Infantile spasm typically occurs within the first year of life, characterized by sudden, rapid whole-body convulsions, possibly accompanied by bending, nodding, and upward lifting of hands and flexing of both lower limbs. While some cases may occur upon waking, not all infantile spasms are like this. The causes of infantile spasm are complex, with about 50% of cases having identifiable causes, including maternal infection during pregnancy, brain developmental anomalies, genetic metabolic diseases, difficulty breathing at birth, intracranial hemorrhage, birth injuries, and postnatal nervous system infections. Severe pain symptoms may also resemble the symptoms of infantile spasm and can occur at any time, not necessarily upon waking.