Different approaches to the clinical care and treatment of epileptic seizures in dogs / Caracterização da conduta clínica no atendimento e tratamento de cães com crises epilépticas

This survey analyzed data obtained through a questionnaire on the clinical approaches used by veterinarians to treat dogs with epileptic seizures. We found that neurological examinations were performed by 12% of the respondents, blood tests by 85%, and computed tomography by 72%. In addition, serology for infectious disease detection was mentioned by 30% of the respondents, and 72% did not classify epileptic seizures. According to the answers, the treatment of choice was phenobarbital in 100% of cases which was combined with potassium bromide in 19%. Moreover, 51% of the respondents mentioned that they monitored the serum phenobarbital levels. The study results showed disagreements on the conduct and care recommended by the International Veterinary Epilepsy Task Force consensus.

O objetivo deste estudo foi analisar a conduta clínica de médicos veterinários no atendimento de cães apresentando crises epilépticas por meio de um questionário. 12% afirmaram realizar exame neurológico, enquanto 85% realizam exames hematológicos; 72% solicitam tomografia computadorizada e 30% pedem sorologias para investigação de doenças infecciosas. Todos os veterinários prescrevem fenobarbital para o tratamento. O brometo de potássio foi citado por 19% dos entrevistados em associação ao fenobarbital. A dosagem sérica de fenobarbital é realizada por 51% dos entrevistados. Os resultados apontaram que não houve homogeneidade na conduta preconizada pelas diretrizes científicas sobre o tema.

PER2 rs2304672, CLOCK rs1801260, and PER3 rs57875989 polymorphisms are not associated with juvenile myoclonic epilepsy.

Sleep disturbance is common in several epilepsy types, such as juvenile myoclonic epilepsy (JME). Genetic background could increase susceptibility to seizure and sleep abnormalities. From this perspective, a susceptibility gene for sleep disturbance or chronotype could contribute to the genetic susceptibility threshold for epilepsy and vice versa. Accordingly, we investigated whether functional clock gene polymorphisms (PER2 111C>G, CLOCK 3111T>C, and PER3 VNTR) might influence the risk for JME. All these polymorphisms have recently been reported to be associated with sleep disturbance, diurnal variation, and neurological diseases. The polymorphisms were genotyped in 97 patients and 212 controls using polymerase chain reaction or restriction fragment length polymorphism methods. No significant differences were observed in the genotypic and allelic frequencies of these polymorphisms between cases and controls even when analyses were restricted to patients that presented a diurnal preferential seizure occurrence. We also tested for interactions between polymorphisms by multifactor dimensionality reduction analysis. None of the combined genotypes differed significantly between the groups. These results present no evidence for an association of these polymorphisms with JME. Further studies including other types of epilepsy and/or other functional polymorphisms are required to investigate the possible relationship between clock genes and the genetic susceptibility to chronic seizure.

Epilepsia en perros / Canine epilepsy

Idiopathic epilepsy (IE) and other convulsive disorders represent at least 14% of neurological consultations in veterinary medicine. In spite of this, there is a gap in the information usually handled by the small animal clinician, because the pathophysiological aspects of this disease are still not completely understood. Since there is no specific method for diagnosing IE, exclusion criteria are used to reach diagnosis. Although the electroencephalogram (EEG) can provide diagnostic elements, abnormalities in the EEG record are not always found. Pharmacologic treatment options are reduced and not void of ad verse effects. The possibility of encountering IE refractory to antiseizure pharmacological treatment is high and it has been concluded that non pharmacological treatment options should be explored through systematic clinical studies. Up to date, early diagnosis, appropriate pharmacological treatment, owners' education and a combination with non pharmacological options represent the only way to improve prognosis for dogs with IE.

La epilepsia idiopática (EI), así como otras enfermedades convulsivas representan al menos 14% de las consultas neurológicas en la medicina veterinaria. A pesar de esto último, se reconoce que existe un vacío en la información que maneja el clínico especialista en pequeñas especies porque aún no se han elucidado todos los aspectos patofisiológicos de ese padecimiento. Debido a que no existe un método diagnóstico específico, se llega a él por exclusión. Aunque el electroencefalograma (EEG) brinda algunos elementos diagnósticos no siempre se tiene la fortuna de ubicar anormalidades en el registro. Las alternativas terapéuticas farmacológicas son reducidas y no carentes de efectos adversos. Es mucha la posibilidad de encontrar EI refractaria al tratamiento farmacológico y se ha concluido que deben evaluarse las alternativas de tratamiento no farmacológico mediante estudios clínicos sistemáticos. El diagnóstico temprano, la instauración de un tratamiento farmacológico, la educación de los propietarios de animales y la combinación con terapias no farmacológicas representan a la fecha la única forma de mejorar el pronóstico de perros afectados con EI.

Genes e epilepsia I: epilepsia e alterações genéticas / Genes and epilepsy I: epilepsy and genetic alterations

INTRODUÇÃO: Epilepsia é uma desordem neurológica caracterizada por crises espontâneas e recorrentes, que afeta de 2 por cento a 3 por cento da população mundial. As crises epilépticas refletem atividade elétrica anormal e paroxística, preferencialmente em uma ou várias áreas do córtex cerebral, que podem ser causadas por inúmeras patologias estruturais ou neuroquímicas. Dentre os importantes estudos das últimas décadas no campo da epileptologia, destaca-se a identificação de genes associados a certos tipos de epilepsia. OBJETIVO: Nesta revisão, descrevemos as principais alterações genéticas associadas ao processo epileptogênico, discutindo as mais recentes descobertas e suas contribuições para a compreensão das bases genéticas das epilepsias idiopáticas monogênicas (EIM) e das epilepsias geneticamente complexas. RESULTADOS E CONCLUSÃO: Estudos de ligação e associação mostram que alterações em genes que codificam canais iônicos são as principais causas genéticas das epilepsias idiopáticas monogênicas e de predisposição nas epilepsias geneticamente complexas. Além disso, as síndromes nas quais a epilepsia é um aspecto importante do quadro clínico podem ser provocadas por genes envolvidos em diferentes vias celulares, tais como: migração neuronal, metabolismo de glicogênio e cadeia respiratória. Portanto, acredita-se que diferentes categorias de genes possam atuar na determinação do traço epiléptico. A identificação de tais famílias de genes não apenas nos ajudará a entender as vias moleculares associadas à hiperexcitabilidade neuronal e ao processo epileptogênico, mas também poderá conduzir ao desenvolvimento de novas e mais precisas estratégias de tratamento da epilepsia.

INTRODUCTION: Epilepsy is a neurological disorder characterized by spontaneous and recurrent seizures with an estimated prevalence of 2-3 percent in the world population. Epileptic seizures are the result of paroxystic and hypersynchronous electrical activity, preferentially in cortical areas, caused by panoply of structural and neurochemical dysfunctions. Recent advances in the field have focused on the molecular mechanisms involved in the epileptogenic process. OBJECTIVES: In the present review, we describe the main genetic alterations associated to the process of epileptogenesis and discuss the new findings that are shedding light on the molecular substrates of monogenic idiopathic epilepsies (MIE) and on genetically complex epilepsies (GCE). RESULTS AND CONCLUSION: Linkage and association studies have shown that mutations in ion channel genes are the main causes of MIE and of predisposition for GCE. Moreover, mutations in genes involved in neuronal migration, glycogen metabolism and respiratory chain are associated to other syndromes involving seizures. Therefore, different gene classes contribute to the epileptic trait. The identification of epilepsy-related gene families can help us understand the molecular mechanisms of neuronal hyperexcitability and recognize markers of early diagnosis as well as new treatments for these epilepsies.