Focal Accumulation of Iron in Cerebral Regions in Early ALS (Amyotrophic Lateral Sclerosis) Patients

Inclusion Criteria: * Amyotrophic lateral sclerosis defined in accordance to the El Escorial criteria (possible, probable or defined) * 18 to 85 years old patient, male or female * Patient with social security cover Exclusion Criteria: * Achieved respiratory defined by a FVC \<70% * Evolution of more than 24 months * Demented subject * Severe malnutrition * Patients with treatment potentially at risk of agranulocytosis and neutropenia * Patients with a history of agranulocytosis or iatrogenic under haematological disease * Incapable of giving consent * Indication against MRI * Indication against lumbar puncture * Patient refused lumbar puncture * Hypersensitivity to iron chelators * Concomitant treatment with antacids containing aluminum * Presence of another serious illness to life-threatening or disabling cons to the use of the treatment mixture of oxygen and nitrous oxide equally