Focal seizures, also called partial seizures, occur in only one part of the brain.
They are a key symptom of epilepsy but can also occur due to other causes. There are two types of focal or partial seizures: simple and complex. This article looks at the types, causes, symptoms, and treatment of focal seizures.
The human brain contains neurons, or brain cells, that use electrical signals to communicate.
During a seizure, which is temporary, a person experiences an atypical surge of electrical activity in their brain. People can experience physical symptoms before, during, and after a seizure.
Unlike generalized seizures, focal seizures
All seizures occur due to atypical electrical discharge within the brain. However, there are types of seizures that differ according to how they affect the brain. Health experts
Generally, seizures fall into the following categories:
|type||absence, sometimes called “petit mal”||tonic-clonic, sometimes called “grand mal”||focal|
|brain impact||zoning out or staring into space||motor impact-like shaking |
and muscle spasms and
sometimes loss of
|impact depends on |
seizure starts in the brain
Simple focal seizure
Doctors also refer to simple focal seizures as focal aware seizures, which do not involve the loss of consciousness.
During a simple focal seizure, a person remains alert throughout the event and remembers it when it finishes. This seizure typically lasts less than
Complex partial seizure
Doctors also refer to complex partial seizures as focal impaired awareness seizures.
When a person has a complex partial seizure, they lose consciousness and do not remember the seizure after it is over.
The seizure may last up to
Secondary generalized seizure
Some focal seizures can start in one part of the brain and then move to another, essentially turning into generalized seizures, which can last around
Seizures can have many different causes and triggers, some of which doctors still do not know.
Potential causes of focal seizures
- head injury
- brain tumor
- substance withdrawal
- low blood sugar
- endocrine disorders
- metabolic disorders
- genetic abnormalities
Potential triggers of focal seizures
- sleep deprivation
- seeing flashing lights
- alcohol or drug use
- low blood sugar
- certain medications
Doctors also classify focal seizures into two additional types, depending on their cause. One type is an unprovoked seizure, which occurs without a known cause, and the other is an acute symptomatic seizure, which results from a triggering event or injury.
Because a focal seizure begins in one part of the brain, its
However, if the focal seizure becomes a generalized seizure, they may begin to experience convulsions on both sides.
Symptoms that may occur during a focal seizure
- muscle contractions
- unexpected sensations
- atypical head or eye movements
- automatisms, such as skin picking or lip smacking
- vision changes or auras
People who remember having a seizure often describe an aura at its onset.
An aura is a confusing feeling or the perception of an unexpected light or smell just before a seizure begins. Therefore, auras usually indicate the start of the atypical electrical activity in the brain prior to a seizure.
Following the aura, the individual may then have odd sensations, changes in motor abilities, or visual disturbances, usually on one side of the body.
However, bystanders may notice different symptoms in these individuals, such as staring, rapid eye blinking, or body stiffening, followed by confusion and tiredness after the event.
A healthcare professional will try to figure out whether the seizure was focal or generalized. They will also attempt to distinguish the seizure episode from other events that look similar to seizures.
Doctors will also take note of any potential triggers for a seizure. If they are unable to identify any, they will assess a person’s likelihood of another seizure.
If there are risk factors for another seizure, the doctor might decide if an individual would benefit from medication.
During the physical examination, they will look for signs that may indicate a condition that causes seizures, such as epilepsy, a brain infection, or other chronic syndromes, including neurofibromatosis or tuberous sclerosis.
Finally, they may recommend electroencephalography, a procedure that monitors brain activity.
Doctors use antiepileptic medications to prevent seizures.
Several options are available for focal seizures. They come in two categories: broad-spectrum antiepileptic medications and narrow-spectrum antiepileptic medications.
Examples of broad-spectrum antiepileptic medications include:
- lamotrigine (Lamictal)
- levetiracetam (Keppra)
- topiramate (Topamax)
- valproate (Depakote)
- zonisamide (Zonegran)
Examples of narrow-spectrum antiepileptic medications include:
- carbamazepine (Tegretol)
- oxcarbazepine (Oxtellar XR)
- phenytoin (Dilantin, Phenytek)
- lacosamide (Vimpat)
Following a ketogenic diet, which limits carbs and focuses on high fat and certain proteins,
A doctor may recommend this treatment if
Vagus nerve stimulation
Another therapy for epilepsy when medications are ineffective work is vagus nerve stimulation (VGS).
In this procedure, a technician attaches an electric stimulator to the left vagus nerve in the neck, which can help reduce electrical activity in the brain. In turn, this can reduce the intensity and severity of seizures.
However, this treatment can take as long as
When other treatments are not providing beneficial outcomes, a person may need a surgical procedure
An individual can discuss these options with their doctor. They should also mention whether they take any other medications or are pregnant, as these factors may influence the course of action that the doctor recommends.
While it is not always possible to prevent focal seizures, a person can reduce their occurrence if there is an identifiable cause or trigger. In this case, individuals
For example, they can monitor their blood sugar, get adequate sleep, avoid flashing lights, or reduce alcohol consumption.
The outlook for someone who has had a focal seizure depends on its underlying cause. However, effective treatments are available to help sustain a person’s quality of life.
Additionally, getting sufficient sleep, eating a nutritious diet, exercising regularly, and taking medication under guidance from a doctor can benefit those who experience seizures.
Here are some frequently asked questions and answers on focal seizures.
How common are focal seizures?
Focal seizures are the most common type of seizure that affects both adults and children. Approximately 36% of people who experience seizures have complex focal seizures involving a loss of consciousness.
What are continuous focal seizures?
It is possible to have continuous focal seizures. If a person with epilepsy experiences a focal seizure for
How are focal seizures in children different from those in adults?
Focal seizures due to epilepsy are very common in children. When epilepsy is the cause, children may experience additional symptoms to adults,
Focal seizures, or partial seizures, occur when there is a disruption of electrical impulses in one part of the brain.
A person may be aware they are having a seizure — health experts call this a simple focal seizure. In contrast, those who may be unaware are often experiencing a complex focal seizure.
Some focal seizures occur after a person encounters a trigger, but some may happen without a known cause. Treatment often involves antiepileptic medication, dietary changes, VNS, or surgery. The outlook depends on the underlying cause of the seizure.