Glioma is difficult to treat and epilepsy is not well treated. What happens when both occur at the same time? Epilepsy is an abnormal discharge of nerve cells in the brain that causes brief episodes of brain dysfunction, and is divided into two types: primary and secondary. Patients with glioma presenting with seizures are often the latter. There are two main causes of tumor-triggered epilepsy. The first is due to the location of the glioma growth, or growing larger and larger, compressing the functional areas of the brain, causing abnormal discharges of neurons in the brain and thus manifesting symptoms of epilepsy. This kind of epileptic symptoms will appear before surgery, but through surgery, most patients’ epileptic symptoms will disappear; some other patients still have seizures after surgery and need to continue taking antiepileptic drugs. The second type is those who did not have seizures before surgery but developed them after surgery, which is further divided into two cases. One type of epilepsy appears very early after surgery, which may be caused by edema and bleeding of the local lesion after surgical removal of the tumor. Patients should wait for the edema and bleeding to be absorbed on one hand, and on the other hand, they can consult the doctor to use the appropriate antiepileptic drugs. The other type of epilepsy that occurs only a few months after surgery is due to scar formation in the brain area where the tumor was removed, and as the scar grows, it can also lead to epilepsy, and this is also the time to consult a doctor for antiepileptic drugs. If the epilepsy cannot be controlled even with medication, surgical treatment should be considered. However, it is not recommended to surgically remove the epileptic lesion immediately before taking antiepileptic medication, because after removing some of the scar tissue, the scar will grow back as the brain tissue heals. Both of these categories can be attributed to perioperative epilepsy, which occurs in up to 30 percent of cases. The emergence of secondary epilepsy halfway through the treatment of a glioma can be a real concern. How can we deal with this “roadblock”? In fact, the best thing to do is to prevent epilepsy in advance. In general, the lower the grade of the glioma, the more likely it is to develop epilepsy because of the irritation of the lesion, while the higher the grade of the glioma, because the cells in the lesion are often destroyed, the chance of epilepsy is smaller, or the seizures are not typical. Regardless of whether there was epilepsy before surgery, antiepileptic drugs are required after surgery. If you did not have epilepsy before surgery and you do not have epilepsy for a short period of time after surgery, you can gradually reduce your medication for 2 weeks after surgery until you stop taking it. If you had epilepsy before surgery, then you should take antiepileptic drugs for at least 3 months after surgery. If the EEG does not show any more seizure waves, you can consider tapering off the medication until you stop taking it (see the chart below for the tapering pattern); if the EEG is not normal or if there are recurrent seizures after a period of time, you should continue to take the antiepileptic medication. When antiepileptic drugs are discontinued, they need to be gradually reduced over a period of several weeks and not immediately discontinued to prevent recurrence of seizures. If seizures occur again during the taper, or after stopping the medication, this means that it is not appropriate to taper or stop the medication and that you need to continue taking it until the seizures are no longer occurring and the EEG is normal. If the epilepsy is never controlled, the medication may have to be used for life. Many patients stop taking their medication when they feel that they are seizure-free. This can easily cause seizures again, and then they will have to start taking anti-seizure medication again at the original dose, making the whole anti-seizure process more difficult and complicated. In addition, not all anti-epileptic drugs are available for patients with glioma, so it is important to consult a professional doctor before using them. The most important thing is to consult with your doctor before taking any medication. Especially if you are having chemotherapy after surgery, you should not take any anti-seizure medication. This is because antiepileptic drugs such as phenobarbital, phenytoin sodium, carbamazepine and oxcarbazepine have hepatic enzyme-inducing effects, which can reduce the blood concentration of other drugs and decrease their effectiveness. Patients with malignant glioma (grade III or IV) requiring chemotherapy after surgery should not use these antiepileptic drugs as much as possible; and it is also best not to drink alcohol or beverages containing alcohol during chemotherapy, which can also affect the efficacy of chemotherapy drugs. If these antiepileptic drugs must be used due to the type of seizures, the dose of chemotherapy drugs should be increased accordingly, otherwise the chemotherapy drugs will not work and the tumor will easily recur. But the problem comes again, increasing the dose of chemotherapy drugs will obviously increase the toxic side effects and cause more damage to liver and kidney, which will seriously endanger the health. So comprehensive consideration or try not to combine the above anti-epileptic drugs with chemotherapy drugs. So, which antiepileptic drugs are suitable for glioma patients? Anti-epileptic drugs such as sodium valproate, lamotrigine or levetiracetam do not affect liver drug enzyme activity and can be combined with chemotherapy drugs. Likewise, during the administration of antiepileptic drugs, it is important to regularly review the blood routine and liver and kidney functions, and check the blood concentration if necessary. On the one hand, monitor the effect of antiepileptic drugs and chemotherapy drugs, and on the other hand, monitor the side effects of drugs. Only in this way can the drugs work fully to prevent tumor recurrence and antiepileptic at the same time, and also to minimize the side effects of the drugs. However, not all patients need to be monitored at all times, otherwise it will cause unnecessary financial burden to the patients. In general, blood concentration testing is necessary in the following cases: 1. Currently, it is considered necessary to monitor only those drugs whose blood concentration is closely related to the drug effect and whose effective blood concentration range is narrow, such as carbamazepine, phenytoin sodium, and phenobarbital. Especially phenytoin sodium, its therapeutic dose and poisoning dose are close to each other, the low dose cannot control the seizure, and the high dose is prone to poisoning, so its blood concentration should be measured at the initial dose and before each dose adjustment. The blood concentration of sodium valproate fluctuates greatly, and there is no good correlation between its blood concentration and therapeutic effect, so the measurement is not very meaningful. 2. Due to individual differences, even the efficacy of the same drug may vary for different patients. When the drug dose has reached the conventional dose and still cannot control the seizure, the blood concentration should be measured first to clarify whether it has reached the effective blood concentration. 3. If there is no significant change in seizures after the first dose or increase in dose, the blood concentration must be known before adjusting the dose. The time should be measured after 5 half-lives after the initial dose or increased dose. When two or more antiepileptic drugs are used in combination, the measurement of blood concentration can help to understand the nature and extent of drug interactions, so as to judge the therapeutic effect of each drug. The blood concentration should be monitored when the patient with epilepsy has liver, kidney or gastrointestinal diseases or when other drugs are added, which may have an effect on the metabolism and elimination of the antiepileptic drugs being taken. 6. Blood concentration should be measured as soon as ataxia, mental abnormality or cognitive impairment occurs during treatment, and the dose should be adjusted promptly if the drug concentration is found to be higher than the upper limit of normal.