ProbCluster trial aims at making the proof of concept of antiseizure efficacy of the old antigout PBN in SC, in which Panx1 involvement is relevant on SC pathophysiology and in which efficient therapies are still lacking. The trial will be performed on patients with focal epilepsy in presurgical evaluation undergoing video-EEG monitoring, a setting characterized by a high risk of SC and an efficient video-EEG monitoring of seizures, reducing the risk of erroneous report based on patient home assessment. PBN is a good candidate for a repurposing in epilepsy, due to its brain penetration allowing Panx1 in situ blockade and of its good security profile. The repurposing process allows a faster, safer and cheaper development.

Inclusion Criteria:

• Patients between 6 and 50 years old
• weighting > 20 kg
• With focal seizures epilepsy
• Requiring video-EEG recording in Epilepsy Monitoring Units (EMU) for the presurgical evaluation of a focal epilepsy, with planned ASM withdrawal in order to precipitate seizure occurrence
• Able to take an oral therapy
• Ability to record the patient > 12 hours after the second seizure of the cluster
• Having received informed information about the study and having signed a consent form to participate in the study. Written consent of both holders of parental authority for minor patients.

Exclusion Criteria:

• Hypersensitivity to PBN or to any of the excipients (Microcrystalline cellulose, Hypromellose, Sodium carboxymethylamidon, Colloidal anhydrous silica, Magnesium stearate)
• Impaired renal function (creatinine clearance < 50 mL/min)
• Lithiasis diathesis
• Treatment by the following drugs: penicillins cephalosporins, acetylsalicylic acid, methotrexate, acetaminophen, naproxen, indomethacin, ketoprofen, meclofenamate, lorazepam, rifampicin, acyclovir, ganciclovir and zidovudine, sulfonamide, dyprophylline
• Acute gout attack
• Hyperuricemia secondary to cancer chemotherapy, radiotherapy or myeloproliferative neoplasia
• Primary hyperuricemia due to overproduction of uric acid.
• Pregnant or breast-feeding woman
• Patient benefiting from legal protection

Secondary exclusion criteria (before randomization) :

- Patient not randomized: Not experiencing at least 2 seizures lasting less than 10 minutes in 6 hours or less period (defining a SC) during the video-EEG monitoring period OR having no seizure recorded before the cluster.

Patients secondarily excluded will be excluded before randomization and will be replaced.