Pediatric convulsions (convulsions) are sudden involuntary contractions of generalized or localized skeletal muscle groups caused by a variety of etiologies, mostly accompanied by impaired consciousness.
I. Etiology
The immature development of the pediatric nervous system makes it easy for excitation to spread, and various abnormal brain electrical activities can easily induce convulsions.
There are many diseases that cause pediatric convulsions, and they are classified according to the site of occurrence as follows.
1, intracranial diseases
(1) Various kinds of idiopathic epilepsy;
(2) abnormal brain development: such as brain gyrus malformation, corpus callosum agenesis, gray matter ectopic, various chromosomal aberrations and abnormal brain cell and myelin development caused by genetic metabolic diseases, etc;
③ Cerebrovascular diseases: such as intracranial hemorrhage, thrombosis, embolism, vascular malformation, collagen disease, etc;
④Brain injury caused by viral or bacterial infection, cranial trauma, hypoxia and ischemia, drug or chemical poisoning, water-electrolyte disorders, endocrine disorders and vitamin deficiency;
⑤ Intracranial occupational lesions: tumors, intracranial parasites, protozoa, tuberculomas, brain abscesses, etc;
(6) Brain degenerative diseases: such as various demyelinating lesions, cerebral gray matter degeneration;
2.Extracranial diseases
(1) febrile convulsions;
② systemic infections caused by toxic encephalopathy (such as toxic dysentery, sepsis, severe pneumonia, etc.);
③ water, electrolyte metabolism disorders (low blood sodium, low blood calcium, low blood magnesium, high blood sodium, etc.);
④ poison or drug poisoning (such as central excitatory drug poisoning, pesticide poisoning, rodenticide poisoning, etc.);
⑤ systemic diseases (hypoglycemia, uremia, hepatic coma, Reye’s syndrome, etc.).
Clinical manifestations
1. Typical manifestations
In a typical seizure, the child has a sudden loss of consciousness, involuntary, continuous, tonic contraction of skeletal muscles throughout the body, respiratory arrest, followed by clonic contraction, alternating contraction of different muscle groups, respiratory arrest, repeated twitching of both eyes or eyelids, head tilted back or to the side, rhythmic jerking of limbs and trunk, foaming at the mouth, twitching lasting tens of seconds to several minutes, followed by deep breathing, muscle relaxation, relief of twitching and recovery of respiration. However, shallow and irregular, incontinence may occur; fall asleep or cry after the seizure, older children tend to fall asleep, headache and fatigue may occur after waking up, and the seizure cannot be remembered. Commonly seen in d epileptic grand mal seizures, febrile convulsions, poisoning, toxic encephalopathy, tetanus, etc.
2.Atypical performance
Infantile convulsions often do not begin with tonic seizures, only limb clonic convulsions, but tetanus is dominated by tonic convulsions. Neonatal convulsions are mostly manifested as respiratory pauses, double gaze, repeated eyelid fluttering or frequent blinking, sucking or chewing movements, limb rowing-like movements, etc. Premature infant convulsions are more mild, can be manifested as paroxysmal eye rotation, squinting, staring or upturning, facial muscle twitching like chewing, sucking action, can also be manifested as paroxysmal facial redness, pallor, salivation, sweating or respiratory pause without convulsions; but premature infants intracranial hemorrhage can be manifested as tonic convulsions.
3.Febrile convulsions
It is the most common cause of pediatric convulsions, with an incidence of about 2% to 8%. The pathogenesis is not yet completely clear, probably because the brain of children aged 6 months to 3 years is not well developed, even weak stimuli can cause strong excitation and diffusion in the brain, resulting in sudden abnormal discharge of nerve cells and convulsions.
(1) Simple febrile convulsions.
① Most often seen in children aged 6 months to 3 years, rare after 6 years;
(2) The child is in good physical condition;
(3) Convulsions mostly occur at the beginning of the disease when the body temperature rises suddenly, often with a fever of 38.5℃ or more;
④Convulsions are generalized tonic to clonic seizures, few in number, short in duration (10 minutes), quick in recovery, and no abnormal neurological signs;
(5) The EEG returns to normal after 1 to 2 weeks of fever remission, and generally does not occur again until school age;
(6) There may be a family history of febrile convulsions;
(7) Good prognosis.
Auxiliary examination
1. Three major routine examinations, cerebrospinal fluid routine examination, blood gas analysis and serum electrolyte measurement, etc;
2. Imaging tests: cranial X-ray, cranial ultrasound, electroencephalogram, cranial CT, nuclear magnetic resonance (WRI), etc;
IV. Diagnosis and differential diagnosis
Convulsions are a symptomatic diagnosis and can be diagnosed by detailed medical history and careful clinical observation, but the important and difficult part is the etiological diagnosis.
1, there are febrile convulsions
(1) central nervous system infection: convulsions accompanied by fever and other symptoms of infection, mostly with impaired consciousness and increased intracranial pressure manifestations, cerebrospinal fluid examination has diagnostic significance.
(2) toxic encephalopathy: in addition to convulsions, there are often severe symptoms of systemic infection poisoning, most of which can be found in the foci of infection, but sometimes convulsions can occur before the appearance of systemic symptoms (such as bacterial dysentery), and special attention should be paid.
1, there are febrile convulsions
(3) Febrile convulsions: They occur mostly in children within 3 years of age, and are common at the beginning of various febrile diseases, mostly with high fever.
(4) Reye syndrome: there may be a history of prodromal viral infection with symptoms of acute non-inflammatory encephalopathy, accompanied by hepatomegaly, abnormal liver function, no jaundice, elevated blood ammonia, decreased blood glucose, and prolonged prothrombin time, etc.
2.No febrile convulsions
(1) Intracranial hemorrhage: mostly occurs in newborns or small infants who are exclusively breastfed. It occurs in the neonatal period with a history of obstructed labor, asphyxia and birth injury, and in older children due to cranio-cerebral trauma. Cranial imaging has diagnostic significance.
(2) Electrolyte disorders: hypocalcemia, hyponatremia, hypernatremia, hypomagnesemia, etc. can cause convulsions, and children often have a history of improper feeding or diarrhea, and serum electrolyte examination can confirm the diagnosis.
(3) Hypoglycemia: Convulsions accompanied by cold sweat, pale face, weak pulse, can be coma, mostly occur in children with hunger, malnutrition and use of insulin preparations. Blood glucose test can confirm the diagnosis.
(4) Drug, poison, food poisoning: There may be a history of exposure to drugs or poisons or a history of eating unclean food; it is common in young children and school-age children, with a rapid onset and may be accompanied by other symptoms of poisoning, and sometimes it is not easy to confirm the diagnosis, so careful history taking is very important.
(5) Hypertensive encephalopathy: If the child has one of the three items: convulsions, visual impairment and coma, and the blood pressure is significantly elevated, hypertensive encephalopathy can be diagnosed. Most of the primary diseases can be found, and are prone to occur in pediatric acute and chronic nephritis.
(6) Epilepsy: Most have a history of recurrent convulsive seizures, with a variety of seizure forms and mostly accompanied by EEG abnormalities.
(7) Inherited metabolic diseases: In addition to convulsions, children often have developmental disorders or certain specific signs.
(8) Brain developmental abnormalities: recurrent convulsions are often accompanied by head malformations, mental retardation, physical developmental disorders, etc.
Differential diagnosis
(1) Breath-holding seizures: They occur mostly in infants and children aged 6 to 18 months and will gradually disappear naturally by the age of 5 years. Apnea seizures often occur during rapid emotional changes, such as anger, fear, sadness, severe pain, violent shouting, often with hyperventilation, so that the respiratory center is inhibited, holding the breath when crying, cerebral vasodilatation, cerebral hypoxia may be fainting, loss of consciousness, blue lips or clonus, lasting about 0.5 to 2 minutes to resume breathing, and the symptoms are relieved. The seizures may occur several times a day. The EEG is normal during the interictal period. This infant is irritable and capricious. Education should be strengthened.
2. Syncope: sudden fall, loss of consciousness and loss of generalized muscle tone during seizure. Loss of consciousness for more than 15-20s can occur clonic movements, sometimes apnea, slowed heart rate, salivation, etc.. Even cardiac arrest, pupil dilatation and urinary incontinence may occur. The onset is brief, usually lasting 1 to 2 minutes.
The pathogenesis is due to a stimulus (trigger) through the vagal reflex. The peripheral vascular bed is dilated, peripheral vascular resistance is reduced, and the amount of blood returned to the heart is decreased. As a result, cardiac output decreases, leading to a temporary decrease in cerebral blood flow, or a sharp drop in blood pressure leading to cerebral perfusion pressure is affected and causes syncope.
There are obvious triggers before syncope, such as emotional stress, pain, fear, minor bleeding, medical puncture and injection, etc. It is more likely to occur in hot weather, dirty air, fatigue, and fasting. In this case, if you take the head low lying position can prevent the attack. It rarely occurs in the flat position. Natural awakening after seizure. EEG examination during the seizure and interictal period shows widespread, symmetrical 2-3Hz slow waves of 3-10s, without epileptic discharges.
3. Tic disorder is a fixed or wandering rapid contraction of a single or multiple muscle groups in a part of the body caused by multiple etiologies, with the characteristics of sudden, instantaneous, no aura, involuntary, rhythmless and recurrent attacks.
Clinically, it can manifest as motor tics, vocal tics, sensory tics, and tic-obfuscation syndrome. About 50% of children may have non-specific changes in EEG, and a few have abnormal discharges. Neuroimaging is not specific, but can be useful for differential diagnosis.