What is the reason for sudden convulsions in young children?

Patient's question:

The patient suddenly experienced convulsions, without fever, and turned purple all over. What could be the reason? Gender: Male

Doctor's answer:

Hello: Common causes of childhood cramps
　　Childhood convulsions (also known as cramps, seizures, or febrile convulsions) are a common emergency symptom of central nervous system organ or functional abnormalities during childhood.
　　I. There are many common causes of childhood convulsions, among which high fever convulsions are most common in children aged 6 months to 3 years, occasionally seen in infants aged 4 to 5 years. They often occur during acute respiratory infections when the body temperature suddenly rises to 39°C to 40°C or higher. After the convulsions stop, consciousness returns to normal without causing brain damage, and the electroencephalogram temporarily shows slow waves before returning to normal. If the convulsions are accompanied by a family history of epilepsy, there may be a risk of developing epilepsy later.
　　II. Convulsions caused by central nervous system infections are the second most common cause after high fever convulsions. In addition to a rapid rise in body temperature, most children experience drowsiness, lethargy, delirium, or coma before or after convulsions. Common diseases include various encephalitis, meningitis, toxic dysentery, sepsis, etc.
　　III. Convulsions caused by non-central nervous system disorders can occur at any age, and the body temperature is often not high before or after convulsions, but they are often accompanied by intellectual delays.
　　IV. Central nervous system functional abnormalities, such as primary epilepsy, as well as various toxicities, such as carbon monoxide poisoning, pesticide or insecticide poisoning, plant or food poisoning, etc., can also manifest as convulsions.
　　V. Certain nutritional deficiencies in infants and young children often resemble convulsion symptoms, such as vitamin D deficiency, hypocalcemia, etc.
There are many causes of childhood convulsions. It is necessary to analyze the child's medical history, the characteristics of convulsion episodes, other accompanying symptoms, and combine various examinations to make a comprehensive assessment.