Epilepsy related to radiotherapy in patients with nasopharyngeal carcinoma.

Radiotherapy is the standard radical treatment for nasopharyngeal carcinoma (NPC) and may cause radiation encephalopathy (RE). To investigate the characteristics of epilepsy in RE after NPC radiotherapy, we observed 101 RE patients after NPC radiotherapy during a 5-year study period. Seizure semiology, brain magnetic resonance imaging (MRI), electroencephalography (EEG) were studied. We found that epilepsy is a common symptom in these patients, with an incidence of 15.8%. In the variables of age, sex, post-radiotherapy interval, radiation dose, radiotherapy techniques, and radiation field, there were no significant differences between RE patients with and without epilepsy. Furthermore, we investigated seizure semiology and EEG records in RE patients with epilepsy, and found that generalized tonic-clonic seizure (GTCS) was the most common type. Cystic lesions in temporal lobes in MRI were more common in RE patients with epilepsy (18.74%), as compared with RE patients without epilepsy (9.41%).