The incidence of SE varies by age, with the highest risk seen in infants and individuals over 50 years old. [8]
In children, the most common aetiologies are infective. In adults, the most common aetiology is cerebrovascular disease.
The underlying aetiology of SE can be divided into three groups:
1.Chronic epilepsy
In one-third of patients, there will be an underlying background of chronic epilepsy.
In patients with a pre-existing history of epilepsy, SE most commonly results from:
However, it may also occur in the presence of:
2. Future epilepsy onset
In one-third of patients, the episode will represent the onset of future epilepsy.
3. No prior or future history
In one-third of patients, the episode occurs with no prior or future history of epilepsy.
In the absence of an established diagnosis of epilepsy, SE may result from:
These may also be the causes of SE in a patient without epilepsy and should always be borne in mind when assessing patients.