• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.244-250
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• 1992

Both interictal and ictal $^{99m}Tc-HMPAO$ brain SPECT were performed in 22 patients with medically intractable epilepsy. Localization of epileptic foci in our patients was made by combined results of EEG and other tests, including Wada test, magnetic resonance imaging, and neuropsychometric test. Among them, ictal $^{99m}Tc-HMPAO$ SPECT, localized epilptic foci in 20 of 22 patients and provided evidence of epileptic focus in 12 patients by demonstrating maximally increased regional cerebral perfusion (rCP) in epileptic foci during the ictal study with decreased rCP in interictal study. Ictal $^{99m}Tc-HMPAO$ SPECT was particularly useful for investigating epileptic foci, and when correlated with simultaneously recorded ictal EEG, provided further insight for localizing epileptic foci. Conclusively, $^{99m}Tc-HMPAO$ SPECT is. a useful, noninvasive method of localizing epileptic activity which may be particularly important for presurgical investigations, especially in those patients without large morphological lesions.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.262-272
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• 1999

Purpose: Interictal F-18-fluorodeoxyglucose (FDG) PET and ictal Tc-99m-HMPAO SPECT are found to be useful in localizing epileptogenic zones in neocortical lateral temporal or frontal lobe epilepsy. We investigated whether interictal F-18-FDG PET or ictal Tc-99m-HMPAO SPECT was useful to find epileptogenic Bones in occipital lobe epilepsy (OLE). Materials and Methods: We reviewed patterns of hypometabolism in interictal F-18-FDG PET and of hyperperfusion in ictal Tc-99m-HMPAO SPECT in 17 OLE patients (mean age=$27{\pm}6.8$ year, M:F= 10:7, injection time= $30{\pm}17$ sec). OLE was diagnosed based on invasive electroencephalography (EEG) study, surgery and post-surgical outcome (Engel class I in all for average 14 months). Results: Epileptogenic zones were correctly localized in 9 (60%) out of 15 patients by interictal F-18-FDG PET. Epiletogenic hemispheres were correctly lateralized in 14 patients (93%). By ictal Tc-99m-HMPAO SPECT, epileptogenic hemispheres were correctly lateralized in 13 patients (76%), but localization was possible only in 3 patients (18%). Among patients who showed no abnormality with MR imaging and no correct localization with ictal Tc-99m-HMPAO SPECT, interictal F-18-FDG PET was helpful in 2 patients. Conclusion: Ictal Tc-99m-HMPAO SPECT was helpful in lateralization but not in localization in OLE. Interictal F-18-FDG PET was helpful for localization of epileptogenic zones even in patients with ambiguous MR or ictal SPECT findings.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.445-450
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• 1995

The epileptogenic zones should be localized precisely before surgical resection of these zones in intractable epilepsy. The localization is more difficult in patients with neocortical epilepsy than in patients with temporal lobe epilepsy. This study aimed at evaluation of the usefulness of ictal brain perfusion SPECT for the localization of epileptogenic zones in neocortical epilepsy. We compared the performance of ictal SPECT with MRI referring to ictal scalp electroencephalography(sEEG). Ictal $^{99m}Tc$-HMPAO SPECT were done in twenty-one patients. Ictal EEG were also obtained during video monitoring. MRI were reviewd. According to the ictal sEEG and semiology, 8 patients were frontal lobe epilepsy, 7 patients were lateral temporal lobe epilepsy, 2 patients were parietal lobe epilepsy, and 4 patients were occipital lobe epilepsy. Ictal SPECT showed hyperperfusion in 14 patients(67%) in the zones which were suspected to be epileptogenic according to ictal EEG and semiology. MRI found morphologic abnormalities in 9 patients(43%). Among the 12 patients, in whom no epileptogenic zones were revealed by MRI, ictal SPECT found zones of hyperperfusion concordant with ictal SEEG in 9 patients(75%). However, no zones of hyperperfusion were found in 4 among 9 patients who were found to have cerebromalacia, abnormal calcification and migration anomaly in MRI. We thought that ictal SPECT was useful for localization of epileptogenic zones in neocortical epilepsy and especially in patients with negative findings in MRI.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.287-293
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• 1995

Anterior temporal lobectomy has become a widely used resective surgery in patients with medically intractable temporal lobe epilepsies. Prerequisites of this resection include the accurate localization of the epileptogenic focus and the determination that the proposed resection would not result in unacceptable postoperative memory or language deficits. The purpose of this study was to evaluate the performance of ictal SPECT compared to MRI findings for localization of epiletogenic foci in this group of patients. 11 patients who had been anterior temporal lobectomy were evaluated with ictal $^{99m}Tc$-HMPAO SPECT and MRI. MRI showed 8/11(73%) concordant lesion to the side of surgery and ictal SPECT also showed 8/11(73%) concordant hyperperfusion. In 3 cases with incorrect or nonlocalizing findings of MRI, ictal SPECT showed concordant hyperperfusion. In 2 cases confirmed by pre-resectional invasive EEG, MRI showed bilateral and contralateral lesion but ictal SPECT showed concordant hyperperfusion. 3 delayed injection of ictal SPECT showed discordant hyperperfusion. Thus, ictal SPECT was a useful method for localizing epileptogenic foci in temporal lobe epilepsis and appeared complementay to MRI.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.9-14
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• 1995

뇌졸증환자의 뇌 SPECT 소견상 나타나는 소뇌교차해리현상(crossed cerebellar diaschisis)은 잘 알려진 현상이다. 한편 간질 환자의 발작시 뇌 SPECT에서 반대편 소뇌에 혈류증가를 보이는 역교차해리현상(reverse type of crossed cerebellar diashisis)은 드물게 보고되었었다. 따라서 본 저자들은 발작시 뇌 SPECT에서 역교차해리현상의 빈도 및 간질병소를 찾는데 있어서의 유용성에 대해 알아보고자 하였다. 복합부분발작환자 중 임상적, 뇌파검사상 및 SPECT 소견등에서 간질병소가 일치하는 12명의 환자를 대상으로 하였다. 환자 모두에서 시행한 발작시 스캔은 발작중 혹은 환자가 aura를 호소할때 $^{99m}Tc$-HMPAO 15-20mCi를 정맥주입 후 시행하였으며 발작간 스캔은 11명의 환자에서 발작시 스캔 후 적어도 3일 간격을 두고 시행하였다. 간질병소는 우측측두엽이 6예, 좌측측두엽이 4예, 우측후두엽이 1예, 좌측전두엽이 1예 등이었다. 발작시 스캔상 간질병소 및 반대편 소뇌에 혈류가 증가하는 역해리현상은 모두 8명(75%)의 환자에서 나타났으며 특히 2명의 환자에서는 간질병소보다 반대편 소뇌의 동위원소 섭취가 더욱 뚜렸했다. 역해리현상을 보였던 환자의 발작간 스캔소견에서는 발작시 증가되었었던 소뇌의 동위원소 섭취가 7예에서 정상화되었고 나머지 1예에서는 감소되었다. 따라서 소뇌의 역교차해리현상은 발작시 뇌 SPECT의 자주 볼 수 있는 현상으로 간질병소의 편측화에 도움을 줄 수 있을 것으로 생각된다.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.312-321
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• 2000

Purpose: The aim of this study was to determine whether crossed cerebellar hyperperfusion (CCH) was helpful in discriminating mesial from lateral temporal lobe epilepsy (TLE) and what other factors were related in the development of CCH on ictal brain SPECT. Materials and Methods: We conducted retrospective analysis in 59 patients with TLE (M:41, F:18; $27.4{\pm}7.8$ years old; mesial TLE: 51, lateral TLE: 8), which was confirmed by invasive EEG and surgical outcome (Engel class I, II). All the patients underwent ictal Tc-99m HMPAO brain SPECT and their injection time from ictal EEG onset on video EEG monitoring ranged from 11 sec to 75 sec ($32.6{\pm}19.5sec$) in 39 patients. Multiple factors including age, TLE subtype (mesial TLE or lateral TLE), propagation pattern (hyperperfusion localized to temporal lobes, spread to adjacent lobes or contralateral hemisphere) and injection time were evaluated for their relationship with CCH using multiple logistic regression analysis Results: CCH was observed in 18 among 59 patients. CCH developed in 29% (15/51) of mesial TLE patients and 38% (3/8) of lateral TLE patients. CCH was associated with propagation pattern; no CCH (0/13) in patients with hyperperfusion localized to temporal lobe, 30% (7/23) in patients with propagation to adjacent lobes, 48% (11/23) to contralateral hemisphere. Multiple logistic regression analysis revealed that propagation pattern (p=0.01) and age (p=0.02) were related to the development of CCH. Conclusion: Crossed cerebellar hyperperfusion in ictal brain SPECT did not help differentiate mesial from lateral temporal lobe epilepsy. Crossed cerebellar hyperperfusion was associated with propagation pattern of temporal lobe epilepsy and age.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.20-31
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• 1998

A robust algorithm to disclose and display the difference of ictal and interictal perfusion may facilitate the detection of ictal hyperfusion foci. Diagnostic performance of localizing epileptogenic zones with subtracted SPECT images was compared with the visual diagnosis using ictal and interictal SPECT, MR, or PET. Ietal and interictal Tc-99m-HMPAO cerebral perfusion SPECT images of 48 patients(pts) were processed to get parametric subtracted images. Epileptogenic foci of all pts were diagnosed by seizure free state after resection of epileptogenic zones. In subtraction SPECT, we used normalized difference ratio of pixel counts(ictal-interictal)/interictal ${\times}100%$) after correcting coordinates of ictal and interictal SPECT in semi-automatized 3-dimensional fashion. We found epileptogenic zones in subtraction SPECT and compared the performance with visual diagnosis of ictal and interictal SPECT, MR and PET using post-surgical diagnosis as gold standard. The concordance of subtraction SPECT and ictal-interictal SPECT was moderately good(kappa=0.49). The sensitivity of ictal-interictal SPECT was 73% and that of subtraction SPECT 58%. Positive predictive value of ictal-interictal SPECT was 76% and that of subtraction SPECT was 64%. There was no statistical difference between sensitivity or positive predictive values of subtraction SPECT and ictal-interictal SPECT, MR or PET. Such was also the case when we divided patients into temporal lobe epilepsy and neocortical epilepsy. We conclude that subtraction SPECT we produced had equivalent diagnostic performance compared with ictal-interictal SPECT in localizing epileptogenic zones. Additional value of these subtraction SPECT in clinical interpretation of ictal and interictal SPECT should be further evaluated.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.463-468
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• 1996

본 연구는 간질 병소의 국소화에 있어 발작기 및 발작간 뇌스캔의 정확도를 알아보고 발작기 뇌 스캔에서 나타나는 간질 확산이 정확한 간질 병소를 국소화 하는데 어떠한 영향을 미치는가에 대하여 알아보고자 하였다. 15명의 복잡 부분 발작 환자를 대상으로 하였으며, 간질 병소의 최종적인 국소화는 두피 및 발작 뇌파, 피질 뇌파, 자기 공명 영상, 임상양상 및 병리 소견을 종합한 근거로 하였다. 발작기 뇌스캔은 뇌파상 발작 중 또는 환자가 aura를 호소할 때 Tc-99m HMPAO 20mCi(740 MBq)를 정맥주입후 시행하였으며 발작간 뇌스캔은 발작기 뇌스캔 후 3일 이내 임상적으로 발작 증상이 없는 기간에 시행하였다. 간질 병소는 우측 측두엽이 8예, 좌측 측두엽이 6예, 측두엽 이외의 기원이 1예 였다. 발작기 뇌스캔상, 모두 11예(73.3 %)에서 단발성 또는 다발성 섭취 증가가 간질 병소 및 간질확산 부위에서 관찰되었으며, 간질 병소에만 국한된 섭취 증가는 4예(26.7%)에 불과 하였다. 발작간 뇌스캔에는 모두 11예(73.3 %)에서 간질 병소에만 섭취가 감소되었다. 자기 공명 영상에서는 8예(53.3 %)에서 hippocampal sclerosis를 포함한 간질 병소가 확인되었다. 본 연구로 복잡 부분 발작 환자에서, 간질 확산이 발작기 뇌 스캔 중 자주 관찰됨을 알 수 있었으며, 이러한 간질 확산에 따른 다발성 방사능 섭취가 발작기 뇌스캔상, 간질 병소의 국소화에있어 한계가 있음을 결론 내릴 수 있었다.