Focal Seizure: Symptoms, Causes, and Management of Partial Seizures

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

Source currency note: This guide reflects medical information reviewed in April 2022. Always confirm current guidance with your healthcare professional.

Quick Answer

A focal seizure is a seizure that starts in one part of the brain, formerly called a partial seizure, and is the most common type. Symptoms depend on the brain region and include twitching, odd smells or loss of awareness. Antiseizure medications treat epilepsy. Get medical care for a first seizure, one lasting more than two minutes, or an injury. [3]

What the research says

• About 6 in 10 people with newly diagnosed epilepsy become seizure-free on medication. In a study of 525 people with newly diagnosed epilepsy, 63% stayed seizure-free during drug treatment or after it was stopped. Among 470 previously untreated patients, 47% became seizure-free on their first antiepileptic drug and a further 14% on a second or third drug, so a poor response to the first drugs can signal refractory epilepsy (Kwan and Brodie, New England Journal of Medicine, 2000).

• Surgery beat continued medication in temporal lobe epilepsy. In a randomized trial of 80 people with temporal lobe epilepsy, 58% of those assigned to surgery were free of seizures that impair awareness at one year, compared with 8% of those treated with antiepileptic drugs (P<0.001). Four of the 40 surgical patients (10%) had adverse effects of surgery (Wiebe et al., New England Journal of Medicine, 2001).

What Is a Focal Seizure?

A focal seizure begins in a specific part of the brain rather than affecting both hemispheres at the same time. These seizures were formerly called partial seizures. Because they start in one area, the symptoms reflect what that region of the brain does, such as controlling movement, processing sensation or regulating emotion [3].

Focal seizures are the most common type of seizure and make up more than half of all seizures. They tend to be less severe than generalized seizures. However, as the surge of electrical activity intensifies it can move from one location to another and even cross to the other hemisphere. When that happens, providers call it a focal to bilateral tonic-clonic seizure [3].

Feature	Focal seizure	Generalized seizure
Where it starts	One location in one hemisphere of the brain	Both hemispheres of the brain
Body involvement	Symptoms start in the part of the body controlled by that brain region, often one side	Symptoms affect both sides of the body
Typical severity	Tend to be less severe	Usually more severe

Types of Focal Seizures

Healthcare providers group focal seizures by whether you stay aware of what is happening around you. This distinction matters for diagnosis and for knowing how to respond [3].

Focal aware seizures

Formerly called simple partial seizures, these happen while you are aware. You may have unusual sensations or emotions but you know what is happening. Auras that occur with these seizures are the seizure itself [3].

Focal impaired awareness seizures

Formerly called complex partial seizures, these disrupt your awareness of what is happening. They usually last no more than three minutes. About 36% of all seizures are this type, making it the most common type of seizure. During one, a person may make repetitive or automatic movements such as lip smacking, blinking or tapping a hand or finger [3].

Focal to bilateral tonic-clonic seizures

These were once called secondarily generalized tonic-clonic seizures. They involve full-body muscle movements and convulsions, and they can begin as a focal seizure that spreads [3].

Warning Signs and Symptoms

Auras

Some people with focal seizures notice an aura first. An aura happens while you are still aware, and it can take the form of sensory symptoms, emotional changes or autonomic symptoms. When a focal seizure does not spread, the aura can be the only sign of the seizure. Auras do not happen in people with generalized epilepsy, so having one suggests focal epilepsy. An aura can also work as a warning, because it can progress to a seizure with loss of awareness [3].

The four symptom groups

Focal seizure symptoms fall into four groups, and one seizure can involve more than one [3]:

• Motor: involuntary movements, often of the face, hands and toes on one side, such as twitching or jerking, muscles tightening, or repetitive movements like lip smacking, blinking or finger tapping.

• Sensory: hallucinations that can involve any of the five senses, such as bright lights or flashes, unexpected sounds, smells or tastes (often metallic, sour or bitter), or pins-and-needles and tingling sensations.

• Autonomic: sweating, drooling, skin color changes (going pale or red) or a rising feeling in the stomach.

• Cognitive and emotional: fear, anxiety, joy or uncontrollable laughter, dream-like feelings, déjà vu (a new experience feels familiar) or jamais vu (a familiar experience feels new), plus changes in awareness, memory or language.

The Jacksonian march

In some focal motor seizures, twitching or jerking starts in a small area, such as a finger or toe, and gradually "marches" across that body part and onto other parts of the body or face on the same side. This pattern is called the Jacksonian march [3].

Todd paralysis

After focal motor symptoms, many people have temporary paralysis or weakness in the affected body part. This is called Todd paralysis. It is temporary, but it can last several hours. Telling your healthcare provider about it can help with diagnosing and treating your seizures [3].

Causes and Risk Factors

Anyone can have a seizure under the right circumstances. Focal seizures happen more easily in people with certain brain conditions, including head injuries, brain abnormalities present at birth, febrile seizures in childhood, brain infections such as encephalitis, strokes and brain tumors [3]. Focal seizures are not contagious, although some conditions that cause them are inherited [3].

• Injury: concussion and traumatic brain injury

• Brain conditions: strokes or transient ischemic attacks, brain tumors, aneurysms, problems with brain structure and degenerative diseases such as Alzheimer's disease or frontotemporal dementia

• Infections: encephalitis or meningitis, and high fevers

• Metabolic problems: low sodium, calcium or magnesium, and high or low blood sugar

• Withdrawal and substances: drug or alcohol withdrawal, and use of drugs or alcohol, including some prescription medications and even caffeine

• Other causes: genetic disorders, inflammation from immune system disorders, sleep problems, hormone-related changes, eclampsia, lack of oxygen to the brain and irregular heart rhythms

How Focal Seizures Are Diagnosed

A healthcare provider, usually a neurologist, diagnoses focal seizures from the symptoms you had (or that others describe) and from diagnostic tests. Tests can usually confirm whether you had a seizure and whether it was provoked or unprovoked. A key part of diagnosis is finding the focal point, the area where the seizure started, because locating it can greatly help with treatment [3].

Possible tests include [3]:

• Blood tests to look for metabolic or blood chemistry imbalances, immune system problems and toxins, and to check levels of antiseizure medications

• Electroencephalogram (EEG) and video-EEG monitoring

• Magnetic resonance imaging (MRI)

• PET scan, ictal SPECT and magnetoencephalography (MEG)

• Intracranial EEG monitoring with electrodes placed on or in the brain in some cases

• Spinal tap (lumbar puncture) when an infection or immune-related brain disease is suspected

Treatment and Management

Treatment starts with finding out whether the seizures were provoked or unprovoked. When possible, treating the underlying cause of provoked seizures can often stop them. Providers usually recommend against treating a first unprovoked seizure unless you have a high risk of having another. If you have a high risk, or have had an unprovoked seizure before, you will likely be diagnosed with epilepsy and advised to start treatment [3].

Treatment options for epilepsy-related focal seizures

• Medications: some stop seizures as they happen, while daily pills prevent seizures or make them less frequent.

• Diet changes: low- or no-carbohydrate (ketogenic) diets can sometimes stop epileptic seizures or reduce how often they happen.

• Epilepsy surgery: surgery can sometimes stop seizures by removing or disconnecting the problem area from the rest of the brain.

• Vagus nerve stimulation (VNS): electrical stimulation of the vagus nerve can reduce how often seizures happen.

• Responsive neurostimulation (RNS): a device detects epileptic activity and delivers stimulation to the brain region generating it.

• Deep brain stimulation (DBS): an implanted device delivers a mild electrical current that interferes with the electrical malfunctions that cause seizures.

Some people with focal epilepsy develop drug-resistant (medically refractory) epilepsy, which means medicines do not do enough. Drug-resistant epilepsy is often treatable with surgery, so it is worth seeking care from a provider with expertise in epilepsy surgery [3].

Living with focal seizures

• Take your medication as prescribed. Only stop it with guidance and monitoring from your healthcare provider [3].

• Keep your follow-up visits so your provider can monitor your condition and adjust treatment [3].

• Don't ignore or avoid symptoms. The outlook is usually better with early diagnosis and treatment [3].

• If seizures continue, seek care at an epilepsy center with expertise in advanced testing [3].

First aid when someone has a focal seizure

• Stay with the person until the seizure ends.

• Move dangerous objects out of the way.

• Time the seizure.

• Do not restrain the person and do not put anything in their mouth. Call 911 if the seizure lasts longer than 5 minutes, another seizure follows soon after, the person has trouble breathing or does not wake up, is injured, is pregnant, or the seizure happened in water.

Prevention

Seizures can happen unpredictably, so they cannot always be prevented. The best approach is to avoid possible causes [3]:

• Eat a balanced diet and maintain a healthy weight to protect your heart and circulation, since stroke is commonly connected to focal seizures.

• Don't ignore infections. Eye and ear infections need timely treatment so they don't spread to the brain.

• Wear safety equipment such as helmets and seat belts, because head injuries are a major cause of focal seizures.

• Manage chronic conditions such as type 1 or type 2 diabetes, especially blood sugar problems.

Outlook and Complications

Overall, focal seizures aren't dangerous, but they can turn into tonic-clonic seizures that are dangerous if they last too long or happen too often. For unprovoked seizures, the vast majority come under control with an appropriate antiseizure medication, and it's possible for epilepsy to go into remission and stay that way for life [3].

Controlling focal seizures matters because, over time, uncontrolled seizures can lead to memory problems or trouble with thinking, and they can increase the risk of mood disorders such as depression and anxiety. There is also a small risk of sudden unexpected death in epilepsy (SUDEP). The yearly risk is about 1 in 1,000 for people whose epilepsy is well managed and about 2 in 1,000 for people whose epilepsy is not managed [3].

When to Seek Medical Care

• If you have never had a seizure and you pass out unexpectedly or for an unknown reason, go to the hospital [3].

• If you are alone and think you have had a seizure, contact your healthcare provider as soon as possible [3].

• People with epilepsy often don't need an ambulance or hospital visit after a seizure, but they may still need care for injuries or for seizures lasting more than two minutes [3].

Conclusion

Focal seizures start in one part of the brain, and what you feel or do during one reflects that region. They are common and often treatable. With the right diagnosis, antiseizure medication and, when needed, surgery or neurostimulation, many people live with minimal effects from their condition [3].

If you or someone you know has had a seizure, especially a first one, see a healthcare provider so the cause can be found. Early diagnosis and steady follow-up give treatment the best chance of working.

Frequently Asked Questions

What is the difference between a focal seizure and an aura?

An aura is often the first symptom of a focal seizure and happens while you are still aware. If the seizure doesn't spread to other areas of the brain, the aura can be the only sign of the seizure. [3]

Are focal seizures dangerous?

Overall, focal seizures aren't dangerous, but they can turn into tonic-clonic seizures, which are dangerous if they last too long or happen too often. Seizures can also be risky if they happen during activities such as driving or swimming. [3]

Can focal seizures be outgrown?

In many cases, children with focal epilepsy outgrow the condition and remain seizure-free for the rest of their lives. [3]

What is Todd paralysis?

Todd paralysis is temporary paralysis or weakness in a body part after focal motor symptoms. It is temporary, but it can last several hours. Tell your healthcare provider if it happens. [3]

How long do focal seizures usually last?

Focal impaired awareness seizures usually last no more than three minutes. Seizures lasting more than two minutes may need medical care. [3]

Can stress trigger a focal seizure?

Stress isn't a direct cause of seizures, but stress and poor sleep are commonly reported triggers in people who already have epilepsy. Talk with your healthcare provider about your own triggers.

What should I do if I see someone having a focal seizure?

Stay with the person, move dangerous objects out of the way and time the seizure. Do not restrain them and do not put anything in their mouth.

Is focal epilepsy the same as focal seizures?

No. A seizure is a single event, while epilepsy is a condition in which a person has recurrent unprovoked seizures. [3]

Can focal seizures affect memory?

Yes. Over time, uncontrolled focal seizures can lead to memory problems or trouble with thinking, and they can raise the risk of mood disorders such as depression and anxiety. [3]

When is a seizure a medical emergency?

Get medical care if it is someone's first seizure or they pass out unexpectedly for an unknown reason, if a seizure lasts more than two minutes, or if the person is injured. [3]

Related Reading

Responsive Neurostimulation (RNS) for Epilepsy: How It Works, Surgery and Results explains the implant that detects focal seizure activity and responds with small electrical pulses.

SEEG (Stereoelectroencephalography): Finding Where Seizures Start explains the deep-brain electrode test used to find where seizures start.

References

1. Kwan P, Brodie MJ. Early identification of refractory epilepsy. New England Journal of Medicine. 2000;342(5):314-319. PMID 10660394. https://doi.org/10.1056/NEJM200002033420503

2. Wiebe S, Blume WT, Girvin JP, et al. A randomized, controlled trial of surgery for temporal-lobe epilepsy. New England Journal of Medicine. 2001;345(5):311-318. PMID 11484687. https://doi.org/10.1056/NEJM200108023450501

3. Cleveland Clinic. Focal seizure. Cleveland Clinic. April 29, 2022. https://my.clevelandclinic.org/health/diseases/22893-focal-seizure

Medical disclaimer

This article was prepared for general information only and is not a substitute for professional medical advice.