1. What is epilepsy?
Epilepsy is a chronic brain disorder that causes patients to have recurrent brief episodes of abnormal behavior (called “epileptic seizures” in medical terminology). The brain functions based on the bioelectrical activity between brain cells, which we call EEG. Certain brain disorders may interfere with the electrical activity of brain cells, and the resulting abnormal brain cell discharges are responsible for triggering epilepsy. Epilepsy is one of the most common neurological disorders and can affect up to 1% of the population.
The symptoms of epilepsy are highly variable. The medical community has thus summarized hundreds of different manifestations of epileptic seizures and dozens of epilepsy syndromes. If the brain causes that may trigger epilepsy are pursued, a large number of different types of causes are also found, some of which require only medication, while others require surgery to remove.
2. What are the brain disorders that may trigger epilepsy?
With current medical conditions, approximately 65% of newly diagnosed epilepsy patients still have no clear cause. For the other 35% of patients, common causes include stroke, congenital abnormal brain development, brain tumors, traumatic brain injury, and infection. Understanding the underlying causes of epilepsy is crucial for doctors to choose the appropriate treatment.
3. How is epilepsy diagnosed?
For a first-time patient, the doctor first needs to determine whether the patient’s seizure is a seizure or not (it may also be psychogenic or psychotic) to avoid misdiagnosis. In the second step, the doctor also needs to determine the type of seizure the patient is having. Third, an epilepsy specialist also needs to do his or her best to figure out what the underlying cause of the patient’s epilepsy is. Doctors will take the following approaches when diagnosing epilepsy.
(1) Asking the patient about the condition in person. In the diagnostic room, the doctor may ask questions such as
How old were you when you first had a “seizure”?
What were you doing at the time of your first seizure?
Do you think there were any possible triggers for your seizure?
Did you have any unusual physical or psychological sensations in the seconds before the seizure?
Were you conscious at the time of the seizure? What sensations did you have? Did you have any abnormal sensations in the minutes after the seizure?
How long did the seizure last?
What previous treatment have you received?
What medications have you taken? At what dose?
Did the seizures lessen after taking the medication?
(2) If a relative or friend of the patient witnessed the seizure, the physician will need them to describe the specific manifestations of the seizure.
(3) A neurological physical examination.
(4) The doctor will give the patient an outpatient checklist with items such as
A long-range video electroencephalogram (EEG).
Magnetic resonance imaging (MRI) of the brain.
Blood tests may be required if systemic disease is suspected.
PET, SPECT, MRS, or electronic visual field examinations may be required if specific etiologies are suspected.
Of the above tests, the EEG is the most important one. This is because EEG is the only objective method of obtaining electrical activity in the brain that is currently available. To do an EEG, some miniature metal discs are attached to the surface of the patient’s scalp and the other end is connected to a monitor with a thin wire. At the same time, a continuous video recording is made and all the patient’s actions during the seizure are recorded for simultaneous EEG analysis. In order to obtain real and valuable data, the doctor may require the patient to undergo continuous monitoring for 1 to 7 days, so this test requires hospitalization to complete. The results of the EEG monitoring are used by the doctor to determine if the patient can be diagnosed with epilepsy and exactly what type of epilepsy it is.
4. How is epilepsy treated?
Most epilepsy can be well controlled with oral antiepileptic drugs. Doctors choose medications for patients based on a number of factors, such as whether the seizures are partial or generalized, how often they occur, how severe they are, the patient’s age, the patient’s overall health status, and past medications.
Antiepileptic drugs each have some different side effects, so the doctor may adjust the medication usage and dosage based on the patient’s response after taking the medication. The process of adjusting medications may take several months to complete, and eventually the patient will settle on 1 or 2 medications that are best for him or her (with the least significant side effects) over time. It is important to maintain regular contact with your doctor during this phase. Overall, about 60% to 70% of patients can achieve good control of their condition on oral antiepileptic drugs.
For the other 30 to 40% of patients, despite taking more than 2 to 3 antiepileptic drugs, the seizures are still not well controlled, and it is time to seek the help of an epilepsy specialist to discuss the possibility of surgery.
5. What are the side effects of antiepileptic drugs?
It is important to recognize that any medication may have side effects in addition to its therapeutic effects. Whether side effects occur after taking antiepileptic drugs depends on the individual’s sensitivity, the type of drug, the dose and how long the drug is taken. In general, side effects are less common with smaller doses and more common with larger doses. The side effects may be more pronounced at the beginning of the course of the medication, and may be tolerated over time as the medication is taken. To minimize discomfort, doctors usually start with a small dose of antiepileptic drugs and gradually increase the dose until it is effective as the patient tolerates it.
Common side effects include blurred vision, double vision, fatigue, drowsiness, irritability, stomach upset, rash, decreased blood cells, liver damage, swollen gums, hair loss, weight gain, and tremors.
6. What should pregnant women be aware of?
It is entirely possible to conceive and deliver a healthy baby, even if you have epilepsy (provided that you are under the right pregnancy guidance conditions). A consultation with an epilepsy specialist should be held before planning a pregnancy. You should take a multivitamin and folic acid during pregnancy. This is because some antiepileptic drugs can lower important vitamins in the body.
There are some antiepileptic drugs that can interfere with the action of birth control pills and cause contraception to fail (unplanned pregnancy). In case of an unplanned pregnancy, a pregnant woman should first consult her own doctor and should never stop her medication (meaning antiepileptic drugs) on her own. This is because sudden discontinuation of medication may lead to severe seizures, which may threaten the safety of the fetus.
The frequency of seizures does not usually change significantly during pregnancy. Blood levels of antiepileptic drugs should be monitored during pregnancy. This is because the blood levels of antiepileptic drugs gradually decrease during pregnancy, dropping to a minimum around the time of delivery, which is a major trigger for seizures. Again, pregnant patients with epilepsy are reminded not to stop their medication without medical supervision.
Most people with epilepsy are still able to deliver vaginally (commonly known as “normal delivery”), with a few exceptional cases requiring a cesarean delivery. Mothers taking antiepileptic drugs can also breastfeed their babies. Sometimes, a small amount of medication in the breast milk may make the baby a little drowsy or irritable. If this happens, suspend breastfeeding and consult your doctor.
7. Can epilepsy be treated by surgery?
Patients with certain specific causes of epilepsy (e.g., tumors, hippocampal sclerosis), or certain patients with drug-refractory epilepsy with exact localization, should undergo surgical treatment. The basic principle of surgery is to remove a portion of the diseased brain tissue that is the origin of the abnormal discharges in the brain, known in medical terms as the “epileptic zone of origin”. In order to accurately determine the “epileptic zone of origin” before surgery, the epilepsy surgeon needs to carefully examine the patient’s seizure symptoms, MRI images, and EEG performance. For some patients, surgery has the opportunity to “cure” epilepsy.
Which patients with epilepsy are suitable for surgery?
In principle, cases of focal seizures that are not well treated with medication are candidates for epilepsy surgery. Surgery may remove a small lesion of only a few millimeters or a large lesion involving 2-3 lobes of the brain. After the epilepsy specialist initially determines that a case is suitable for surgery, he or she will refer the patient to an epilepsy surgery specialty (subdivided under “neurosurgery”) for surgical treatment.
9. What types of surgery are available in epilepsy surgery?
Epilepsy surgery focuses on the removal of intracerebral lesions that cause seizures, including hippocampal sclerosis, brain tumors, cerebrovascular malformations (hemangiomas), old stroke lesions, and developmental malformations of the brain.
The most commonly performed type of surgery is temporal lobectomy, which involves removing a portion of abnormal temporal lobe brain tissue and is used to treat patients with “medial temporal lobe epilepsy syndrome”. In addition to surgery for temporal lobe epilepsy, the next most common type of surgery is surgery of the frontal, parietal, and occipital lobes. For epilepsy surgery in these areas, it is possible to use intracranially implanted invasive EEG techniques for precise localization of the epileptic region of origin. After obtaining satisfactory intracranial EEG data, precise resection of the epileptic focus will be performed based on the monitoring results.
In addition to the “excisional” procedures described above, when the condition is very severe and the entire hemisphere is involved, a procedure to disconnect the fibers connecting the hemispheres bilaterally or vagus nerve stimulation may be used to relieve the condition.
10. What is vagus nerve stimulation (VNS)?
VNS is a new type of surgical treatment for epilepsy. It involves continuous micro-electrical stimulation of the vagus nerve in the neck by means of an electrical stimulation generator implanted in the body. Since the vagus nerve is connected to many parts of the brain, electrical stimulation of the vagus nerve in the neck produces an inhibitory effect on cortical epileptiform discharges. This therapy provides an additional 40 to 60% chance of remission in patients with epilepsy for whom drug therapy has failed and resection is not possible.
The above, in only limited space, describes some of the basic principles in epilepsy treatment. In specific cases, you will need to consult with an epilepsy specialist to get the best plan for you.