Epileptic Son Screaming In Agony

I have a 7 year old boy who has complex partial seizures. He also has recently been diagnosed with abdominal Migraines. When these abdominal migraines happen, he screams bloody murder, holding his hands out in front of him. He says his hands and stomach hurt. It doesn't stop until I give him a Lorazepam.

Before the Lorazepam kicks in, he will then have a coughing fit and then a normal complex partial seizure. Before Lorazepam, I'd take him to the ER and these episodes would last hours. It happens for about two days, once a week.

Question: Does anyone know if an abdominal migraine can cause or lead into a seizure? I don't know if we have a correct diagnosis. Abdominal seizures, his original diagnosis, don't go on for hours, we have been told, hence the abdominal migraine diagnosis.

Thank you!!