Febrile convulsions are a common pediatric emergency with a prevalence of 3%-4% in childhood, with the first seizure occurring between 6 months and 3 years of age, especially in infants and young children, averaging 18-22 months. It is characterized by fever with sudden generalized or localized tonic and clonic convulsions of the muscles and is often accompanied by impaired consciousness.
Convulsive manifestations
The symptoms of convulsions have a variety of manifestations. In some cases, only the eyes turn, the eyes look straight or upward, and the face is flushed; in some cases, the muscles of the eyes, face, hands and feet twitch slightly, and then gradually spread to other parts of the body; in newborn children, the symptoms of convulsions are not obvious, only not eating milk, both eyes are open, the eyes are fixed, the eyelids may twitch slightly, and the lips around the mouth are blue, which must be carefully observed; in some cases, the children have convulsions along with headache, irritability, jet Some children are unconscious, with fixed or upturned eyes, squinting, head turned to the side or tilted back, foaming at the mouth, tonic face and hand muscles or involuntary twitching and breath-holding at times. The duration of convulsions can be long or short, generally a few seconds to ten minutes, and long convulsions can occur incontinence.
Classification: simple and complex febrile convulsions
Diagnostic criteria for simple febrile convulsions
(a) The main criteria
1. first onset at the age of 4 months to 3 years and last recurrence at the age of no more than 6 to 7 years.
2, fever above 38,5 ℃, fever followed by convulsions, convulsions occurring within 24 hours after fever.
3.Convulsions are generalized convulsions with loss of consciousness lasting for several minutes (maximum 15 minutes), waking up soon after the attack, and no recurrence within 24 hours.
(ii) Secondary criteria
1. normal electroencephalogram 2 weeks after the convulsive episode.
2, normal cerebrospinal fluid examination.
3, normal physical and intellectual development.
4.Hereditary tendency.
Classification: simple and complex febrile convulsions
2. Diagnostic criteria for complex febrile convulsions.
(a) The main criteria
1, the occurrence of convulsions lasting more than 15 minutes.
2.Convulsions occur more than once within 24 hours.
3. the form of convulsion is partial seizure, with temporary paralysis and other neurological abnormalities after the seizure.
4. Febrile convulsions recur more than 5 times a year.
(ii) Secondary criteria
1. the age of the first seizure can be less than 3 months or more than 6 years.
2. Convulsions occur when the body temperature is not too high.
Risk factors for the development of convulsions into epilepsy.
The percentage of children with febrile convulsions that are predictive of conversion to epilepsy increases when the following risk factors are present
(1) Complex febrile convulsions with seizure duration of approximately 15 minutes, restricted seizures, seizures at less than 38°C, and consecutive seizures from a single febrile episode.
(2) Multiple recurrences of febrile convulsions.
(3) Febrile convulsions are preceded by neurological abnormalities, developmental abnormalities, mental retardation, or perinatal abnormalities.
(4) The first seizure is within 1 year of age.
(5) History of epilepsy or febrile convulsions in the family.
Injuries of convulsions
Convulsions are commonly known as cramps or jerks. It is well known that brain injury can cause convulsions. Since the concept of “convulsive brain injury” was introduced by foreign scholars in 1951, research has gradually increased, and most scholars believe that convulsions can cause both temporary brain dysfunction and irreversible brain lesions. A single convulsion has a transient effect on near memory, comparable to the damage caused by concussion, while a sustained state of convulsion can produce severe brain damage, resulting in symptoms such as mental decline, epilepsy, and limited brain dysfunction.
The causes of brain damage caused by severe convulsions are: ① increased brain metabolism and increased oxygen consumption in the brain during convulsions. ② The whole body oxygen and energy supply is reduced during convulsions. Systemic hypoxia can occur during convulsions. Patients often have breathing irregularities, even respiratory arrest, and obstruction of respiratory secretions during convulsions, so cyanosis occurs in more severe convulsions, and systemic hypoxia can cause cerebral hypoxia in severe cases. In addition, the patient’s blood pressure drops during convulsions, the heart rhythm is disturbed, which can affect the blood supply to the brain, and the drop in blood pressure has a direct impact on the occurrence of brain damage. There are also late convulsions can occur hypoglycemia, causing irreversible brain damage.
Convulsive injury
Short-term convulsions may not appear as a manifestation of brain damage is the role of compensatory function of the brain, but repeated multiple convulsions, or when convulsions continue, the utilization of chemical energy by brain neurons increases greatly, compensatory function declines, and the brain’s energy reserves are depleted, finally leading to irreversible brain damage. Pediatric convulsions lasting more than 30 minutes can produce ischemic lesions in the neurons of the brain, while in adults convulsions last more than 6 hours before such lesions occur. This shows that severe convulsions have a great impact on the development of the pediatric brain, especially in children between 6 months and 4 years of age, when the brain is in a stage of continuous development and perfection, and convulsions cause the most damage to the brain.
The chronic and persistent sequelae caused by severe convulsions are mental retardation, paralysis, epilepsy, and mild brain dysfunction syndrome. The mild brain dysfunction syndrome is characterized by an aroused state, abnormal behavior, inattention, emotional disturbances, sensory abnormalities, language delay, and learning difficulties.
Since repeated convulsions or prolonged convulsions cause great brain damage to children and seriously affect the brain development of children, especially those aged 6 months to 4 years, pediatric convulsions must be controlled and long-term medication must be taken for prevention when there is a possibility of recurrence of convulsions.
Convulsive seizure management principles
The most effective drugs should be used to control convulsions when they occur, and under no circumstances should convulsions be allowed to last more than 20 to 30 minutes, even if they are only minor, localized convulsions. Timely control of convulsive seizures and prevention of persistent convulsions are the most important measures to prevent brain injury. The most effective anticonvulsant drug of choice is Valium; anti-hypoxic measures should also be taken to enhance care, keep the airway open, suction, oxygen, tracheal intubation if necessary, artificial respiration; and symptomatic treatment of hyperthermia, hypoglycemia, cerebral edema and other conditions. After the convulsions are controlled, we should actively search for the cause, determine which of the following diseases is the cause of the convulsions through clinical symptoms and laboratory tests, take appropriate measures to treat them, and eliminate the cause is the key to prevent recurrent convulsions.