The Epilepsy Foundation defines a breakthrough seizure as a bout of seizure activity a patient with epilepsy experiences when on a stable regimen of anti-epileptic drugs. While the patient may have control over her seizures a majority of the time, at some point she experiences a seizure for no apparent reason. A reason does exists, though it varies with each person. Knowing what the possible reasons are might prevent breakthrough seizures from occurring.

Non-compliance

For a person to maintain control over his seizures, he must remain compliant with the care plan his doctor has in place. The key aspect in treating seizures are the dozens of anti-epileptic medications a doctor can prescribe. For these medications to be effective, however, they must build up in the bloodstream. If the patient does not take his medication as the doctor states, this cannot happen. In addition, various medications, both prescription and over the counter, can interfere with this process. A patient should always speak with his doctor before taking any other drug.

Personal Triggers

Every person with epilepsy has their own set of triggers; something that causes a seizure to occur. The Epilepsy Foundation cites severe emotional stress, sleep deprivation, flashing lights and video games as reasons for a breakthrough seizure. While medication is helpful, it is not a cure-all. The patient must do her part by avoiding her personal triggers as much as possible.

Discontinuing Medication

Sometimes a patient chooses to discontinue his medication because of the side effects, the number of pills he needs to take each day or because he has been seizure-free for a period of time and feels he no longer needs the medication, according to the National Institute of Neurological Disorders and Stroke. A sudden discontinuation tends to result in breakthrough seizures, as it confuses the body. If and when a doctor chooses to stop or change a medication, he will do so slowly by gradually reducing the dose; even the doctor doesn't know how a patient's body will react to the change.

The Hormonal Factor

Women may be at greater risk for breakthrough seizures only because of the fluctuation of hormones they experience. The University Hospital in Newark, New Jersey explains that a woman who still has menstrual cycles may have a greater number of seizures mid-cycle, as well as prior to her cycle beginning. This is due to the fluctuation in hormones; while estrogen increases seizures, progesterone inhibits them. Progesterone levels are at their lowest, however, just before and in the middle of a menstrual cycle.