Patient's question:
At the ages of 11 and 14 months, the child had two episodes of sudden convulsions while in good spirits. The symptoms included staring, pursed lips (sometimes with slightly purple lips and foam), slight head shaking, and clenched fists. Each time, the convulsions recurred two or three times within an hour, followed by another episode after a few days. Both times he was taken to the hospital, he was diagnosed with febrile seizures. The first time, a brain CT was performed, and the second time, an EEG was conducted, both of which were normal. However, no fever was detected before each convulsion (though sometimes his hands and feet felt a bit cold), and only after measuring his temperature afterward did we find it was 38 or 39 degrees Celsius. Is he really experiencing febrile seizures? Why did they come on so suddenly? How can they be prevented? If it's not due to fever, what could it be?Doctor's answer:
Hello,Any sudden high fever can potentially cause febrile seizures, with an incidence rate of approximately 2–8%. It is the most common cause of seizures in children, accounting for about 30% of all pediatric seizures. Febrile seizures are more common in children aged 6 months to 3 years, as this stage of brain development is not yet fully mature, and their inhibitory abilities are weak. Even mild stimuli can trigger strong excitement and spread in the brain, leading to abnormal neuronal discharge and seizures.
In addition to age factors, genetic factors also contribute to the development of febrile seizures. Approximately 40–58% of close relatives of patients with febrile seizures or epilepsy also have a history of these conditions.
Typical febrile seizures (simple febrile seizures) have the following characteristics:
⑴ More common in children aged 6 months to 3 years, occasionally seen in children aged 4–5 years, and rare in those over 6 years old.
⑵ The child generally has good health.
⑶ Seizures often occur when the body temperature rises sharply to ≥39°C at the onset of illness, commonly seen in acute viral upper respiratory tract infections.
⑷ Seizures are generalized, infrequent (most children only experience one seizure during a fever), short in duration (seconds to 10 minutes), and recover quickly without abnormal neurological symptoms. Simple febrile seizures have a good prognosis and generally do not affect intelligence, learning, or behavior. 30–50% of children may still be prone to seizures during subsequent fevers, but these usually cease by the time they reach school age.
A febrile seizure is classified as complex febrile seizure if it meets any of the following criteria:
⑴ Onset before 6 months of age or after 6 years of age.
⑵ Duration exceeds 15 minutes.
⑶ Multiple seizures during a single febrile illness.
⑶ Focal seizures.
⑷ Temporary paralysis or other neurological abnormalities after the seizure.
⑸ Initial onset with high fever (≥39°C), but subsequent seizures occur with moderate or low fever.
⑹ Abnormal EEG findings one week after fever subsides.
⑺ Positive family history of epilepsy, and some scholars advocate classifying this type as "febrile-induced epilepsy."
Febrile seizures may progress to epilepsy, with risk factors including:
⑴ Pre-existing neurological developmental abnormalities.
⑵ Family history of epilepsy.
⑶ The first seizure exhibits complex febrile seizure characteristics.
If only one risk factor is present, the likelihood of developing epilepsy is 1–2%. With 2–3 risk factors, the risk increases to 10%. If the first seizure presents with 2–3 complex features (focal seizure, duration >15 minutes, or recurrence within 24 hours, followed by neurological abnormalities), the risk of developing epilepsy rises to 20%.
There is no specific medication for complex febrile seizures, but prophylactic treatment can be used for children with frequent recurrences. Methods include:
⑴ No medication during normal periods, but use anticonvulsant drugs (e.g., diazepam enema) at the onset of fever to reduce recurrence.
⑵ Long-term medication with phenobarbital or sodium valproate for several weeks to 1–2 years. However, due to the need for long-term use and potential side effects, this approach should be used cautiously.
It is recommended that your sister take the child to a local hospital for diagnosis and treatment.
During a seizure, parents should note:
- Do not panic to prevent injuries from falls due to convulsions.
- If the seizure is brief, you may not have time to act before it stops.
- If the seizure is prolonged or recurrent, seek immediate medical attention for anticonvulsant medication and oxygen therapy.
- After the seizure stops, clear any vomit from the airway to maintain respiratory.
How to prevent seizures:
- Avoid upper respiratory tract infections as much as possible.
- Use antipyretic drugs (e.g., metamizole nasal drops) at the onset of infection.
- Long-term medication can be used for complex febrile seizures.
Preventing recurrence of complex febrile seizures is particularly important, as each seizure may cause hypoxia in brain cells, affecting the child's long-term prognosis.
How to handle seizures in children:
Children are sensitive to external stimuli, and their thermoregulatory centers are unstable, often leading to unexplained fever. If the child is alert despite fever, there is no need to overreact. However, infants and young children with underdeveloped nervous systems are prone to seizures (or convulsions) due to excessive brain cortex excitement during high fever, causing generalized or focal muscle spasms. Seizures often occur when the temperature exceeds 40°C.
1. Cooling: Open windows to ensure fresh air. Dry the body with a towel if sweating is excessive and change into loose clothing. Drink plenty of water or juice.
2. Cold compresses: Apply cold, damp towels to the groin, armpits, and behind the knees, changing them every 3–5 minutes. These areas have rich blood vessels close to the skin, making them ideal for heat dissipation.
3. Warm bath: Place the child in water at about 32–34°C for 10–15 minutes, then dry the body with a towel.
4. Oral antipyretics: Such as phenobarbital tablets.
5. During a seizure:
- Loosen the child's clothing to ensure breathing is not obstructed.
- Place a clean gauze or handkerchief between the upper and lower teeth to prevent biting the tongue.
- Avoid forcing it too hard or filling the mouth too full to prevent choking or airway obstruction.
- Tilt the child's head to one side to keep the airway clear and facilitate the expulsion of vomit.
- Press the philtrum to help the child regain consciousness.
- If the temperature is above 39°C, take cooling measures.
- Seek immediate medical attention.
When febrile seizures should not be diagnosed:
Febrile seizures are not simply the sum of "fever" and "seizure." In medicine, febrile seizures are defined as: onset in infancy (usually between 6 months and 5 years), seizures accompanied by fever but not caused by intracranial infection or other clear etiologies. If afebrile seizures have occurred before, the current episode is not considered a febrile seizure. Therefore, the following conditions should not be diagnosed as febrile seizures:
(1) Central nervous system infection with seizures.
(2) Other central nervous system diseases (e.g., cranial trauma, intracranial hemorrhage, space-occupying lesions, cerebral edema, epilepsy) with febrile seizures.
(3) Severe systemic metabolic disorders (e.g., hypoxia, electrolyte imbalances, endocrine disorders, hypoglycemia, hypomagnesemia, vitamin deficiencies or dependencies, poisoning) with seizures.
(4) Obvious genetic diseases, birth defects, or neurocutaneous syndromes (e.g., tuberous sclerosis), or congenital metabolic disorders (e.g., phenylketonuria or gangliosidosis) with febrile seizures.
What to do if a child has recurrent febrile seizures:
Children with a history of febrile seizures often worry that fever will trigger another seizure. This concern is valid. How can recurrent febrile seizures in children be prevented?
For general non-complex febrile seizures, the best approach is to use traditional Chinese medicine (TCM) for post-seizure recovery. TCM believes that febrile seizures in children are caused by excessive heat (heat pathogen) stirring up "liver wind." Therefore, after the fever subsides and the seizure resolves, TCM treatment should focus on calming and extinguishing wind to clear liver fire, extinguish liver wind, restore normal organ function, and prevent recurrence. TCM post-seizure treatment should be tailored to each child's constitution and the cause of the high fever. Commonly used calming and extinguishing wind herbs include:
- Uncaria, (butterfly wings), pearl mother, raw oyster shell, dried silkworm pupa, earthworm, safflower, white peony root, roasted jujube seeds, etc.
Additionally, children often suffer from yin deficiency after febrile illnesses, so yin-tonifying herbs should be used appropriately, such as:
- Raw rehmannia, sandalwood, orchis, asparagus, and radix trichosanthis, etc.
If a child has multiple febrile seizures, TCM treatment is recommended. Below are several proven TCM formulas from renowned pediatric TCM practitioners for reference:
(1) Prevention Decoction:
- Ingredients: Uncaria, (butterfly wings), gardeniae, roasted jujube seeds, white peony root, indigo, safflower, coptis, pearl mother, and licorice (each 3–5 grams).
- Method: Decoction, taken once daily or every other day for one week. Effective in preventing recurrence.
(2) Qing Gong Powder:
- Ingredients: Curcuma, raw gardeniae, alabaster, scutellaria, coptis, tortoiseshell, amber, cinnabar, and menthol.
- Method: Grind into fine powder, with dosage determined by age. Helps clear residual heat and calm seizures.
(3) Qing Re Powder:
- Ingredients: Cinnabar, amber, Uncaria, talc, mint, persimmon frost, cardamom, and licorice.
- Method: Grind into fine powder, with dosage determined by age. Helps calm seizures.
How to prevent recurrence of febrile seizures:
In addition to controlling seizures, febrile seizures require prompt fever reduction and active investigation of the underlying cause. Since febrile seizures have a high recurrence rate, prevention is crucial. The goal is to avoid recurrence in the vulnerable age group (under 6 years), prevent prolonged seizures, reduce the risk of epilepsy, and prevent intellectual developmental delays.
Currently, intermittent medication is commonly used: after the first seizure, medication is taken immediately upon fever. This method is easily accepted by parents. However, phenobarbital alone does not prevent recurrence, as it requires at least 7 days of consistent use to reach stable blood concentrations, and a single dose takes 4–6 hours to reach peak levels. Thus, diazepam suppositories (5 mg each, every 8 hours during fever) have been tried with some success.
For long-term medication to prevent recurrence, some advocate daily dosing regardless of fever. However, given the high incidence of febrile seizures and the rarity of severe long-term sequelae, this approach imposes unnecessary burdens on most patients. Additionally, phenobarbital can cause side effects such as drowsiness, agitation, and hyperactivity. Therefore, current guidelines recommend long-term medication for the following cases:
(1) Complex febrile seizures.
(2) Cases with risk factors, especially after the second seizure.
Long-term medications may include phenobarbital, primidone, sodium valproate, or carbamazepine.