A team of Swiss researchers has introduced a groundbreaking method to induce and visualize seizures in individuals with epilepsy, transforming the approach to obtaining real-time data essential for personalizing epilepsy procedures. The research findings are published in the Journal of Nuclear Medicine.
Identifying the specific brain regions where seizures originate, and spread is crucial for customizing surgery to treat focal epilepsy. Ictal single-photon emission computed tomography (SPECT) is a valuable technique for tailoring epilepsy surgery, but capturing the onset of unpredictable seizures poses medical and logistical challenges. In contrast to traditional practices that required neurologists and nuclear medicine specialists to wait for spontaneous seizures for hours or even days, this innovative method proves to be more convenient, resource-efficient, and clinically viable. Obtaining timely images of seizures, as facilitated by the new method, enhances the formulation of surgical plans with greater precision.
Dr. Barlatey and colleagues emphasized the importance of precisely delineating epileptic brain tissue for successful surgeries. The ictal SPECT method has been utilized since the 1990s as the sole neuro-imaging technique capable of capturing images of epileptic seizures propagating in the brain. However, due to escalating costs and time constraints in healthcare, many epilepsy centers abandoned this potentially informative technique. In contrast to the conventional approach of waiting for spontaneous occurrences, the researchers experimented with imaging planned seizures induced by targeted electrical stimulation to the brain, highlighting the novelty of this simple yet previously untested idea.
The research involved a case study with three adult participants diagnosed with left temporal epilepsy. Stereotactic electroencephalography (sEEG) leads were strategically placed to induce patient-specific seizures in targeted cerebral regions. Following the onset of seizures, the radiotracer 99mTc-HMPAO was promptly administered within 12 seconds, and SPECT images were obtained within 40 minutes. All participants successfully experienced triggered seizures, accurately replicating patient-specific semiology and electrographic patterns without encountering any adverse events. The individualized nature of each triggered seizure and the captured early seizure propagation provided greater precision to the study. In the first two cases, ictal SPECT offered supplementary insights by revealing the early involvement of brain areas that lacked electrode coverage. Conversely, in the third case, the combined data from sEEG and ictal SPECT provided overlapping information.
The streamlined acquisition of ictal SPECT enhances image quality, potentially contributing to the refinement of resection planning and improving seizure and cognitive outcomes in epilepsy surgery. This breakthrough promises to reshape the landscape of epilepsy treatment, offering hope for more effective and tailored interventions in the future.
Reference
Barlatey SL, Mignardot CG, Friedrichs-Maeder C, Schindler K, Wiest R, Nowacki A, et al. Triggered Seizures for Ictal SPECT Imaging: A Case Series and Feasibility Study. Journal of Nuclear Medicine. 2024 Mar 1;65(3):470–4.