Читать книгу Canine and Feline Epilepsy - Luisa De Risio - Страница 7

Simon Platt BVM&S MRCVS Dipl. ACVIM (Neurology) Dipl. ECVN Professor Neurology and Neurosurgery Service, Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA

Several decades have been devoted to the study of the pathophysiology of epilepsy. Increasing knowledge in the field has only contributed to a partial understanding of the underlying mechanisms. Nevertheless, insight into the pathophysiology of epilepsy and its underlying histological and neurochemical alterations has contributed to rational development strategies of new anti-epileptic medications (AEMs). Although various epileptic syndromes in people have been shown to differ pathophysiologically, they apparently share common ictogenesis-related characteristics such as increased neuronal excitability and synchronicity. Emerging insights point to alterations of synaptic functions and intrinsic properties of neurons as common mechanisms underlying hyperexcitability. Progress in the field of molecular genetics has revealed arguments in favour of this hypothesis as mutations of genes encoding ion channels were recently discovered in some forms of human epilepsy.

Epileptic seizures arise from an excessively synchronous and sustained discharge of a group of neurons. The single feature of all epileptic syndromes is a persistent increase of neuronal excitability. Abnormal cellular discharges may be associated with a variety of causative factors such as trauma, oxygen deprivation, tumours, infection and metabolic derangements. However, no specific causative factors are found in many dogs and cats suffering from epilepsy.

Underlying causes and pathophysio-logical mechanisms are (partially) understood for some forms of epilepsy, at least in people, e.g. epilepsies caused by disorders of neuronal migration and monogenic epilepsies. For several other types of epilepsy, current knowledge is only fragmentary. This chapter will review several areas that are understood to contribute to the evolution and maintenance of epilepsy. The genetics of epilepsy are discussed in Chapter 6.