A group of disorders of the nervous system that is characterized by the predisposition to undergo episodes of abnormal brain electrical activity that cause seizures and other symptoms is called “epilepsy”. Sometimes other brain disorders associated with epilepsy also appear, such as delayed cognitive development.
In this article we will describe the causes, symptoms and treatment of focal or partial epilepsyThe most common subtype of this disease, which is defined by the alteration of electrical activity in limited regions of the brain.
What is focal epilepsy?
The different types of epilepsy differ from each other in different clinical dimensions. One of the most relevant is the degree of generalization of electrochemical dysfunction from a cerebral point of view; in this sense, the fundamental divergence is that which occurs between focal or partial epilepsy and generalized epilepsy.
We speak of partial epilepsy when there is a clear predominance of partial seizures. This means that episodes of dysfunctional brain activity, due to seizures, start in a specific area of the brain, although they can then spread to the entire organ. When this phenomenon occurs, it is referred to as “secondary generalization”.
On the other hand, generalized or “very severe” seizures affect the entire brain, Or much of it, from the time they start. Generalized type epilepsy is associated to a greater extent than focal epilepsy with the onset of the epileptic aura, a set of prodromes that include alterations in sensory perception or psychological confusion.
In the literature we can also find references to the involvement of one or both hemispheres to distinguish focal and generalized epilepsy. Loss of consciousness and the epileptic aura are more characteristic of generalized seizures, although they can also occur in partial seizures, especially if they affect a large area of the brain.
Symptoms of partial seizures
Sometimes focal epileptic seizures affect the level of alertness, consciousness and memory, and can also influence observable behavior. In such cases we are talking about complex focal or partial seizuresWhereas if there are no alterations in memory and consciousness is maintained, they are considered to be mere focal seizures.
Another important difference is that the epileptic aura is more common in complex seizures than in simple seizures. Symptoms and signs of focal epilepsy they can also vary widely depending on the areas of the brain affected.
The most common phenomena associated with partial seizures are:
- Sudden onset of intense emotions
- Feel nauseous
- Sensation of movement or of falling to the ground, distorted perception of space
- Sensory alterations and olfactory, auditory, tactile, taste and visual hallucinations
- Dissociative phenomena: depersonalization and unrealization
- Abnormal muscle contractions
- Behavioral automatisms, such as walking or chewing
- Lateral eye movements, pupillary dilation
- Increased heart rate
- Abdominal pain and discomfort
- Difficulty or inability to speak
outraged symptoms depend on the affected brain lobes. If the seizure occurs in the frontal lobe, strange movements and difficulty speaking may appear; if in the storm, fear, automatisms and déjà vu; if in parietal, tactile sensations and distortions of perception; and if they occur in the occipital, dysfunctions and sensations in the eyes.
As we said above, some partial seizures spread to the rest of the brain after starting in a specific region of it; it is this last aspect which gives them the consideration of focal lengths. The size of the area of the brain affected by the electrical alteration influences the severity of the symptoms.
Causes of this type of epilepsy
Partial epilepsy is the most common type of this disease. It is particularly common in the elderly (around 65 years or older) and the presence of cerebrovascular disorders or brain tumors is a very important risk factor.
It is common for focal epilepsy, especially when it begins in adulthood, to appear due to different factors that injure the brain. These included Ischemic stroke, traumatic brain injury, Tumors and infections of the brain. In other cases, the cause of focal epilepsy is unknown.
In children, it is more common that the cause does not arise due to factors such as these, but is primary in nature; in these cases, we speak of “idiopathic epilepsy”. It is necessary to mention the existence of a benign focal epilepsy of the child, which is characterized by the presence of focal seizures, their relative lightness and their disappearance in adolescence.
Treatment of this disorder
Usually epilepsy, both focal and generalized, is treated with pharmacological treatments. The most common anti-epileptic drugs are gabapentin, lamotrigine, topiramate, valproate, and oxcarbazepine. Adopting it can also be very useful ketogenic diet (low in carbohydrates and high in protein).
In some severe cases of focal epilepsy, it may be advisable to perform surgery to avoid greater risks or reduce interference in life. This type of surgery consists of removing the part of the brain with which epilepsy is associated so that the episodes of deregulation of the electrical activity of the brain disappear.
However, the variability of treatments is high; when its manifestation is particularly mild, epileptic spectrum disorders may not have significant consequences or may require treatment.