Phase II study of alpha-tocopherol in improving the cognitive function of patients with temporal lobe radionecrosis

Radiotherapy is an important treatment modality for brain tumors and is the standard radical treatment for nasopharyngeal carcinoma (NPC). However, the treatment is not free of side effects, and one possible neurologic sequela is the occurrence of temporal lobe radionecrosis (TLN) associated with cognitive dysfunction. Currently, there is no effective intervention to improve patients' cognitive performance.

Twenty-nine patients with TLN after radiotherapy for NPC were recruited on a voluntary basis. Among them, 19 patients (15 males and 4 females) received a megadose of alpha-tocopherol (vitamin E) (2000 international units per day) for 1 year, whereas the other 10 (5 males and 5 females) served as control patients. Their cognitive function (i.e., global cognitive ability, attention, memory, language, and executive function) was evaluated by a battery of neuropsychological tests before and after treatment.

Significant improvement in global cognitive ability (P = 0.035) and memory (verbal: P = 0.036; visual: P = 0.007) occurred among patients in the treatment group after a 1-year medication period. In addition, the executive function of the treatment group improved significantly (P = 0.04). No difference was found between the two groups with respect to attention or language.

The current investigation was a preliminary study on the effect of alpha-tocopherol on the cognitive function of patients with TLN after radiotherapy for NPC. In view of the absence of effective treatment for patients with cerebral radionecrosis, alpha-tocopherol has the potential to be a complementary intervention for patients with cognitive dysfunction due to TLN.