Multimodal Study for the Diagnosis and Treatment of Drug-resistant Focal Epilepsies

Epilepsy is a clinical condition that affects about fifty million people worldwide, with an estimated occurrence of 16-51 new cases per 100,000 people each year. In 60% of these patients, the origin of seizures is due to a localized (focal) alteration of the brain. In about 25 percent of patients with focal epilepsy, drug treatment is ineffective, a condition defined by the International League Against Epilepsy (ILAE) as drug-resistant epilepsy ; this condition results in a drastic reduction in quality of life associated with psychosocial dysfunction and an increased risk of sudden death. A possible treatment alternative for drug-resistant patients is ablation of the epileptogenic zone through surgical methods that are effective and safe when patients are carefully selected. The percentage of patients with epilepsy who are completely cured after surgery is about 70% for temporal lobe epilepsies, and can be as high as 90% in the case of some brain malformations.

Pre-surgical screening and therapeutic intervention (particularly surgery) have health care costs that are amortized over 2-6 years depending on the procedures required before surgery. In the last decade, moreover, the refinement of noninvasive/mini-invasive methods such as radiosurgery, Magnetic Resonance-guided Focused Ultrasound (MRgFUS) and laser interstitial thermal therapy (LiTT) have allowed us to hypothesize a possible specific treatment of drug-resistant patients with epileptogenic areas that are difficult to reach with traditional surgery and patients with complex comorbidities for whom the risks of standard resective surgery would outweigh the possible benefits. Finally, there is a subgroup of patients with drug-resistant epilepsy who cannot undergo ablative surgery. In these patients, seizures originate from multiple areas of the brain (multifocal epilepsy) or the epileptogenic area affects functionally eloquent areas. In these cases, alternative functional treatments are proposed, which aim to decrease the frequency and intensity of seizures and the need for medication, such as: i) application of a vagal stimulator, a pulse generator that is implanted in the chest and connected to the vagus nerve, ii) implantation of deep brain stimulation devices, iii) neuromodulation. Therefore, careful selection of patients during the diagnostic/pre-surgical process is crucial. The multimodal assessments under study, proposed in support of clinical practice, aim to improve such selection by analyzing the causative factors of seizures, the location of the epileptogenic zone, and the clinical-epileptological course of patients who are candidates for surgical or functional treatment of epilepsies.