Oh, having other conditions such as GERD, sinusitis and sleep apnea can all aggravate his asthma. Making it more difficult to control yet. Many asthmatics present with night time symptoms when their asthma is out of control.
It sounds a bit like sleep apnea to me. I'm not a doctor, but this is a common condition and can happen to children. You could always ask for a sleep oximetry test, which is done at home. A device is attached to their finger and measures the amount of oxygen in their blood. If the person has sleep apnea, then there will be multiple times during the night where they will stop breathing and a drop in the oxygen levels will be noted. The body on it's own will restart the breathing. However, this type of sleep is very disruptive and can make for a very tired person. If he has this, then he will have even more behavioral problems as a result. It is something worthwhile to look into.