Epilepsy pathology

2021-02-05 12:00 AM

Single motor local epilepsy caused by damage to the frontal lobe (motor) jerking the focal part of the body, spreading from one part to another called the Jackson arm journey.

Outline

Definitions

Seizures are short, fixed, sudden onset, cyclical and recurrent attacks due to a sudden excessive discharge from the cortex or through the cortex of groups of neurons, causing dysfunction of the mediastinum nursing (movement, sensations, senses, plants, ...), EEG recorded the stimulus waves. Loss of consciousness is also common during or after an attack.

The above definition is also the diagnostic standard.

Epidemiology

Epilepsy is a common disease, accounting for about 0.5-2% of the population, with three quarters of cases occurring before the age of 20. The incidence of first seizures by age ranges from 18.9 to 190 / 100,000 people and men are both higher than women (male: female = 1.7: 1.2). The prevalence of active epilepsy in developed countries ranges from 3.7 to 8 per 1,000 population. According to Le Quang Cuong and Nguyen Van Huong (2002) in Vietnam, the study in Soc Son, Hanoi is 5 / 1,000 people. Epilepsy epidemiological studies in Rochester 1935-1979, at Bordeau and Luhdof 1986 for 5 years also showed that the highest frequency was before 20 and then lower and after 60 years old tended to increase. Seizures after 20 years of age are most likely caused by physical damage to the brain. The most common clinical form of epilepsy is major seizures accounting for about 81 to 86.1% and is found in developing countries higher than developed countries. Epilepsy without consciousness ranges from 0.8 to 11%. Local epilepsy from 3 to 72%. The types that are not classified are 1,2 to 20%.

Pathophysiology

There have been many studies, but up to now, only known electrophysiological phenomena, metabolic changes, ... occurring during and after an attack. What epilepsy is still a mystery? The pathological feature observed during epilepsy is a paroxysmal, intermittent, and repeated discharge of a population of neurons. Strong depolarization in the cell membrane (also called depolarization site movement), occurs in the neurons of the epilepsy drive, giving rise to an action potential.

During epilepsy, many brain metabolic reactions occur such as hyperkalaemia and extracellular calcium decrease, release of abnormal amounts of neurotransmitters and nerve peptides, increased blood flow at the site of injury, and increased local glucose absorption. The above metabolic phenomena are both consequences and cause increased stimulation of neurons that contribute to epilepsy drive and epilepsy spread.

There are many different mechanisms for causing experimental seizures on normal or pathological brain. Any increase in stimulation or decrease in inhibition excessively increases the excitability of the neuron leading to an orbital discharge. The method commonly used to induce experimental epilepsy in animals in recent years is based on inhibitory blocking mechanisms such as the use of the gamma-aminobutyric acid antagonist (GABA). GABA is an inhibitory neurotransmitter, so its antagonists cause seizures in humans and animals. It is thought that some generalized epilepsy is due to an abnormality of the GABA inhibitory system and it has also been demonstrated that many drugs such as phenobarbital, benzodiazepine, and valproic acid increase the inhibition of GABA, thereby having an effect. use against epilepsy.

By methods of chemical stimulation, physical can cause seizures. As in humans, an electric current of a certain intensity can easily cause seizures. This attack sustains itself in addition to initial stimulation. Sub-threshold stimuli do not cause epilepsy but if repeated, fixed in even spacing, reactions will accumulate and at some point, a similar stimulus can cause seizures. Spontaneous seizures can also occur without stimulation called a trigger.

In summary, neuronal enhancement is the result of the 
two-factor combination:          

Threshold of the epilepsy for which the genetic level has been determined.

Metabolic abnormalities, brain damage ... make the above threshold temporarily or permanently lower.

Epilepsy has the characteristic of repeating many attacks, and epilepsy can indicate a transient reaction due to transient disorders due to hypoglycaemia, fever ...

Classification of epilepsy

According to the classification of the World Health Organization 1981.

Clinically

A local attack:

Pure localized attack (motor, sensory, phytonutrients).

Complex localization.

Department of generalization.

Whole attack

Absence of consciousness (baby bouts).

Stiffness - muscle jerking (massive attack).

Muscle twitching.

Hypotonia.

Muscle spasms.

 Additional attack:

Persistent epilepsy.

Epilepsy state.

Pet not rated.

According to the cause

Epilepsy symptoms - localized entity damage to the brain.

Primary (idiopathic) epilepsy.

According to EEG

The type of localized dramatic discharge is local epilepsy.

The type of episode exhibits paroxysmal, symmetrical, bilateral diffuse discharges, which correspond to the generalized episode.

Reason

Idiopathic epilepsy

There may be genetic factors seen in 10-25%. Due to the genetic mutation of a single gene related to ion channels on the genes encoding (4 or (2 of the nicotinic receptors, acetylcholine, potassium channel dependent.

Epilepsy symptoms

There is acquired brain damage.

Traumatic brain injury

The first seizure usually occurs within 5 years of injury, very rare after 10 years (significant in medical assessment).                     

Classical trauma is more common, causing many types of seizures except for lack of consciousness and bilateral muscle twitching.

After cranial surgery.

Brain tumours

 Most of u are on the tent. In adults (20-50 years old) 75% of epilepsy is caused by tumours. Compared with other causes, epilepsy due to tumour accounts for 10%. Tumours often cause benign tumour epilepsy, less branched cell tumours, meningiomas, astrocytes. Rarely is it due to cancer or metastasis (from lung, breast cancer ...).

Vascular causes

Cerebrovascular accident: The attacks encountered in the hematoma (haemorrhage) are usually in the acute phase, while the cerebral infarction is in the scar-forming phase.

Aneurysms - veins: Usually detected by a seizure, after surgery, still 2/3 have seizures due to scarring.

Intracranial infection

Abscess brain (26%).

Encephalitis, meningitis in the most acute stage is in children.

Parasites

Swine fluke larvae, filariasis.

Other causes

Alcohol.

Electrolyte disorders: Lower K +, Ca ++, decrease or increase Na + blood.

Acute O2 deficiency, CO2 poisoning, heroin, tricyclic antidepressants, antimalarial drugs, INH, sleeping pills, Alzheimer's, Creutzfeldt - Jakob, blind spot tumours (old Bourneville fibrosis) sclerosis, due to Complex genetic modes involve the environment ...

Symptom learning

clinical

Local attack

Single motor local epilepsy (Bravais - Jackson attack) due to damage to the frontal lobe (motor) jerking the half of the body, spreading from one part to another called the Jackson arm-leg-face journey; tongue - face - hands; feet - face - hands. Loss of consciousness often occurs when it spreads to the face. The starting position is valuable for determining the lesion. After a potentially paralyzing attack called Todd paralysis, it should subside in a few hours.

Less common sensory attacks are sometimes accompanied by movement.

Plant epilepsy (intermediate brain epilepsy). With or without loss of consciousness, flushing of the face and neck, sweating sometimes halfway up, throbbing, slow or fast heartbeat, sudden hypotension, hiccups, yawning, fever, chills, stomach pain ...

Complex local attacks (temporal epilepsy, psychomotor attacks) include the following groups of symptoms:

Hallucinations: Unpleasant smells, unpleasant tastes, seeing scenes as far away as û (in dreams), unseen feelings, fear, anxiety, forced laughs ...

Automatic movements: Chewing, licking mouth, clicking tongue, swallowing continuously, doing movements such as driving, undressing, turning eyes slowly, shaping singing, wandering after an episode with dreamy state and has automatic movements so it is easy to endanger others by illegal acts, murder, rape, theft, ...

Generalization:

Local initiation is usually rapid movement into a major episode that is difficult to detect without careful inquiry or careful observation. At this time, it is necessary to rely on EEG (paroxysmal one-drive after totalization in all leads) or after a focal sign.

Whole attack

Major seizures: Headache, flatulence, moodiness, or coldness may occur for a few hours or a few days before an episode occurs. The forewarning symptoms (50%) of aura are usually sensory abnormalities, movement, upper extremity spasms, hallucinations, and psychosis but last only 1/10 second. There are really 3 phases:

The stage of spasticity: Suddenly falling down unsteady can cause injury, the limbs are stretched, fingers folded, the head is arched to one side, the jaw clenched can bite the tongue, the eyes are rolled back. purple because of inability to breathe due to immobilization of the chest muscle, urinary incontinence is rare than incontinence This phase lasts 10-20 seconds.

Stage of jerking: Body and limbs jerky consecutively, short, strong, rhythmic; eyes twitched sideways or jerked up. Can bite the tongue, foam in the mouth. This phase lasts 1-2 minutes, rarely more than 6 minutes.

Stretching phase: Coma, muscle relaxation, decreased tendon reflexes, possible Babinski, strong compensatory breathing, fast, noisy, snoring after a few minutes of regaining consciousness, not remembering what happened. This stage is usually 5-10 minutes.

This type of episode first appeared at the age of 10-20 (80% of cases), if there were few attacks, it responded well to treatment.

Baby motor seizures (absence of consciousness): Consists of many types but some common characteristics are common in children, short episodes from 1/10 to 10 seconds, many attacks a day. Often suddenly completely unconscious, motionless, falling dishes while eating, stopping work, ... Maybe not or lose energy, muscle stiffness ... it's a complicated absence. Common age 3-12 years old, progression has 3 abilities:

Out of attack.

Continue to maintain the attack of 6%.

Onset of spastic muscle spasms: 40% usually 6 years after the absence of consciousness. If the first absence of consciousness after 7 years of age often has poor response to treatment, is easily stimulated by light, is also often isolated from society, so the prognosis is bad.

Children's tachycardia (West syndrome): Rarely, seen in children 4-7 months old with 3 main signs:        

Cough and stiff neck, limbs, body.

Disturbance of character and behaviour.

EEG has high amplitude arrhythmias of the spikes.

This kind of prognosis is bad because dull.

Lennox Syndrome - Gastaut: Children from 2 to 6 years old with atypical triceps of consciousness, stiffness, loss of tone. Mental depression - movement. EEG is pointed - diffuse slow waves. The prognosis is bad.

Additional flare

Continuous epilepsy: One after another (many attacks), but between episodes, there is no consciousness disorder (absence of consciousness, big one, Kojewnicow ...).

Epilepsy state: Successive attacks between attacks of patients with consciousness disorder are often coma. Commonly encountered state of epilepsy from major epilepsy or partial seizure full movement.

Subclinical

EEG

Helps identify epilepsy, type of attack, location in epilepsy. However, normal EEGs cannot eliminate epilepsy. In contrast, 10-15% of normal people with EEG abnormalities never have seizures.

Gibbs and Lennox describe three typical types of attacks:

Small epilepsy: Round peak amplitude wave, frequency of 3 seconds, accompanied by sharp point called sharp-wave, simultaneously on all leads.

Large epilepsy: A few seconds before the episode, there appear scattered low-amplitude slow waves, then quickly turn into sharp, high-frequency, high-frequency spikes, spikes on all channels corresponding to the stage of muscle spasticity. After 10-30 seconds the spines form spikes - slow waves corresponding to the convulsive phase; Then the spikes frequency decreases and the number of slow waves is much higher initially, the slow-wave is 3 cycles seconds then 1 cycle second corresponding to the muscle phase.

Complex local epilepsy (temporal epilepsy, psychomotor - motor). Expressed by slow waves, square peak voltage, frequency 2 -4 second cycles. Interfering with fast waves with low amplitude (due to movement). This type of epilepsy is evident during sleep. Outside the attack, there are 2-phase, 3-phase sharp, wave (, (in the temporal region with high amplitude.

Sometimes it must be stimulated to express epilepsy on EEG by deep breathing, light stimulation, noise, natural sleep, ...

Other tests find the cause

Cranial imaging, brain angiography, blood glucose, electrolytes, cerebrospinal fluid, brain computed tomography, brain magnetic resonance ...

Diagnose

Implementing the quadrants

Clinical and electro encephalic basis.

Differential diagnosis 

The hysterias

 Usually occurs in front of people, the episode is prolonged, the eyelids are closed but blinking, not lethargic, the facial expression does not change, the tongue does not bite, the urination is not bruised, the jerking is not rhythmic. A normal neurological examination. A sudden, strong stimulus stopped the attack. After a memory of what happened. Normal brainpower. Possible hysterias - epilepsy.

Lower blood glucose

Abdominal hunger, irritability, sweating, convulsions, lethargy. Low blood glucose, rapid consciousness when injecting hypertonic intravenous glucose.

Lack of brain circulation

Temporary cerebral vascular stroke, sudden, difficulty speaking, sensory disturbance, half of body weakness, attack lasting longer than epilepsy, the patient is usually alert.

Fainting

Before the attack often dizziness, hypotension.

High fever convulsions in children

A seizure that is not epilepsy, but repeated in the body will suffer later epilepsy.

Developments

Varies depending on the type, cause, brain damage or effect on the brain. Epilepsy in children 8-10 years old progresses better in adults because, in adults, there is often physical damage to the brain, so the mental disorder sooner. There are 5 types of development:            

Increase the nature and intensity of attacks, so must count the number of attacks.

The attack from day to night is dangerous and severe because no one knows when there is an attack.

Clinical transformation: At first, when the attack is small when the attack is mature, it becomes more severe, localized into totalization. Or increase the rhythm of the attack into two types of continuous epilepsy or epilepsy state, leading to anaesthesia, cerebral oedema, neurological disorders.

Localized symptom onset immediately after an episode: Seeing localized signs is important for detecting localized generalized epilepsy. So right after the attack, a careful neurological examination is required to detect local damage.

There are mental changes, dementia.

Treatment

Real-life, living and labour regime

Do not use stimulants such as coffee, cigarettes, alcohol, and spices, not eat too much, especially in the evening. Some authors suggest that eating a lot of fat, low in carbohydrates and protein causes an increase in ketones, resulting in seizures. Wake up and sleep at the correct time depending on each person's occupation to avoid loss of nerve activity in 24 hours. Avoid jobs that may be dangerous to patients or others, such as working at high altitudes, underwater, near the fire, driving a car, avoiding long-term work in the sun because they lose water and electrolytes easily, and do not work in bright light. blurred or not to watch TV and play video games for long because these are the stimuli that can trigger attacks.

Drug treatment

Principles of using antiepileptic drugs

Must choose antiepileptic drugs and monitor response to treatment, starting low dose then high dose (reliever dose), but when the toxic dose without relapse or spike, the drug must be changed in case of emergency. For children with high fever with seizures, give it to drink for 2 months to erase the reflex to avoid recurrence that can cause seizures in the future. In adults after-treatment of the aetiology, treatment for an additional 2 years after the last attack and EEG monitoring; and the cause that cannot be resolved such as (scarring) is a lifelong treatment.

The amount of the drug is divided several times a day to get a full 24-hour concentration (but also depends on the form of the drug). Now there are drugs with long-acting effects.

Do not stop abruptly, when changing drugs, gradually reduce old drugs, gradually increase new ones.

Prevent drug-induced complications.

Only one drug should be used, except for an attack of a combination of many types, so it is easy to cause toxicity and to watch out for adverse drug interactions.

If only an attack is detected on EEG without a clinical episode, treatment is not needed.

When giving the drug to follow the first 10 days to see drug tolerance to continue or cut, follow up for a month to evaluate results.

When to stop antiepileptic drugs. If there is no attack in 2-3 years, the dose should be reduced by 25% every 3-6 months until the remaining 25% before stopping the drug. If there is no clinical episode but an abnormal EEG can also stop the drug.

The drug is easy to find and suitable for the patient's family economic situation.

Antiepileptic drugs

Table: Dosage (mg / kg / day or mg / day) and effects

 Species

 Brand name drug

NL

TO

Big attack

Local

Baby

Temples

Valproate de sodium

Depakine

20

25-30

+

+

+

+

Barbituric

Gardenal

2-3

3-4

+

+

-

-

Carbamazepine

Tegretol

10

20

+

+

-

+ +

Vigabatrin

Sabril

40-

80

40-100

+

+

-

+

Clonazepam

Rivotril

0,1

0,2

+  

+

+

+

Ethosuximide

Zarontin

20

40

-

-

+

-

Trimethadione

Tridione

20-

40

20-60

-

-

+

-

Methisuximid

Celontin

10-

20

10-20

-

-

+

-

Lamotrigine

Lamictal

200-

500

mg

 

+

+

+

Notes: + Lennox Gastaut

Gabapentin

Neurontin

900-

3600

mg

 

-

+

-

-

Oxcarbazepine

Trileptal

600-

1200

mg

 

+

+

-

++

Topiramate

Epitomax,

Topamax

200-

250

mg

3-6

+

+

±

Notes: + West, Lennox Gastaut

Levetiracetam

Keppra

1000-

3000

mg

 

+

+

+

+

Tiagabine

Gabitril

15-

50

mg

 

-

+

-

-

Zonisamid

Zonegran

400-

600

mg

 

+

+

-

-

Treatment of epilepsy

General management as in coma: Respiratory resuscitation, cardiovascular resuscitation, nurturing, anti-ulcer, anti-multiple ...

Choice of drugs is Rivotril 1-2mg or Valium 10mg intravenous slowly, after 1 hour can be repeated again and then give 50mg Valium or 4-5mg Rivotril in 5% glucose solution by IV X-XV drops / min.. Combined with phenobarbital 200 mg intramuscularly, this regimen is that of P. Augustin that is simple but has yielded high results.           

If not, you can use thiopental by intravenous injection of 25-100mg of initial dose and then mix 1g in 500ml 5% glucose x 2 times a day. In addition to anti-epileptic effects, it also has anti-oedema effects.

Supportive treatment of epileptic factors: Anti-oedema, antipyretic, infection control, metabolic disorders, electrolytes, ... In addition, it is necessary to actively find the cause for timely intervention.

Table: Managing epilepsy over time

Time (minutes)

Treatment attitude

0-10

Guaranteed vital functions:

- Clear airway by lying on the side, head low and back, do not put anything in the patient's mouth.

O2 ventilation (mask / nasal inhalation / artificial ventilation)

-Set an intravenous line, and take blood for testing (Glucose, electrolyte, blood gas, antiepileptic drug concentration, CTM, liver and kidney function ...). If hypoglycaemia infusion dextrose 50% + vitaminB1 2mg / kg.

- Monitoring electrocardiogram by monitoring, measuring BP, temperature, examination, if it is PD measurement.

0- 20

-Diazepam (0.3-0.5mg / kg) / clonazepam (0.03-0.05mg / kg) / lorazepam (0.1mg / kg at rate of 1-2 mg / min).

20-40

-If there are convulsions after injection of 1 of the 3 drugs above, then phenytoin 20 mg/kg intravenous (IV) 50 mg/min over 30 minutes and monitor the heart by monitoring. With arrhythmia or hypotension, do not use or stop the drug.

40-50

-If convulsions persist 10-20 minutes after phenytoin injection, add phenytoin at a dose of 10 mg/kg.

50-70

-If convulsions persist after adding phenytoin, then intubate and intravenous phenobarbital 10-20 mg/kg at a rate of 50-100mg min when not used at 0-20 minutes.

-Review test results to correct abnormalities.

70-90

- For untreated autism, pentobarbital first dose intravenously 5-10 mg / kg then maintain 0.05mg / kg / hour or propofol 1-2mg / kg initially, then 3-10mg / kg / hour or midazolam 0.15-0.20mg / kg, then maintain 0.06-1.1mg / kg / hour.

Surgical treatment

Local epilepsy does not have widespread damage.

Complete local epilepsy.                      

Vascular malformations in superficial, brain tumour.

Treatment attitude

New epilepsy (first time)

Take the medication.

General seizure: Large seizures, muscle twitching, and or baby seizures should be used with shipbreaking after liver damage has been ruled out. A generalized seizure may choose phenobarbital or thongakine.

Local epilepsy: Tégrétol.

West Syndrome: Sandalsakine or Rivotril or uranyl in combination with corticoids or ACTH.

Old epilepsy (treated)

Must check for triggers such as drinking alcohol, insomnia, taking drugs as directed or stopping the drug suddenly or not (it is best to measure the concentration of antiepileptic drugs in the blood to promptly adjust the dose. ), physical examination, blood glucose test, blood ionization, EEG, brain scan if necessary to treat the cause or replace other drugs. If psychological is affected, psychotherapy should be performed.