Febrile seizures in children

Introduction to children with febrile seizures Febrile convulsion (FC) is the most common convulsive disease in infants and young children. It is defined as a seizure episode with fever that occurs in infants and young children, and excludes central nervous system infections and those with a history of febrile seizures. It is currently considered that children with simple FC may not be diagnosed as epilepsy. Thermal convulsions are not a simple addition of "fever" and "convulsions". In 1981, Nelson and Ellenberg proposed that febrile seizures refer to the onset of infants and young children, often between 3 months and 5 years. There is fever but not caused by intracranial infection. There are no other clear reasons for convulsions. For example, if there is a seizure before the attack, the seizure is not considered as febrile seizures. Definitions in the book "Pediatric Nervous System Diseases" (edited by Zuo Qihua): The first episode is from 1 month to 5 to 6 years old. In the early stage of upper respiratory tract infection or other infectious diseases, when the body temperature is above 38 °C, Sudden seizures can be diagnosed as febrile seizures after the exclusion of intracranial infections and other organic or metabolic abnormalities that cause convulsions. basic knowledge Proportion of disease: 5% of the risk of illness in infants and young children Susceptible people: children Mode of infection: non-infectious Complications: strabismus

Causes of febrile seizures in children

(1) Causes of the disease

Febrile seizures are the most common convulsions in childhood. Most of them are caused by various infectious diseases. The above respiratory tract infections are the most common. They are found in the early stages of colds and other diseases. When the body temperature suddenly rises, it is also called febrile convulsion. The febrile seizures do not include the brain. Inflammation, meningitis and convulsions coexist when heated.

(two) pathogenesis

In the case of convulsive discharge, a large number of neurons in the brain tissue occur rapidly, repeated lipid depolarization, more energy is needed to maintain the function of the sodium-potassium pump, the synthesis and release of neurotransmitters are also increased, and the cellular metabolic process is accelerated. And the temperature rises during convulsions, muscle twitching also increases systemic metabolism, high fever can increase animal brain metabolism by 25%, the energy required for these activities is 2 to 4 times higher than normal, and the abnormal discharge activity of the brain is the convulsion discharge itself. The need for energy has also increased significantly, which is also an important cause of brain damage, so convulsions have caused the greatest metabolic burden on the brain.

Febrile seizures are the most common type of convulsion in children. The prognosis is generally good, and the incidence of mental retardation is very low. This is because simple episodes of febrile seizures, fewer episodes, shorter time, faster recovery, no abnormal neurological signs. Therefore, there are fewer episodes of seizures on the brain, but a few of them can cause mental retardation. There are two explanations for this. One is that severe febrile seizures can cause brain damage, resulting in epilepsy and mental retardation. This means that the longer the duration of convulsions, the greater the number of convulsions and recurrences, and the greater the likelihood of brain damage. Another view is that the nervous system has abnormalities before febrile seizures, even if the child does not develop heat. Sexual convulsions can also lead to mental retardation, that is, the neurological symptoms of children with febrile seizures are not caused by convulsions themselves, but exist before the onset of febrile seizures. Thermal convulsions and mental retardation are not causal, but common causes. Determined.

In addition, convulsions cause brain damage and age are also closely related. Children with convulsions for more than 30 minutes can produce neuronal ischemic changes. This change occurs only after episodes of convulsions for more than 6 hours. This is because brain tissue metabolism is active in infants and young children. During the period of growth and differentiation, the developing brain tissue is most vulnerable, so the earlier the age of convulsions, the higher the incidence of mental retardation.

In general, if there is an abnormality of the nervous system before febrile seizures, it may lead to mental retardation in the future. Severe persistent seizures can also cause brain damage and affect intelligence.

Pediatric fever convulsion prevention

1. For children with easy onset, pay attention to daily care, strengthen nutrition, enhance resistance, and minimize the occurrence of respiratory and digestive diseases.

2. After the convulsion control, it should be possible to find the original disease of convulsion, and select the corresponding treatment for the primary disease.

Complications of febrile seizures in children Complications

Febrile seizures are more common in childhood and are an urgent symptom of central nervous system dysfunction. More common in infants and young children, the age of good hair is 6 months to 5 years old, with a peak of 9 months to 20 months, the incidence rate is about 2% to 4%, the incidence rate in Europe and the United States is 2% to 5%. . Most of the heat convulsions are caused by various infectious diseases. The above respiratory tract infections are the most common. The typical clinical manifestations of the attacks are: sudden loss of consciousness, more with double eyeballs, gaze or strabismus, facial muscles or muscles of the limbs. Hey or twitching. The onset time can range from a few seconds to a few minutes, sometimes recurrent, or even persistent. Severe febrile seizures can leave behind the sequelae of the nervous system.

Symptoms of febrile seizures in children Common symptoms Loss of paralysis or paroxysmal convulsions, convulsions, convulsions, low heat, fatigue, convulsions

Most of the convulsions occurred within 12 hours after fever, most of which were generalized tonic or clonic seizures, a few were tonic or ambulatory seizures, 15% were one-sided or limited seizures, most of the episodes were short-lived, one heat stroke There was only one episode in the episode, one third of the children had recurrent FC, the convulsion time exceeded 20min (24%), there was recurrence of convulsion within 24h (about 1/4) or the limited local author called complex fever Sexual convulsions, only 2.4% of febrile convulsions turned into epilepsy, the following high-risk factors related to later into epilepsy: within 6 months or after 6 years of onset, family history of epilepsy, abnormal mental performance, complex heat Convulsions, neurological abnormalities such as Todd paralysis after episodes, epileptiform EEG abnormalities after 1 week of heat withdrawal, it is reported that 6.8% of the above high risk factors are converted to epilepsy, 2 are 17% to 22% Up to 50% of the three high-risk factors, and one-third of children with temporal lobe epilepsy have a history of FC, but the causal relationship between the two is still controversial.

Examination of convulsions in children

Because the upper respiratory tract infection often causes this disease, the general peripheral blood test is normal; when there is bacterial infection, the white blood cell count and neutrophils can be significantly increased.

Children with FC showed an increase in slow wave activity or mild asymmetry in the EEG during fever, and the occipital region was obvious for several days. This non-specific abnormality has no significance in evaluating the prognosis. Generally, EEG should be performed after 1 week of heat withdrawal. Examination, some children can see rhythm when awake, photosensitive reaction or occasional spikes in shallow sleep, there are obvious spines, sharp wave release, and the risk of conversion to epilepsy increases.

Diagnosis and diagnosis of febrile seizures in children

diagnosis

Simple thermal convulsion

The diagnostic criteria are as follows:

(1) Minimum standard:

1 The first onset age is 4 months to 3 years old, and the final recurrence is no more than 6 to 7 years old.

2 fever at 38 ° C or more, first fever and convulsions, convulsions occurred within 24 hours of fever.

3 convulsions are systemic convulsions, with loss of consciousness, lasting within a few minutes, and soon awake after the attack.

4 no central nervous system infection and other brain damage.

5 can be accompanied by acute infections such as breathing and digestive system.

(2) Auxiliary standards:

1 EEG was normal after 2 weeks of seizures.

2 Cerebrospinal fluid examination is normal.

3 physical and mental development is normal

4 has a genetic predisposition.

2. Complex thermal convulsions

Also known as atypical febrile seizures, in addition to the diagnosis of simple febrile seizures, any of the following conditions should be considered as complex febrile seizures:

(1) The episode lasts for more than 15 minutes.

(2) Stunned more than once in 24 hours.

(3) The seizure form is a partial seizure or a positive neurological abnormality sign after the seizure.

Complex episodes of febrile seizures can be less than 6 months or older than 6 years of age. When the body temperature is not too high, convulsions occur and the number of relapses is high.

Differential diagnosis

Different from intracranial infectious diseases, according to the disease without neurological symptoms and signs, consciousness is quickly restored to normal after seizures and so on. Identification with epilepsy, the first age of this disease is 4 months to 3 years old, and the clinical features such as early onset of fever are easy to identify.

(1) Intracranial infection: meningitis, encephalitis, brain abscess, etc.

(B) seizures complicated by febrile diseases.

(3) Encephalopathy caused by physical, chemical, and metabolic factors.

(4) Non-convulsive episodes such as chills, jitter, and breath holding episodes.

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