Altered Metabolic Networks in Mesial Temporal Lobe Epilepsy with Focal to Bilateral Seizures

Area of Science:

• Neuroscience
• Epileptology
• Medical Imaging

Background:

• Mesial temporal lobe epilepsy (MTLE) is a common epilepsy syndrome.
• Focal to bilateral tonic-clonic seizures (FBTCS) represent a severe seizure type in MTLE.
• Understanding the underlying pathophysiology of FBTCS is crucial for targeted treatment.

Purpose of the Study:

• To investigate differences in brain metabolic network topology between MTLE patients with and without FBTCS.
• To compare metabolic networks of MTLE patients with FBTCS to healthy controls.
• To identify distinct epileptogenic networks associated with FBTCS.

Main Methods:

• Retrospective analysis of 30 healthy controls and 54 MTLE patients (27 with FBTCS).
• Utilized fluorodeoxyglucose positron emission tomography (FDG-PET) for metabolic imaging.
• Applied graph theoretical analyses to assess metabolic connectivity and network topology.

Main Results:

• MTLE patients with FBTCS showed significant alterations in local and global network topology compared to controls, including lower assortative coefficient and altered betweenness centrality.
• MTLE patients without FBTCS had altered betweenness centrality in specific regions but no significant global network differences compared to controls.
• Four brain regions exhibited significantly altered betweenness centrality when comparing MTLE patients with and without FBTCS.

Conclusions:

• MTLE patients with FBTCS demonstrate greater metabolic network abnormalities than those without FBTCS.
• Distinct epileptogenic networks likely underlie the occurrence of FBTCS in MTLE.
• Findings offer insights into the pathophysiological basis of FBTCS.