Análise morfológica e funcional do coração de ratos submetidos ao modelo de Epilepsia induzida pela Pilocarpina

• Ano de defesa: 2009
• Autor(a) principal: Colugnati, Diego Basile [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Epilepsia; Pilocarpina; Coração; Morte súbita; Frequência cardíaca/fisiologia
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9668

Epilepsy is one of the most common neurologic problems worldwide. Approximately 3 percent of persons in the general population will have epilepsy at some point in their lives. Unfortunately, individuals with epilepsy are at higher risk of death than the general population and SUDEP is the most important direct epilepsy-related cause of death. SUDEP is responsible for 7.5% to 17% of all deaths in epilepsy and has an incidence among adults between 1:500 and 1:1,000 patient-years. A number of associated factors for SUDEP have been reported but the results are not wholly consistent between studies. These include refractoriness of the epilepsy, presence of generalized tonic-clonic seizures, polytherapy with antiepileptic drugs, young age, duration of the seizure disorder ranging from 15 to 20 years, early onset of epilepsy and winter temperatures. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmia due to myocardial ischemia play a potential role. Based on this factor, we evaluated the cardiac function and morphology of rats during the three evolution periods (acute, silent and chronic) of the pilocarpine model of temporal lobe epilepsy. From functional point of view, we analyzed the electrocardiogram and the autonomic heart modulation. For that, both autonomic modulation and electrocardiogram were verified without, before seizure and during seizure. It is important to note that all analyses were compared to the age-matched control group. During seizure period, our results showed an intense cardiac rhythm alteration due an important influence of parasympathetic nervous system. On the other hand, in the seizure free period, we found a large sympathetic activity in the rats with chronic epilepsy in relation to the control group. From a morphological point of view, we found specific histological features in the rats with epilepsy, such as necrosis and mitochondrial proliferation. On the whole, our results suggest that chronic epilepsy condition lead to alterations on both autonomic modulation and cardiac morphology that may contribute to the higher risk of sudden unexpected death in epilepsy.