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.

"Unvoluntary" Movement Disorders: Distinguishing between Tics, Akathisia, Restless Legs, and Stereotypies.

Tics, stereotypies, akathisia, and restless legs fall at different places on the spectrum of discrete, unwanted and potentially disabling motor routines. Unlike tremor, chorea, myoclonus, or dystonia, this subgroup of abnormal movements is characterized by the subject's variable ability to inhibit or release undesired motor patterns on demand. Though it may be sometimes clinically challenging, it is crucial to distinguish these "unvoluntary" motor behaviors because secondary causes and management approaches differ substantially. To this end, physicians must consider the degree of repetitiveness of the movements, the existence of volitional control, and the association with sensory symptoms, or cognitive-ideational antecedent. This review aims to summarize the current existing knowledge on phenomenology, diagnosis, and treatment of tics, stereotypies, akathisia, and restless leg syndrome.

Rapid Onset Functional Tic-Like Disorder Outbreak: A Challenging Differential Diagnosis in the COVID-19 Pandemic.

During the COVID-19 pandemic, several countries have observed an unexpected increase in the number of adolescents and young adults presenting with rapid onset functional tic-like behaviours after being exposed to social media content of others displaying a similar pattern of functional tics. Many of these patients have been referred to Movement Disorders Clinics with misdiagnoses of late-onset refractory Tourette Syndrome after failing different pharmacological treatments for tics. Tourette Syndrome is a well-known condition with clear clinical diagnostic criteria and which presents with the insidious onset of simple motor and phonic tics in a rostro-caudal evolution starting in early childhood. Clinical and demographic aspects can differentiate rapid onset functional tic-like behaviours from Tourette Syndrome, including the former having abrupt and explosive presentation of severe symptoms, later age of onset, female gender predominance, lack of suppressibility, comorbid anxiety and depression, atypical premonitory urge and history of exposure to social media content displaying tic-like behaviours. This new presentation of a functional neurological disorder may be explained in part by the relationship between social media exposure to tic-like behaviours, and maladaptive response to anxiety caused by life stressors (e.g. COVID-19 pandemic), especially in young individuals. Rapid onset functional tic-like behaviours may be considered a spreading neuropsychiatric disorder that is potentially fostered by the psychosocial impact caused by the COVID-19 pandemic.

Durant la pandémie de la COVID-19, plusieurs pays ont observé une hausse inattendue du nombre d'adolescents et de jeunes adultes présentant des comportements fonctionnels de type tic à apparition rapide après avoir été exposés au contenu des médias sociaux d'autres personnes affichant un modèle semblable de tics fonctionnels. Nombre de ces patients ont été adressés à des cliniques de trouble du mouvement avec des diagnostics fautifs de syndrome de Tourette réfractaire d'apparition tardive après avoir échoué à différents traitements pharmacologiques pour les tics. Le syndrome de Tourette est un trouble bin connu dont les critères diagnostiques cliniques sont clairs et qui présente le début insidieux de simples tics moteurs et phoniques dans une évolution rostro-caudale au début de l'enfance. Les aspects cliniques et démographiques peuvent différencier l'apparition rapide de comportements fonctionnels de type tic du syndrome de Tourette, notamment parce que les premiers ont une présentation abrupte et explosive de symptômes graves, apparaissent à un âge plus avancé, ont une prédominance chez le sexe féminin, manquent de suppressibilité, anxiété et dépression comorbides, envie prémonitoire atypique et antécédents d'exposition au contenu des médias sociaux affichant des comportements de type tic. Cette nouvelle présentation d'un trouble neurologique fonctionnel peut s'expliquer en partie par la relation entre l'exposition aux comportements de type tic dans les médias sociaux et la réponse inadaptée à l'anxiété causée par les stresseurs de la vie (p. ex., pandémie de la COVID-19), surtout chez les jeunes personnes. Les comportements fonctionnels de type tic à apparition rapide peuvent être considérés comme un trouble neuropsychiatrique qui se propage et qui est potentiellement favorisé par l'effet psychosocial causé par la pandémie de la COVID-19.

Quality of life and epidemiological profile of patients undergoing botulinum toxin treatment / Qualidade de vida e perfil epidemiológico de pacientes submetidos a tratamento com toxina botulínica

The botulinum toxin (BTX) is a therapeutic modality used in diverse range of diseases in neurology such as dystonia, tics and tremors and spasticity. The literature about the relation between the use of BTX and its impact in quality of life scales are conflicting, our study proposes to aid answering this question. We selected 110 patients between April 2014 and January 2015, from two tertiary hospitals (movement disorder outpatient clinic), which have been evaluated for age, gender, type of BTX applied, technic of application, adverse events, clinical syndrome and etiology. To evaluate quality of life we used the SF-36® scale. The most prevalent clinical syndromes were dystonia, spasticity and daytime bruxism. We applied the scale in 55 patients pre and post treatment to trace a clinical and epidemiological profile of patients treated with botulinum toxin, evaluating its impact on quality of life. Main etiologies were: idiopathic, stroke and peripheral facial palsy. SF-36® scale applied to 55 patients showed that 35 of them improved, with higher impact upon the mental health, vitality, physical functioning and body pain subsections. Incidence of adverse events (21,8%) was similar to the literature. Botulinum toxin application was associated with higher scores on SF-36®, therefore representing a good therapeutic option dystonia and spasticity. (AU)

A toxina botulínica (TB) é uma modalidade terapêutica utilizada em diversas condições em neurologia, dentre elas distonia, espasticidade, tremor e tique. A literatura médica é conflitante em estabelecer a relação entre o uso da TB e seu impacto nas escalas de qualidade de vida. O presente estudo se propõe a avaliar esta relação. Foram selecionados 110 pacientes, no período entre abril de 2014 e janeiro de 2015 provenientes do ambulatório de Distúrbios do Movimento de 2 hospitais terciários, que foram avaliados de acordo com a idade, gênero, tipo de TB aplicada, técnica de aplicação, eventos adversos, síndrome clínica e etiologia. Para avaliar a qualidade de vida foi utilizada a escala SF-36®. As síndromes mais prevalentes foram distonia, espasticidade e bruxismo diurno. Aplicamos a escala em 55 paciente pré e pós tratamento para traçar um perfil clínico e epidemiológico dos pacientes tratados com toxina botulínica, avaliando o seu impacto na qualidade de vida. As principais etiologias foram: idiopática, acidente vascular encefálico e paralisia facial periférica. A aplicação da escala SF-36® em 55 pacientes revelou que 35 deles apresentaram beneficio, com maior impacto na avaliação dos subitens: saúde mental, vitalidade, performance física e dor. A incidência de efeitos adversos foi de 21,8%, similar à literatura. A aplicação de toxina botulínica foi associada com maior pontuação na escala SF-36®, portanto trata-se de boa opção terapêutica nos casos de distonia e espasticidade. (AU)