"It is crucial to be able to record seizures using continuous EEG recordings, coupled with video, when there is doubt about another diagnosis, or when surgical treatment is being considered". Professor Vincent Navarro, Head of the Epilepsy Unit, DMU Neurociences, Pitié-Salpêtrière Hospital.
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The symptoms of epilepsy are the clinical signs described by the patient and those around him during a seizure. The clinical signs depend on the region of the brain affected by the abnormal electrical activity (epileptogenic focus) and the extent of the area of the brain affected.

The symptoms of epilepsy

1) In focal seizures, the most common symptoms are:

  • Uncontrolled muscular contractions of the upper or lower limbs. These may be :
      • Myoclonus: brief, intense muscle contractions that can lead to falls
      • Clonics: repeated rhythmic jerks
      • Tonic seizure: isolated muscle contractions
      • Tonic seizure: abolition of muscle tone, which may cause the patient to fall.
  • Visual, auditory, gustatory or olfactory hallucinations
  • Numbness of a limb with a sensation of “pins and needles” or tingling
  • Speech problems
  • heart or breathing rhythm problems (apnoea), hypersalivation
  • Memory problems: impression of déjà vu, déjà vécu, incongruous recollections of old memories.

Focal seizures may be accompanied by a loss of contact (or loss of consciousness), during which the patient does not interact with those around them, exposing them to serious trauma. Sometimes, focal seizures can ignite the entire cortex: the patient loses consciousness, falls, convulses (secondary generalised or bilateral seizures).

2) In immediately generalised seizures, 3 types of symptoms can be identified:

Epileptic seizures generally combine several of these symptoms, the most spectacular and well-known being the “tonic-clonic” seizure. During this epileptic episode, there is a sequence of “tonic” then “clonic” motor signs and loss of consciousness. These seizures are often accompanied by tongue biting, loss of urine, screaming and hypersalivation. Afterwards, the patient becomes drowsy and sluggish.


At the Paris Brain Institute

Absence epilepsy is a frequent epileptic syndrome, accounting for 10-15% of childhood epilepsies. It is expressed by the repeated occurrence of seizures (up to 200 times a day) interrupting all forms of conscious process. Although it has been established that these symptoms are caused by a defect in the cerebral cortex of children, it is not yet known how this cerebral region gradually acquires its ability to generate seizures. Professor Stéphane CHARPIER’s team has shown that in this epilepsy there is a focus of cortical neurons, at the origin of the absences, which spread via a deep brain structure, the thalamus, to all the cortical neurons.


A rare (1 in 1000 patients) and tragic consequence of epilepsy is Sudden Unexpected Death in Epilepsy (SUDEP), which occurs after a convulsive seizure. The mechanisms involved – respiratory, cardiac or cerebral – are not yet fully understood. A study conducted by Stéphanie BAULAC’s team at the Institut du Cerveau looked at cardiac function in a cohort of patients at risk of SUDEP, who carry a mutation in the DEPDC5 gene. It was possible to rule out a cardiac origin. Seizure-induced apnoea appears to be the trigger. Future research into brain activity during SUDEP should help to elucidate the mechanisms behind this tragic consequence of epilepsy.


Status Epilepticus

Status epilepticus is defined as the persistence of a seizure for more than several minutes.

  • A generalised convulsive seizure usually stops spontaneously after 1 or 2 minutes. Exceptionally, such a seizure may persist for more than 5 minutes: this is known as a generalised convulsive state. This is a life-threatening emergency, as the patient is no longer breathing and is at risk of cardiorespiratory arrest.
  • Any other type of seizure can also evolve into a malignant state: we define focal malignant states, for example with motor activity in one arm when it lasts for more than 10 minutes. This type of seizure is not life-threatening, but can result in neurological sequelae, through damage to neurons subjected to hyperstimulation.


The epilepsy and neurological intensive care teams at the Pitié-Salpêtrière Hospital are experts in the management of the most severe forms of malignant seizures, particularly those that begin suddenly, with no previous history of epilepsy. NORSE (new onset refractory status) can last for weeks, requiring anaesthetic drugs and immunosuppressants, as they are most often linked to severe cerebral inflammation.

Dr Aurélie Hanin, as part of Professor Vincent Navarro’s research team at the Institut du Cerveau, has conducted a number of studies on biomarkers in the malignant state, showing in particular that a daily blood test can accurately assess whether or not a patient in intensive care is ready for a recurrence of the malignant state (Hanin et al, European Journal of Neurology 2022). In collaboration with Dr Mario Chavez, within the same team, it has been possible to define prognostic factors for recovery, based on a combination of biological assays and clinical information, and a machine learning method (Hanin et al, Journal of Neurology, 2022).