Epilepsy is a common disease. Its overall prevalence is estimated to be 0.5% of the population, with a maximum risk during childhood, since 50% of epilepsies in fact occur before the age of 10. The etiology of epilepsy remains unexplained in more than 50% of cases.
I – DEFINITION
Epilepsy is a neurological disorder manifested by paroxysms related activity hypersynchronous and abnormal neuronal population. Note:
- There is not no without clinical epilepsy: paroxysmal abnormalities in the EEG without clinical not enough to define epilepsy.
- The paroxysmal nature and its clinical translation are necessarily rough.
- It is stereotypical for each patient depending on the neuronal localization
- The clinical and EEG allow the formulation of a hypothesis when the neuronal localization
- The chronological sequence of symptoms may change during disease
II – THE CLASSIFICATION OF EPILEPSY.
The difference between partial and generalized epilepsy is the concept of neuronal discharge localized or generalized. There are also secondary epilepsy due to a lesion or dysfunction in general.
III – generalized seizures.
A – tonic-clonic generalized
This crisis is manifested by a sudden loss of consciousness without prodrome, with a fall. In its complete form it has a tonic phase of 10 to 20 seconds, during which there is a contraction of all muscles, with a phase flexion and extension of four limbs and trunk, contraction of the masseter. Clonic phase follows an approximately 30 seconds, characterized by sudden twitching of members in bending with clone facial and jaw.
Apnea associated with the phase of tonic contraction causes cyanosis accompanied by autonomic signs (mydriasis, piloerection, hypertension, tachycardia) and secretory phenomena (salivation and tracheo-bronchial congestion). It was also during this phase of tonic-clonic crisis that may occur biting language conventionally side.
At the end of the clonic phase, may occur a loss of urine, not specific to seizure. Breathing blocked since the start of the crisis resumed at that time, large, noisy (stertor), and cyanosis disappears gradually.
The recovery of consciousness is gradual, with postictal confusion, which can last up to an hour, during which the patient may behave with agitation.
Upon awakening, the subject has no memory of his crisis, he complained of muscle pain, headache or pain related to trauma caused by the initial drop. In some cases, the tonic phase or clonic phase are only present.
B – myoclonus:
These brief muscle jerks, predominantly proximal, affecting mostly the upper extremities, more rarely four or only the lower limbs. They are extended or flexed, causing the upper limbs dropping or a projection of the object held between the hands, legs and a sharp drop. Because of their brevity, they are not accompanied by apparent disturbance of consciousness. They may be spontaneous or provoked by stimuli, particularly visual, in an intermittent light stimulation. Myoclonus are common immediately after waking. The myoclonic jerks of sleep are not epileptic in nature.
C – “petit mal”:
This is a pure and brief suspension of consciousness during most often less than 20 seconds, totally amnesiac, without automation, sometimes associated with some eyelid tremors. In the absence of the patient interrupts his activity and resumes where it left off when he regains consciousness. The total and immediate recovery of consciousness at the end of the absence is semiological important point. In their pure form, these absences are observed mainly in children.
D – atonic:
This crisis manifested by a sudden loss of postural tone, often resulting in the fall without prodrome, with a brief suspension of consciousness. A minor form of the atonic is represented by a brief absence with loss of muscle tone in the neck and head drop forward.
E – Tonic seizures:
Some overall tonic hyperextension differ from the great tonic-clonic generalized by their brevity and preferentially occurred at night during sleep.
IV – partial seizures.
The clinical manifestations of these crises depend on the headquarters of seizure discharge:
A – The crisis Bravais-Jacksonian:
It is the archetype of partial seizures described at the end of last century, indicating a critical concern to the discharge area rolandic opposed to clinical manifestations. The crisis manifested by unilateral partial clonic jerks, which may be preceded or followed by paresthesias or tonic spasm involving the same territory. The spread of the discharge in the motor cortex manifested clinically by an extension of the clones, which respects the somatotopic organization of motor cortex. Thus, the hand and hemiface whose somatotopic representation is very important, they are preferentially affected the evolution cheiro-oral clones beginning in the fingers and then passing to the hemiface the same side is especially evocative. Many partial motor seizures are manifested by clones or tonic spasm limited to part of one body half, without having provided all the features of the crisis Bravais-Jacksonian complete.
B – clonic hemicorporelles:
They deserve to be distinguished from earlier because they immediately spread to all muscles of a body half, their long-term nature of the context in which they occur (see below) and frequency with which they can cause a deficit postictal motor or permanent sequelae.
- Seizures adversative:
When the discharge of interest to the inner or outer surface of the frontal cortex pre-rolandic, it results in motor behavior, predominantly involving the eyes, head axial muscles and upper limbs. These seizures are characterized generally by a deviation and a turn, usually but not always on the side opposite hemisphere headquarters of the landfill. It is common to see fulfilled all the crises of this type under the general term crises adversive semeiologic despite their diversity.
The oculogyric crisis manifests itself as a tonic conjugate deviation of eyes. It can be complemented by a deflection of the head in the same direction.
When the discharge of interest to the supplementary motor area to the inner surface of the hemisphere, the crisis involves: 1) a suspension of speech, or of a cry, or the repetition of a syllable (palilalia), 2) adversion oculocéphalique 3) an automatic stereotype of upper opposed the release, with elevation of the latter half-flexed position.
More unusually, crises adversive have a turn of the body, which may cause the collapse (heart roundabout).
- Postural seizures:
Can be grouped under this term all the crises in which there is paroxysmal dystonic events, often affecting the upper limb or body half the opposite side of the ictal discharge or both upper limbs and axial musculature and may then cause fall. Some of these crises are rooted in the parietal lobe, others show a spread of discharge in both frontal regions. The bilateral nature of the frontal discharges can also cause a fall atonic. Often, only the video of the crisis coupled with that of the ictal EEG allows a precise observation of the ictal semiology.
- Seizures somatomotor inhibitory:
This crisis manifested only by a transient motor deficit, their existence is discussed as they are exceptional, only the concept of a deficit of a few seconds, stereotyped and recurring frequently, can at best do consider this diagnosis . Such crises should not be confused with the deficit postictal can follow any motor prolonged crisis.
C – Seizures somato-sensory:
They have in most cases the same progression as motor seizures jaksoniennes, is also related to a landfill in an area of cortex somatotopically organized, namely the primary somatosensory area of the parietal cortex. They are expressed by paresthesia and may be followed by motor manifestations of Jacksonian type because of the spread of discharge in the motor area. More unusually, there are sensations of heat or cold and very brief exception of pain affecting their stereotyping and their paroxysmal character. Stereotypy and brevity can also relate to a seizure disorder somatognosis more sophisticated sensations of loss of all or part of one body half (asomatognosia), sensations of supernumerary phantom limb, deformation of a member … in connection with a discharge affecting the posterior parietal cortex.
We distinguish visual seizures, manifested typically by phosphenes, more rarely, visual illusions, a macroscopic or microscopic; crises hearing, manifested most often by ringing with also, but more rarely, with auditory hallucinations theme music, or noise. The verbal hallucinations are rare. It should be noted that for the patient, these illusions are perceived as real.; Note also the existence of crises olfactory and gustatory, vertiginous crises, crises that disrupt the language of crisis with a feeling of loss of contact with the world external disturbance of affection, autonomic manifestations …. There are so many crises that specific neuronal areas affected, is whether the clinical expression may be diverse and varied.
V – GET
Examination electro-encephalographic (EEG), despite the development of anatomical imaging techniques (CT scan and MRI) and functional (positron emission single photon or positron), retains all its interest in the diagnostic process and therapeutic monitoring of epilepsy or progressive. The standard EEG is always a record of activity at rest, hyperventilation and photic stimulation.
VI – ETIOLOGY.
Generally, any epilepsy depends on a genetic predisposition and acquired factors, aggression potentially epileptogenic brain. When the genetic predisposition is the predominant factor, the disease manifests itself as a primary epilepsy, or idiopathic, in the apparent absence of any acquired brain injury. The distinction between acquired lesional epilepsy and idiopathic epilepsy associated with a genetic predisposition is not simple. A lesion equal to the risk of crisis is aggravated in patients with family history of epilepsy. Conversely, aggression cerebral childhood may promote clinical manifestation of idiopathic epilepsy.
- in acute head injuries;
- during an encephalitis or meningo-encephalitis viral, bacterial or parasitic;
- in toxic comas (including acute intoxication) or metabolic
- in a patient with a brain abscess;
- the acute phase of stroke;
- after alcohol withdrawal in an ethyl;
- after weaning barbiturates or benzodiazepines.
- ill with a brain lesion known potentially epileptogenic (tumor, vascular malformation) or carrying a encephalopathy identified.
The vast majority of epilepsy is treated medically. The goal of treatment is prevention of crises, it is a continuous process that must never be interrupted without notice médical.80% of patients are stabilized with monotherapy. Monotherapy as first-line required: Guardenal, valproate (Depakine), Lamictal, Tegretol, Neurontin, etc. ….
Surgical treatment aims to remove the epileptogenic zone and thus the entire crisis. It should not be confused with the surgical treatment of a focal lesion (tumor, angioma) responsible for seizures. It appeals only to a small number of partial epilepsy with frequent seizures refractory to medical treatment and in particular with temporal lobe epilepsy.