Diffusion MRI features of acute encephalopathy due to stopping steroid medication abruptly in congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is characterized by adrenal steroid biosynthesis defect. Steroid replacement therapy should be performed regularly in these patients. Adrenal crisis may be present in acute stress due to increased cortisol requirements or in steroid deficiency due to stopping steroid medication abruptly. In patients with acute adrenal insufficiency, severe hypotension or hypovolemic shock occurs typically. Acute encephalopathy can be seen due to hypoxia, hypervolemia, or hypoglycemia. Diffusion restriction can be seen in cortical-subcortical regions of frontal and parieto-occipital lobes and in splenium of corpus callosum. In CAH patients with neurologic symptoms, Diffusion weighted images (DWI) is very important in the diagnosis and follow-up of acute encephalopathy.