My four year old son was diagnosed with type�1 diabetes almost exactly a year ago and has had two seizures In the last month. His first occurred just after administering his morning insulin when his blood sugar was 4 mmol/L [78 mg/dl], and the second occurred in his sleep yesterday morning. We woke up to the sound of his almost choking or struggling to breathe. We tested his sugar during the seizure and he was 4.1 mmol/L [74 mg/dl] and 5.1 mmol/L [92 mg/dl] five minutes after. The first lasted about 90 seconds, and the second one lasted over three minutes. Both seizures were followed by severe headache, nausea, and vomiting up to ten times over the next few hours. He was also very drowsy and slept on and off for several hours afterward.

Our son’s endocrinologist is convinced that these are low blood sugar seizures, but the pediatrician and neurologist are not sure because his numbers are not that low and want to send him for an EEG to try to determine if there is another problem. I have never heard of diabetic seizures. Can this be the cause? The pediatrician and neurologist do not feel his sugar levels were low enough to trigger a glucagon dump and the resulting seizures. Do you think this is a valid reason for the seizures? Is it worth subjecting a four year old to a battery of possibly useless tests?

What you describe is an all too common occurrence, and I am sure that your son’s endocrinologist is right in thinking that the seizures were due to hypoglycemia. In simple terms, these are the result of too much insulin and too little absorbable carbohydrate available in the early morning hours. The immediate remedy would be to talk to the doctor about reducing his evening NPH and perhaps the Regular too, and to make sure that he has a snack at bedtime that is high in protein and unhydrolysed starch like half an ‘Extendbar’. Guessing that his routine evening dose of insulin is about half the morning one, it looks as though it might be a little high anyway.

In retrospect, you may also find that the seizures were associated with an unusual amount of physical activity on the previous afternoon. In the meantime, you need to monitor his early morning (2 am to 5 am) blood sugars from time to time to see if there are still low levels and to what extent they can be related to exercise and erratic appetite so that the evening insulin dose can be appropriately adjusted. To avoid waking him for these extra blood sugars you might like to consider one of the new essentially painless monitors like the FreeStyle or One Touch® Ultra.

The fact that the blood sugars by the time you were able to do them were not all that low simply means that the normal counterregulatory mechanism was already underway, but too late to prevent the seizure response to an even lower level. In the not too distant future it may be possible to use a device like the GlucoWatch on the calf to warn when blood sugars are getting to a danger level. Finally, it is important to resolve this problem quickly because at this age, hypoglycemia can take its toll on cognitive development, if it isn’t dealt with promptly.

My own feeling is that more elaborate investigations like an EEG could be deferred until these relatively simple adjustments have been made and evaluated.

DOB
Additional comments from Dr. David Schwartz:

It may well be that the glucose levels were lower and triggered the convulsions or that your meter is giving slightly false information. You do not indicated how “tight” your child’s glycemic control usually is, as reflected by the hemoglobin A1c. Sometimes, it is not the absolute glucose value, but the rate that the glucose is falling that causes seizures. In addition, a normal EEG does not necessarily eliminate the possibility of the child having a predisposition to a seizure disorder or epilepsy, but if there is an underlying predisposition to seizures, then your child’s “seizure threshold” (i.e. the degree of resistance to having a seizure) may be lowered by glucose fluctuations. I think I would get the input of the neurologist and, personally, would consider the EEG as as easy screen. If it is abnormal, you will have a leg up on trying to prevent future seizures.

DS