Aliza Kumpinsky Emory Neurology, PGY

 Case conference  Video  Images/report

 Uses 99m Tc-HMPAO or 99m Tc-ECD to study cerebral blood flow  Ictal images are obtained by injecting radiotracer at onset of seizure (within seconds)  97% sensitive in temporal lobe epilepsy to identify focus

 Do the results of ictal SPECT add value beyond what is already learned by ictal scalp EEG and MRI?  Will it change our management?

 Randomized clinical trial to address whether ictal SPECT added value in mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS)  Hypothesis is that ictal SPECT would NOT decrease invasive EEG and would NOT decrease the probability of offering surgery to MTLE

 Primary  Proportion offered surgery  Proportion who had invasive EEG monitoring  Secondary  Post-surgical seizure outcome  Hospital cost  Length of stay during pre-surgical evaluation  Percent with secondarily generalized seizure

 Single center in Brasil,  Enrolled at the time of admission for inpatient cvEEG  Requirements  ≥ 18 years old  Clinical picture of medically refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), such as complex partial seizures with epigastric, autonomic, or psychic auras  Interictal EEG that included pathology over temporal lobe  MRI showed hippocampal atrophy on T1 and increased hippocampal signal on T2 MRI sequences  Failure of 2 AED’s  Also included patients with features that did not meet all criteria

 Randomly assigned to +/- SPECT  SPECT interpreted by blinded nuclear radiologist  Surgical decision process  Weekly multi-discipinary meetings where treatment plan was formulated  If results suggested that one temporal lobe was responsible for sz and risk of post-op memory deficits was low   If results suggested bitemporal MTLE based on MRI or EEG; and SPECT or neuropsychology testing did not lateralize   If invasive EEG suggested unilateral sz onset and risk of post-op memory deficits was low   If at risk for post-op memory deficits  ▪ If could recall 9/16 items  surgery invasive EEG surgery WADA surgery

 Intention to treat analysis  Hypothesis is that both groups would have similar findings of primary and secondary end points  Estimated that a 10% difference would need 120 patients per group

 3 had movement artifact  2 had uneven distribution of radiopharmaceutical  Average time seizure onset to radiotracer injection was approx 40 sec

 Proportion offered surgery was similar between SPECT and non-SPECT  Proportion who had invasive EEG monitoring was similar between SPECT and non-SPECT

 Mean hospital stay longer in SPECT compared to non-SPECT  Hospital costs were 35% higher for SPECT compared to non-SPECT  Proportion with secondary generalized seizures was higher in SPECT compared to non-SPECT

 Ictal SPECT was concordant with ictal EEG in 80% (95% CI 72% - 87%)  Accuracy was lower in those with bilateral interictal spikes (68%) compared to those with unilateral interictal spikes (90%)

 Out of 240, surgery was considered in 199 and performed in 163  Anterior resection of temporal tip followed by microsurgical resection of mesial temporal structures  Typical f/u 56.7 months post-op (range )  57.1% were seizure free (95% CI )  Proportion with Engel class I was similar between SPECT and non-SPECT

 "Ictal SPECT does not add additional localizing value over standard ictal EEG-video telemetry and high quality MRI in pre- surgical evaluation of patients with MTLE- HS"

 If a patient had bilateral independent seizure onsets on EEG -->  If patient had MRI and video-EEG that were concordant but ictal SPECT was non-lateralizing -->  If video-EEG was ipsilateral to hippocampal atrophy and SPECT was non-concordant -->  If results were bilateral -->  The authors felt that ictal SPECT would be useful in those with unilateral hippocampal atrophy and ipsilateral interictal EEG + bilateral synchronous ictal EEG findings invasive evaluation surgery no invasive monitoring invasive monitoring

 Not blinded  In decision making process, patients with bilateral independent ictal EEG pattern or ictal onset contralateral to hippocampal atrophy required invasive monitoring to confirm ictal EEG onset regardless of other studies  More weight to ictal EEG compared to ictal SPECT  Only applicable to adults with MTLE-HS

 Not blinded  “Comment" section suggested blinding clinicians to results of SPECT and comparing to intracranial EEG rather than using it as a factor in decision-making process  Alternate use of ictal SPECT  Lateralization or localization of epilepsy is uncertain  Guide placement of invasive monitoring  Identify bilateral foci

 Utility of ictal-interictal SPECT relies on the decision-making process of the group  More investigation is needed on how to use SPECT in a meaningful way in pre-surgical work-up for epilepsy  Important to look critically at imaging studies in terms of usefulness and cost-effectiveness

 Utility of ictal single photon emission computed tomography in mesial temporal lobe epilepsy with hippocampal atrophy: a randomized trial. Tonicarlo R Velasco Lauro Wichert-Ana Gary W Mathern David Araújo Roger Walz Marino M Bianchin Charles L Dalmagro Joao P Leite Antonio C Santos Joao A Assirati Carlos G Carlotti Americo C Sakamoto. Neurosurgery online, 2011, Vol.68(2), p.431-6; discussion 436  A methodology for generating normal and pathological brain perfusion SPECT images for evaluation of MRI/SPECT fusion methods: application in epilepsy. C Grova P Jannin A Biraben I Buvat H Benali A M Bernard J M Scarabin B Gibaud. Physics in medicine & biology., 2003, Vol.48(24), p