Neonatal convulsions

Introduction to neonatal seizures Neonatal seizures are a symptom of a temporary disorder of central nervous system function caused by various diseases, and can also be called convulsions and convulsions. Congenital convulsions in newborns often indicate serious illness. And the performance is not typical, it is difficult to identify, often misdiagnosed, so the mortality rate is high, and there are more sequelae. basic knowledge The proportion of illness: 80% Susceptible people: seen in newborns Mode of infection: non-infectious Complications: epilepsy, cerebral palsy, aspiration pneumonia, neonatal asphyxia

Causes of neonatal seizures

(1) Causes of the disease

With the advancement of diagnostic techniques, the etiology of neonatal seizures has been enriched. In recent years, hypoxic ischemic encephalopathy (HIE) has leapt to the top of the cause, while the proportion of infection and metabolic factors has decreased from earlier years, causing neonates. There are many causes of convulsions, which are divided into 9 categories according to the incidence rate. The previous 4 categories are the most common.

1. Perinatal complications: HIE, intracranial hemorrhage, brain damage.

2, infection: meningitis caused by various pathogens, encephalitis, brain abscess, infection with toxic encephalopathy, tetanus, high fever.

3, metabolic factors: low blood calcium, low blood magnesium, low blood sodium, high blood sodium, hypoglycemia, alkalosis, vitamin B6 deficiency, nuclear jaundice, uremia.

4, cerebral hypoxia: hyaline membrane disease, meconium aspiration syndrome, pulmonary hemorrhage, acute cardiogenic cerebral ischemia syndrome, hypertension, polycythemia, fever syndrome.

5, brain abnormalities: congenital brain dysplasia, craniocerebral malformations, intracranial tumors.

6, congenital enzyme defects: maple diabetes, urea circulatory disorders, hyperglycemia, propionic acidemia, methylmalonic acidemia, isovaleric acid, galactosemia, vitamin B6 dependence.

7, familial: benign familial epilepsy, adrenal white matter atrophy, neurocutaneous syndrome, Zellwegen syndrome, Smith-Lemli-Opitz syndrome.

8, drugs: stimulants, isoniazid, aminophylline, local anesthetics, organic phosphorus, withdrawal syndrome.

9, the cause is unknown: about 3% of neonatal seizures.

It is worth noting that some children may have multiple diseases at the same time, such as hypoxic ischemic encephalopathy with hypocalcemia, hypomagnesemia or hyponatremia.

(two) pathogenesis

The incidence of neonatal seizures is high, and its manifestations and EEG are also very different from those of adults and children. The neonatal central nervous system is still immature and susceptible to various pathological factors. And when the cerebral cortex is highly inhibited, it is prone to abnormal discharge of the subcortical center or brain stem release phenomena. At the same time, the cerebral cortex of the neonatal cerebral cortex and the membrane of the neuron, Incomplete cytoplasmic differentiation, dendrites, synapses, and myelin formation are also imperfect. The normal connection between neurons and glia is not established. When abnormal local discharge occurs in the cortex, it is difficult to conduct and spread to adjacent sites. It is not easy to spread to the contralateral hemisphere to cause synchronous discharge, so convulsions of generalized tonicity in neonatal seizures are rare.

Convulsions require a synchronized discharge of a group of neurons, that is, the number of excited neurons needs to reach a certain threshold. The permeability of the cell membrane of neonatal cerebral cortical neurons is strong, sodium ions are easy to enter, potassium ions are easily leaked, and the membrane The sodium-potassium pump function and ATP level are significantly lower than those of mature neurons, and it is difficult to quickly and effectively pump out sodium ions and repolarize, while in a relatively high polarization state, it is difficult to produce rapid repetitive discharge and cause nearby neurons. Synchronous discharge, so neonatal cortical convulsions are relatively rare, sometimes only a few neurons discharge, did not reach the threshold of causing clinical convulsions, constitute a subclinical type with only EEG abnormal discharge without clinical convulsions.

Neonatal cerebral temporal lobe and diencephalon, brain stem, limbic system, hippocampus, substantia nigra, reticular activation system and other subcortical structures are relatively mature, and their oxidative metabolism is more vigorous, more sensitive to hypoxia, in various pathologies. Under the stimulation of factors, subcortical convulsions are prone to occur, manifested as paroxysmal mouth, cheeks, tiny twitching of the eyelids, gaze, abnormal movement of the eyeball, and autonomic seizures such as salivation, pupillage, complexion, respiration, heart rate and blood pressure. Changes, etc., the mechanism of episodes of subcortical seizures may be due to abnormal discharge of the subcortical gray matter, this deep abnormal discharge, the EEG of the EEG can not be found; or the brain caused by brain damage is highly inhibited Dry release phenomenon, clinically 60% to 90% of children with convulsions have no cortical abnormal discharge, so the positive EEG findings can help confirm the diagnosis, no abnormal discharge can not negate the convulsions.

Neonatal seizure prevention

Do a good job in pregnancy health care, actively prevent and cure various infectious diseases during pregnancy, prevent premature birth and maternal diabetes, hypocalcemia, etc.; do perinatal health care, prevent hypoxia and damage during intrauterine production, prevent HIE, ICH; prevention of metabolic abnormalities; also need to do genetic counseling to prevent genetic metabolic diseases, chromosomal diseases, and also reduce the incidence of congenital malformations of the central nervous system.

Neonatal seizure complications Complications epilepsy cerebral palsy, aspiration pneumonia, neonatal asphyxia

Such as intracranial hemorrhage or HIE, seizures often aggravate intracranial hemorrhage and cerebral ischemia and hypoxia, aggravate brain injury, increase the mortality and sequelae, can not control convulsions in time, can be epilepsy, cerebral palsy, Mental retardation, learning difficulties, etc., and easy to concurrent infection, aspiration pneumonia and asphyxia.

Neonatal seizures Symptoms Common symptoms of neonatal gaze on infants and young children convulsions twitching neonatal convulsions convulsions dysfunction muscle myoclonus infantile sputum unconscious

The manifestations of neonatal seizures are different from those of children and adults. They are characterized by limitations and concealment, sometimes causing difficulties in diagnosis. Therefore, it is important to be familiar with their manifestations, especially the concealed (small) type of expression, so as to avoid missed diagnosis. On the other hand, don't mistake any abnormal movements that are not horrified, such as convulsions, tremors, and rapid eye movements, as horror. The convulsions and tremors can be induced by cold, sound, skin irritation, or passive movement. Unconsciousness And the abnormal movement of the eyeball, soothing can calm it down, and the convulsion is the opposite. In recent years, long-term EEG monitoring has found two noteworthy clinical phenomena: First, clinical manifestations of convulsions, EEG monitoring without abnormal discharge; Second, in some cases, the EEG has abnormal discharge, but there is no clinical convulsion.

1, onset time: convulsions appear shortly after birth can be seen in HIE, intracranial hemorrhage, congenital TORCH infection, vitamin B6 dependence.

(1) within 24 hours after birth: more common in hypoxic-ischemic brain damage, severe cerebral hemorrhage, hypoglycemia, vitamin B6 dependence.

(2) 24 ~ 72h after birth: more common in intracranial hemorrhage, hypoxic ischemic encephalopathy, hypoglycemia, hypocalcemia, drug withdrawal syndrome, hypomagnesemia and so on.

(3) 72h to 1 week after birth: more common in infectious diseases, such as viral encephalitis (Coxsackie B virus, cytomegalovirus, herpes virus and toxoplasmosis infection), purulent meningitis, abnormal amino acid metabolism, Nuclear jaundice, neonatal parathyroidism, cerebral hemorrhage (substantial).

2. The manifestations and classification of neonatal seizures

(1) focal sputum type: manifested as a paroxysmal rhythmic twitch of a muscle group, common in a single limb or one side of the face, sometimes can spread to other parts of the same side, usually conscious, mostly accompanied Abnormal discharge of the cerebral cortex, the main EEG manifested as focal cusps, usually including spikes, and sometimes spread to the entire hemisphere, often suggesting local brain damage such as bleeding or infarction, subarachnoid hemorrhage and metabolic abnormalities.

(2) multi-focal sputum type: manifested as paroxysmal rhythmic tics of multiple muscle groups, common multiple limbs or multiple parts alternately or sequentially twitched, or in one episode, convulsions by a limb tour Walk to another limb, from one part to another, from one side of the body to the other side, without any order, often accompanied by disturbance of consciousness, EEG is characterized by multi-focal spikes or The slow rhythm wave travels from one area of the cortex to another, and about 75% of the children have a wave with a slow wave and/or wave of 1 to 4 weeks/s. This type is common in hypoxic ischemic Sexual encephalopathy, intracranial hemorrhage and infection, occasionally in metabolic disorders.

(3) tonic type: manifested as a single limb or limbs tonic extension, or both lower limbs tonic and double upper limb flexion, body tonic type may have trunk back or flexion, often accompanied by fixed eye movement and apnea, except broken Outside the cold is generally unclear, similar to the brain or cortical tonic, this type is rarely associated with abnormal discharge of the cortex, occasionally spikes, the main form is high amplitude slow wave, sometimes appear on the background of burst suppression, common in preterm birth Intraventricular hemorrhage, tetanus, nuclear jaundice and so on.

(4) Myoclonus type: manifested as one or more short flexional agitation in the limb or an isolated part, may also involve double upper limbs or lower limbs, systemic myoclonus, limbs and trunk may be the same Hey, similar to infantile spasms, only some children with clinical onset with abnormal cortical discharge, EEG common outbreak suppression, often suggesting significant brain damage.

(5) Concealed (small) type: It is the most common form of convulsion in neonates. The seizures are fine, confined and concealed, including the following performances:

1 face, mouth, tongue abnormal movements: eyelids vibrate, repeated blinking, frowning, facial muscles twitching, chewing, sucking, pouting, stretching tongue, swallowing, yawning.

2 abnormal movement of the eye: gaze, the eyeball is turned upside down, the eyeball is fixed to one side and fixed, and the eyeball trembles.

3 Abnormal limb movements: upper limb rowing, drumming, swimming-like movements, lower limbs, bicycle-like movements, and rotational movements of the limbs.

4 autonomic seizures: apnea, breath holding, increased breathing, snoring, increased respiratory rate, elevated blood pressure, paroxysmal flush or pale, runny, sweating, dilated or enlarged pupils, most concealed convulsions Clinical onset without cortical abnormal discharge, but EEG common background wave abnormalities, manifested as low amplitude and burst suppression, common in hypoxic ischemic encephalopathy, severe intracranial hemorrhage or infection in children.

Neonatal seizures are not typical, and the form of seizures is not fixed, which brings many difficulties to the diagnosis. Due to advances in neurophysiology and neuroimaging, including the examination of neurometabolites, the diagnosis of convulsions, the etiology and the evaluation of prognosis have all started. Great role should be combined with EEG, head B ultrasound, head CT or MRI and other imaging examinations to make a diagnosis.

Neonatal seizure check

(1) Physical examination: A comprehensive physical examination is very important. The type of convulsions, the size of the head circumference, the change of muscle tension, the degree of jaundice, and the increase of intracranial pressure are all helpful for diagnosis.

(2) Auxiliary inspection:

1, blood sugar, electrolyte determination, abnormalities suggest corresponding metabolic abnormalities, such as hypoglycemia, hypocalcemia, hypomagnesemia, hyponatremia, hypernatremia and so on.

2, tryptophan load test: oral 50 ~ 100mg / kg tryptophan solution, a large amount of jaundice in the newborn urine, can be diagnosed as vitamin B6 deficiency or dependent disease.

3, hemoglobin, platelets, decreased hematocrit, prolonged prothrombin time, cerebrospinal fluid is bloody, microscopic examination of red blood cells, suggesting the possibility of intracranial hemorrhage.

4. The total number of white blood cells in peripheral blood increased, C-reactive protein was positive, IgM content increased, and erythrocyte sedimentation rate accelerated.

5, cerebrospinal fluid examination for the diagnosis of intracranial infection, intracranial hemorrhage.

6, skull X-ray examination: visible skull fracture, deformity, calcification of congenital infection, head transillumination, can help diagnose subdural hematoma and hydrocephalus.

7, EEG examination: neonatal seizure performance is often difficult to be recognized, EEG examination is an indispensable examination method to determine seizures, and at the same time in the evaluation of neonatal nervous system damage plays an important role in the diagnosis of convulsions, Identification and efficacy analysis, prognosis judgment, conditional long-term EEG monitoring, EEG recorded during neonatal seizures are often not easy to find abnormalities, so EEG should be recorded in time for possible episodes, EEG Analysis of background activity can make objective judgments on the severity of central nervous system function. Neonatal convulsion abnormal EEG is generally divided into the following four categories:

(1) Limited episodes of normal background activity: such as small sharp waves, usually accompanied by clinical upper-level episodes of convulsive seizures, generally not serious, and good prognosis.

(2) Periodic patterns of limited single rhythm: such as , , , rhythm, mild clinical manifestations or myoclonic seizures, found in herpes encephalitis, acute cerebrovascular disease, injury and hypoxic ischemic Encephalopathy, the prognosis is related to the primary disease.

(3) multi-focal episodes: often accompanied by abnormal interictal activity, seen in various causes of convulsions.

(4) Limitations of abnormal background activity: such as low-voltage explosive suppression, asymmetry or maturity delay between the two hemispheres, usually combined with organic encephalopathy, such as severe HIE, if there is no perinatal abnormality, also found in the brain congenital Sexual malformation or metabolic abnormalities, poor prognosis.

8, head CT and brain ultrasound: a certain degree of significance in determining the location and nature of brain lesions.

Neonatal seizure diagnosis

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

It is sometimes difficult to identify whether a newborn, especially a premature infant, is convulsive. Any strange transient phenomenon or subtle twitching repetitiveness occurs periodically, especially when there is an eyeball upturn or abnormal activity and convulsions. Convulsions.

Convulsions should be identified with the following phenomena.

1. Neonatal startle: for a large amplitude, high frequency, rhythmic limb shaking or clonic motion, passive flexion or change of body position can be eliminated, without eye movement or cheek movement, common in normal newborn When the child turns from sleep to awake, when it is stimulated by the outside world or when it is hungry, the convulsions are non-temporal twitching, the magnitude is different, and it is not affected by stimulation or flexion. The twitching limb tries to stop the attack and still feel muscle contraction, often accompanied by There are abnormal eyes and cheek movements.

2, non-convulsive apnea: the attack in the full-term children is 10 to 15 seconds / time, premature infants are 10 to 20 seconds / time, with heart rate slowed by more than 40%, and convulsive apnea episodes, full-term children ) 15 seconds / time, premature baby) 20 seconds / time, without heart rate changes, but with other parts of convulsions and EEG changes.

3, rapid eye movement sleep phase: there are eye tremors, short apnea, rhythm movements. Facial strange, smile, body twisting, etc., but disappear after waking.

4, trembling: the difference between neonatal seizures and trembling.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.