Childhood X-linked adrenoleukodystrophy: Clinical-pathologic overview and MR imaging manifestations at initial evaluation and follow-up

X-linked adrenoleukodystrophy (ALD) is a rare metabolic disorder caused by peroxisomal enzyme failure. Several phenotypes can be distinguished on the basis of clinical onset and manifestations. Childhood cerebral X-linked ALD is the most severe phenotype, resulting in rapid neurologic deterioration and early death. Patients with this disease may be hospitalized with far-advanced central nervous system (CNS) lesions or may complain of symptoms similar to those of certain psychiatric disorders, possibly leading to a wrong diagnosis. Although the general prognosis for patients with childhood cerebral X-linked ALD is still poor, new treatment modalities have been introduced, some of which are helpful in relieving clinical symptoms and prolonging life. With the introduction of these new therapies and increased clinical detection of childhood cerebral X-linked ALD, brain magnetic resonance (MR) imaging has become an essential tool for initial and follow-up evaluation. MR imaging allows early detection of CNS lesions and helps differentiate childhood cerebral X-linked ALD from other disorders. The characteristic MR imaging features of childhood cerebral X-linked ALD have been well documented, although most radiologists have limited experience with serial follow-up MR imaging in this context. Familiarity with the clinical-pathologic manifestations and progressive MR imaging features of childhood cerebral X-linked ALD will be helpful in evaluating affected patients.