure and the distribution of health resources, and the availability of knowledgeable and interested practitioners. Research on the influence of transitional care programs on outcomes in childhood onset movement disorders is much needed.

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.