Generalized seizures

Introduction to comprehensive seizures The initial clinical manifestations of generalized seizure suggest bilateral hemisphere involvement, in a variety of forms, which may be convulsive or non-convulsive, with multiple disturbances of consciousness; myoclonic seizures have a short duration and may be unconscious; movement symptoms are often Side, but not necessarily systemic, or no motor symptoms, EEG discharge can be seen in the bilateral hemispheres. The clinical manifestations of all kinds of comprehensive seizures are quite characteristic, and the EEG is specific and has a large difference. For example, regardless of the difference in clinical manifestations of seizures, the changes in basic EEG are all spine-slow wave discharges; Tension episodes Although there are many manifestations of EEG in the attack period, they all have certain specificities. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: non-infectious Complications: epilepsy

Comprehensive seizure cause

(1) Causes of the disease

The causes of epilepsy are extremely complex and can be divided into four main categories:

1. Idiopathic epilepsy and epilepsy syndrome: suspicious genetic tendency, no other obvious cause, often in a certain age group, with characteristic clinical and EEG performance, the diagnostic criteria are clear, not clinical I can't find the cause is idiopathic epilepsy.

2. Symptomatic epilepsy and epilepsy syndrome: is a clear or possible central nervous system lesion affecting structure or function, such as chromosomal abnormalities, focal or diffuse brain diseases, and certain systemic Due to the disease, the advancement and wide application of neuroimaging techniques in recent years, especially the development of epilepsy functional neurosurgery, have been able to detect neurobiochemical changes in patients with symptomatic epilepsy and epilepsy syndrome.

(1) localized or diffuse brain disease: the incidence of neonatal epilepsy is about 1%, such as birth injury, combined with birth injury and cerebral hemorrhage or cerebral hypoxia damage, neonatal cerebral congenital malformation or production Injury, the incidence of epilepsy is as high as 25%.

(2) Systemic diseases: such as sudden cardiac arrest, CO poisoning, asphyxia, N2O anesthesia, anesthesia accidents and respiratory failure can cause hypoxic encephalopathy, leading to myoclonic seizures or systemic episodes; metabolic encephalopathy such as Hypoglycemia most often leads to epilepsy, other metabolic and endocrine disorders such as hyperglycemia, hypocalcemia, hyponatremia, and uremia, dialysis encephalopathy, hepatic encephalopathy and thyroid toxemia can lead to epilepsy attack.

3. cryptogenic epilepsy: more common, clinical manifestations suggest symptomatic epilepsy, but did not find a clear cause, can start at a particular age, no specific clinical and EEG performance.

4. situation related epileptic attack: seizures are associated with special conditions, such as high fever, hypoxia, endocrine changes, electrolyte imbalance, drug overdose, long-term drinking withdrawal, sleep deprivation and excessive drinking, etc. It can occur that although the nature of the seizure is epileptic seizure, the removal of the relevant state no longer occurs, so no epilepsy is diagnosed.

(two) pathogenesis

1. Genetic factors: single gene or polygene inheritance can cause epileptic seizures. More than 150 rare gene defect syndromes are known to present epileptic seizures or myoclonic seizures, of which 25 are autosomal dominant genetic diseases, such as Nodular sclerosis, neurofibromatosis, etc., about 100 autosomal recessive diseases, such as familial black montmorillonosis, spheroid leukoencephalic malnutrition, and more than 20 sex chromosome genetic defects syndrome .

2. Normal people can induce seizures due to electrical stimulation or chemical stimulation: normal brains have an anatomical and physiological basis for seizures, and are susceptible to various stimuli. Current stimulation with a certain frequency and intensity can cause seizure discharge in the brain. ), after the stimulation stops, the discharge continues, resulting in a generalized tonic attack; after the stimulation is weakened, only a short post-discharge occurs. If the stimulation is repeated regularly (or even once a day), the post-discharge interval and diffusion range gradually increase until Causes systemic seizures, even without any stimulation, spontaneously appears to cause seizures. The characteristic change of epilepsy is that many neurons in the restricted area of the brain are synchronously activated for 50-100ms, and then inhibited, and EEG has a high amplitude negative. The phase-wavelet discharge, followed by a slow wave, can cause a partial partial seizure with repeated synchronous discharge of the neurons in the localized area for a few seconds. The discharge can spread through the brain for several seconds to several minutes, and a complex partial or systemic attack can occur.

3. Electrophysiological and neurobiochemical abnormalities: Excessive excitation of neurons can lead to abnormal discharge, and intracerebral cortex hyperexcitability is detected by intracellular electrodes in epileptic animal models. Continuous depolarization and hyperpolarization occur after neuronal action potential outbreaks, generating excitement. Post-synaptic potential (EPSP) and depolarization drift (DS) increase intracellular Ca2 and Na, increase extracellular K, decrease Ca2, produce large amounts of DS, and move to peripheral nerves several times faster than normal conduction. Meta-diffusion, biochemical studies have found that hippocampus and temporal lobe neurons can release a large number of excitatory amino acids (EAA) and other neurotransmitters during depolarization. After activation of NMDA receptors, a large amount of Ca2 influx leads to further enhancement of excitatory synapses. Increased extracellular K of epileptic lesions can reduce the release of inhibitory amino acids (IAA), reduce the presynaptic inhibitory GABA receptor function, make the excitatory discharge easy to project to the surrounding and distant regions, and the epileptic foci migrate from isolated discharge to seizure At the time, the post-DS inhibition disappearance was replaced by the depolarization potential, and the neurons in the adjacent region and the synaptic junction were activated, and the discharge was through the cortical local loop, and the long joint pathway (including The corpus callosum) and the subcortical pathway spread, focal episodes can spread locally or throughout the brain, and some rapidly turn into systemic seizures. The development of idiopathic generalized seizures may be achieved through the thalamic cortical circuit of extensive reticular branches. .

4. Seizures may be associated with decreased synaptic inhibition of intracranial inhibitory neurotransmitters such as gamma aminobutyric acid (GABA), excitatory transmitters such as N-methyl-D-aspartate (NMDA) receptor-mediated valleys. The amino acid response is related.

Inhibitory transmitters include monoamines (dopamine, norepinephrine, serotonin) and amino acids (GABA, glycine). GABA is only found in the CNS. It is widely distributed in the brain, with the highest content of substantia nigra and globus. Important inhibitory transmitters of CNS, epileptic seizures include acetylcholine and amino acids (glutamate, aspartic acid, taurine), CNS synaptic neurotransmitter receptors and ion channels in information transmission Play an important role, such as glutamate has three receptors: kainic acid (KA) receptor, making a quisqualic receptor and N-methyl-D-aspartate (NMDA) receptor, epilepsy Glutamate accumulation during sexual seizures, acting on NMDA receptors and ion channels, exacerbating synapses, is one of the leading causes of seizures. Endogenous neuronal outbreaks are usually voltage-dependent calcium current enhancement, some Focal epilepsy is mainly due to the loss of inhibitory interneurons. Hippocampal sclerosis may result in epilepsy due to abnormal return of excitatory connections between surviving neurons. The absence of seizure may be due to the enhancement of voltage-dependent calcium currents in thalamic neurons, and cortically diffuse synchronous spines occur. Slow wave activity.

5. Pathological morphological abnormalities and epileptogenic focus: Cortical epileptic lesions using cortical electrodes to detect electrical discharge, found varying degrees of gliosis, gray matter ectopic, microglioma or capillary hemangioma, electron microscopy of epileptic foci The electron density in the synaptic gap increased, and the vesicle emission marked by synaptic transmission activity increased significantly. Immunohistochemistry confirmed that there were a large number of activated astrocytes around the epileptogenic focus, which changed the ion concentration around the neurons, making the excitability easy to spread to the surrounding.

Comprehensive seizure prevention

Prevention of epilepsy is very important. Prevention of epilepsy is not only related to the medical field, but also related to the whole society. Prevention of epilepsy should focus on three levels: one is to focus on the cause and prevent the occurrence of epilepsy; the second is to control the seizure; the third is to reduce epilepsy. The physical, psychological and social adverse effects of the patient.

1. Prevention of epilepsy: Genetic factors make some children have susceptibility to seizures, and seizures occur under the trigger of various environmental factors. In this regard, the importance of genetic counseling should be emphasized, and family surveys should be conducted in detail. To understand whether there are seizures and their seizures in the parents, siblings and close relatives. For some serious hereditary diseases that can cause mental retardation and epilepsy, prenatal diagnosis or neonatal screening should be performed to decide to terminate the pregnancy or Early treatment.

For secondary epilepsy should prevent its specific cause, prenatal attention to maternal health, reduce infection, nutritional deficiencies and various systemic diseases, so that the fetus is less adversely affected, prevent birth accidents, neonatal birth injury is an important cause of epileptic seizure One of them, avoiding birth injury is of great significance in preventing epilepsy. If you can regularly check pregnant women, implement new methods, and deal with dystocia in time, you can avoid or reduce the birth injury of newborns, and pay enough attention to the febrile seizures in infants and young children. Try to avoid seizures, and should be controlled immediately when the attack occurs. It is necessary to actively prevent various diseases of the central nervous system in children, timely treatment, and reduce sequelae.

2. Control episodes: mainly to avoid the predisposing factors of epilepsy and comprehensive treatment to control the onset of epilepsy. Statistics show that after the first epileptic seizure, the recurrence rate is 27% to 82% in a single episode. It seems that most patients will relapse, so it is especially important to prevent the recurrence of epileptic symptoms.

For patients with epilepsy, timely diagnosis, early treatment, the earlier the treatment, the smaller the brain damage, the less the recurrence, the better the prognosis, the correct and rational use of drugs, timely adjustment of dosage, attention to individual treatment, long course of treatment, slow withdrawal process, And should adhere to regular medication, if necessary, evaluate the efficacy of the drugs used and blood drug concentration monitoring, avoid drugs indiscriminately, do not regulate the use of drugs, remove or reduce the primary disease causing epilepsy, such as intracranial space-occupying diseases, metabolic abnormalities, Infection, etc., is also important for recurrent cases.

3. Reducing the sequelae of epilepsy: Epilepsy is a chronic disease that can last for years, even decades, and can have serious adverse effects on the patient's body, mind, marriage, and socioeconomic status, especially deep-rooted. Social prejudice and public discriminatory attitudes, patients' misfortunes and frustrations in family relations, school education and employment, and restrictions on cultural and sports activities can not only cause disgrace and pessimism, but also seriously affect the physical and mental development of patients. Families, teachers, doctors and nurses, and even the society itself, so many scholars have emphasized that the prevention of sequelae of epilepsy is as important as the prevention of the disease itself. The sequela of epilepsy is both the patient's body and the whole. Social, this requires the community to understand and support epilepsy patients, to minimize the social sequelae of epilepsy.

Comprehensive seizure complications Complications

It is currently believed that epileptic disease is a clear pathological state caused by a single specific cause, not just the type of seizure. Epileptic encephalopathy is an epileptic discharge that causes progressive brain dysfunction. Therefore, different causes And the brain dysfunction caused by the attack is different, the clinical complications are also different, but the common point is that there may be accidents such as trauma or asphyxia caused by the attack.

Comprehensive seizure symptoms Common symptoms Intelligent decline tired consciousness disorder Facial pale convulsions Consciousness loss consciousness Blurred down Dementia myoclonus

1. Comprehensive tonic-clonic seizures: referred to as grand mal, is a common type of seizure, showing systemic muscle rigidity and clonic, with loss of consciousness and autonomic dysfunction, most patients have no aura before the attack, part The patient may have ambiguous or difficult to describe aura before the attack, such as chest and abdomen rush, local slight twitching, nameless fear or dreamy feeling, etc., which lasts for a short period of time and can be divided into three phases:

(1) During the period of tonicity: the patient suddenly loses consciousness, often falls with a scream, the body skeletal muscle is tonic contraction, the neck and trunk are turned from the front to the angle bow, and the upper limb is lifted and the rotation is the adduction. The lower extremity changes from self-buckling to strong straightening and varus, and the contraction of the respiratory muscles causes apnea. The complexion changes from pale or congested to cyanosis, and the eyeball turns up. After 10 to 30 seconds, there is fine tremor at the extremities. Increase and extend to the whole body, that is, enter the cleft period.

(2) Circumcision: Muscles alternately contract and relax, and alternately twitch, the frequency of sputum gradually slows down, the relaxation time is gradually extended, the current period lasts for 30 to 60 s or longer, and the last time after intense convulsions, convulsions suddenly Termination, all muscle relaxation, tongue bite can occur in the above two periods, with autonomic nerve changes such as increased heart rate, elevated blood pressure, dilated pupils and loss of light reflex, Babinski sign can be positive.

(3) Late stage: short-term tonic sputum may occur after the clonic period, mainly on the face and masseter muscles, resulting in tightness of the jaws, tongue bite may occur, muscle relaxation in the whole body, sphincter relaxation and self-flow of urine may occur Incontinence, breathing first recovers, heart rate, blood pressure and pupils return to normal, consciousness gradually wakes up, there is a period of confusion after the patient's attack, misorientation or irritability (post-onset state), the ambiguity period usually lasts for a few minutes From the beginning of the attack to the recovery of consciousness for 5 to 10 minutes, some patients can go to sleep, lasting for several hours or longer, often with headache after waking, body aches and fatigue, no memory for the attack, individual patients appear auto-symptoms before waking, rage Or panic, etc., prolonged seizure status is seen in the status of epilepsy, also in diffuse structural encephalopathy (such as dementia, mental retardation or encephalitis) or after a single seizure in patients with metabolic encephalopathy, transient hemiplegia after seizures (Todd) suggests that the disease is due to focal brain damage, sudden onset of sudden loss of consciousness, trauma can occur, such as intracranial hematoma, muscles at the time of attack Severe contraction can cause dislocation of the mandibular joint, dislocation of the shoulder joint, fracture of the spine or femur, and inhalation of saliva and vomit into the respiratory tract during coma can be accompanied by aspiration pneumonia. In the long-term episode, patients with brain lesions may experience mental decline and dementia.

2. Tonic seizures: more common in children with diffuse brain damage, more sleep, showing strong or severe contraction of the whole body or part of the muscles, without clonic, head, eyes and limbs fixed at a certain position, the trunk is angled Bow reversal, with transient loss of consciousness, facial bruising, apnea and dilated pupils, such as standing in the standing position can suddenly fall, the episode lasts for a few seconds to tens of seconds, the typical episode EEG is a fulminant multi-spike.

3. Clonic seizures: Almost all occur in infants and young children, characterized by repeated clonic tics with loss of consciousness, no previous strong period, bilateral symmetry or a limb-based twitch, amplitude, frequency and distribution are variable, For the characteristics of infant attacks, lasting for one to several minutes, EEG changes lack specificity, visible fast activity, slow waves and irregular spines - slow waves.

4. Myoclonic seizures: characterized by sudden and short tremor-like muscle contractions, which can symmetrically affect the bilateral muscle groups, showing whole body lightning-like shaking, facial, a certain limb or individual muscle groups, jumping alone or in series When you just fall asleep or wake up in the morning, it is more frequent. It is common in all ages and is common in idiopathic epilepsy with good prognosis, such as benign myoclonic epilepsy in infants. It is also found in rare hereditary neurodegenerative diseases, such as Lafora bodies. Disease, mitochondrial myopathy, such as myoclonic epilepsy with muscle pilgrimage-like red fiber (MERRF) syndrome, diffuse brain damage leads to poor prognosis of Lennox-Gastaut syndrome, typical EEG changes to multiple spines-slow wave.

5. Absence of seizures: There are significant differences between typical absence and atypical absence, clinical manifestations, EEG background activity and episode changes, and prognosis.

(1) typical absence seizures: also known as small episodes (petit mal), childhood onset, pre-puberty cessation, some children turn into a major seizure, characterized by sudden transient (5 ~ 10s) loss of consciousness and ongoing The action is interrupted, the eyes are gazing gaze, and the call should not be like, "like the gods", can be accompanied by clonic, loss of tension, muscle rigidity, autonomic symptoms, autonomic symptoms, one or all of them, without aura, lasting 5 to 20s, Very few more than 30s, sudden sudden stop, no memory for the episode, several times to hundreds of times per day, affecting school; a small number of children only have confusion, still can carry out simple activities, occasionally conscious obstacles, extremely light and difficult to find , only confirmed during video EEG monitoring.

1 with a slight sputum such as eyelids, mouth or upper limbs are not easy to detect the tremor, eyeball about 3 times / s upward tremor, 3 times / s upper limb twitch;

2 with loss of tension such as head tilting, lower limbs falling and waist flexion, holdings in the hands may fall, the children in the eating when the fall of the tableware often cause parents to pay attention, occasionally fall;

3 with muscle rigidity such as some muscle group tonic sputum, head back or sideways, back arch, causing a sudden retreat;

4 with automatic disease, more common in the state of absence, mechanically carry out the original activities;

5 with autonomic symptoms such as pale, flushing, salivation and urinary incontinence, etc., clinically good, intelligence is not affected, valproic acid can be effectively controlled, typical EEG during the attack.

(2) Atypical absence of seizures: The occurrence and disturbance of disturbance of consciousness are slower than the typical absence of seizures, and the changes in muscle tone are more obvious. They are more common in children with diffuse brain damage and have a poor prognosis.

6. Loss of tension: caused by loss of posture tension, partial or systemic muscle tension suddenly decreased, causing the neck (nodding), mouth opening, limb sagging (holding fall) or trunk loss of tension or tripping, lasting for a few seconds to 1min Short-term consciousness disorder is not obvious, the elders lose consciousness temporarily, and wake up and stand up immediately after the attack. EEG shows more spine-slow wave or low-potential activity, which may occur alternately with tonicity, atypical absence, and developmental disorders. Diffuse brain damage, such as Lennox-Gastaut syndrome, Doose syndrome (epilepsy with myoclonus - cataplexy episodes) and subacute sclerosing panencephalitis (SSPE) are common early.

Comprehensive seizure check

1. Blood, urine, routine examination of stool and blood sugar, electrolyte (calcium, phosphorus) determination.

2. Cerebrospinal fluid examination: increased intracranial pressure suggests space-occupying lesions or CSF circulatory pathway disorders, such as larger tumors or deep vein thrombosis, increased cell number suggesting meningeal or brain parenchymal inflammation, such as brain abscess, cerebral cysticercosis, meningitis or Encephalitis secondary to epilepsy; increased CSF protein content suggests that the blood-cerebrospinal fluid barrier is destroyed, seen in intracranial tumors, cerebral cysticercosis and various inflammatory diseases leading to epilepsy.

3. EEG check:

(1) The GTCS typical EEG tonic period begins with a 10th/s spike-like rhythm, the frequency is continuously decreasing, the amplitude is increasing (raising rhythm), and the diffuse slow wave with intermittent episodes is In the late stage of sputum, there is obvious EEG suppression (low level). The longer the attack time, the more obvious the inhibition. The sympathetic synchronization of spikes or spine-slow waves in GTCS patients can be considered. Idiopathic epilepsy can be considered and local lesions can be found. It suggests that secondary epilepsy should be further examined; family hereditary comprehensive seizures have characteristic EEG changes, and both hypertonic-clonic seizures show bilateral fast rhythms above 10 Hz, occasional spines during episodes - slow waves or sharp-slow Wave is issued.

(2) EEG can be seen in a diffuse bilateral bilateral synaptic 3 times / s spine-slow complex wave in the typical absence of seizures. The episodes can be induced by hyperventilation. The episodes have the same or shorter arrays of power generation activities, and the background activity is normal.

(3) Atypical seizures are slow (2.0 to 2.5 Hz) irregular spines - slow waves or sharp-slow waves, both sides are often out of sync, and background activity is abnormal.

(4) Myoclonic bursts are used as 3 times/s pleomorphic spikes, sharp waves or slow waves.

If conventional EEG can not detect epileptic foci, some inducing tests, such as deep breathing, sleep tracing, sleep deprivation, rhythmic flash and acoustic stimulation, can be used to improve the abnormal detection rate of interictal episodes; drugs induced such as pentylenetetrazol or Intravenous injection can also cause normal human epileptiform discharge. It is not recommended for use. It is only used to determine the location of epilepsy before surgery. Deep electrodes such as nasopharyngeal electrodes and sphenoidal electrodes can be used to detect the temporal lobe. Side, bottom or deep discharge.

4. Neuroimaging: General CT- or MRI examination of patients with generalized epilepsy has no characteristic findings.

Comprehensive seizure diagnosis

Diagnostic criteria

First determine whether it is epilepsy, mainly based on medical history, such as aura symptoms, state of attack and confusion after the attack, not based on nervous system or laboratory tests.

1. GTCS patients can not accurately describe the performance of seizures, which can be described by family members and bystanders. The International Anti-Epilepsy Alliance stipulates that the diagnosis and seizure classification of epilepsy patients should provide a video of the whole process of clinical episodes and EEG monitoring records during the onset, analyzing the first symptoms and epilepsy. Whether the sexual discharge is related, clear the source of epileptic discharge and anatomical location; patients with epileptic discharge not recorded in EEG monitoring during clinical onset should carefully consider the diagnosis of epilepsy.

(1) should pay attention to the sudden and repetitive characteristics of seizures, pre-seizure aura and seizures with loss of consciousness, according to the characteristic clinical manifestations to determine the type of seizure.

(2) Family history should pay attention to similar cases. Personal history should pay attention to birth injury, history of head trauma or brain surgery, history of febrile seizures in children, and history of pox poultry in northern areas.

(3) signs of nervous system localization: congenital malformation of the brain or epilepsy caused by perinatal brain injury may have signs of nervous system damage, nodular sclerosis can be seen in facial sebaceous adenoma, idiopathic epilepsy usually has no local signs, long-term attack May have mental retardation, mental decline or epilepsy personality.

2. The typical absence of seizures is based on repeated short-lived seizures, which are easily induced by deep breathing and characteristic changes in EEG.

Differential diagnosis

1. syncope: short-term global cerebral hypoperfusion leads to short-term loss of consciousness and falls, even causing limb tonic convulsions or urinary incontinence, preventing patients from falling and aggravating perfusion is more likely to occur, long standing, severe pain, See blood, emotional, urination, cough and suffocation can be the cause, often dizziness, nausea, black spots and weakness in front of the eyes, slower fall, pale, sweating, sometimes irregular pulse, syncope occurs in an upright position Or sitting position, lying in the supine position suggestive seizures, fainting caused by loss of consciousness rarely exceed 15s, consciousness quickly recovered and fully awake, self-limiting, no anti-epileptic drug treatment; after the episode, confusion is highly suggestive of seizures, limb twitching and Urinary incontinence can also be seen in syncope, and does not necessarily suggest a seizure.

2. pseudoepileptic attack (pseudoepileptic attack): such as snoring episodes may have exercise, sensation and confusion, and other symptoms of seizures, often have a spiritual incentive, others appear in the onset, usually not limb twitching, but swinging arms , kicks and other random movements, performance, seizures are not lost, suggesting that can induce or terminate the seizure, video EEG helps identify.

3. Narcolepsy: can cause stumble, easy to be misdiagnosed as epilepsy, according to the sudden can not inhibit sleep, sleep paralysis, before going to sleep hallucinations and wake up can be identified.

4. Hypoglycemia: when the blood glucose is lower than 2mmol/L, local epileptiform twitching or limb tonic attack, accompanied by loss of consciousness, is common in islet -celloma or type 2 diabetes patients who take long-term hypoglycemic agents. diagnosis.

5. Organic encephalopathy: cerebral cortex ischemia, hypoxia and certain diffuse encephalopathy can lead to GTCS, occasionally, GTCS or epilepticus, should be identified; such as Creutzfeldt-Jacob disease (CJD), subacute EEG such as sclerosing whole encephalitis (SSPE) can have periodic discharge and has a large characteristic diagnostic significance.

6. Different types of treatment and prognosis vary greatly, should pay attention to identification, complex partial seizures need to pay attention to identification, such as some complex partial seizures only consciousness disorder or consciousness disorder, need to identify with the absence of seizure, the former occurs At any age, seizures are more common in children, with frequent seizures and characteristic EEG changes; complex partial seizures with local or asymmetrical rigidity, clonic or various postural movements need to be differentiated from tonic-clonic seizures.

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