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Epilepsy: types of seizures and most common causes

Epilepsy: types of seizures and most common causes

The epilepsy It is an abrupt and transient disorder of normal brain physiology, usually of the cerebral cortex. It is associated with an alteration of brain electrical activity, due to abnormal activity discharges from a group of neurons located, generally, in the cortex.

Content

  • 1 Types of epileptic seizures
  • 2 Possible causes of epilepsy
  • 3 References

Types of seizures

Epileptic seizures can be divided into two types, partial and generalized crises.

Partial seizures of epilepsy

In partial epileptic seizures the electric shock originates from a more or less localized group of neurons cortical known as epileptic focus or epileptogenic zone.

Normally there are different clinical manifestations of this type of crisis, which are determined by the location of the epileptic focus and the direction of propagation of these discharges.

You have to keep in mind that in some cases partial seizures can progress and become a generalized tonic-clonic crisis.

Generalized epilepsy crisis

On the other hand, in generalized crises, synchronous and simultaneous activation of the two cerebral hemispheres occurs, including the central fronto cortex, diencephalic structures, thalamic nuclei and thalamocortical connections.

When consciousness is altered, primitive, repetitive and in turn coordinated behaviors called automatisms are presented. Which are presented without a specific purpose, in an unconscious and automatic way, for example: of the food-grade type such as chewing, swallowing or pacifying.

Many times people suffering from epilepsy can anticipate a seizure due to epileptic aura. which are characteristic symptoms that appear before the crisis occurs.

Possible causes of epilepsy

Epilepsy is caused by electrical hypersynchronization of the neural network of the cerebral cortex, where an abnormal discharge of nerve impulses of recurrent and paroxysmal characteristics causes a malfunction of the nerve cells triggering involuntary movements and loss of consciousness.

Patients with epilepsy may suffer a series of uncontrolled and involuntary body movements. called seizures repetitively. This is called "epileptic seizure."

Clinically epilepsy is defined as a condition in which at least two unprovoked seizures occur with a time separation of more than 24 hours.

Less than half of epilepsy cases have an identifiable cause and it is believed that epilepsy in most patients is genetically determined. In the rest of patients in whom the cause cannot be identified or determined, the list of possible causes of epileptic seizures are very varied

Possible causes of unidentifiable epilepsy

  • Head trauma
  • Brain tumor
  • Stroke
  • Intracranial infection
  • Brain degeneration
  • Congenital brain formations
  • Congenital metabolism errors

Emergence and development of the disease

Epilepsy can occur throughout a person's life, either because of a structural lesion in the brain or also because of a brain scar. In most cases, this disease occurs during birth or later at birth.

In fact, there are two major types of epilepsy:

  • Symptomatic, It is mainly caused by brain injuries. So it can cause cognitive impairment and even malformations in cortical development
  • AND idiopathic, in which its origin is unknown. Therefore, the cause of these epileptic seizures is unknown. But it is likely to be due to tumors or brain malformations, or certain diseases that affect the nervous system.

Characteristic symptoms of the disease

Epilepsy is a chronic neurological disorder that can affect people around all ages. In most cases, they have frequent seizures.

These seizures are called by brief episodes in which the movements are involuntary.They can usually affect a part of the body and these are considered partial seizures or they can affect in their entirety. The latter, generalized seizures, They are usually accompanied by loss of consciousness and loss of control of the sphincters.

The epilepsy crisis is considered as an abnormal activity that occurs in neurons, directly affecting brain tissue, and causing the brain to be in an excitable state. This causes it to emit abnormal signals, causing repetitive and unexpected seizures, which in turn can cause sudden changes in attention and behavior.

Such episodes caused by seizures usually occur by an electrical discharge of nerve stimuli, generating, in turn, such discharges problems in the brain. These discharges can be manifested through very succinct episodes of absence, or also by the muscular contractions typical of seizures.

Its continuity can vary from less than one seizure in the year, to several that occur in the day. Therefore, a presence of epilepsy is considered when two or more unprovoked seizures occur.

References

Peña-Herrera, B. and Marcial, P. (2018) Neurosciences: Etiology of brain damage. Samborondón: Espiritu Santo University - Ecuador.