Intertechnique Agreement in Epilepsy Imaging

Abstract

Aim:To analyze seizure semiology, scalp video-electroencephalography,magnetic resonance imaging (MRI) and 18F-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) findings in patients with medically refractory epilepsy,to assess the concordance rate (CR) between clinical-electroencephalography findings (CEF) and neuroimaging studies (NS) for localizing epileptogenic foci.

Material and methods:This retrospective study included 108 consecutive patients (male/female=59/49;mean age=26.6±10.5 years) who were classified according to CEF (either temporal or extra-temporal lobe epilepsy [TLE]) between January 2011 and January 2017.Statistical analysis was performed using a t, Mann-Whitney U, McNemar, or χ² tests.

Results:Fifty-six patients had TLE (M/F=30/26,mean age=30.1±8.9 years) and 52 had extra-TLE (M/F=29/23,mean age=22.8±10.9 years) according to CEF.12/108 patients (M/F=6/6,mean age=28.7±10.2 years) underwent epilepsy surgery and the mean postoperative follow-up period was 32 months.The highest CR between CEF and NS (76%) was found in patients with non-hippocampal sclerosis abnormality in TLE group.In patients with malformations of cortical development on MRI,the CR (84.2%) between CEF and MRI was better than those between CEF and FDG-PET (52.6%) (P=0.010).The CR between CEF and NS for TLE (48.2%) was better than for extra-TLE (9.6%) (P<0.001).No significant difference was found in the localization of the epileptogenic focus between MRI and FDG-PET according to the seizure outcome of patients (P=1).

Conclusions:FDG-PET may not help in revealing epileptic region in cases with abnormal MRI especially in malformations of cortical development.The highest CR between CEF and NS is found in TLE patients with findings inconclusive of hippocampal sclerosis.With low CR between CEF and NS in extra-TLE,meticulous use of multiple modalities is necessary for accurate pre-surgical evaluation.

Keywords

• Medically refractory epilepsy,Magnetic resonance imaging

Epilepsi görüntülemesinde Modaliteler Arası Uyum

Abstract

Amaç: Medikal tedaviye dirençli epilepsi hastalarında nöbet semiyolojisi, skalp-video elektroensefalografi, manyetik rezonans görüntülüme (MRG) ve 18-floro-2-deoksi-glukoz pozitron emisyon tomografi (FDG-PET) bulgularının değerlendirilmesi, epileptojenik odağı lokalize etmede klinik-elektroensefalografi bulguları ile nörogörüntüleme yöntemleri arasındaki uyumun değerlendirilmesi amaçlandı.

Gereç ve Yöntemler: Retrospektif olan çalışmamız hastane etik kuru onayı alınarak yapıldı. Çalışmaya, Ocak 2011 ile Ocak 2017 tarihleri arasında, klinik-elektroensefalografi bulgularına göre temporal (30 erkek, 26 kız, ortalama yaş 30,1±8,9 yıl) ve ekstra-temporal lob epilepsi (29 erkek, 23 kız, ortalama yaş 22,8±10,9 yıl) gruplarına ayrılan ardışık 108 hasta (59 erkek, 49 kız, ortalama yaş 26,6±10,5 yıl) dahil edildi. Kategorik-sayısal değişkenler t, Mann-Whitney U, McNemar veya Ki-kare testi ile analiz edildi.

Bulgular: Çalışmaya dahil edilen 108 hastanın 12’si (6 erkek, 6 kız, ortalama yaş 28,7±10,2 yıl) epilepsi cerrahisi geçirdi ve bu hastaların operasyon sonrası ortalama takip süresi 32 aydı. Klinik-elektroensefalografi bulguları ile nörogörüntüleme yöntemleri arasında en yüksek uyum (%76) hippokampal skleroz dışı anormallikler sahip temporal lob epilepsili hastalarda saptandı. MRG’de kortikal gelişimsel anormalliklere sahip hastalardaki, klinik- elektroensefalografi bulguları ile MRG arasındaki uyum (%84,2), klinik-elektroensefalografi bulguları ile FDG-PET arasındaki uyumdan (%52,6) yüksekti (p=0,010). Temporal lob epilepsilerindeki klinik-elektroensefalografi bulguları ile nörogörüntüleme yöntemleri arasındaki uyum (%48,2), ekstra-temporal lob epilepsilerine (%9,6) göre daha yüksekti (p<0,001). Opere olan hastaların takiplerine göre MRG ile FDG-PET arasında epileptojenik odağı lokalize etmede anlamlı farklılık saptanmadı (p=1).

Sonuç: FDG-PET epileptojenik odağın lokalize edilmesinde, özellikle MRG’de kortikal gelişimsel anormalliklerin saptandığı hastalarda yardımcı olamayabilir. Klinik-elektroensefalografi bulguları ile nörogörüntüleme yöntemleri arasındaki en yüksek uyum hippokampal skleroz dışı anormalliklere sahip temporal lob epilepsili hastalarda saptandı. Ekstra-temporal lob epilepsilerindeki klinik-elektroensefalografi bulguları ile nörogörüntüleme yöntemleri arasındaki düşük uyum, ekstra-temporal lob epilepsilerinin cerrahi öncesi değerlendirilmesinde, farklı yöntemlerin kullanılmasını gerektirmektedir.

Keywords

• Epilepsi,Manyetik rezonans görüntüleme

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