03. Epilepsy

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"The history of epilepsy is to just 4000 years of ignorance, superstition and stigma, followed by 100 years of knowledge, superstition and stigma" Rajendra Kale, 1997 [ 190 ].

1. General:

The term epilepsy comes from the Greek, it means: take by surprise [ 186 ].

Epilepsy [ 41 , 69 , 179 , 185 ] is a neurological disorder characterized by repeated seizures that involve:

  • Clinically: A tonic-clonic motor manifestations, sensory and autonomic dysfunction and / or impaired consciousness.
  • Electro-encephalography: Layout feature [ 187 ].

Epilepsy is the most common chronic neurological condition after migraine [ 187 ]. This is a relatively mild disease in most cases, but its psychological, family and social repercussions are far superior to the severity of the disease itself.

It should be noted that epilepsy is not a mental illness [ 69 ], as found in popular belief, even though it may be accompanied in some cases some comportemento-cognitive disorders.

2. Pathophysiology:

An epileptic seizure is the clinical consequences of paroxysmal discharges excessive hypersynchronic and self-sustaining population of more or less extent of brain neurons [ 75 ].

This synchronized discharge is the result of an imbalance between excitatory and inhibitory mechanisms [ 188 ], which explains the involvement of an intense and disordered neuronal activity. This activity, sometimes as a small source cortex (epileptogenic zone) [ 187 ], will spread step by step through the cerebral cortex.

Seizures occur in very different ways, in relation to the area of the brain from which the discharge and its mode of propagation. For example, a partial seizure located in the occipital lobe, resulting in an abnormal visual perception, if it spreads forward, it may cause motor or sensory phenomena. If it spreads to the whole brain, it can turn into generalized tonic-clonic seizure [ 31 ] (grand mal) [ 75 ].

An epileptic seizure is a very dynamic phenomenon that involves so abnormal and successively various brain structures and, consequently, their functions (language, motor or sensory phenomena, eye movements, etc..).

The first clinical signs are very localizing value. Often, there may be a (aura) [ 187 ], a phenomenon almost always the same for the same person, announcing the impending crisis. Able to describe it helps to clarify the origin of the crisis.

Usually, the discharge will follow the same path, so the signs are the same for the same subject.

3. Classification:

We can distinguish several types of seizures. For example, there seizures and other silent, they may be partial or generalized, they may or may not be accompanied by loss of consciousness, they can only be driven, or sensory and occur mindfulness ...

3.1 The Origin:

  • Symptomatic seizures [ 187 ]: Secondary to a definite cause (trauma, tumors ...) [ 187 ].
  • Essential epilepsy [ 107 ] The most common idiopathic form, without significant organic cause. It is in this case of epilepsy.
  • Cryptogenic epilepsy: which has an organic cause [ 145 ] but which escapes the investigations [ 187 ].

3.2 According to the clinical manifestations of seizures:

When seizures originate in a localized area of the brain, it is called partial. When they come from the entire brain, they are called generalized.

3.2.1. Generalized seizures [ 67 , 187 ]: The tonic-clonic (grand mal) [ 107 ]:

This is the best known, because it is the most spectacular. It is manifested by a fall, loss of consciousness, tonic-clonic convulsions, tongue biting, sometimes loss of urine or stool ... It may result in minor or less serious, it stops after about a minute.

The status epilepticus [ 69 ] is generalized succession without interruption and return to consciousness seizures, coma is deep with severe autonomic dysfunction involving the prognosis of the patient. This is a therapeutic emergency. The absence:

The absence [ 188 ] is a type of generalized seizure with a brief suspension of consciousness without motor, sensory or vegetative symptoms. The look is empty and the communication is interrupted for a few seconds between the subject and his surroundings.

Absence seizures are usually repeated throughout the day and correspond to what used to be called: petit mal [ 75 ]. Other forms of generalized seizures:

Clonic seizures, myoclonic, tonic and atonic.

3.2.2. Partial seizures (focal) [ 188 ]: Simple partial seizures [ 185 ]:

In his prime form, called Bravais-Jacksonian [ 189 ], the crisis starts with localized motor signs that extend gradually according to the progress at the contralateral primary motor cortex.

There are other types of non-motor simple partial seizures with sensory disorders, autonomic or psychic. Complex partial seizures [ 187 ] with disorders with or without automation conscience. Secondarily generalized partial seizures [ 183 ].

4. Diagnosis:

Must first ensure that it is indeed epilepsy and seek a possible cause. Must eliminate crises or discomfort that may resemble epilepsy [ 188 ]: hysteria, vagal malaise, sobbing spasms, syncope, tetany, hyperventilation ... with suitable tests.

To assert epilepsy, it is often necessary to press:

4.1. The electroencephalogram (EEG) [ 5 , 185 ]:

The ECG can highlight inter-critical defects (between attacks) to record and sometimes seizures. The ideal is to couple the EEG with video recording [ 187 ].

A normal EEG does not formally rule out the diagnosis of epilepsy [ 69 ], then it should be renewed.

When epilepsy is severe, sometimes you make a long recording coupled with video on one or more days in a specialized center.

4.2. Neuroradiological examinations [ 188 ]:

They are not always indispensable. If you search an injury, MRI (Magnetic Resonance Imaging) can show abnormalities than plain radiography or CT can not detect. Other imaging techniques can be proposed, mainly if we consider a surgical option.

5. Treatment:

The treatment of epilepsy often requires a (psychological, social and even surgical pharmacological) multidisciplinary approach [ 31 ].

The two requirements of antiepileptic treatment are complete seizure control and the absence of adverse effects. Treatment options depend on an accurate assessment of the type of crisis. They also depend on the psychological profile and medico-social condition of the patient.

The therapeutic management is essentially based on antiepileptic drugs [ 31 ] (or anticonvulsants): barbiturates (eg, phenobarbital), benzodiazepines (diazepam, clonazepam), sodium valproate, phenytoin, carbamazepine ...

Each product is preferentially active on one or a few varieties of epilepsy, and its purpose is to prevent new crises, or reduce their frequency.

Benzodiazepines are emergency reference medicines for seizures (convulsions), or for status epilepticus.

For some forms of epilepsy essentially partial drug-resistant, it is possible to consider surgery [ 188 ] (cortectomies or disconnections).