Symptoms of epilepsy are the clinical signs described by the patient and those around him during an attack. The clinical signs depend on the area of the brain affected by the abnormal electrical activity (epileptogenic focus) and the extent of the area of the brain affected.
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.
Symptoms of epilepsy
In focal seizures, the most common symptoms
Uncontrolled muscular contractions of the upper or lower limbs. These may include:
- Myoclonia: short, intense muscle contact that can lead to falls
- Clonias: repeated, rhythmic shaking
- Tonic attack: isolated muscle contractions
- Tonic crisis: abolition of muscle tone, which may cause the patient to fall.
Visual, auditory, gustatory or olfactory hallucinations
A numbness in a limb with an “ant” or tingling sensation
Language problems
Heart or respiratory rhythm disorders (apnea), hypersalivation
Memory disorders: feelings of déjà vu, already lived, incongruous reminders 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 others and exposes him or her to serious trauma. Sometimes focal seizures can engulf the entire cortex: the patient loses consciousness, falls, convulses (secondarily generalized or bilateralized seizures).
In generalized seizures, 3 types of symptoms can be identified:
- “Absences” during which the patient loses consciousness, does not fall, remains immobile, for an average of 5 seconds
- Myoclonias, especially in the morning, when the patient has slept little
- Widespread “tonic-clonic” seizures are immediately convulsive.
Epileptic seizures usually combine several of these symptoms, the most spectacular and well-known being the “tonic-clonic” seizure. During this epileptic episode, one observes a sequence of “tonic” and then “clonic” motor signs and a loss of consciousness. These attacks are often accompanied by tongue biting, loss of urine, screaming and hypersalivation. In the decoder, the patient is drowsy, slowed down.
At Paris Brain Institute
Epilepsy-absence is a common 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 processes. 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 brain region progressively acquires its ability to generate seizures. Prof. Stéphane CHARPIER’s team has shown that in this epilepsy there exists a focus of cortical neurons, which cause absences, which spread via a deep brain structure, the thalamus, to all cortical neurons.
A rare (1 patient / 1,000 patients) and tragic consequence of epilepsy is sudden and unexpected death (SUDEP for Sudden unexpected death in epilepsy) that occurs at the scene of a seizure. The mechanisms involved, whether respiratory, cardiac or cerebral, have not yet been fully elucidated. A study conducted by Stéphanie BAULAC’s team at Paris Brain Institute looked at cardiac functions in a cohort of patients at risk of SUDEP who carried a mutation in the DEPDC5 gene. Cardiac origin could be ruled out. Crisis-induced apnea appears to be the trigger. Future research on brain activity during SUDEP should help elucidate the mechanisms responsible for this tragic outcome of epilepsy.
Status of epilepsy
Epileptic status is defined as the persistence of a seizure after a delay of several minutes.
- Generalized seizures usually stop spontaneously after 1 or 2 minutes. In exceptional cases, such a seizure may persist for more than 5 minutes: a state of generalized convulsive sickness. This is a life-saving emergency because the patient is no longer breathing and is at risk of cardiopulmonary arrest.
- any other type of crisis can also evolve into a state of sickness: this defines states of focal sickness, with for example a motor activity of an arm when it lasts longer than 10 minutes. This type of condition does not commit the vital prognosis, but can lead to neurological sequelae, through damage to neurons subjected to hyperstimulation.
The epilepsy and neurological resuscitation teams at the Pitié-Salpêtrière hospital are expert in the management of the most severe forms of disease, particularly those that begin abruptly, with no previous history of epilepsy. NORSEs (new onset refractory status) can persist for weeks, and require anesthetic medications and immunosuppressants, as they are most often associated with severe brain inflammation.
Dr. Aurélie Hanin, part of Dr. Vincent Navarro’s research team at Paris Brain Institute, has conducted numerous studies on biomarkers in the condition, showing, among other things, that a daily blood test can accurately assess in a resuscitation patient whether or not the condition is ready to reoccur (Hanin et al, European Journal of Neurology 2022). In collaboration with Dr. Mario Chavez, within the same team, it was possible to define prognostic factors for healing, based on a combination of biological assays and clinical information, and a machine learning method (Hanin et al, Journal of Neurology, 2022).
