Häufigkeit und Behandlung von zerebralen Anfällen und Epilepsie nach Schlaganfall

Abstract

Cerebrovascular events are an important and well-known cause of seizures in adults. In an elderly population the incidence ranges from 2 to 43% in various studies, depending on seizure type, duration of follow-up and study design. The incidence rates for epilepsies have two peaks regarding age: one in the first decade of life, a second at higher age with a steep increase between age 70 and 80. Cerebral ischaemia is the single most common cause of first seizures and epilepsy in later life above the age of 60 years. The leading type of stroke-related seizures is focal with a high rate of secondary generalisation. In general, early onset seizures are differentiated from late onset seizures after stroke. However, this is only of clinical relevance if both groups are associated with different prognosis which is discussed controversially in the literature. Also, a variety of definitions for early seizures have been used regarding the time span following stroke. Large cortical infarctions in the anterior circulation have a high risk of developing seizures. Results of recent studies revealed early seizures as independent risk factor for late seizures and development of epilepsy. Despite the importance of the problem there are few data on the natural history of stroke-related seizures and no good guideposts to suggest when to initiate anticonvulsant therapy after stroke. The exact statistical risk of further seizures after a first poststroke seizure is not known, therefore, it has to be a case-by-case decision when to start medication. After a single early seizure long-term anticonvulsant therapy is usually not recommended even though recent studies could not reproduce the previously thought good prognosis of early seizures. There is also still debate about treatment after a first late seizure. After a second seizure the diagnosis of symptomatic epilepsy can be made and long-term anticonvulsant therapy is usually recommended. Poststroke seizures are in most patients well controlled with a single anticonvulsant drug. The choice of drug is given by the general recommendations of anticonvulsant medication in patients with focal seizures. In these mainly elderly patients interactions with other medications and cognitive side effects have to be considered especially. Whether the new anticonvulsants have advantages as compared to the standard medication with carbamazepine, oxcarbazepine or valproic acid is still open and under investigation.