Pediatric myoclonic epilepsy

Introduction to pediatric myoclonic epilepsy Myoclonic epilepsy, Lennox syndrome, is an age-related cryptogenic or symptomatic systemic epilepsy syndrome, a type of age-dependent epileptic encephalopathy (also known as small-motion type). Minormotorseizures, Lennox-Gastaut syndrome, small episode variants, blink-head-head falls, myoclonus nostalgia (myoclonoastatischelpetitmal). Gibbs recorded the disease in 1938, but considered it to be a type of pediatric epilepsy, belonging to the small attack variant. It is characterized by early onset of onset, onset in early childhood, various forms of seizures, difficult treatment, and mental development. Lennox studied and reported EEG changes in this disease from 1945 to 1960, followed by Gastaut in 1966. In the year, the relationship between clinical manifestations and EEG was further studied and considered to be an independent disease. Age-determined epilepsy encephalopathy is a special type of epilepsy with significant age-specificity. It consists of three factors: Early-infantileepileptic encephalopathywithsuppressiveburst, West syndrome and Lennox syndrome. The three are closely related, and they move along with age, ie, neonatal epilepsy encephalopathy West syndrome Lennox syndrome. basic knowledge The proportion of illness: 0.0025% Susceptible people: children Mode of infection: non-infectious Complications: muscle spasm

Pediatric myoclonic epilepsy etiology

Causes

This symptom can be caused by congenital developmental disorders, metabolic abnormalities, perinatal hypoxia, nervous system infection or cerebral hypoxia caused by status epilepticus. The prenatal factors account for 10% to 15%, and the perinatal period accounts for 15%. % to 36%, 10% to 25% after birth, 30% to 70% for unknown reasons, the genetic factors of this disease are still controversial.

Brain lesions (30%):

Brain developmental malformations, such as neural tube development disorders, brain neuronal migration disorders, gray matter ectopic, cerebral gyrus deformity, hydrocephalus, etc.; cerebral development disorders caused by chromosomal diseases and congenital metabolic diseases; brain degeneration and demyelinating diseases , such as white matter malnutrition; neurocutaneous syndrome; central nervous system infections, such as various encephalitis, meningitis, brain abscess, congenital infections, cerebral cysticercosis and other diseases caused by viruses, bacteria, protozoa, parasites and fungi Infection; cerebrovascular disease, such as intracranial hemorrhage, thrombosis, embolism, cerebral vasculitis, arteriovenous malformation, aneurysm, etc; cerebral edema, encephalopathy, increased intracranial pressure; brain trauma, craniocerebral trauma; brain tumor, misfit Tumors, etc.

Metabolic disorders (25%):

Congenital metabolic abnormalities, such as brain lipid deposition, abnormal glucose metabolism, abnormal amino acid metabolism, etc.; water and electrolyte disorders, such as hyponatremia, hypernatremia, hypocalcemia, hypomagnesemia, etc.; vitamin deficiency, Such as vitamin B6 dependence; liver, kidney disease; hypertensive encephalopathy; endocrine dysfunction.

Poisoning (15%):

Drugs, metals, other chemicals, such as lead, sputum, isoniazid, convulsions, steroids and other poisoning; drug break syndrome, such as sudden withdrawal of anticonvulsant drugs caused by status epilepticus.

Pathogenesis

Symptomatic epilepsy

Caused by known brain lesions, including organic matter of the brain, structural lesions, or biochemical metabolic disorders.

2. Hidden source epilepsy

Refers to the current knowledge and technology can not find structural or biochemical reasons, but suspected symptomatic, with the deep understanding of epilepsy and the advancement of diagnostic techniques, there will be more and more cryptogenic epilepsy to find the brain An abnormality in function or anatomy to elucidate its cause.

Pediatric myoclonic epilepsy prevention

The prevention of epilepsy in children should start from many aspects. The cause of idiopathic epilepsy is still unclear. Further research is needed to find a preventive method. The prevention of symptomatic epilepsy should pay attention to the following aspects:

1. Pay attention to perinatal health care to protect the fetus and newborn from hypoxia, birth injury, infection, etc., especially to prevent neonatal asphyxia and hypoxic ischemic encephalopathy.

2. Active prevention and treatment of febrile seizures should pay enough attention to the febrile seizures in infants and young children, try to prevent seizures;

3. Actively prevent the timely treatment of various diseases of the nervous system in children and reduce the sequelae.

4. Prevention of biochemical metabolic disorders.

5. Do a good job of genetic counseling For some serious hereditary diseases that cause epilepsy, genetic counseling can be carried out, and some can be used for prenatal diagnosis or newborn screening to determine the necessity of stopping pregnancy or early treatment.

Pediatric myoclonic epilepsy complications Complications

The main complications are mental developmental disorders, physical growth retardation, spastic paralysis, quadriplegia, and microcephaly. Myoclonic seizures are mainly found in the shoulders and upper limbs, bilateral or lateral. It appears as a sudden short-lived electric shock, not a rhythm. Although it can be repeated, the amplitude and intensity of the twitch are different. JME's myoclonic seizures are conscious of disability, and even if the seizure occurs continuously within a few hours ("myoclonus persistence"), the disturbance of consciousness is also slightly. Facial twitching is rare. When the systemic myoclonus is present, there may be sudden and severe shaking of the whole body. The torso bends forward or backward, lifts the arm, bends the leg, and cannot maintain a normal posture. In severe cases, it may cause a fall. When the upper limb muscles are fibrillated, you can see violently hitting objects, knocking on the table, or throwing the object you are holding; when the lower limbs are muscles, you can suddenly kick the furniture, or when you step down the stairs, your feet touch the steps and cause pain.

Symptoms of myoclonic epilepsy in children Symptoms of consciousness, disturbance of consciousness, calcium ion, internal flow, diaphragmatic muscle tension, decreased consciousness, loss of intelligence, personality decline, fall, seizure, enuresis

This disease is an age-related epileptic encephalopathy with a peak age of onset of 3 to 5 years. The most common type of seizures are axial tonic (71%), atypical absence (49%) and ambulatory seizures (36). %), also seen myoclonus (21%), generalized tonic-clonic seizures (37%) and partial seizures (24%), this symptom is frequent, and epileptic seizures are not uncommon (23%) According to the variety of seizures, there are the following:

Myoclonus episode

Sudden and rapid twitching of the face, trunk or limb, twitching more than one, can also be repeated twitching, without conscious disturbance at the time of attack, can occur at any time, the attack can be induced by stimulation (such as light stimulation, tapping the midline of the face or the midline of the sternum) .

Whole body myoclonic, myoclonic tension and destabilizing episodes, these three kinds of seizures can cause head or body to fall suddenly, clinically difficult to distinguish from each other, the accurate diagnosis depends on muscle activity tracing.

The EEG can be expressed as a slow multi-spindle-slow wave, a slow spine-slow wave or a fast rhythm discharge, the anterior head is dominant, and a short sputum can be seen at the end of the episode. The clinical features are similar to myoclonus.

The above-mentioned several common forms of seizures can occur in the same patient, and which one is dominant depends on the age of the patient (short-term sputum is common in young children), the cause (atypical absence with fall and tonic seizures) Common in children with no obvious cause before the disease) and consciousness (tonic seizures often occur in sleep).

2. No motion

It is a transient muscle loss, but can not maintain posture, the episode lasts for 1 to 3 s, and sometimes it can be repeated several times.

3. Tonic seizure

It is characterized by sudden tonic contraction of certain muscles, fixed in a certain posture, lasting for a period of time, loss of consciousness for a short time, wakefulness after the attack, and it is not easy to form a series of episodes.

Tonic seizures and their EEG-specific changes are one of the main features of LGS. Both axial and tonic seizure can occur during day and night, axonal miso seizure and generalized tonic seizures. (global tonic seizure), bilateral limbs can be symmetric or asymmetrical in the onset, young children often have seizures during waking, while in late-onset children, slow-wave sleep is prone to transient tonic episodes, deep sleep The number of seizures increases. If the attack time is short, we can only see it from EEG surveillance. It is characterized by slow limb extension, eyeball upturn and respiratory rhythm. If the episode lasts for more than 20s, the child will have a quick body. A small amplitude of convulsions; loss of consciousness is not a feature of this episode; sometimes before and after the onset of the mouth, digestive autonomic or behavioral autopsy; seizures may be accompanied by enuresis, dilated pupils.

The electroencephalogram in the episode is characterized by a generalized fast rhythm (10 Hz), which may have a transient EEG hypoplasia. If accompanied by an automatic syndrome, a broad slow-slow wave occurs after the fast rhythm.

4. Atypical small episodes

It appears as a moment of cyanosis, daze, two eyes straight, movement stops, a tendency to appear periodically, atypical absence seizure (atypical absence seizure) Most LGS patients have this form of seizure, the beginning and end of the attack are Gradual, sometimes difficult to observe clinically, when the consciousness is not completely lost, the child can still do simple activities, atypical absence of seizures often affect muscle tension, causing them to fall and fall, such as the reduction of muscle tension appears in the face, When the neck muscles, the patient will have a sudden head tilt, mouth opening, runny, etc.

The EEG during the episode is a widely irregular 2~2.5Hz slow spine-slow wave, and the bilateral cerebral hemisphere discharge can be symmetric or asymmetrical.

Examination of pediatric myoclonic epilepsy

The results of general laboratory tests are not special.

1. EEG examination: characteristic EEG changes are the most valuable. EEG performance is different under different arousal states. When awake, it shows continuous slow spine-slow wave release (mostly atypical absence) After falling asleep, it showed a paroxysmal fast rhythm (mostly a tonic attack). The background brain electrical activity during the interictal period was slower than that of the same age, and the brain wave structure was mutated.

2. Cranial CT, MRI examination: help to find the cause, but 3/4 patients did neuroimaging, no abnormalities were found.

Diagnosis and diagnosis of myoclonic epilepsy in children

diagnosis

Detailed medical history, understanding of the child's past history and seizure form, combined with the characteristics of EEG changes during awake and sleep, and the occurrence of mental decline and personality changes as the disease progresses, can make a diagnosis, according to the form of seizure As far as possible, try to achieve a seizure by the treating physician. It should be differentiated from other diseases that cause myoclonus, and if necessary, neuroimaging can be performed.

EEG has a common spine slow wave (<3 Hz) during the awake episode, and sudden spikes and sharp wave activity can be seen during the episodes of sleep. These abnormalities are more pronounced in the non-rapid eye movement sleep period and occur synchronously.

Differential diagnosis

The disease should be differentiated from infantile spasms, absence of seizures, psychomotor epilepsy, etc., and need to be differentiated from late-onset West syndrome, both have the same cause, there will be mental retardation, and some patients with West syndrome After a few years of development, the disease may be converted to LGS. Therefore, it is sometimes difficult to distinguish clearly between the two syndromes. At this time, special attention should be paid to tracking and monitoring the EEG. When the child with LGS has a fall, it needs to be associated with myoclonus. In the case of recurrent seizure syndrome (Doose syndrome), the latter is characterized by myoclonic, myoclonic loss and tonicity, no tonic attack, and some patients with this syndrome have a good prognosis, such as LGS When there is only atypical absence of seizures with autopsy, it needs to be differentiated from temporal lobe epilepsy, the latter is not accompanied by intelligent damage, and there is no characteristic EEG changes in LGS.

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