What kind of illness is epilepsy?

 It is a brain disease that causes repeated seizures, regardless of age, gender, or race. At the World Health Organization (WHO), epilepsy is a "chronic disorder of the brain" characterized by repeated seizures caused by sudden, intense electrical excitement in nerve cells (neurons) in the brain, with various clinical symptoms and tests. It is defined as an illness with abnormalities.

About 10% of the population will have one seizure throughout their lives, about 4% will have more than one seizure, of which about 1% will be diagnosed with "epilepsy", and about 1 million epilepsy patients in Japan. Exists.

Epileptic seizures vary depending on where the electrical excitement of the cerebrum occurs, but the symptoms of the seizures are almost constant for each patient and are characterized by repeated seizures. In addition, since the electric current in the brain is disturbed during an attack, abnormal waves (spike waves / kokuha) appear when the brain waves are measured, and it is used for the diagnosis of epilepsy.

It is widely seen from infancy to old age, and affects 0.5 to 1 (0.5 to 1%) of 100 people. The age of onset is most often 3 years or younger, and it decreases in adults, but in the elderly over 60 years old, the onset of diseases caused by cerebrovascular accidents increases. Some patients with childhood epilepsy may be cured before they reach adulthood, but most often continue treatment.

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Incidence rate of epilepsy by age group Incidence rate of epilepsy by age group

Source: Anderson VE, Hauser WA, Rich SS. Adv Neurol 44: 59.1986

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What Causes Epilepsy?

There are various causes, but they can be divided into "idiopathic epilepsy" and "symptomatic epilepsy".

Idiopathic epilepsy

Epilepsy of unknown cause with no abnormalities found by inspection.

Epilepsy is not thought to be inherited, but it has been pointed out that some people may inherit a "prone to seizures."

Symptomatic epilepsy

Epilepsy caused by some kind of brain damage or damage to a part of the brain.

It occurs when the brain is injured due to birth problems, hypoxia, encephalitis, meningitis, cerebral hemorrhage, cerebral infarction, brain trauma, Alzheimer's disease, etc.

1) Epilepsy is a disorder of brain function

Nerves are stretched around the human body, and various information is transmitted by passing weak electrical signals through the nerves. Nerve cells gather in the brain and process various information. For example, information from the eyes, ears, skin, and tongue is transmitted to the brain through nerves, which makes us feel "clean," "hot," and "sweet." On the contrary, it also moves the body by transmitting commands from the brain, such as "speaking" and "running". In addition, the brain controls unconscious heart movements, respiratory regulation, and mental activities and memories such as emotions, emotions, and reason.

When the electrical signals in the brain that have such a function are generated excessively all at once for some reason, the function of the brain in that part is disturbed, the brain cannot receive information properly or give commands, and the body's body You will lose control of your movement.

Nerve cell

Electricity generated by nerve cells

2) Relationship between the site where the seizure occurs and the symptoms

The cerebrum is largely divided into a right hemisphere and a left hemisphere with a central groove as a boundary. The right hemisphere regulates the nerves of the left half of the body, the left hemisphere regulates the nerves of the right half of the body, and the brain is responsible for each part, so the symptoms of seizures may occur depending on the part where the electrical signal is disturbed or excited. It will change.

Patients with epilepsy have the same symptoms with each seizure because the site of the seizure is fixed. For example, excessive electrical excitement in the nerve area that moves the hand causes hand spasms.

Cerebrum

3) Mechanism of seizures

The nerves of the brain have a good balance of excitement and suppression. When the excitement becomes too strong, the nerves of the inhibitory system work to suppress the excitement, and so on.

However, when a seizure occurs, the nerves of the excitatory system work strongly and the nerves of the inhibitory system weaken, causing severe electrical disturbance (overexcitation) in the brain.

How seizures occur

4) Functions of each part of the cerebrum

The human brain is composed of the cerebrum, cerebellum, diencephalon, and brain stem. Among them, the cerebrum controls complex human-like behaviors, which are mainly divided into four parts: frontal lobe, parietal lobe, occipital lobe, and temporal lobe, and their functions differ depending on each part.

Frontal lobe

It issues commands to move each part of the body, such as limbs.

It controls advanced information processing such as thinking, reasoning, reason, learning, and selection.

Parietal lobe

Analyzes sensory information coming from the skin and ears.

Recognize space.

Occipital lobe

It recognizes information that comes from the eyes, such as the shape of a person's face or an object.

Temporal lobe

It is related to the information and emotions of sounds and words coming from the ears.

Inside the temporal lobe is the hippocampus, an area involved in memory, which is often the starting point for epileptic seizures.

Head division (normal interruption image)

Lateral surface of the cerebral hemisphere

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Types of epilepsy attacks

"Epilepsy" and "seizure" are different, and medically they are used properly.

Epilepsy

A disease with the symptoms of an epileptic seizure. It is also called "Seizure Syndrome".

Epilepsy seizures

Seizures that occur in epilepsy patients.

Classification of epilepsy attacks

Epileptic seizures are divided into "partial epilepsy (focal epilepsy)" and "general epilepsy" depending on the site where excessive electrical excitement occurs and how the electrical excitement spreads. , Is subdivided by seizure symmetry.

 Can be expanded

Classification of epilepsy

1) Partial epilepsy

A seizure in which excessive electrical excitement is confined to a part of the brain. It can be divided into "simple focal epilepsy" and "complex focal epilepsy" depending on the presence or absence of impaired consciousness. Some partial seizures spread from a limited area to the entire cerebrum, and some have partial seizures followed by generalized seizures, which are called "secondary generalized seizures."

Simple focal epilepsy

Disturbance of consciousness: None

Because the patient is conscious, he remembers all the symptoms from the beginning to the end of the attack.

Symptoms:

・ Impairment of motor function

(Tightening, twisting, jerking, jerking, pulling the whole body to one side, rotating, etc.)

・ Abnormalities in vision and hearing

(You can see shining spots and light, it is shiny, the sound echoes, it is hard to hear, you can hear the sound easily, etc.)

・ Autonomic nervous system abnormalities

(Headache, nausea, etc.)

Complex partial epilepsy

Disturbance of consciousness: Yes

Consciousness gradually shifts away, and there are consciousness disorders and memory disorders that make it difficult to understand the surrounding situation.

However, it is unlikely that you will collapse during impaired consciousness.

Symptoms:

・ Impairment attack

(Suddenly stop the movement, make your face dull, etc.)

・ Automatic disease

(Repeating meaningless movements such as walking around, clapping hands, and mogging the mouth, etc.)

Secondary generalized seizures

It begins with the symptoms of simple or complex focal epilepsy, generalizes to secondary and progresses to tonic-clonic seizures. Signs may be seen before the seizure begins. Although it may be difficult to distinguish from tonic-clonic seizures based on seizure symptoms alone, it can be diagnosed by measuring brain waves.

Secondary generalized seizures Secondary generalized seizures

2) Generalized seizures

A seizure that causes excessive excitement over a wide area on both sides of the cerebrum. At the time of the attack, most patients are unconscious.

Tonic-clonic seizures

It develops suddenly and causes tonic and clonic seizures.

After an attack, it may shift to sleep for about 30 minutes to 1 hour (end-of-life sleep), and then return to normal.

Immediately after a seizure, you will be conscious, so you need to be more careful about accidents in a frustrated state than the seizure itself, such as hitting an object or touching a hot object and getting burned.

Ankylosis seizures

Suddenly you lose consciousness, clench your mouth tightly, stop breathing, stretch your limbs and stiffen your whole body, lasting for a few seconds to a few tens of seconds. You may be injured if you fall down violently while being stiff.

Clonus seizures

Convulsions occur in which the knees are bent and the limbs are bent and stretched at a constant rhythm. It usually takes tens of seconds, but sometimes it lasts more than a minute.

Absence seizures

It is a seizure that causes you to lose consciousness for several tens of seconds.

It does not cramp or fall.

When I'm talking or doing something, I suddenly lose consciousness and suddenly stop talking or stop working.

People around you often do not realize that you have an epileptic seizure because you may be alert or unable to concentrate. Symptoms often appear during school age and before school, and are common seizures in girls.

Symptoms:

・ Suddenly you lose consciousness and have a vague look

・ The eyeball turns up

・ Eyelids are tingling (frequency of about 3 times per second)

・ Stop operation

・ Does not respond to calls

Atonic seizure

It is a seizure that causes the muscles of the whole body to collapse and collapse because the tension decreases and disappears. Seizures last only a few seconds and are often hard to notice.

Myoclonic seizures

It is a seizure in which some muscles, such as the whole body or limbs, contract for a moment.

It is a seizure that is rarely noticed because it is a momentary symptom, but it may occur several times in a row, and it may be so strong that it falls or throws away what it has.

It can be triggered by light and is more likely to wake up or fall asleep.

3) Status epilepticus

Seizures can be life-threatening, with seizures lasting longer than a certain length or repeated short seizures that can be unconscious during that time. In the past, it was said that the seizure lasted for 30 minutes or more, but recently, if the seizure lasts for 5 to 10 minutes or more, it is judged to be in status epilepticus and treatment is started. ..

Classification of epilepsy

Epilepsy can be broadly divided into "partial epilepsy" and "general epilepsy." Furthermore, it is divided into "idiopathic" and "symptomatic" depending on the cause of the seizure. Also, it may not be possible to clearly classify. Accurate diagnosis of epilepsy is very important as it has important implications for treatment and future course prospects.

 Can be expanded

Diagnosis of epilepsy

1) Epilepsy classification can be difficult

If it cannot be clearly classified, such as a newborn attack, it may be treated as "unclassifiable".

The seizure and symptom classifications listed are representative and do not always apply clearly.

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Differences from seizures

"Convulsions" are paroxysmal motor symptoms in which muscles contract strongly regardless of one's will. In addition to epilepsy, convulsions can be caused by high fever, infections, electrolyte imbalances, drugs, intracranial lesions (tumors, trauma, hypoxic encephalopathy, etc.), and irritation of the spinal cord and peripheral nerves. Treatments for seizures and seizures caused by these diseases are different.

Febrile seizures cause seizures, but be aware that epilepsy can also be triggered by fever and can be difficult to determine.

Typical convulsions

Febrile seizures Caused when a child has a high fever

Blepharospasm,

Simple muscle cramps Repeat blinking, eyelids move jerks

Hemifacial spasm on one side The eyes, mouth, and cheeks move jerks

Tic The various muscles of the face sometimes snap

Flapping tremor Moves limbs to flap

Major complications

Complications specific to epilepsy patients can be divided into three main types depending on the cause.

1) Brain damage

Motor disorders, intellectual disabilities, and speech disorders may occur depending on the part of the brain that has a disorder, such as a stroke or intracerebral hemorrhage. In particular, intellectual disability is often found in symptomatic generalized epilepsy. On the other hand, idiopathic epilepsy generally has no intellectual disability.

2) Psychiatric symptoms

Mental symptoms may appear as symptoms of a seizure, such as becoming angry before the seizure occurs. Psychiatric symptoms are complexIt is more common during partial seizures and may also cause anxiety and excitement after the seizure.

Epilepsy-related psychiatric symptoms

Disorders of consciousness Change consciousness (change of consciousness), try to get sick, consciousness becomes cloudy

Emotional disorder becomes moody, angry

Personality change Becomes tedious (circumstantial, humorous), persistent (adhesive)

Psychotic state Becomes delusional with hallucinations

Behavioral disorders Repeated meaningless movements (automatism), abnormal behavior, violence, crime

3) Mental anxiety (secondary symptoms)

Patients with epilepsy have psychological burdens or problems in their social life, and mental problems such as depression due to anxiety, despair, reluctance, isolation, crawling, sensitivity, defense, unhappiness, etc. based on them. May cause, and needs the help of others.

Anxious man

Personality characteristics of epilepsy patients

Although not directly related to seizures, the most common personality traits of epilepsy patients include high stickiness, easy sticking to things, and a roundabout way of speaking. This is thought to be the result of repeated seizures affecting the brain, but recently treatment has been started from an early stage, so this effect on personality has hardly been seen.