My Question Is About My 18 Month Old Grandson, XXXXXXX

Question: My question is about my 18 month old grandson, XXXXXXX I have two areas of concern. When XXXXXXX was around 7 months old we noticed him having what we thought were small siezures. He would suddenly hold his arm up in the air. He never lost consciosness. We took XXXXXXX for extensive testing to see if he had a significant problem. He went for testing at the University of Kentucky, The doctors there concluded that he had no serious problem-just a condition which he would grow out of. XXXXXXX has been having no problens and seems to have grown out of this condition. Everything has been just fine until about a week ago. XXXXXXX caught a viral infection which caused him to start throwing up. He could not stop throwing up all day. He couldnt hold any liquid down. His parents took him to his pediatrician, who put him in the hospital for most of a day. XXXXXXX got nausea medication and IV fluids. The doctor thought XXXXXXX would be OK to go home later that night. When XXXXXXX got home he would not eat and did not drink much liquid. This went on for another 3 days, with him continuing to throw up and not eat. His mother contacted the pediatric nurse on call and she thought he would be better soon. ON Christmas Eve XXXXXXX ate a small and started to drink water. He would not tolerate Pedialite. On Cristmas day XXXXXXX seemed better. He was playing with his toys. Suddenly things changed. XXXXXXX went from playing to collapsing on the floor. He turned blue. His grandfather, who thankfully knows CPR tried to breathe in Cade's mouth but XXXXXXX had clenched his mouth, so he had to breathe into his nose. Cade's dad was working on Cade's chest. Finally after about 20 seconds XXXXXXX made some noises and finally started breathing on his own.We had called 911 and had an ambulance crew and 3 volunteer firemen. They checked XXXXXXX over. He was extremely drowsy and seemed weak. After finding out about Cade's illness, they concluded that his blood sugar had dropped causing him to quit breathing.
Thankfully, we averted a tragedy that day. The whole family is very worried about XXXXXXX He is going to see the neurologist on Monday. Is it very likely that a child could stop breathing due to his viral illness? Is this likely to happed again? Also what part could his early baby siezures play in this. He has been cleared of any neurologial issues. Basically we are scared and don't know what to think.