Headache as a risk factor for neurovascular events in pediatric brain tumor patients.

OBJECTIVE: To determine whether severe recurrent headache is a risk factor for neurovascular events in children who received radiation for brain tumors. METHODS: This is a retrospective cohort study of children with brain tumors who received cranial irradiation at a large tertiary care center, aged 0-21 years at diagnosis, with initial treatment between January 1, 1993 and December 31, 2002, and 2 or more follow-up visits. Patients were considered to have severe recurrent headache if this appeared as a complaint on 2 or more visits. Headaches attributed to tumor progression, shunt malfunction, or infection, or appearing at the end of life, were excluded. Medical records were reviewed for events of stroke or TIA. RESULTS: Of 265 subjects followed for a median of 6.0 years (interquartile range 1.7-9.2 years), stroke or TIA occurred in 7/37 (19%) with severe headaches compared to 6/228 (3%) without these symptoms (hazard ratio 5.3, 95% confidence interval 1.8-15.9, p = 0.003). Adjusting for multiple variables did not remove the significance of this risk. Median time to first neurovascular event for the entire cohort was 4.9 years (interquartile range 1.7-5.5 years). CONCLUSIONS: Severe recurrent headache appears to be a risk factor or predictor for subsequent cerebral ischemia in pediatric brain tumor survivors treated with radiation. This finding has clinical implications for both monitoring survivors and targeting a specific population for primary stroke prevention.