Abstracts

Rationale: Children with pharmacoresistant epilepsy may be candidates for epilepsy surgery. Many require subdural electrodes to better define the region of seizure onset or determine the region of primary function. It is believed by many that larger GRIDS increase the risk of increased intracranial pressure(ICP). It has also been theorized that frequent secondarily generalized seizures cause a significant increase in ICP. ICP monitors were placed in younger children and some children with difficult communicative abilities. We attempted to determine associations between age, number of electrodes and seizure type and frequency and ICP. We also identified periods of maximal ICP.Methods: We reviewed our surgical database from January 2010 to June 2011 for patients who had phase 2 evaluations and ICP monitors placed. Number of electrodes, seizure frequency and duration and days post placement of mean minimum and maximal ICP s were identified.Results: 22 patients had ICP monitors placed ages ranging from 2 to 18 years. 15 patients had negative pressures on the first post operative day. Maximal pressure occurred on days 2/3 in all patients above 5 years of age then gradually decreased over time, remaining stable after 4-5 days. Maximal changes in pressure were seen between days 1 and 2. Young children (<5years) had lower mean ICPs and their fluctuations were less predictable with hourly and daily changes. No associations were found between number of seizures, seizure type and ICP. Conclusions: Negative ICP on day one post op, a rapid increase over 24 hours, followed by relatively higher ICP s on days 2/3 in older children explains the fluctuations in alertness, gastrointestinal upset, headaches and overall discomfort experienced in the first few days post GRID placement. A similar prediction could not be made in younger children. Further studies are required to determine if medication changes or changes in surgical technique could alter the pressure changes and clinical discomfort described.