Inclusion Criteria:  Diagnosis of ALS defined or probable according to the criteria established by the World Federation of Neurology Age between 18 and 70 years. Patient who offers sufficient guarantees of adherence to the protocol. Neurophysiological data confirming lower motor neuron involvement at the lumbar and cervical level. Assessment of the motor deficit in the dorsal flexion of both feet (between 3 and 5 points on the MRC scale).  Exclusion Criteria:  Mellitus diabetes. Other diseases that may be associated with polyneuropathies. Previous history of cerebral stroke. Previous pathology of the peripheral nervous system that affected one or both lower or upper limbs, with or without clinically evident neurological sequelae. Pregnant or actively breastfeeding patients Patients physiologically capable of becoming pregnant, unless they are using a reliable contraceptive method (Annex III) Patients with cardiac, renal, hepatic, systemic, immune disease that may influence the survival of the patient during the test. Positive serology for hepatitis B, hepatitis C or HIV. Clinical and anesthesiological criteria that contraindicate either sedation or the extraction of BM itself (Alteration of the coagulation system or anticoagulated patient with inability to withdraw anticoagulation, hemodynamic instability, skin alteration in the puncture site, etc.) Inclusion in other clinical trials in the last 6 months. Inability to understand informed consent.