Prognosis for epilepsy

The most severe complication of epilepsy is status epilepticus. These are prolonged (more than 30 minutes) or recurrent seizures without the patient returning to a normal state between seizures. The clinical manifestations are quite varied, ranging from generalised motor seizures (generalised status epilepticus) to focal impaired awareness seizures (non-convulsive status epilepticus) or focal aware seizures (aura continua or focal motor status epilepticus). The annual incidence of status epilepticus ranges from 15–50 episodes per 100,000 people. It is more common among children and the elderly.

The most common precipitating factors include poor adherence to drug therapy, strokes, anoxia (insufficient oxygen to the brain), metabolic disorders, tumours, infections and fever. Status epilepticus, above all generalised convulsive status epilepticus, is a very serious complication that can be life-threatening for the patient. Therefore, they must be treated urgently by medical personnel to control the seizure as soon as possible. The death rate associated with different types of status epilepticus ranges from 4% to 37%.

Prolonged episodes of status epilepticus can often have long-term consequences. The prognosis following status epilepticus will primarily depend on its cause, its duration and the patient’s age.

Epilepsy is associated with a slightly higher risk of mortality than in the general population. The causes of direct epilepsy-related death are: sudden unexpected death in epilepsy (SUDEP), an accident during a seizure or status epilepticus. In the case of SUDEP, death generally occurs after a generalised tonic–clonic seizure because the patient develops cardiac arrhythmia or suffers respiratory failure. SUDEP most frequently occurs during nocturnal seizures or ones that occur while the patient is alone. The risk of SUDEP is around 1 in every 1,000 epilepsy patients/year, but the risk falls to 0% if the condition is in remission and increases to 1% in patients with frequent generalised tonic–clonic seizures. This risk diminishes if seizure control is improved, if patients avoid seizure precipitating factors or if they are stimulated after the seizure.

Seizures cause temporary changes in the brain’s neural networks that give rise to temporary cognitive or sensory–motor disturbances immediately after the event. However, epilepsy can also produce permanent changes in these networks resulting in chronic cognitive and behavioural problems. The chronic cognitive effects are usually very mild in most patients with epilepsy, particularly in those with well-controlled seizures thanks to their antiepileptic medication.

At the opposite end of the scale, some patients may develop more severe cognitive impairments. In these cases, the cognitive problems could be very focal; for example, patients with temporal lobe epilepsy secondary to hippocampal sclerosis may suffer from selective visual or verbal memory deficit. Psychiatric complications (above all anxiety and depression) are also frequent, especially in patients with severe epilepsy. These disorders must be treated to improve the patient’s quality of life.

Some chronic complications are also associated with antiepileptic treatments, particularly older drugs, as they can cause problems with sexual health, metabolism and bone health, and cardiovascular diseases.