Infant and childhood epilepsy and epilepsy syndromes
Introduction
Introduction to infant and childhood epilepsy and epilepsy syndrome About 75% of epilepsy and epilepsy syndrome occur in infants and children, except for the common idiopathic and symptomatic epilepsy syndrome, and many other infantile and childhood epilepsy (epilepsies of infancy and childhood) and epilepsy syndrome. The unique type of epilepsy suggests that epilepsy plays an important role in pediatric diseases. Some types of childhood epilepsy are age-related, childhood (4 to 13 years old) epilepsy is mainly various types of small seizures; children's sports epilepsy is often called myoclonus, but late-type epilepsy also has "muscle palsy" Words, need to pay attention to should not be confused; febrile seizures are more common in a certain age group, such as 6 months to 6 years old children; temporal lobe or extensive sharp wave activity with benign exercise or complex partial epilepsy seen in 6 ~ 16 Aged children; adolescent myoclonic epilepsy occurs in the middle and late stages of puberty; neonatal epilepsy is mainly a focal episode, showing flexor myoclonus, sometimes extensive. basic knowledge The proportion of illness: 0.0025% Susceptible people: children Mode of infection: non-infectious Complications: neonatal asphyxia
Cause
Infants and childhood epilepsy and etiology of epilepsy syndrome
(1) Causes of the disease
1. Primary reading epilepsy: may be a variant of juvenile myoclonic epilepsy, less common, and related to genetic factors.
2. Kojevnikow syndrome: Also known as chronic progressive partial epilepsy in childhood, the common cause of this disease is infection, including Rasmussen syndrome (focal continuous epilepsy), caused by focal encephalitis; other possibilities Causes include neonatal asphyxia, trauma, vascular disease caused by infarction or bleeding, tumors and so on.
3. Hemiconvulsion-hemiplegia syndrome (HHS): The disease is caused by intracranial infection, craniocerebral trauma, cerebral ischemic lesion or cerebral venous thrombosis, and perinatal lesions lead to encephalopathy.
4. temporal lobe epilepsy, frontal lobe epilepsy, parietal lobe epilepsy and occipital lobe epilepsy: mostly in children or adolescents, often with febrile seizures, history of encephalopathy or family history of epilepsy, can be a secondary seizure.
5. Myoclonus - standing can not have epilepsy: often genetic factors, normal development before the disease.
6. Early myoclonic encephalopathy: It is a rare epilepsy syndrome with the same incidence rate for men and women. There are often similar cases in the family, which may be congenital metabolic abnormalities.
7. Otawara Syndrome: It is a malignant epilepsy encephalopathy with many causes. It is common in brain malformations such as penetrating brain malformation, brain dysplasia such as dentate-oliponuclear dysplasia, and the etiology of a few cases is unknown.
8. Landau-Kleffner syndrome: The cause is unknown, may be an obstacle to the auditory processing process, and there have been cases of cases with temporal lobe tumors.
9. Autosomal dominant nocturnal frontal lobe epilepsy: autosomal dominant inheritance, the apparent rate is about 70%, the abnormal gene is located on the long arm of chromosome 20, and may be allele with one of the benign neonatal familial epilepsy genes.
10. Subependymal heterotopia: A special epileptic syndrome caused by abnormal gray matter migration (Raymond et al, 1994).
(two) pathogenesis
1. Normal people may induce seizures due to electrical stimulation or chemical stimulation: suggesting that normal brains have an anatomical-physiological basis for seizures, which are susceptible to various stimuli, and certain frequency and intensity current stimulation can cause pathogenic discharges in the brain (seizure discharge) ), 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.
2. Electrophysiological and neurobiochemical abnormalities: In recent years, the advancement and wide application of neuroimaging techniques, especially the development of epilepsy functional neurosurgery, have been able to detect neurobiochemical changes in patients with symptomatic epilepsy and epilepsy syndrome, neurons Excessive excitability can lead to abnormal discharge. The intracerebral cortex hyperexcitability is detected by intracellular electrodes in epileptic animal models. Continuous depolarization and hyperpolarization occur after neuronal action potential outbreaks, producing excitatory postsynaptic potential (EPSP) and depolarization. Drifting (DS) increases intracellular Ca2 and Na, increases extracellular K, decreases Ca2, and produces a large amount of DS, which spreads to peripheral neurons several times faster than normal conduction. Biochemical studies have found that hippocampus and temporal lobe When neurons are depolarized, a large number of excitatory amino acids (EAA) and other neurotransmitters can be released. After activation of NMDA receptors, a large amount of Ca2 influx leads to further enhancement of excitatory synapses. Extracellular K+ increase in epileptic lesions can reduce inhibition. Release of amino acids (IAA), reducing presynaptic inhibitory GABA receptor function, making excitatory discharge easy to project to the surrounding and distant regions, epileptic foci from isolation When the electrical migration to the episode, the post-DS inhibition disappearance is replaced by the depolarization potential, and the neurons in the adjacent region and the synaptic junction are activated, and the discharge is through the cortical local loop, the long joint pathway (including the corpus callosum) and The subcortical pathway spreads, 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 a broad network of thalamic cortical circuits.
3. 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 Related to the enhancement of the amino acid reaction, inhibitory transmitters include monoamines (dopamine, norepinephrine, serotonin) and amino acids (GABA, glycine).
GABA exists only in the CNS, has a wide distribution in the brain, and has the highest content of substantia nigra and globus pallidus. It is an important inhibitory transmitter of CNS. Epileptic priming transmitters include acetylcholine and amino acids (glutamate, aspartic acid, Taurine), CNS synaptic neurotransmitter receptors and ion channels play important roles in information transmission. For example, glutamate has three receptors: kainic acid (KA) receptor, which makes glutamate And N-methyl-D-aspartate (NMDA) receptors, accumulation of glutamate during seizures, acting on NMDA receptors and ion channels, causing excessive synaptic excitation, leading to seizures In one case, endogenous neuronal burst discharges 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. Atheistic seizures may be due to increased voltage-dependent calcium currents in the thalamic neurons, and cortical diffuse synchronous spine-slow wave activity occurs. Antiepileptic drugs act on the above mechanisms, such as phenytoin, carbamazepine, phenobarbital and propylidene. Acid is blocked by voltage Lymphatic sodium channel reduces high frequency repetitive discharge without affecting single action potential; phenobarbital and benzodiazepine enhance GABA-mediated inhibition, ethosuxamine blocks neuron low threshold transient calcium current, urethane To reduce excitatory neurotransmitters, lamotrigine reduces glutamate release and affects voltage-dependent sodium channels, stabilizing neuronal membranes, and the like.
4. Pathological morphological abnormalities and epileptogenic foci: Cortical epileptic lesions were detected by cortical electrodes. Different degrees of gliosis, gray matter ectopic, microglioma or capillary hemangioma were observed. Electroencephalography showed 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.
Prevention
Infant and childhood epilepsy and prevention of epilepsy syndrome
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.
Early prevention and early diagnosis of symptomatic epilepsy syndrome, early treatment is also very important. For those with genetic factors, the importance of genetic counseling should be emphasized. The family survey should be conducted in detail to understand the parents, siblings and close relatives. Whether there are seizures and their seizure characteristics, for some serious hereditary diseases that can cause mental retardation and epilepsy, prenatal diagnosis or neonatal screening should be carried out to decide to terminate pregnancy or early treatment.
Complication
Infants and childhood epilepsy and complications of epilepsy syndrome Complications, neonatal asphyxia
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.
Symptom
Symptoms of infantile and childhood epilepsy and epilepsy syndrome Common symptoms Frequent laughter Sensory disorder can not lead to moro reaction convulsions, snoring, dyspnea, irritability, seizures, body stiffness...
Primary reading epilepsy
Typical cases start after puberty. The reading time is different before the onset of facial and mandibular muscles during reading. For the first time, almost all of the jaws have local seizures. The masticatory muscles are often described as squeaky locks, which can express lips. Trembling throat is stunned or difficult to talk, etc., muscle myoclonic episodes can also occur after visual symptoms, and some children continue to read can become full-strength-clonic seizures.
2.Kojevnikow syndrome
Also known as chronic progressive partial epilepsy in childhood, clinically rare, showing local persistent twitching, seizures can not automatically stop, is a continuous state of local seizures, sometimes accompanied by Jackson. Often caused by focal encephalitis; other possible causes include neonatal asphyxia, traumatic vascular disease caused by infarction or hemorrhagic tumors, affecting the cortical motor area and subcortical.
Demonstrates focal muscle twitching, can occur several times a day or epilepticus, facial horn, individual fingers or unilateral limbs continue to twitch for hours or days, unconscious disorder, after the termination of the episode, the toxin paralysis can be left behind, It can also be extended to a full-bodied-clonic attack.
3.Rasmussen syndrome
Also known as focal continuous epilepsy, it is a chronic progressive focal motion episode that occurs mainly in children, followed by myoclonic seizures, which are symptomatic epilepsy. Most are within the age of 10, with an average incidence of 5 to 6 years old. About half of the patients had a history of infection within 1 month before the first onset of the disease, and the onset gradually increased gradually. The focal episode often started from one side of the face or fingers and toes. The disease was arrhythmia, sometimes with Jackson epilepsy. The method is extended to the adjacent part, the trunk muscle is rarely affected, the unconscious disorder occurs, and some patients have other types of seizures. With the progressive hemispheric atrophy of the diseased side hemisphere, the condition can gradually deteriorate, and the patient develops progressive hemiplegia with mental retardation, which can eventually leave serious sequelae or death.
4. Hemiplegia hemiplegic syndrome
The disease is caused by intracranial infection, craniocerebral trauma, cerebral ischemic lesions or cerebral venous thrombosis, and perinatal lesions leading to encephalopathy.
Examine
Examination of infant and childhood epilepsy and epilepsy syndrome
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; increased CSF protein content suggests a disruption of the blood-cerebrospinal fluid barrier, seen in intracranial tumors, cerebral cysticercosis and various inflammatory diseases leading to epilepsy.
3. EEG examination: Different types can have different characteristics, please refer to the clinical performance section.
4. Neuroimaging: CT and MRI are important for the diagnosis of primary disease.
Diagnosis
Diagnosis of infant and childhood epilepsy and epilepsy syndrome
The diagnosis of infantile and childhood epilepsy and epilepsy syndrome is mainly based on the history of seizures. Witnesses provide a reliable and detailed description of the seizure process, supplemented by EEG epileptic discharge evidence to confirm the diagnosis. Different clinical types of epilepsy need to be based on different characteristics ( Diagnosis is made in clinical and electroencephalograms. For symptomatic epilepsy, the cause of the disease is a diagnosis of a brain disease or a systemic disease.
The International Alliance Against Epilepsy (ILAE, 2001) recommends the use of a diagnostic axis in the diagnosis of seizures and epilepsy syndrome, first describing seizures, determining the type of seizures and epilepsy syndrome, and further identifying the cause and central nervous system damage.
