Abstracts

Ictal single photon emission computerized tomography (SPECT) is an important tool in evaluating candidates for epilepsy surgery. Previous studies have demonstrated that results are strongly dependent on the timing of the ictal injection. In order to perform injections appropriately (i.e. [lt] one minute after seizure onset) many centres including our own have a health care professional remain at the bedside for the duration of the test (which raises considerable issues regarding availability of resources). The purpose of this study was to compare the timing of isotope injection and SPECT results using a pre-loaded isotope injection system (without a nurse at the bedside) to our standard method with a nurse at the bedside. We compared two methods of performing ictal isotope injections: 1) with a nurse at the bedside (n=22) and 2) with a family member alerting ward nurses at seizure onset (n=14). For method 2, prior to the test a lead-shielded syringe containing isotope was connected to the patient[apos]s intravenous through a y-connector. Timing of injection between methods was compared using a student[apos]s unpaired t-test. Successful injections were obtained in 13/22 patients in method 1 and 11/14 for method 2. No difference in the mean injection time was observed between the two methods (method 1= 23 s and method 2 = 25 s, p=0.65). Positive findings (focal region of cerebral hyperperfusion) were observed in 7/13 patients for method 1 and 4/11 patients for method 2 (note: 2/11 patients from method 2 had a previous negative ictal SPECT). Ictal SPECT injections performed with family alerting nursing staff and a pre-loaded injection system was demonstrated to have comparable timing to our previous method (i.e. nurses at the bedside) without requiring additional resources (the tests were performed on our epilepsy monitoring unit with regularly scheduled nursing staff).