Epilepsy is a neurological condition (defined, in some cases, as chronic and in others as transitory, such as where an episode occurs but is never repeated). The condition is characterized by recurrent and sudden manifestations with an abrupt loss of consciousness and violent convulsive movements of the muscles, referred to as “epileptic seizures”.
In most cases, the etiology is unknown, although some individuals may develop epilepsy as a result of a brain injury, following a stroke, a brain tumour or the use of drugs and alcohol. Even some rare genetic mutations can be related to the onset of the condition. Epileptic seizures are the result of excessive and abnormal activity of neurons in the cerebral cortex. In general, biomedical imaging of the brain and blood tests are used for the diagnosis. The diagnosis of epilepsy can often be confirmed by an electroencephalogram (EEG), but a normal result in this test does not necessarily rule out the condition.
Epileptic seizures are generally controlled by drugs in about 70% of cases. In those who do not respond to pharmacological therapy, it is possible to resort to surgery, neurostimulation or changes in diet.
About 1% of the world’s population suffers from epilepsy and almost 80% of cases are found in developing countries. Epilepsy becomes more common in older people.
Epilepsy is characterized by a long-term risk of recurrent epileptic seizures. These disorders can occur in various ways depending on the part of the brain that is involved and the age of the person.
The epileptic seizure is a paroxysmal event by which epilepsy manifests itself, caused by the sudden excessive and rapid discharge of a more or less extensive population of neurons that are part of the grey matter of the brain.
The aggregation of neurons involved in the discharge is referred to as an “epileptogenic focus”.
The most common type (about 60%) of epileptic seizures is the convulsive type. Of these, a third begin as tonic convulsive seizures and clonic seizures, also called “generalized crises” or “grand mal” seizures, which originate from both hemispheres of the brain. Two thirds, however, start with simple or complex partial seizures that affect a single cerebral hemisphere and which can, however, progress to generalized seizures. The remaining 40% of epileptic seizures are non-convulsive. This is the typical or “petit mal” seizure which occurs as a decrease in the level of consciousness with a duration of about 20 seconds.
Epilepsy can have negative effects on social and psychological well-being.
Some additional disorders occur more frequently in people with epilepsy, depending on how the condition presents. These can include depression, anxiety and migraine. Attention-deficit hyperactivity disorder (ADHD) affects children with epilepsy three to five times more than those in the general population.
Epilepsy occurs more frequently in patients with autism spectrum disorders.
Epilepsy is usually treated by taking daily medication prescribed after a second seizure, but for those at high risk, drug therapy can be used from the onset.