Inclusion Criteria: 1. Diagnosed with X-linked adrenoleukodystrophy (ALD), including proven mutation in the ABCD1 gene through confirmatory genetic testing, and supported by elevated circulating VLCFA levels. 2. Clinical evidence of spinal cord involvement but still able to ambulate independently Exclusion Criteria: 1. Evidence of or past diagnosis of inflammatory cerebral disease. 2. 15 years or more have elapsed since the initial onset of myeloneuropathy manifestations such as walking or running difficulties, bladder dysfunction, increased muscular tone, spasticity, weakness, balance problems, etc. 3. Contraindications for MRI procedure and/or contrast materials. 4. Contraindication to steroids, sirolimus, tacrolimus, and/or anesthetic medications. 5. Unstable adrenal function (e.g., untreated or inappropriately treated adrenal insufficiency). 6. History of diabetes or abnormal fasting plasma glucose (≥126 mg/dL) or hemoglobin A1C ≥6.5%. 7. Patients who have received a gene therapy.