Impact of Epilepsy on the Brainstem Adenosine Pathway and Its Relation With Arousal and Respiratory Reactivity

Inclusion Criteria: * For patients 1. Written informed consent obtained from study subject and ability for study subject to comply with the requirements of the study 2. Aged 18 to 55 years old 3. Diagnosis of focal epilepsy or of idiopathic generalized epilepsy, as defined by the International League Against Epilepsy 4. Diagnosis of refractory epilepsy, as defined by the International League Against Epilepsy as failure of adequate trials of two tolerated, appropriately chosen and used antiseizure drug schedules (whether as monotherapies or in combination) to achieve sustained seizure freedom 5. Patients with ≥3 focal to bilateral tonic-clonic seizure (FBTCS) or generalized tonic-clonic seizure (GTCS) during the past 18 months 6. For women of childbearing potential, use highly effective contraception until the end of relevant systemic exposure (V2) * For healthy volunteers 1. Written informed consent obtained from study subject and ability for study subject to comply with the requirements of the study 2. Aged 18 to 55 years old 3. For women of childbearing potential, use highly effective contraception until the end of relevant systemic exposure (V2) Exclusion Criteria: * For patients 1. Ongoing or chronic respiratory insufficiency defined as breathlessness Grade ≥ 2 using the modified Medical Research Council Dyspnea Scale and/or patient treated by a pneumologist for respiratory insufficiency 2. Cardiac insufficiency defined as symptoms Grade ≥ 2 using New York Heart Association Functional Classification and/or patient treated by a cardiologist for chronic heart failure 3. Ischaemic heart disease defined as history of myocardial ischemia and/or of typical angina confirmed by a cardiologist. 4. Obstructive sleep-apnea syndrome, defined as participant who had been diagnosed for Obstructive sleep apnoea by polysomnography, whether a dedicated therapy is ongoing or not 5. Ongoing treatment with selective serotonin reuptake inhibitor (Selective Serotonin Reuptake Inhibitors): Citalopram, Escitalopram, Fluoxetine, Fluvoxamine, Paroxetine, Sertraline and SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors): Duloxetine, Milnacipran, Venlafaxine 6. Hypercapnic challenges contra-indication (History of stroke in the last 5 years, space-occupying lesion in the brain associated with brain oedema and/or mass effect on MRI/CT scan) 7. MRI contra-indication (presence of metallic elements, claustrophobia) 8. Patient treated with vagal nerve stimulation or deep brain stimulation 9. Pregnant women, women in labor or breastfeeding women, based on declarations at V0 10. Patients suffering from a psychiatric disorder, regardless of its etiology, whose care is provided under compulsory measures 11. Persons deprived of their liberty by a judicial or administrative decision 12. Adults subject to a legal protection measure (guardianship, curatorship) 13. Persons not affiliated to a social security scheme or beneficiaries of a similar scheme 14. Positive urine pregnancy test at V2, if applicable 15. Hypersensitivity to \[18F\]-CPFPX * For healthy volunteers 1. History of epilepsy 2. Ongoing or chronic respiratory insufficiency defined as breathlessness Grade ≥ 2 using the modified Medical Research Council Dyspnea Scale and/or patient treated by a pneumologist for respiratory insufficiency 3. Cardiac insufficiency defined as symptoms Grade ≥ 2 using New York Heart Association Functional Classification and/or patient treated by a cardiologist for chronic heart failure 4. Ischaemic heart disease defined as history of myocardial ischemia and/or of typical angina confirmed by a cardiologist. 5. Obstructive sleep-apnea syndrome, defined as participant who had been diagnosed for Obstructive sleep apnoea by polysomnography, whether a dedicated therapy is ongoing or not 6. Ongoing treatment with selective serotonin reuptake inhibitor : SSRIs (Selective Serotonin Reuptake Inhibitors) : Citalopram, Escitalopram, Fluoxetine, Fluvoxamine, Paroxetine, Sertraline and SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors) : Duloxetine, Milnacipran, Venlafaxine 7. Hypercapnic challenges contra-indication (History of stroke in the last 5 years, space-occupying lesion in the brain associated with brain oedema and/or mass effect on MRI/CT scan) 8. MRI contra-indication (presence of metallic elements, claustrophobia) 9. Pregnant women, women in labor or breastfeeding women, based on declarations at V0 10. Patients suffering from a psychiatric disorder, regardless of its etiology, whose care is provided under compulsory measures 11. Persons deprived of their liberty by a judicial or administrative decision 12. Adults subject to a legal protection measure (guardianship, curatorship) 13. Persons not affiliated to a social security scheme or beneficiaries of a similar scheme 14. Positive urine pregnancy test at V2, if applicable 15. Hypersensitivity to \[18F\]-CPFPX