X-linked adrenoleukodystrophy is a rare, demyelinating and neurodegenerative disorder, due to loss of function of a fatty acid transporter, the peroxisomal ABCD1 protein. Its more frequent phenotype, the adrenomyeloneuropathy in adults, is characterized by axonal degeneration in spinal cord, spastic paraparesis and a disabling peripheral neuropathy. Actually, there is no efficient treatment for the disease. The work of the researchers in the last twelve years dissecting the physiopathological basis of the disorder has uncovered an involvement of the early oxidative stress in the neurodegenerative cascade and mitocondrial depletion. In a preclinical trial they have observed that pioglitazone, a PPARγ/PGC-1α axis metabolic activator with immunomodulatory, anti-inflammatory and antioxidant response regulator properties, efficiently reverse the clinical symptoms and the axonal degeneration in the mouse model for the disease and normalize stress and mitochondrial depletion biomarkers. The researchers will test the effectiveness of the drug in terms of motor function and correction of oxidative damage markers in proteins and DNA and inflammation markers in an open trial. Fifteen-twenty patients will be included and clinically explored and assessed in the HU of Bellvitge and the HU of Donostia using clinical scales for spasticity, evoked potentials, electroneurinograms and cranial RMN. The information will be collected in a data base that will be of great value to improve the present attention and the future follow-up of the patients and to facilitate their inclusion in therapeutic randomized, double blind, against placebo, multicentric and international clinical trials.