Épilepsie et tumeurs cérébrales

Epilepsy is common in patients with brain tumors. Usually, an epileptic seizure is the presenting sign of the cerebral lesion but late seizures may also occur. The tumors type and their locations are determining factors that significantly influence seizure frequency. Brain tumors with a high risk for epilepsy are developmental tumors, slow-growing tumors (low-grade gliomas), hemorrhagic tumors and multiple metastases. Seizures associated with brain tumors are sometimes difficult to treat. This relative drug-resistance may be attributed to several factors: the tumor development, modifications of tumor and peritumor tissues, oncologic treatments. Genetic factors also play an important role and multidrug-resistance proteins associated with brain tumors can be a major cause of epilepsy refractoriness. The choice of the antiepileptic treatment is very important and must take into account individual factors but, in general, the first-line prescription of enzyme-inducing antiepileptic drugs, especially phenytoin, is not mandatory. Given the frequency of epilepsy in patients with brain tumors, a prophylactic antiepileptic treatment could be warranted; but, unfortunately, no study has proven the effect of antiepileptic drugs as prophylactic treatment and a consensus statement from the AAN recommends not using antiepileptic drugs routinely as prophylaxis in patients with brain tumors. Nevertheless, these recommendations are based on studies performed with conventional antiepileptic drugs. Further randomized large cohort studies seem thus required to assess the effectiveness of new antiepileptic drugs to prevent and cure epilepsy in patients with brain tumors.