Abstracts

RATIONALE: Although interictal hypoperfusion and ictal hyperperfusion are considered localizing in partial epilepsy, their relative value is disputed. We compared the concordance of hypoperfusion and hyperperfusion in video EEG monitored interictal (IISPECT) and ictal (PISPECT) in non-lesional patients who underwent temporal lobectomies. METHODS: We searched our database for patients who underwent temporal lobectomies from 1995-1998. Records were reviewed for IISPECTs and PISPECTs which were performed by injecting Technicium Bicisate (Neurolite) upon seizure onset. RESULTS: Of 42 patients who had temporal lobectomies localized by EEG and MRI, 40 had IISPECT and 29 had PISPECT. 32 (80%) had hypoperfusion ipsilaterally in IISPECT. 4 were contralateral and 4 were non-localizing. 18 (62%) had hyperperfusion ipsilaterally in PISPECT. Two had contralateral increase. Only 28 had both studies. 14 (50%) had hypoperfusion in IISPECT and hyperperfusion in PISPECT. 13 were ipsilateral and 1 was contralateral. 9 (32%) had accentuation of hypoperfusion ipsilaterally. CONCLUSIONS: 1) IISPECT was more concordant than PISPECT, but not significantly (p=0.11). 2) Ipsilateral accentuation of hypoperfusion in PISPECT occurred in 32% resulting in decreased concordance of PISPECT with EEG. 3) Accentuation of hypoperfusion in PISPECT may have localizing value in seizures of temporal lobe origin.