What happens in a person’s brain when they have seizures?

We clarify the neurobiological causes of seizures.

The convulsive seizures are one of the most characteristic and recognizable symptoms in a wide variety of cases. The tremors that run through the whole body, as well as the altered states of consciousness (or even loss of consciousness) are the classic characteristics of seizures, and the fact that they affect the whole body and psychological processes suggests that an abnormal functioning of the nervous system is behind this symptom.

Specifically, seizures are due in part to changes in the firing patterns of neurons located in the brain..

At the origin of seizures

Seizures may be due to several causes, including high fever, degenerative diseases of the brain, or functional failures that produce epileptic seizures. However, regardless of the specific cause, seizures are caused by a characteristic pattern of neuronal activity.. This neuronal activity is recognizable by the rhythms with which various neurons send electrical signals to other networks of nerve cells. Seizures occur because neurons in the brain are acting abnormally, resulting in alterations of consciousness and the tension and relaxation of Muscle groups.

What is this pattern of activity?

Basically, it is many neurons firing electrical signals at the same time.. In a normal situation in which the person remains conscious, EEG readings show a pattern of activity with few ups and downs, because there are no large groups of neurons coordinating with each other to transmit information at the same time. However, during seizures, the EEG reveals large spikes of electrical activity that contrast with moments of low activity.

All this takes place in a very short time, and is reflected in the typical typical tremors of a person with convulsive seizures. Just as tremors are actually the repeated tension and relaxation of muscles, something similar occurs in the brain: neurons coordinate to send discharges together, but also do so at times when they do not send electrical signals. Hence, spikes of activity appear in the EEG readings: at a given moment, the effect of many nerve cells activating at the same time is not as well compensated by the non-activation of other neurons, so that the overall electrical activation is far from the average.

But seizure attacks are not only characterized by having many neurons coordinated with each other. In addition, each of these neurons is firing signals at a higher frequency than usual. with a higher frequency than usual. In other words, the nerve cells are in a clear state of excitation for the duration of the seizure.

At the same time, these mutually synchronized neurons responsible for the abnormal functioning are causing more and more neurons to start obeying and activating at the same time, so that the effects of the seizure are magnified each time. As the seconds pass, there will be more and more neurons in a state of constant excitation and coordinated with each other, although fortunately seizures do not usually last indefinitely.

And, while we sleep...

As a curiosity, it seems that something similar happens in the moments of sleep. sleep when we are not aware of anythingWhile when we dream, the results shown by the encephalograms are very similar to those of an awake person.

However, these cases have already been foreseen by evolution and mechanisms have been established so that we are not forced to have convulsions while we sleep.