Abstracts

Rationale: Drug withdrawal is often necessary in the Epilepsy Monitoring Unit (EMU) to facilitate seizures, and particularly used for children undergoing pre-surgical evaluation. There is an increasing emphasis worldwide on EMU safety, however literature detailing outcomes of drug withdrawal is sparse. In units with limited resources (including access to ictal SPECT) strategies for drug withdrawal need to be tailored to accommodate patient safety and the individual unit resources. This is a review of data from a newly established service. Methods: Retrospective review of EMU and hospital record data of patients with intractable epilepsy admitted for pre-surgical Video-EEG evaluation ( /- ictal SPECT) and undergoing drug withdrawal at the Royal Children s Hospital EMU, Brisbane. This EMU currently has limited access to ictal SPECT services (4-6 morning sessions per month, each with a 3 hour window, and a maximum of two consecutive sessions per week). During periods of drug withdrawal patients have a carer present at all times, intravenous access and continuous overnight oximetry, and an individualized management plan for prolonged seizures. Patients are reviewed 1-2 times daily by a Paediatric Epileptologist/Epilepsy fellow, and EEG scientists monitor patients during normal working hours. Patient data reviewed included seizure history, seizure frequency during admission, status epilepticus (SE), the inpatient drug withdrawal strategy, success of admission (i.e. typical seizure achieved, /- SPECT when relevant), and need for emergency management. Results: There were 31 admissions (28 patients) from May 2008 to May 2010. Pre-admission seizure frequency was less than weekly in 7 patients; 12 patients had a history of SE. Drug withdrawal was individualized, based on the patient seizure history and anticonvulsant medication type. Drug withdrawal was full (3 admissions) or partial (28 admissions) and commenced on the first day in 17 admissions. Three patients had partial withdrawal of chronic benzodiazepine treatment. The admission was successful in 25 patients (typical seizures obtained); of these, ictal SPECT imaging was achieved in 17. SPECT imaging was not able to be achieved during 3 admissions due to lack of seizures occurring in the allotted time, including 1 patient with an unsuccessful attempt on repeat admission. Overall seizure frequency increased during 15 admissions, decreased in 4 admissions, and remained unchanged in 12. Benzodiazepine treatment was required for prolonged seizures on 6 occasions, including 2 episodes of SE. There were no admissions to the intensive care unit. Conclusions: Tailored drug withdrawal can achieve successful results in the EMU, even in the presence of limited resources. There is a requirement for individualized patient management to provide the safest possible outcomes.