SEIZURES AND EPILEPSY : part 1

A seizure (from the Latin sacire, “to take possession of”) is a paroxysmal event due to abnormal, excessive, hypersynchronous discharges from an aggregate of central nervous system (CNS) neurons. Depending on the distribution of discharges, this abnormal CNS activitycan have various manifestations, ranging from dramatic convulsive activityto experiential phenomena not readilydiscernible byan observer.Although a varietyof factors influence the incidence and prevalence of seizures, 5 to 10% of the population will have at least one seizure,
with the highest incidence occurring in earlychildhood and late adult-hood.
                              The meaning of the term seizure needs to be carefullydistinguished from that of epilepsy. epilepsy describes a condition in which a person has recurrent seizures due to a chronic, underlying process. This definition implies that a person with a single seizure, or recurrent seizures due to correctable or avoidable circumstances, does not necessarily have epilepsy. Epilepsy refers to a clinical phenomenon rather than a
single disease entity, since there are many forms and causes of epilepsy. However, among the many causes of epilepsy there are various epilepsy syndromes in which the clinical and pathologic characteristics are distinctive and suggest a specific underlying etiology.
                                            Using the definition of epilepsyas two or more unprovoked seizures, the incidence of epilepsyis 0.3 to 0.5% in different populations throughout the world, and the prevalence of epilepsyhas beenestimated at 5 to 10 persons per 1000.