Abstracts

Rationale: To examine the incidence, characteristics and morbidity of headache in children who have undergone hemispherectomy at a tertiary centre for Rasmussen Syndrome. Methods: Data were collected retrospectively and prospectively on 20 children (10 female), age 4-16 years (mean 10 years) with drug resistant epilepsy who underwent hemispherectomy for Rasmussen Syndrome, 1994-2011. At follow up parents were asked to complete the Pediatric Migraine Disability Assessment Score questionnaire (PEDI MIDAS) which measures headache disability (score of 0-10 none or mild disability; 11-30 mild; 31-50 moderate and above 51 severe disability). We also recorded incidence, frequency, characteristics, treatment and family history of headache. Results: At surgery all children had drug resistant epilepsy, mild to moderate hemi-paresis and cognitive decline. None reported troublesome headache prior to surgery, 1 reported a family history of headache. Mean duration of follow up was 7.4 years (range 0.5-17.0). Following surgery, almost all were seizure free (Engel grade I (17/20); II (2/20) and III (1/20). Nearly half (9/20) reported episodes of severe disabling headache (PEDI MIDAS score >51), commencing at 1-24 (median 10) months post hemispherectomy, impacting on ability to function, with days off school and missed social activities. All children with headache met the International Headache Society Classification for migraine (with or without aura) with bilateral or unilateral (fronto or temporal) headache and associated symptoms of nausea, vomiting and/or sound and light sensitivity: 1/9 developed severe headache related to hydrocephalus requiring VP shunt; 2/9 were investigated with ICP monitoring but pressures found to be normal. No clear correlation between AED wean and emergence of headache was determined: 4/9 with headache were taking AEDs compared to 3/11 without headache. Symptom management was disappointing. In all children over-the-counter non-steroidal anti-inflammatory drugs were unsuccessful. Oral triptans for acute headache and pizotifen or propranolol prophylaxis showed some symptom improvement for 3/9. Conclusions: Seizure freedom is likely following hemispherectomy for Rasmussen Syndrome. However a significant number of children have chronic postoperative headache with significant impact on daily life. Incidence of headache in children post epilepsy surgery is not well documented. Headache semiology in this group was migrainous suggesting potential for better symptomatic management (both pharmacological and non-pharmacological). Though numbers are small, the incidence here is greater than expected in the normal population. Further investigation is required specifically whether chronic headache is related to the underlying disease process rather than as a result of surgery.