SUBTRACTION ICTAL SPECT IN NEOCORTICAL EPILEPSY: THE ANALYSIS OF CLINICAL USEFULNESS AND FACTORS AFFECTING THE RESULTS
Abstract number :
3.185
Submission category :
Year :
2002
Submission ID :
463
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Chang Ho Yun, Sang Kun Lee, Yu Kyung Kim, Dong Soo Lee, Myoung Jin Jang. Neurology, College of Medicine, Seoul National University, Seoul, Republic of Korea; Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Republic of Korea
RATIONALE: To demonstrate the role of subtraction ictal SPECT coregistered with MRI (SISCOM) in surgically treated neocortical epilepsies, authors investigated the localizing value and the related clinical factors affecting the results of SISCOM.
METHODS: Interictal/ictal SPECT and SISCOM images were retrospectively analyzed in 56 patients with neocortical epilepsy, who had undergone resective surgery with documented outcomes (Engel class I, II, III with follow-up duration more than two years). SISCOM images and side-by-side ictal-interictal SPECT evaluation were classified by two blinded reviewers as localizing or nonlocalizing. The results of SISCOM were analyzed according to the related clinical factors (seizure originating lobe, MRI finding, ictal surface and invasive EEG pattern, radiotracer injection time, and presence or absence of generalized tonic clonic seizure at the time of radiotracer injection).
RESULTS: SISCOM images were more often localizing than traditional side-by-side SPECT evaluation with marginal significance (27 of 56 vs. 18 of 56; 48.2% vs. 32.1%; p = 0.08). Logistic regression analysis showed rapid radiotracer injection obviously increased the likelihood of localized hyperperfusion (p [lt] 0.05). Nineteen of 32 patients (59.4%) without generalized seizure at the time of injection had localizing SISCOM, but 8 of 24 (33.3%) with generalization (p = 0.05). Intracranial initial ictal rhythm involving more than four of recorded electrodes during invasive monitoring tended to increase the yield of SISCOM (p = 0.06). Different ictal onset lobe, absence or presence of lesion in MRI and ictal surface EEG pattern did not affect SISCOM results.
CONCLUSIONS: The localization of neocortical seizure foci may be powered by using SISCOM images. The usefulness of SISCOM is affected by radiotracer injection time, supported by the relationship between the absence of generalized seizure at the injection time and SISCOM localization. Sufficient ictal onset areas may facilitate the visualization of localized hyperperfusion.
[Supported by: Seoul National University Hospital]