Historical references for stroke as a cause of seizures date back to Greco-Roman times when Hippocrates in 400 BC described epilepsy as a disease of the brain due to natural rather than supernatural causes. Hippocrates described older persons with paralysis following seizures consistent with seizures occurring at the onset of stroke. However, it was not until 1864 that Hughling Jackson clearly documented stroke as a cause of epilepsy. Jackson noted that ‘it is notuncommonto find when a patient has recovered or is recovering from hemiplegia, the result of embolism of the middle cerebral artery, or ofsomebranch of this vessel, that he is attacked by convulsions beginning in some part of the paralysed region’. (Taylor, 1958). Since these times it has become clear that stroke is an important cause of seizures and epilepsy, particularly in the older age group. There are, however, some important questions still to be answered.
Post stroke seizures – comparison of cerebral infarction with hemorrhage
Timing and frequency of seizures
Reports on the frequency of seizures at the onset of, and following, stroke vary quite widely because of differing stroke patient populations, sample sizes studied, follow up periods, definitions used for stroke and seizures, use of investigations such as computerized tomography (CT) and types of statistical analysis. In most studies to date the follow-up period was less than a few weeks, so the documentation of later onset or recurring seizures is limited. Studies of early and late onset poststroke seizures where patients with prestroke seizures, were largely excluded and CT was used in the diagnosis of cerebral ischemia or hemorrhage in 90% or more of patients, are summarized in Table 13.1.