Seizure disorder/ epilepsy: making the diagnosis. The role of an EEG.


A question and an answer.


Hello Everyone, I am glad to meet you. I am new here.

I noticed that a lot of you are having seizures, as well as your diabetes. Seizures are a complication of diabetes. I am going to give you a link:

I also have epilepsy, diabetes and Alzheimer’s. When I was diagnosed with diabetes, I stuck to my diet. My seizures are under control now.

When you have hypoglyclemia, you can have seizures, coma and death. The same is true of hyperglycemia..When your blood glucose goes to low, you need to have a small snack. i never let my BG goes below 90 or higher than 140.

Take care of your diabetes diet and you should not have any problems.

The reason your hypoglycemia seizure does not show up on the EEG, is because it is a Diabetic Seizure. Only epileptic seizures will show up on an EEG.

Your Friend, R





Dear R,

Thank you for writing in. I am glad you are taking such good control of your blood sugar. You say only an epileptic seizure shall show up on an EEG and not a diabetic seizure–that is not quite true. A seizure is a seizure and if you happen to have one while the EEG is running, it shall be recorded on the EEG.

What you are mentioning R is what we neurologists refer to as interictal epileptiform discharges. Think of them as abnormal blips which show up on the EEG when the EEG study is done inbetween the seizures (inbetween means the patient has an EEG study when he or she is not having a seizure at that very moment). Patients who have underlying epilepsy may show interical epileptiform discharges. On the other hand those who have seizures provoked by metabolic factors (low blood sugar–hypoglycemia, low sodium–hyponatremia, low calcium or magnesium) or toxic factors (excessive intake of alcohol or use of a recreational drug such as cocaine) usually do not show interictal epileptiform features and the EEG is frequently reported as normal.

Here I want to emphasize a point. The diagnosis of a seizure disorder/ epilepsy is not made simply based on an abnormal EEG. Put in another way, a normal EEG does not rule out or rule in epilepsy. Many epileptics may have normal EEGs even when the test is repeated many times. Conversely there are people who have abnormal EEGs but no epilepsy. Hence the diagnosis of a seizure disorder (epilepsy) is made based on a thorough history of the patient event (convulsion): what led to the event, what happened during the event, the clinical semiology of the event, whether there were any provoking factors and so forth. The past medical history is explored (any history of significant head trauma, any history of meningitis or encephalitis). The medications the patient was taking at that time are reviewed. Even the birth history is reviewed–was the patient born full term, were there any complications during child birth such as lack of oxygen.



Nitin Sethi, MD


2 thoughts on “Seizure disorder/ epilepsy: making the diagnosis. The role of an EEG.

  1. New post and category: apologies as I did not see how to post a new question.

    Rough day. 45 yo female. Came from er yesterday where I was sent by my neurologist because of a hx of severe migraine w new sx that being flashes of vision loss right eye previous day and intermittent droopy eyelid right side x 7 for 2 hours lasting 30 sec or so each time w headache. Left side unaffected by headache as usual. Comorbidity of crohns in remission and factor 5 Leiden heterozygous w no known clots in remission. Neurologist wanted MRI to rule out clotting so one was done w contrast on venous side. No clots but md at first said something about bright white spots on my brain you might see w ms or migraines or htn. (no htn or dm for me). Also noted to have thickening sinuses on MRI same was true a year ago and to see md. Also found to have 3 mm tumor by pituitary never before seen. Have issues w tachycardia events 120 to 130 at rest and hair and skin changes over a few years, hyst in o8. Throid tumor removed o8 and benign but biggish. Tinnitus for years, largest concern are white lesions. Second concern is tumor. I was quite deficient in vit d (10,000) which has not been rechecked, not sure about b12.

  2. Hi. Quick question. I had an eeg that showed I went to sleep during the test. I know I didn’t. Could it be wrong or should my dr look into this further?

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