What Can We Learn from EEGs of Patients with Epilepsy?

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What Can We Learn from EEGs of Patients with Epilepsy?

People with some types of epilepsy have unusual electrical activity in their brain even when they are not having a seizure. When they have an EEG test, the results can show certain brainwave patterns that doctors recognise. This information is very helpful for doctors when they are making a diagnosis.

What does an EEG show for epilepsy?

What does an EEG show? An EEG gives information about the electrical activity of the brain during the time the test is happening. When someone has an epileptic seizure their brain activity changes. This change, known as epileptiform brain activity, can sometimes be seen on an EEG recording.

What can be learned from EEG?

An EEG can determine changes in brain activity that might be useful in diagnosing brain disorders, especially epilepsy or another seizure disorder. An EEG might also be helpful for diagnosing or treating the following disorders: Brain tumor. Brain damage from head injury.

Why use an EEG after a seizure?

These studies suggest that obtaining an EEG shortly after a new-onset seizure can improve the yield of identifying epileptiform abnormalities. Moreover, these studies show that it is logistically feasible in the clinical setting.

What are 10 conditions diagnosed with an EEG?

10 Conditions Diagnosed With an EEG
  • Seizure Disorders. The primary use of EEG is diagnosing epilepsy and other seizure disorders. …
  • Sleep Disorders. Sleep disorders range from insomnia to narcolepsy. …
  • Brain Tumors. There are many types of brain tumors. …
  • Brain Injury. …
  • Dementia. …
  • Brain Infections. …
  • Stroke. …
  • Attention Disorders.

Are EEGs accurate?

EEG review yielded 1-week accuracy in 1052% of recordings, and 2-week accuracy in 2875% of recordings (n = 146; Fig. 3E and F).

What is the purpose of an EEG?

The main use of an EEG is to detect and investigate epilepsy, a condition that causes repeated seizures. An EEG will help your doctor identify the type of epilepsy you have, what may be triggering your seizures and how best to treat you.

What does background slowing on EEG mean?

As previously discussed, generalized background slowing in the theta and delta frequency ranges is a normal finding on EEG when it represents developmental slowing in children, adolescents, and some young adults or the evolution of drowsiness and sleep activity.

What does diffuse slowing on EEG mean?

Diffuse slowing: Diffuse slowing indicates global cerebral dysfunction. The slowing can be in the theta or delta ranges. The slowing can be high or low amplitude.

What causes epilepsy?

When epilepsy is diagnosed in older adults, it’s sometimes from another neurological issue, like a stroke or a brain tumor. Other causes can be related to genetic abnormalities, prior brain infection, prenatal injuries or developmental disorders. But in about half of people with epilepsy, there’s no apparent cause.

Can EEGs be wrong?

Yes, EEG can be bad for you. The consequences of being misdiagnosed with epilepsy are obvious and serious [9]. When the diagnosis is based largely on an abnormal EEG, no amount of subsequent normal EEGs will ‘cancel’ the previous abnormal one, and the wrong diagnosis is very difficult to undo.

Can an EEG improve?

EEG can provide early information about the cause of and prognosis in coma states. Repeated EEG recordings increase the diagnostic reliability and make it possible to follow developments in the coma, partly in order to assess a prognosis, partly because epileptic activity requiring treatment may occur along the way.

What causes simple partial seizures?

A seizure occurs when a person experiences a disturbance in their brain’s usual activity. The brain communicates via electric signals. Disruption to these signals can result in a seizure. Simple partial seizures happen when people have an electrical change in a specific part of their brain that affects these signals.

Can EEG show past seizure activity?

The likelihood of recording a seizure during a routine EEG is small. The EEG generally records brain waves between seizures, called interictal brain waves. These waves may or may not show evidence of seizure activity.

Can doctors perform a simple test to diagnose epilepsy?

Diagnosing epilepsy is not simple. Doctors gather lots of different information to assess the causes of seizures. If you have had two or more seizures that started in the brain you may be diagnosed with epilepsy. Getting a diagnosis is not always easy as there is no single test that can diagnose epilepsy.

Can you have an abnormal EEG without having epilepsy?

Furthermore, about 2% of normal school-age children who do not have seizures have epileptic activity on EEG. Conversely, a normal EEG does not exclude epilepsy. Many types of epilepsy may be associated with a normal EEG between seizures. A normal EEG during a “seizure” usually excludes epilepsy as the cause.

How many people have abnormal EEGS?

More than 10% of normal people may have non-specific EEG abnormalities and approximately 1% may have ‘epileptiform paroxysmal activity’ without seizures. The prevalence of these abnormalities is higher in children, with 24% having functional spike discharges.

What does no brain activity on EEG mean?

Medical professionals have long accepted that a flat line EEG indicates an irreversible coma, one of the most serious types of comas. Furthermore, a flat line EEG is often an indication that the brain is no longer alive.

Can an EEG miss a brain tumor?

EEG can also detect abnormal brain waves after a head injury, stroke, or brain tumor. Other conditions such as dizziness, headache, dementia, and sleeping problems may show abnormal brain patterns.

Is an EEG scan useful for detecting structures of function?

Electroencephalography (EEG) is used to show brain activity in certain psychological states, such as alertness or drowsiness. It is useful in the diagnosis of seizures and other medical problems that involve an overabundance or lack of activity in certain parts of the brain.

How are EEG signals generated?

The EEG is thought to be primarily generated by cortical pyramidal neurons in the cerebral cortex that are oriented perpendicularly to the brain’s surface.

What is a seizure called if it begins as a focal seizure then spreads to the whole brain?

A seizure that starts in one area of the brain, then spreads to both sides of the brain as a tonic-clonic seizure is called a focal to bilateral tonic-clonic seizure. This term replaces secondarily generalized seizure. They usually last 1 to 3 minutes, but it may take a longer for a person to recover.

What is theta activity in the brain?

Theta activity is a type of brain activity classified by the frequency range of 48 Hz. It is associated with the behavioral states of alertness, attention, orientation, and working memory including the enhancement of cognitive and perceptual performances (Aftanas and Golocheikine, 2001; Stern et al., 2001).

What do abnormal brain waves mean?

An abnormal EEG means that there is a problem in an area of brain activity. This can offer a clue in diagnosing various neurological conditions.

What does sharp brain waves mean?

Spikes or sharp waves are terms commonly seen in EEG reports. If these happen only once in a while or at certain times of day, they may not mean anything. If they happen frequently or are found in specific areas of the brain, it could mean there is potentially an area of seizure activity nearby.

What is mild diffuse encephalopathy?

Encephalopathy is a term that means brain disease, damage, or malfunction. Encephalopathy can present a very broad spectrum of symptoms that range from mild, such as some memory loss or subtle personality changes, to severe, such as dementia, seizures, coma, or death.

How does an EEG show encephalopathy?

EEG in Common Acute Encephalopathies

The EEG changes in the beginning commonly include slowing of the posterior dominant rhythm, followed by a gradual slowing of the background with the appearance of theta and delta activity.

What is severe diffuse encephalopathy?

In severe cases, dialysis or organ replacement surgery may be needed. Encephalopathy is a term for any diffuse disease of the brain that alters brain function or structure.

How does epilepsy affect daily life?

People with epilepsy often experience changes in their quality of life such as less mobility, as well as the impact on learning, school attendance, employment, relationships, and social interactions.

What foods to avoid with epilepsy?

If you have a sudden spike or crash in blood sugar, this could cause seizures. This is why it is generally best to avoid high sugar, processed foods such as cookies, cakes, candy and white bread. Ideally you should aim to follow a balanced diet which will release energy into your bloodstream at a slower, steadier rate.

What is the pathology of epilepsy?

THE PATHOLOGY OF SEIZURES. Seizures are caused by paroxysmal discharges from groups of neurons, which arise as a result of excessive excitation or loss of inhibition. The key unit of neurotransmission is the synapse, and the fundamental components of synapses are ion channels.

Can you be misdiagnosed with epilepsy?

Misdiagnosis of epilepsy remains common and the consequences for the individual significant. Poor history taking and overreliance on laboratory test are the main causes of misdiagnosis. Risks of a false positive diagnosis must be appraised against risks of a false positive diagnosis.

Can you have a seizure with no brain activity?

Some people experience symptoms similar to those of an epileptic seizure but without any unusual electrical activity in the brain. When this happens it is known as a non-epileptic seizure (NES). NES is most often caused by mental stress or a physical condition.

What percentage of epilepsy is genetic?

About 30 to 40 percent of epilepsy is caused by genetic predisposition. First-degree relatives of people with inherited epilepsy have a two- to four-fold increased risk for epilepsy.

What does a normal EEG rule out?

Your neurologist reads the EEG to look for clues in the brain’s activity that may help define the cause or type of seizure. A normal EEG does not rule out the possibility of epilepsy. In fact, since the EEG records only a 30-minute snapshot of the brain’s activity, many EEGs are normal.

What is a normal EEG reading?

Most waves of 8 Hz and higher frequencies are normal findings in the EEG of an awake adult. Waves with a frequency of 7 Hz or less often are classified as abnormal in awake adults, although they normally can be seen in children or in adults who are asleep.

Is encephalopathy swelling of the brain?

In encephalitis, the brain itself is swollen or inflamed. Encephalopathy, on the other hand, refers to the mental state that can happen because of several types of health problems. But encephalitis can cause encephalopathy.

Which of the following is a metabolic cause of seizure?

Metabolic seizures can be caused by various amino acids metabolic disorders, disorders of energy metabolism, cofactor-related metabolic diseases, purine and pyrimidine metabolic diseases, congenital disorders of glycosylation, and lysosomal and peroxisomal disorders.

What is the difference between simple and complex partial seizures?

Partial seizures are further divided into simple or complex. Simple partial seizures involve a small portion or a focal area of the brain. Complex partial seizures start in one area and travel to another.

What type of seizure originates on one side of the brain?

Partial seizures (also called focal seizures”) originate on one side of the brain. Symptoms vary greatly, depending on which part of the brain is affected. A few signs of a partial seizure can include: Feeling tingling in part of the body.

Can EEG diagnose epilepsy?

Your doctor may also suggest tests to detect brain abnormalities, such as: Electroencephalogram (EEG). This is the most common test used to diagnose epilepsy. In this test, electrodes are attached to your scalp with a paste-like substance or cap.

Can stress cause seizures without epilepsy?

Even in people without epilepsy, stress and anxiety can trigger PNES, which are also known as pseudoseizures. PNES are physiologically different from the neurological seizures found in epilepsy.

What does a neurologist do for epilepsy?

It is the neurologist who will generally diagnose epilepsy, and prescribe and start any treatment, such as medication. You might continue to see a neurologist while trying to get your seizures controlled, and you might also have ongoing regular reviews of your epilepsy with a neurologist.

Why does ketogenic diet help seizures?

The ketogenic diet has been used to reduce seizures since the 1920s. The mechanism by which the seizures are controlled are poorly understood. Both the low sugar component and high fat component uniquely alters the ‘excitability’ of the brain, thereby reducing the tendency to generate seizures.

What is the first aid for seizures?

Epileptic seizure first aid
  1. Stay calm and remain with the person.
  2. If they have food or fluid in their mouth, roll them onto their side immediately.
  3. Keep them safe and protect them from injury.
  4. Place something soft under their head and loosen any tight clothing.
  5. Reassure the person until they recover.

What precautions or lifestyle modifications are needed to help control epilepsy?

Lifestyle Changes to Manage Epilepsy
  • Follow a sleep routine. …
  • Do not drink alcohol. …
  • Always tell your doctors that you have epilepsy. …
  • Keep a seizure diary.
  • Go to all your appointments.
  • Talk to your doctor about a safe diet and exercise program.
  • Ask your doctor if it is safe for you to drive.

What happens in the brain during a seizure?

During a seizure, there is a sudden intense burst of electricity that disrupts how the brain usually works. This activity can happen on one small part of the brain and last for just a couple of seconds, or it can spread right across the brain and keep going for many minutes.

Does EEG show brain damage?

An EEG can determine changes in brain activity that might be useful in diagnosing brain disorders, especially epilepsy or another seizure disorder. An EEG might also be helpful for diagnosing or treating the following disorders: Brain tumor. Brain damage from head injury.

What is the purpose of an EEG?

The main use of an EEG is to detect and investigate epilepsy, a condition that causes repeated seizures. An EEG will help your doctor identify the type of epilepsy you have, what may be triggering your seizures and how best to treat you.

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