What is Focal Impaired Awareness Seizure?
In 2017, the International League Against Epilepsy classified seizures based on three main features: where the seizure starts in the brain, the individual’s awareness level during the seizure, and other characteristics of the seizure. When talking about seizures that start in one part of the brain and cause consciousness issues, the terminology “focal impaired awareness seizure” is used. If a person’s awareness becomes affected during seizures that originate on one side of the brain, these are also called focal impaired awareness seizures. Another way to categorize these seizures is by whether they affect the motor (movement) skills or cause non-motor symptoms like changes in bodily functions, emotions, or behavior.
Seizures that start in one brain region and then spread globally were previously known as secondary generalized seizures, but they’re now described as “focal to bilateral seizures”. The focal impaired awareness seizure can come with or without an early sign of an impending seizure, known as an aura. Notably, the consciousness is maximally impaired initially, with the majority of seizures with repeated movements lasting from 30 seconds to 2 minutes, and sometimes extending up to 10 minutes.
Seizures that originate in the temporal lobe, a region at the sides of the brain, are the most common type, frequently occurring with repeated, almost automatic movements. These seizures can display features similar to frontal seizures, but they typically have a slower onset and progression with more pronounced confusion. Symptoms can vary depending on whether the seizure starts in the dominant (usually left side of the brain, responsible for speech and language in right-handed individuals) or the non-dominant hemisphere. It’s not unusual for very young infants to experience breathing problems during these seizures.
When seizures begin from the frontal lobe, located at the front of the brain, they often happen in clusters multiple times a day, primarily during sleep, and last about 30 seconds with little confusion afterward. With these seizures, motor symptoms, vocalizations, and odd behaviors are common.
Seizures that arise from the parietal lobe, positioned at the top of the brain, are trickier to diagnose due to their subjective nature. Sensory and body orientation symptoms suggest a parietal lobe origin. Seizures originating from the occipital lobe, located at the back of the brain, usually start with a visual aura and are especially hard to diagnose in young children. Lastly, seizures originating from the insular lobe, deep within the brain, can have symptoms that resemble seizures from frontal, temporal, and parietal lobes, like nausea, vomiting, abnormal movements, numbness, tightness, and vertigo.
What Causes Focal Impaired Awareness Seizure?
Over half of the people with epilepsy, we can’t pinpoint the exact reasons behind the condition. However, we do know that there are several potential causes for seizures that lead to epilepsy, including:
* Infections: Epilepsy can be caused by different infections like tuberculosis, neurocysticercosis (a parasitic infection), cerebral toxoplasmosis (a rare brain infection), HIV, cerebral malaria, and bacterial and viral infections that cause inflammation in the brain and spinal cord. These infections remain the most common cause of epilepsy worldwide.
* Structural problems in the brain: Any abnormality in the brain, such as stroke, trauma, infections, tumors, hippocampal sclerosis (scarring of the brain’s temporal lobe due to prolonged, untreated seizures), vascular malformations (abnormally formed blood vessels), or changes after surgery, can increase the risk of seizures and epilepsy.
* Metabolic disorders: There are certain inherited disorders that can cause seizures, such as GLUT-1 deficiency and cerebral folate deficiency. Some conditions like imbalance in body salts (sodium, calcium) or low blood sugar can also cause seizures.
* Genetic/chromosomal abnormalities: Certain chromosomal disorders like AKT3, Fragile X syndrome and genetic conditions like Down syndrome, Klinefelter syndrome, Angelman syndrome can lead to epilepsy.
In addition to these, traumatic brain injury and lack of oxygen supply to the brain can also cause seizures.
In children, birth defects are the most common cause of seizures, while head injuries are often the trigger for young adults. Brain injuries, tumors, and issues with blood vessels are common causes for adults between 35 to 64 years old. Stroke and degenerative disorders become more common in people aged 65 or older.
Certain factors or day-to-day situations can also trigger seizures. These can include tiredness and lack of sleep, stress, alcohol, fever, ongoing illness, hormonal changes, drug abuse, certain medications, bright or flashing lights, and non-adherence to medication.
Risk Factors and Frequency for Focal Impaired Awareness Seizure
Focal impaired awareness seizures are the most common type of seizure experienced by people with epilepsy, especially after the first year of life. Nearly 36% of people with epilepsy experience these focussed, unaware-type seizures. While people of any age can have these seizures, they are more common in children and older adults. This type of seizure does not favor any particular gender or racial group.
- Focal impaired awareness seizures are very common among those with epilepsy, especially after the first year of life.
- About 36% of people with epilepsy experience these specific types of seizures.
- People of all ages can have them, but are frequent among children and older adults.
- These seizures affect all genders and races equally.
Signs and Symptoms of Focal Impaired Awareness Seizure
Seizures are a condition that can be tricky to diagnose. It’s important to be sure that what’s happening is truly a seizure. The diagnosis of a particular type of seizure, called focal impaired awareness seizure, relies a lot on a person’s health history and their description of the seizure. The details of the seizure— how it started, whether there was any loss of consciousness, any body movements, tongue biting, incontinence, staring, automatic movements, eye movements, confusion after the seizure, how long the seizure lasted—are all crucial data points.
A thorough neurological examination can assist the diagnosis of seizures, even when the signs are subtle. Any specific abnormalities identified in this way can help pinpoint the location of the seizure source in the brain.
- Dystonic limb posturing: A clear indication of one-sided dystonic positioning is a strong clue of seizure onset in the temporal lobe, opposite to the affected limb.
- Head version: Forced lateral turning of the head could suggest the seizure starting on the side opposite to the head turning.
- Automatisms: These are automatic behaviors that occur during a seizure, and depending on what they are, can suggest where in the brain the seizure is occurring. Specific automatisms can help to localize to the temporal or frontal lobes, non-dominant hemisphere or the occipital regions. Some include lip-smacking, chewing, cycling movements of the leg, and even crying.
- Postictal nose-wiping: Wiping one’s nose after a seizure, which occurs in about 50% to 85% of people with temporal lobe epilepsy, can provide clues about the location of the seizure in the brain.
Remember, while these signs and symptoms can give clues to where a seizure might be coming from, they are not diagnostic by themselves and should be evaluated in conjunction with other clinical information.
Testing for Focal Impaired Awareness Seizure
If your doctor suspects you’re having focal seizures, which are seizures that start in one area of the brain, they might perform a variety of tests to confirm this. Because the signs and symptoms can sometimes be unclear, they’ll need to rule out other conditions and pinpoint the exact location of the seizures within your brain. They might use the following methods:
- To cross out factors like metabolic issues and infections, they could ask for routine tests. These may include a metabolic profile, complete blood count, urine analysis, and a drug screening test.
- An Electroencephalography (EEG), a procedure that records the electrical activity of your brain, is an excellent way to understand seizures better. Some people might need an EEG that includes video recording or one that runs for a longer time.
- An imaging scan of your brain can help spot any physical causes, like a growth or injury.
Furthermore, your doctor would check your EEG results between seizures (interictal) and during a seizure (ictal), assessing for usually recorded patterns related to focal seizures. Still, it’s important to remember that EEG results can sometimes appear normal even when seizures are occurring.
Your doctor can also use imaging techniques to get a clearer picture of what’s going on inside your brain. Magnetic Resonance Imaging (MRI), which lets your doctor see structures in your brain, is usually very helpful in pinpointing the area responsible for seizures. High-resolution MRIs can improve the chances of spotting any abnormalities. Some of the things your doctor might look for include signs of shrinking in part of the brain (hippocampal atrophy), indications of a head injury, brain tumors, vascular issues, and certain parasitic infections. If necessary, your doctor may also use additional imaging techniques like positron emission tomography or single photon emission computed tomography scans. These are particularly useful for people who have seizures that can’t be controlled.
In all cases, these results must be analysed in the context of your symptoms and medical history.
Treatment Options for Focal Impaired Awareness Seizure
The aim of treating seizures is to stop the seizure activity with minimal side effects. The main form of treatment is anti-seizure medications. Sometimes, other methods are required for seizures that don’t respond to medications.
Medications
There are numerous anti-seizure medications available, except ethosuximide, that could be chosen for focal impaired awareness seizures. This particular type of seizure is when the person is not aware of their surroundings or what they are doing. The ultimate choice of medication is based on the patient’s needs and preferences, any other health conditions they may have, potential interactions with other drugs, and potential side effects. Usually, treatment starts with one medicine. The dose of this single medication may be increased to control the seizure before adding another medication. Many patients, however, will need more than one medication to control their seizures.
Taking more than one anti-seizure medication can cause problems due to potential interactions between the drugs. Medical professionals have to watch these patients carefully and adjust dosages as needed. If two or more anti-seizure drugs are not able to control the seizures, the seizures are considered difficult to treat or “refractory”. Only about half of the patients with focal impaired awareness seizures manage to fully control their epilepsy with medications.
Ketogenic Diet
The ketogenic diet, which is a high-fat, low-carb, and controlled protein diet, may be considered for children with hard-to-treat seizures when at least two anti-seizure medications have been ineffective.
Surgery
Surgery may be an option for focal impaired awareness seizures that are refractory. Surgery is considered when the seizures can be linked to one specific and isolated area in the brain. An ideal candidate for surgery would be a patient whose seizures haven’t responded to two or three anti-seizure medications, the seizures appear to start from the inner part of the temporal lobe (a condition known as mesial temporal onset), and brain imaging shows mesial temporal sclerosis, a scarring condition of the brain often associated with seizures.
Vagus Nerve Stimulation
For those who have refractory seizures and are not suitable for surgery, an alternative could be the implantation of a vagal nerve stimulation device. This device sends mild pulses of electrical energy to the brain via the vagus nerve, a large nerve in the neck, and has been shown to reduce seizures by 35% to 45%. Anti-seizure drugs will still be used in combination with this therapy, but if the vagal nerve stimulation therapy is successful, it may be possible to gradually decrease the medication.
What else can Focal Impaired Awareness Seizure be?
There are several conditions that might show similar initial symptoms as “focal impaired awareness seizures.” These include:
- Absence seizures
- Benign childhood epilepsy
- Benign neonatal convulsions
- Complicated migraine
- Juvenile myoclonic epilepsy
- Parasomnias (abnormal behaviors during sleep)
- Paroxysmal movement disorders (sudden, brief episodes of movement disorders)
- Psychogenic non-epileptic seizures (physical symptoms caused by stress or emotional issues)
- Vasovagal syncope (sudden fainting caused by a drop in heart rate and blood pressure)
What to expect with Focal Impaired Awareness Seizure
People with a type of seizures called ‘focal seizures’ are more likely to experience seizures again compared to those with ‘generalized seizures’. Focal seizures are the ones that affect only a part of the brain, while generalized seizures affect both sides of the brain. The chances of recurrence for both simple focal seizures (where you remain aware) and complex focal seizures (where your awareness is affected) seem to be similar.
Losing consciousness during a seizure can lead to injuries, choking, burns, and accidents. Additionally, the anxiety associated with having seizures, restrictions on work, and driving can substantially affect the quality of life.
People with epilepsy tend to have a 2 to 3 times higher risk of death as compared to the general population. Most of these deaths are due to the underlying cause of epilepsy and accidents. An unexpected and sudden death while having epilepsy, known as sudden unexpected death in epilepsy, tends to be more common in individuals who have seizures that cannot be controlled by medication.
Possible Complications When Diagnosed with Focal Impaired Awareness Seizure
Focal impaired awareness seizures, if not treated, can cause serious health issues and even be fatal. These seizures can progress to a severe state known as focal status epilepticus, which is hard to control. Immediate problems that can follow focal status epilepticus include coma, brain damage, irregular heart rhythms, respiratory failure, choking on food or liquid, and death.
Not only immediate but also long-term problems can occur with focal impaired awareness seizures, such as difficulties with thinking, depression, anxiety, head injury, and an early death. It is very important to screen these conditions in patients who have a history of seizures that start in one area of the brain.
Possible Immediate and Long-Term Problems:
- Coma
- Brain damage
- Irregular heart rhythms
- Respiratory failure
- Choking on food or liquid
- Death
- Difficulties with thinking
- Depression
- Anxiety
- Head injury
- Early death
Preventing Focal Impaired Awareness Seizure
If you or a loved one is dealing with impaired awareness seizures, it’s important to know how to lessen the risks associated with these seizures. You will want to be extra cautious when doing things like driving, working at heights, using heavy equipment or power tools, and cooking. It’s also best to avoid swimming or taking baths alone.
In terms of driving, the rules can change depending on where you live. It’s crucial that you and your healthcare professional regularly talk about these driving restrictions to ensure your safety on the road.
By taking these precautions, you can avoid potential harm and make your situation more manageable. Remember, never hesitate to ask your healthcare provider about any questions or concerns you may have.