Types of seizures and durations12/28/2022 ![]() ![]() The excitatory glutamate and the inhibitory γ-aminobutyric acid (GABA) are the most essential neurotransmitters in the CNS. The early-onset epileptic seizures can also be caused by the disruption of the dynamic balance of neurotransmitters. When the local suppressor cells are unable to inhibit the spread of rhythmic, hypersynchronous discharges, epilepsy would occur. This results in overexcitation of neurons, causing excitatory toxicity and gradual loss of functions of local suppressor cells. When the membrane’s potential depolarization reaches a certain degree, calcium channels will be activated and Ca 2+ rapidly flow in, leading to an increase in intracellular Ca 2+ concentration. The acute brain injury can result in subsequent sodium pump failure, increased Na + influx and depolarization of membrane potential. The stroke-induced acute ischemia and hypoxia can reduce the stability of nerve cell membrane and cause metabolic disorders of neuron. The pathogenic mechanisms of early-onset epileptic seizures Ion channel dysfunction In the following, the pathogenesis of early epileptic seizures and late epilepsy after stroke will be discussed in detail. A comprehensive understanding of the pathogenesis of PSE is of great significance for the treatment and prevention of this disease. PSE can aggravate disabilities, affect patients’ quality of life and the outcome of the disease, and even lead to death. ![]() Patients with late-onset epilepsy have definite epileptogenic foci and form a stable epileptic network, and are susceptible to recurrent seizures, thus they are diagnosed with epilepsy. Ninety percent of patients may have seizures again after one attack. The late-onset epilepsy occurs over 1 week after stroke, with highest incidence at 6–12 months after stroke. Patients with early epileptic seizures do not form a stable epileptic network, and the brain has the ability to self-repair, so they cannot be diagnosed as epilepsy, but be diagnosed as seizures. The early epileptic seizures refer to seizures that occur within 1 week after stroke, mainly within 24 h, accounting for about 57% of early epileptic seizures. The International League Against Epilepsy has divided PSE into early-onset epileptic seizures and late-onset epilepsy. A large population-based study has shown that in the first year after stroke, the risk of epilepsy is about 23 times higher than that in the general population. The PSE accounts for about 30–50% of newly diagnosed epilepsy. PSE refers to epilepsy that occurs after a hemorrhagic or ischemic stroke without a previous history of epilepsy, and is not accompanied by brain structural abnormalities or metabolic disorders of other causes. With the extension of life expectancy, the incidence of stroke increases yearly and the number of patients with post-stroke epilepsy (PSE) is also increasing. In the elderly, the most common cause of epilepsy is stroke. Cerebrovascular disease, craniocerebral trauma, intracranial infection and metabolic abnormality are common causes of seizures and epilepsy in adults. Genetic factors, abnormal labor (such as hypoxia, asphyxia, and head trauma during delivery), CNS infection, and anomalous brain development are important etiologies of seizures and epilepsy in children. It is characterized by recurrent, paroxysmal, and transient central nervous system (CNS) dysfunction caused by excessive discharge of brain neurons. In this review, we discuss the pathogenesis of early-onset epileptic seizures and late-onset epilepsy after stroke, in order to provide a basis for clinicians to understand the disease, and expect to provide ideas for future exploration.Įpilepsy is the most common neurological disorder and a chronic brain disease with multiple causes. It has been found that ion channels, neurotransmitters, proliferation of glial cells, genetics and other factors are involved in the occurrence and development of PSE. Now seizure and epilepsy after stroke is more and more get the attention of the medical profession, has been more and more researchers have devoted to seizures after stroke and PSE clinical and basic research, and hope to get a scientific and unified guideline, to give timely and effective treatment, but the exact pathophysiologic mechanism has not yet formed a unified conclusion. Moreover, the clinical treatment of post-stroke epilepsy is difficult, which increases the risk of disability and death, and affects the prognosis and quality of life of patients. There are various seizure types after stroke, and the occurrence of epilepsy is closely related to the type and location of stroke. The incidence of cerebral stroke is increasing with the extension of life expectancy, and the prevalence of post-stroke epilepsy (PSE) is rising. Stroke is the most frequent cause of secondary epilepsy in the elderly. ![]()
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