Background:

Seizure localisation traditionally has depended upon semiology, surface EEG and anatomical imaging, usually MRI. Single photon emission computed tomography (SPECT) scanning utilising radio-pharmaceutical tracers allows imaging of brain perfusion changes during seizures. Our videotelemetry unit admits patients for epilepsy surgery evaluation over a 5 day period (Mon-Fri) for continuous videotelemetry recording. An ictal SPECT scan is usually part of their pre-surgical assessment but this is currently available only during normal working hours (weekdays 9am -5pm).

Aim and Objective:

The aim of this audit was to identify the number of patients who would benefit from provision of an out of hours ictal SPECT scan service during their admission for videotelemetry for pre-surgical epilepsy work up.

Methods:

Audit design: Retrospective data analysis of adult patients admitted to the Queen Elizabeth University Hospital, Glasgow, for videotelemetry and ictal SPECT over a 17 week period (1 June -30 September 2013).

Data Collection and Analysis: Data was collected from the videotelemetry unit admissions register and from electronic patient records. Seizures were reviewed for time of onset, duration of seizure discharges and suitability of the seizures for an ictal SPECT injection.

Results:

A total number of 31 patients were identified as having been admitted for videotelemetry and ictal SPECT scanning. 10 /31 (32%) patients, who had seizures, did not get ictal SPECT scan. 9/10 (90%) patients who never got a SPECT scan had seizures occur out of hours. In these patients the majority of seizures (69%) occurred out of hours. 4/10 (40%) of patients who never got SPECT scan had seizures out of hours which were suitable for SPECT injection. 2 of these i.e. 2/10 (20%) patients had seizures occurring ONLY during out of hours.

Conclusion:

A 24 hour service could result in a small increase in the number of patients getting an ictal SPECT scan and possibly improve their chances of having successful epilepsy surgery. However, there are significant logistical challenges and cost implications.