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Review
. 2021 Mar 2:2021:6614356.
doi: 10.1155/2021/6614356. eCollection 2021.

Use of Innovative SPECT Techniques in the Presurgical Evaluation of Patients with Nonlesional Extratemporal Drug-Resistant Epilepsy

Ahmed Yassin  1 , Khalid El-Salem  1 , Abdel-Hameed Al-Mistarehi  2 , Aiman Momani  1 , Anas M Zein Alaabdin  2 , Palak Shah  3 , James Michael Mountz  4 , Anto I Bagić  5   6
Affiliations
Review

Use of Innovative SPECT Techniques in the Presurgical Evaluation of Patients with Nonlesional Extratemporal Drug-Resistant Epilepsy

Ahmed Yassin et al. Mol Imaging. .

Abstract

Up to 30% of patients with epilepsy may not respond to antiepileptic drugs. Patients with drug-resistant epilepsy (DRE) should undergo evaluation for seizure onset zone (SOZ) localization to consider surgical treatment. Cases of drug-resistant nonlesional extratemporal lobe epilepsy (ETLE) pose the biggest challenge in localizing the SOZ and require multiple noninvasive diagnostic investigations before planning the intracranial monitoring (ICM) or direct resection. Ictal Single Photon Emission Computed Tomography (i-SPECT) is a unique functional diagnostic tool that assesses the SOZ using the localized hyperperfusion that occurs early in the seizure. Subtraction ictal SPECT coregistered to MRI (SISCOM), statistical ictal SPECT coregistered to MRI (STATISCOM), and PET interictal subtracted ictal SPECT coregistered with MRI (PISCOM) are innovative SPECT methods for the determination of the SOZ. This article comprehensively reviews SPECT and sheds light on its vital role in the presurgical evaluation of the nonlesional extratemporal DRE.

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Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Figure 1
Figure 1
Time activity curve for Tc-99m HMPAO (corrected for radioactive decay). Note that all brain uptake has occurred by the first 60 seconds after IV injection and then very little loss of tracer molecules occurred over hours (counts decreasing mainly by radioactive 6-hour half-life decay of Tc-99m).
Figure 2
Figure 2
Ictal and interictal SPECT scans in a three-year-old boy with drug-resistant epilepsy. (a) Interictal SPECT showed prominent hypoperfusion over the left frontotemporal region. (b) First ictal SPECT attempt was performed in a seizure of 46-second duration, and radioisotope was injected at 40 seconds from the seizure onset. This was a late injection, and ictal SPECT showed similar findings as to the interictal SPECT. (c) Repeated ictal SPECT attempt was performed in a seizure of nine-second duration, and radioisotope was injected at two seconds from the seizure onset. This was an early injection, and ictal SPECT showed a relative increase in perfusion in the left frontotemporal region, compared with the right. This demonstrates the significance of early injection in accurately localizing the seizure onset zone, adapted from Kim et al. [38].
Figure 3
Figure 3
Demonstration of the use of automatic SPECT injectors at the Epilepsy Monitoring Unit (EMU) of the University of Pittsburgh Medical Center (UPMC) at Presbyterian University Hospital (PUH). Automatic injectors are armed by nuclear medicine staff. The radiotracer is injected upon a button press by the EMU staff in the EMU control room (pictures on the left side) upon observing clinical or electrographic seizure affecting the monitored patient (pictures on the right side).
Figure 4
Figure 4
An illustrative example of a patient with distinct brief focal motor seizures involving the left leg without an EEG correlate and with a normal three tesla MRI with epilepsy protocol. SISCOM at two standard deviations (a) matched intracranial monitoring with cortical mapping (b). (a) A SISCOM (Injection latency of 6 seconds during a 14-second habitual clinical seizure without scalp EEG correlate) revealed increased uptake in the right paracentral region (leg area). (b) Cortical mapping identified the left leg motor activity in the area of seizure onset. A typical electroclinical seizure was produced by stimulation in the same region. The patient underwent responsive neurostimulation (RNS) implant leading to 100% seizure reduction.
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References

    1. Kwan P., Brodie M. J. Early identification of refractory epilepsy. New England Journal of Medicine. 2000;342(5):314–319. doi: 10.1056/NEJM200002033420503. - DOI - PubMed
    1. Engel J., Jr. Introduction to temporal lobe epilepsy. Epilepsy Research. 1996;26(1):141–150. doi: 10.1016/s0920-1211(96)00043-5. - DOI - PubMed
    1. Engel J., Jr. Surgery for seizures. New England Journal of Medicine. 1996;334(10):647–653. doi: 10.1056/NEJM199603073341008. - DOI - PubMed
    1. Spencer S. S. The relative contributions of MRI, SPECT, and PET imaging in epilepsy. Epilepsia. 1994;35(Supplement 6):S72–S89. doi: 10.1111/j.1528-1157.1994.tb05990.x. - DOI - PubMed
    1. Murphy M., O’Brien T. J., Morris K., Cook M. J. Multimodality image-guided epilepsy surgery. Journal of Clinical Neuroscience. 2001;8(6):534–538. doi: 10.1054/jocn.2001.0921. - DOI - PubMed

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