Discinesia paroxística primaria kinesiogénica y no kinesiogénica: Reporte de 3 casos y revisión de la literatura / Paroxysmal Kinesiogenic Dyskinesia and Paroxysmal Non-Kinesiogenic Dyskinesia: Three Case Reports and a Review

Las discinesias paroxísticas son un grupo de entidades consistentes en paroxismos de diversos movimientos anormales de corta duración asociados o no a factores precipitantes. Suele afectar a sujetos jóvenes y la prevalencia es desconocida. La fisiopatología es incierta; se han identificado ciertas mutaciones que expliquen su origen. Clínicamente se pueden manifestar como ataques paroxísticos de movimientos de tipo coreoatetósico, distónicos o balísticos de corta duración y con preservación de la conciencia. Los estudios electrofisiológicos y de imagen suelen ser normales. Este grupo de trastornos del movimiento hacen parte del diagnóstico diferencial de las crisis epilépticas. El pronóstico suele ser bueno y el tratamiento es sintomático con anticonvulsivantes. Se presentarán tres casos de dos tipos de trastornos paroxísticos del movimiento y revisión de la literatura.

Paroxysmal dyskinesias are a group of entities consisting of paroxysms of diverse abnormal movements of short duration, associated or not with precipitating factors. It usually affects young subjects and its prevalence is unknown. The pathophysiology is uncertain; some mutations have been identified that explain their origin. Clinically, they can manifest as paroxysmal attacks of choreoathetosis, dystonic or ballistic movements of short duration and with preservation of consciousness. Electrophysiological and imaging studies are usually normal. This group of movement disorders are part of the differential diagnosis of epileptic seizures. Prognosis is usually good and the treatment is symptomatic with anticonvulsants. Three cases of two types of paroxysmal movement disorders and a review of the current literature are presented.

Paroxysmal Dyskinesia in Children: from Genes to the Clinic

BACKGROUND AND PURPOSE: Paroxysmal dyskinesia is a genetically and clinically heterogeneous movement disorder. Recent studies have shown that it exhibits both phenotype and genotype overlap with other paroxysmal disorders as well as clinical heterogeneity. We investigated the clinical and genetic characteristics of paroxysmal dyskinesia in children. METHODS: Fifty-five patients (16 from 14 families and 39 sporadic cases) were enrolled. We classified them into three phenotypes: paroxysmal kinesigenic dyskinesia (PKD), paroxysmal nonkinesigenic dyskinesia (PNKD), and paroxysmal exercise-induced dyskinesia (PED). We sequenced PRRT2, SLC2A1, and MR-1 in these patients and reviewed their medical records. RESULTS: Forty patients were categorized as PKD, 14 as PNKD, and 1 as PED. Thirty-eight (69.1%) patients were male, and their age at onset was 8.80±4.53 years (mean±SD). Dystonia was the most common symptom (38 patients, 69.1%). Pathogenic variants were identified in 20 patients (36.4%): 18 with PRRT2 and 2 with SLC2A1. All of the patients with PRRT2 mutations presented with PKD alone. The 2 patients carrying SLC2A1 mutations presented as PNKD and PED, and one of them was treated effectively with a ketogenic diet. Six mutations in PRRT2 (including 2 novel variants) were identified in 9 of the 13 tested families (69.2%) and in 8 patients of the 25 tested sporadic cases (32.0%). There were no significant differences in clinical features or drug response between the PRRT2-positive and PRRT2-negative PKD groups. CONCLUSIONS: This study has summarized the clinical and genetic heterogeneity of paroxysmal dyskinesia in children. We suggest that pediatric paroxysmal dyskinesia should not be diagnosed using clinical features alone, but by combining them with broader genetic testing.

Tremor de cabeça idiopático em cães - relato de dois casos / Idiopathic head tremor in dogs - two case reports

Tremor de cabeça idiopático é uma forma de discinesia paroxística reconhecida como hereditária e associada a determinadas raças, sendo relatado, sobretudo, em Buldogue Inglês, Dobermann Pinscher e Boxer. Conhecido também como head bobbing ou tremor de cabeça episódico, os cães acometidos apresentam crises caracterizadas por tremores limitados à região de cabeça, de direção horizontal, vertical ou ambos, sendo geralmente relacionados a um evento desencadeante. Foram atendidos, no Hospital Veterinário da UFMS, dois caninos da raça Buldogue Inglês (um macho de um ano e uma fêmea de sete meses) com histórico de tremores episódicos restritos à região de cabeça. Exames físicos e neurológicos completos foram realizados, não sendo constatada qualquer alteração. Com base na raça, no histórico, na ausência de outros sinais clínicos e na exclusão de outras causas de tremores, foi dado o diagnóstico de head bobbing. Tal enfermidade caracteriza-se por tremores restritos à região de cabeça, associados a uma condição genética benigna. Não é considerada uma forma de convulsão, uma vez que o animal permanece alerta e responsivo aos estímulos ambientais, os tremores podem ser interrompidos por distrações ou qualquer interação com o ambiente, não sendo responsivos à terapia com anticonvulsivantes. De acordo com a revisão de literatura realizada, estes são os primeiros casos diagnosticados e relatados no Brasil.(AU)

Idiopathic head tremor is a form of paroxysmal dyskinesia recognized as hereditary or associated with certain races, being reported in English bulldogs, doberman pinschers, and boxers. Also known as head bobbing or episodic head tremor, the affected dogs present with seizures characterized by tremors limited to head region, horizontal direction, vertical or both and are usually related to a triggering event. Two dogs of the English bulldog breed (a male of 1 year and a female of 7 months) with a history of episodic tremors restricted to the head region were seen at the UFMS Veterinary Hospital. Complete physical and neurological examinations were performed, and no alterations were found. Based on race, history, absence of other clinical signs and exclusion of other causes of tremors, the diagnosis of head bobbing was performed. Such a disease is characterized by tremors restricted to the head region, associated with a benign genetic condition. It is not considered a form of seizure, since the animal remains alert and responsive to environmental stimuli, the tremors can be interrupted by distractions or any interaction with the environment, being not responsive to anticonvulsant therapy. According to the literature review, these are the first cases diagnosed and reported in Brazil.(AU)

Clinical Manifestations in Paroxysmal Kinesigenic Dyskinesia Patients with Proline-Rich Transmembrane Protein 2 Gene Mutation

BACKGROUND AND PURPOSE: Given the diverse phenotypes including combined non-dyskinetic symptoms in patients harboring mutations of the gene encoding proline-rich transmembrane protein 2 (PRRT2), the clinical significance of these mutations in paroxysmal kinesigenic dyskinesia (PKD) is questionable. In this study, we investigated the clinical characteristics of PKD patients with PRRT2 mutations. METHODS: Familial and sporadic PKD patients were enrolled and PRRT2 gene sequencing was performed. Demographic and clinical data were compared between PKD patients with and without a PRRT2 mutation. RESULTS: Among the enrolled PKD patients (8 patients from 5 PKD families and 19 sporadic patients), PRRT2 mutations were detected in 3 PKD families (60%) and 2 sporadic cases (10.5%). All familial patients with a PRRT2 gene mutation had the c.649dupC mutation, which is the most commonly reported mutation. Two uncommon mutations (c.649delC and c.629dupC) were detected only in the sporadic cases. PKD patients with PRRT2 mutation were younger at symptom onset and had more non-dyskinetic symptoms than those without PRRT2 mutation. However, the characteristics of dyskinetic movement did not differ between the two groups. CONCLUSIONS: This is the first study of PRRT2 mutations in Korea. The presence of a PRRT2 mutation was more strongly related to familial PKD, and was clinically related with earlier age of onset and common non-dyskinetic symptoms in PKD patients.

Secondary paroxysmal dyskinesia associated with 2009 H1N1 infection / 소아과

Neurological complications associated with 2009 H1N1 infection in children have been reported and recognized worldwide. The most commonly reported neurological complications are seizures and encephalopathy. Secondary movement disorders are also associated with the infection, but such cases are rarely reported. Here, we describe the case of a 14-year-old boy with paroxysmal kinesigenic dyskinesia secondary to 2009 H1N1 infection, who presented with dystonia and choreic movement triggered by sudden voluntary movement.