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Review
. 2022 Jun;93(6):592-598.
doi: 10.1007/s00115-021-01180-3. Epub 2021 Sep 7.

[Imaging in the presurgical evaluation of epilepsy]

[Article in German]
Maria Ilyas-Feldmann  1 , Bernd Vorderwülbecke  2   3 , Mirja Steinbrenner  2
Affiliations
Review

[Imaging in the presurgical evaluation of epilepsy]

[Article in German]
Maria Ilyas-Feldmann et al. Nervenarzt. 2022 Jun.

Abstract
in English, German

While two thirds of patients with epilepsy become seizure-free with antiseizure medications, 30% remain drug-resistant. In drug-resistant focal epilepsy, epilepsy surgery offers an approximately 65% chance of becoming seizure-free; however, for a successful outcome of surgery a seizure focus must be precisely located, for which imaging techniques are essential. In recent years, the proportion of patients with apparently inconspicuous findings in magnetic resonance imaging (MRI) in the presurgical evaluation has increased. The sensitivity of MRI can be increased using special MRI sequences and MRI postprocessing techniques. Ictal and interictal source localization based on electroencephalography (EEG) and magnetencephalography (MEG) aim at determining the onset of interictal discharges and seizures. Nuclear medicine imaging techniques such as interictal positron emission tomography (PET) and ictal single photon emission computed tomography (SPECT) can detect chronic or acute seizure-related changes in brain metabolism and can indicate an epileptogenic focus even if MRI is inconspicuous. The results of these techniques are used to plan invasive EEG recordings and subsequently surgery. Concordant findings are associated with better surgical outcomes and show significantly higher rates of seizure freedom in the long-term seizure outcome.

Während zwei Drittel der PatientInnen mit Epilepsie durch Medikamente anfallsfrei werden, ist die Erkrankung bei 30 % pharmakoresistent. Bei pharmakoresistenter fokaler Epilepsie bietet die Epilepsiechirurgie eine etwa 65 %ige Chance auf Anfallsfreiheit. Vorab muss der Anfallsfokus exakt eingegrenzt werden, wofür bildgebende Methoden unverzichtbar sind. In den letzten Jahren hat sich in der Prächirurgie der Anteil von PatientInnen mit unauffälliger konventioneller Magnetresonanztomographie (MRT) erhöht. Allerdings konnte die Sensitivität der MRT durch spezielle Aufnahmesequenzen und Techniken der Postprozessierung gesteigert werden. Die Quellenlokalisation des Signals von Elektro- und Magnetenzephalographie (EEG und MEG) verortet den Ursprung iktaler und interiktaler epileptischer Aktivität im Gehirn. Nuklearmedizinische Untersuchungen wie die interiktale Positronen-Emissions-Tomographie (PET) und die iktale Einzelphotonen-Emissionscomputertomographie (SPECT) detektieren chronische oder akute anfallsbezogene Veränderungen des Hirnmetabolismus und können auch bei nichtlokalisierendem MRT auf den epileptogenen Fokus hinweisen. Alle Befunde zusammengenommen werden zur Planung eventueller invasiver EEG-Ableitungen und letztlich der chirurgischen Operation eingesetzt. Konkordante Befunde sind mit besseren chirurgischen Ergebnissen assoziiert und zeigen auch im Langzeitverlauf signifikant höhere Anfallsfreiheitsraten.

Keywords: EEG; Epilepsy; MRI; PET; Surgery.

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References

Literatur

Verwendete Literatur
    1. Bagla S, Cukovic D, Asano E, et al. A distinct microRNA expression profile is associated with alpha[(11)C]-methyl-L-tryptophan (AMT) PET uptake in epileptogenic cortical tubers resected from patients with tuberous sclerosis complex. Neurobiol Dis. 2018;109:76–87. doi: 10.1016/j.nbd.2017.10.004. - DOI - PMC - PubMed
    1. Bernasconi A, Bernasconi N, Bernhardt BC, et al. Advances in MRI for ’cryptogenic’ epilepsies. Nat Rev Neurol. 2011;7:99–108. doi: 10.1038/nrneurol.2010.199. - DOI - PubMed
    1. Bernasconi A, Cendes F, Theodore WH, et al. Recommendations for the use of structural magnetic resonance imaging in the care of patients with epilepsy: a consensus report from the International League Against Epilepsy Neuroimaging Task Force. Epilepsia. 2019;60:1054–1068. doi: 10.1111/epi.16324. - DOI - PubMed
    1. Blumcke I, Spreafico R, Haaker G, et al. Histopathological findings in brain tissue obtained during epilepsy surgery. N Engl J Med. 2017;377:1648–1656. doi: 10.1056/NEJMoa1703784. - DOI - PubMed
    1. Brodbeck V, Spinelli L, Lascano AM, et al. Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients. Brain. 2011;134:2887–2897. doi: 10.1093/brain/awr243. - DOI - PMC - PubMed
Weiterführende Literatur
    1. Luders HO, Najm I, Nair D, et al. The epileptogenic zone: general principles. Epileptic Disord. 2006;8(Suppl 2):S1–S9. - PubMed

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