Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is nor recommend specific therapies. However I will try to provide you with some useful information.
Unfortunately, based on research in which patients with
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Epilepsy - resources
Treatment of epilepsy have been studied, the answer to your question is yes, patients with
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Epilepsy - resources
Treatment of epilepsy, including patients with grandmal seizures, can have sudden death. This is "sudden unexpected death in epilepsy", or SUDEP. It is rare, but does occur. The exact cause of the death is not always known. In some patients, a cardiac arrhythmia (disturbance of heart rhythm) is suspected. In others, lack of proper ventilation (impaired breathing) during an unwitnessed seizure, or the lungs filling with fluid (pulmonary edema) may be the cause. Certain measures can be taken to prevent mortality due to seizures. The main one is trying to get the seizures under control, with an appropriate anti-epileptic medication regimen. Also, avoiding activities that can put a person at risk during a seizure (such as swimming unsupervised or being on heights etc) should also be avoided. If there are cardiac concerns, or arrhythmias are of concern, appropriate measures should be taken.
Regarding seizure duration, most seizures last around 1-2 minutes, though seizures of 3 minutes duration are not entirely unusual. Being "out of it" following seizures, what is called the post-ictal state, can last minutes to hours, rarely even days. If prolonged seizures are occurring, and/or frequent seizures, adjustments to the seizure medications may be necessary.
Memory impairment may occur in patients with epilepsy. This could be due to the seizures themselves, due to medications, due to poor sleep, due to depression. Some of these causes, such as depression and poor sleep, and seizure frequency, are treatable, and each of these issues should be addressed. Continued follow-up with your neurologist is recommended, and evaluation by an epilepsy specialist may be of benefit to you.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.