Presentation
History of severe vomiting during pregnancy and elevated liver enzymes, diagnosed with acute fatty liver of pregnancy, that was followed by abortion. The patient showed rapid disease progression which worsened to acute hepatic failure with markedly elevated bilirubin levels and liver enzymes. Neurologically the patient developed seizures and coma. Normal blood pressure, glucose levels, and renal functions.
Patient Data
Bilateral thalamic, insula, mesial temporal lobes, basal ganglia and multifocal cortical areas of abnormal signal eliciting high signal on T2 & FLAIR and showing diffusion restriction, sparing the occipital and perirolandic cortices.
Case Discussion
In acute hepatic encephalopathy, also known as acute hyperammonemic encephalopathy or portosystemic encephalopathy, there are usually abnormal signal and diffusion restrictions involving both thalami, insular regions, posterior limbs of internal capsule, cingulate gyrus and diffuse cortical involvement in severe cases with typical sparing of the occipital lobes and perirolandic cortices.
While in chronic hepatic disease, there are usually bilateral hyperintensities of the globus pallidus, subthalamic regions, and midbrain on T1-weighted images
Differential diagnosis of gyriform diffusion restriction include:
- hemodynamic alteration: hypoxic-ischemic insult or post-ictal
- metabolic causes: hypoglycemia or hyperammonemia
- infections: herpes encephalitis, Creutzfeldt Jakob disease or cerebritis