The cause of seizures in Tetralogy of Fallot is episodic hypoxia leading to cerebral hypoxia, which causes seizures, commonly seen in infants. These seizures can be triggered by feeding, crying, emotional excitement, anemia, or infections, manifesting as episodic breathing difficulties. In severe cases, sudden fainting, convulsions, or even death may occur. The underlying cause is the narrowing of the pulmonary artery infundibulum and sudden muscle spasms, which lead to temporary pulmonary artery obstruction, worsening cerebral hypoxia.