A question from a father and some answers for seizures due to hypoglycemia

A father from the Netherlands recently wrote to me about his son. I thank him for his question.  He asked me a few very specific questions. I am reproducing them here as I feel it shall aid other people. My response to his questions follows. Names have been removed to maintain privacy.

QUESTION:

My son is diabetic type 1, since his 5th year. And he had several seizures in the last 5 years. Mostly once a year, every time he had a hypoglycaemia.
The last time he had a epileptic seizure, with a fracture of thoracic vertebra 2. I have made a MRI scan of the brains, but everything seems normal.
Are there other investigations necessary to be sure it is an epileptic insult due to hypoglycaemia, instead of real epilepsy

HK

ANSWER:

Dear HK,

                                  thank you for writing in to me. If I get you right you are saying that all of your son’s seizures have occured in the setting of hypoglycemia. Do you by any change recall what was his blood sugar during these ictal episodes. For a seizure to occur due to hypoglycemia, the blood sugar has to usually fall down to an extremely low level (we call this neurohypoglycemia). As you are aware the brain needs sugar for energy and its metabolism so when blood sugar falls down to the range of 60 mg/dl or less, that is when a seizure occurs. The seizure in the setting of hypoglycemia is usually a generalized convulsion. That said I and many other physicians have seen patients presenting to the ER with focal findings suggestive of a stroke only to find them completely reverse once the blood sugar was corrected.

I do have a few practical suggestions for you:

–have a home blood glucose meter and check your son’s blood sugar at various times during the day such as in the early morning when he wakes up (fasting blood sugar), prior and after lunch (post prandial blood sugar) and finally before he heads to bed during the night.  Do this for about 2 weeks and keep a record of the values in a notebook. This shall prove to be tremendously helpful to you as a parent and his physician to see how his blood sugar fluctuates during the day. Are there times when his blood sugar falls down/ bottoms out unexpectedly.

–a seizure due to hypoglycemia is rapidly reversible and in fact can be aborted with intravenous dextrose solution. Now it may be hard to administer intravenous dextrose at home.

–another very important point which comes to mind is why is he having so frequent hypoglycemic episodes. This shall require a thorough review by his endocrinologist. His insulin dose may need to be adjusted and/or he may warrant frequent small meals during the day to prevent his sugar from suddenly dropping.

–now to your final question: does your son actually have underlying epilepsy per-se. The answer to that depends upon this:

                -has he ever had a seizure in the setting of normal glucose level?

                -an EEG study shall be extremely useful. If the electroencephalogram shows inter-ictal epileptiform activity then likely your son does suffer from epilepsy. Remember in patients with seizures due to hypoglycemia per-se, the EEG between the seizures should be normal.

                -a routine EEG (30 minutes study) can fail to reveal an answer. In that case a long term EEG monitoring study (24-72 hours either in the hospital or in an outpatient setting) may aid in characterization of his typical events.

-as you may have guessed right, patients with seizures due to hypoglycemia per se do not need to be on anti-convulsant therapy. In these patients what we need to ensure that they do not become hypoglycemic. No hypoglycemia means no seizures.  On the other hand if your son does have underlying epilepsy, he shall warrant anti-convulsant therapy.

                -also a neuroimaging study (ideally MRI of the brain) may he helpful to rule out any intracerebral structural cause of seizure.

I hope you find this information helpful. Please feel free to contact me again.

Personal Regards,

Nitin Sethi, MD

Seizures due to hypoglycemia–a couple of questions and answers.

I got a few insightful questions from my readers which I am sharing here. My reply to them follows.

K

Is it possible to have hypoglycemia and suffer with seizures without diabetes?

My Blood sugar level after a seizure is high though quickly drops down (Shock?)

Can Hypoglycemia be a random problem caused by diet at the time and stress etc?

 
  braindiseases  

Dear K,
thank you for writing in. You ask a good question. There can be many causes of hypoglycemia, diabetes mellitus is one of the more common causes. In diabetes mellitus hypoglycemia commonly occurs in the setting of a missed meal (by that I mean, a diabetic patient takes his anti-diabetic medication/ insulin but forgets to take his meal). Another setting may be if one has what is called brittle diabetes. This is a condition in which the blood sugar varies quite a lot. Such patients need fine control of their blood sugar level to prevent episodes of hypoglycemia or hyperglycemia.
Seizures occur due to hypoglycemia per se (low blood sugar), not because of hypoglycemia due to diabetes. What I mean to say is that hypoglycemia due to any cause can cause a seizure provided the blood sugar falls below a critical level (usually less than 50 mg/dl).
Personal Regards,
Nitin Sethi, MD

  S  

hi
im not here to ask a question sorry, just to ponder your mind a little,
ive had type 1 diabetes since the age of 4 (16 years) and i am now 20. when i was 7 i had my 1st seizure. time went on and since ive been 15 ive had around 20 + full on seizures ive had 2 in the street both ive recovered from, but the rest was in my sleep, with no warning atall. i go ridged and ALWAYS bite my tounge and injure myself, suck as banged my head off the cooker, the floor, raidiator etc. after this happens i get sugar rubbed in my gums by my family or friends till i come round, (no paramedic or hospital service involed) but the confusing thing was when i had them in the street and i came around WITHOUT sugar or anything. witch was also confusing for the hospital and my gp. witch also brings me to my next thing.
ive been to my local gp and also im back attending the hospital on a weekly basis.
as ive now been to see my gp today, and gave him details etc. of each seizure. hes now under the idea of sending me to a neurologist as he dosent beleive that my seizures are in anyway linked to my diabetes.
also ive just had my insulin changed from human mixtard 30 (twice daily) to lantus(morning) & novo rapid(breakfast, lunch, dinner).

what i was wondering was, what your thoughts would be on this ?

 
  braindiseases  

Dear S,
thank you for writing in. This is what I feel. I think it shall be worth your time to see a neurologist and get a thorough evaluation for your seizure disorder. Some of your seizures likely can be accounted for by hypoglycemia (the ones in which you make a rapid recovery when sugar is rubbed onto your gums). It is also possible that you have underlying epilepsy/ seizure disorder. This may result in convulsions which are unrelated to hypoglycemic episodes. Also why should you be having hypoglycemia induced seizures if your diabetes is well controlled? As you can understand there are bits in your history which do not “gel”.
So I feel you need a good work-up. A neuroimaging study of the brain (ideally a MRI scan of the brain) and an electroencephalogram (EEG study) may be warranted. Your doctor may then decide to treat you with an anti-convulsant medication.

Personal Regards,
Nitin Sethi, MD

 

Seizures due to hypoglycemia (low blood sugar)

Seizures in the setting of hypoglycemia are well described. The brain needs sugar to function and when the blood sugar falls “too low”, one of the things that can happen is that the patient may have a seizure (this is usually a generalized convulsion-a tonic-clonic or Grand Mal seizure). There is no one level of blood sugar below which one has a seizure (rather the level varies from person to person). Let me explain that with an example. Lets assume you are a diabetic and you take your insulin shot but for once forget to take a meal (maybe you are a hard working executive on the run). You have a convulsion while at work and are taken to the nearest ER. There your blood sugar at the time of presentation is recorded to be 60 mg/dl. There might be another similar patient whose blood sugar falls to 52mg/dl yet he does not have a convulsion. So there is no set limit below which the brain shall have a seizure but speaking in broader terms usually the brain does not tolerate blood sugar below 60mg/dl and below 40 mg/dl most patients shall be symptomatic (either have a convulsion or be confused and obtunded. The term used for this constellation of neurological signs and symptoms as a result of hypoglycemia is NEUROHYPOGLYCEMIA).

The good news though is that seizures due to hypoglycemia are readily treatable. In the ER we load the patient with glucose (usually this is given via an intravenous drip as the patient is obtunded and confused and cannot accept anything from the mouth). The blood sugar quickly rises and the seizures stop. Patients who suffer from hypoglycemic seizures do not need to be on an anti-epileptic drug. These patients do not have epilepsy. If their blood sugar does not fall down again, they will not have another seizure.

Rather a meticulous search should be conducted to find out the cause of hypoglycemia:

-is the patient a diabetic who took too much insulin by mistake?

 -did he miss his meal but took his insulin?

-is there any other cause of hypoglycemia such an insulin secreting tumor?

-is the patient septic?

Hypoglycemic seizures are most commonly seen in diabetics. This emphasizes the importance of good glycemic control in this vulnerable population.

Nitin Sethi, MD