Introduction
Seizures are a condition that occurs due to abrupt and uninformed electrical activity that occurs in the brain. Focal seizures occur when electrical activity occurs in a limited brain area. Most of the time, seizures occur due to electrical activity in one hemisphere of the brain; in rare cases, they can be caused in both hemispheres involving the whole brain, called generalized seizures. A focal seizure is less severe compared to a generalized seizure.
What Is Meant by Focal Epilepsy?
Focal epilepsy usually occurs in specific brain regions and is less intense as the person does not lose consciousness. This condition is also known as auras. The signs and symptoms of a focal seizure depend on the region of the brain from where they occur; these may be:
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Motor:
When a focal seizure occurs due to electrical activity in the motor region, it affects the muscle activity resulting in jerk movement of the arm and foot. The doctors can find which side of the brain is affected by seeing the side of the affected body.
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Sensory:
When the sensory part of the brain causes a seizure, it affects the senses, like hearing, olfactory (smell), and other senses.
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Autonomic:
A focal seizure associated with the brain's autonomic region affects involuntary functions like blood pressure, heart rhythm, and other parts.
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Psychic:
When this brain region is affected, it triggers emotions and previous memories, causing fear and anxiety.
Who Does Focal Seizure Affect?
Anyone can experience seizures, which can be caused more frequently in people with some head injury, birth abnormalities of the brain, stroke, febrile seizure, tumors, and others. The most prevalent form of seizure is the focal seizure.
What Are the Types of Focal Seizures?
There are three types of focal seizures:
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Focal Aware Seizure:
It is also called a simple focal or partial seizure. This seizure has a specific feature where the person will know when the seizure occurs.
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Focal Impaired Awareness Seizure:
This is the most common form of focal seizure, called a complex seizure, experienced by almost 36 % of the population. This destroys the consciousness of the person. If the aura is formed, it occurs before any disruption to the awareness.
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Bilateral Tonic-Clonic Seizure:
This condition is distinguished by full-body involvement and convulsive episodes.
What Is the Cause of Focal Seizure?
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Brain tumors, including cancer tumors.
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Lack of oxygen.
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Arrhythmias, which is irregular heart rhythm.
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Aneurysms, bulging, and weakening of the blood vessels result in swelling of vessels.
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TBI (traumatic brain injury).
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Withdrawal symptoms of alcohol and drug.
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Reduced levels of calcium, magnesium, and sodium.
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High fever may result in febrile seizures in children.
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Genetic conditions and hormone-related issues.
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High or low blood sugar.
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Response of the immune system against infection.
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Stroke.
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Usage of drugs.
What Are the Warning Signs of Focal Seizure?
Most of the common warning signs that every person can experience is an aura. Aura can occur just before an episode of seizure when a person is very well aware, and the person can experience many signs and symptoms.
How Is Focal Seizure Diagnosed?
Doctors usually diagnose seizures based on the signs and symptoms experienced by the person. With various diagnostic methods, it can be ruled out whether the seizure was provoked or non-provoked. Genetic tests can also rule out the cause of the seizure. Identifying the brain region where the seizure started can help extensively diagnose and treat any form of focal seizure. Some diagnosing tests are:
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Blood test helps rule out any genetic cause or immune system issue.
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EEG, an electroencephalogram, is used to record brain activity.
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MEG, magnetoencephalography, records the magnetic field produced by the brain's electric activity.
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PET, positron emission tomography, is used to monitor physiological function.
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MRI, magnetic resonance imaging, creates images using a magnetic field and a computer.
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Lumber puncture, where a liquid sample is taken from the vertebrae.
How Is Focal Seizure Managed?
The treatment of focal seizure depends on whether the seizure caused is provoked or unprovoked. In case of a provoked seizure, treating the underlying cause can help prevent the occurrence of a seizure. If the underlying cause is not treatable, then managing the seizure through medication and another method can help reduce the severity and frequency of occurrence of focal seizures.
When an unprovoked seizure occurs, no treatment is required if the chance of recurrence is less. If the risk of unprovoked seizure is high, then treatment is needed. Treatment of focal seizure is provided through,
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Medication:
Some intravenous medications can help reduce the severity of the seizure as they occur; other medicines are in the form of pills, which need to be taken regularly.
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Diet Alteration:
A low or no-carb diet can help reduce the frequency of focal seizures.
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Surgery:
Removing the brain region which is responsible for the occurrence of seizures can help.
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VNS (Vagal Nerve Stimulation):
The frequency of seizures can be reduced by stimulating the vagus nerve, which is directly connected to the brain.
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DBS (Deep Brain Stimulation):
During this procedure, a device is surgically implanted into the individual's body, establishing a connection with the brain. This device provides a mild electrical signal that interferes with the brain's electrical signals and prevents seizure occurrence.
Usually, a focal seizure occurs briefly, lasting for a few seconds to minutes. It usually occurs for about one to two minutes. It may only happen for a short duration in some people. Post effect of focal seizure varies from person to person. Some people may feel fine, but some may feel weak after an episode of seizure. Some may feel confused, and others may be unable to move their body, called Todd's paresis, which may last a few minutes.
What Is the Outlook of Focal Seizure?
Focal seizure is not dangerous, but if it causes tonic-clonic seizure or if it occurs more often, then they should be treated. The outlook of focal seizure depends on the severity, underlying cause, and the medication taken. In most cases, education and surgery can help.
Conclusion
Focal seizure is a less severe and common seizure that is caused due to the electric activity of the brain in a particular region. These seizures can be provoked or unprovoked. It may very rarely result in a generalized seizure. This condition can be treated by treating the underlying cause. In case of unprovoked seizures, medication and surgery can help. Many affected people can live with minimal effects caused by this condition.
