Hyperammonemia and intracranial hypertension: lying in wait for patients with hepatic disorders?

In the past decade, a dozen patients with acute liver injury, with idiopathic hyperammonemia and intracranial hypertension in the absence of acute liver failure have been reported, as discussed below. If one combines these patients to those with acute liver failure and Reye's syndrome, in both of which cerebral herniation is a common complication, liver disease may be one of the most common causes of cerebral herniation. Indeed, these reports have similarities to the patients of Clemmesen et al. who found that increased blood ammonia levels are frequently elevated, which led to the observation that increased blood ammonia concentrations may be early warning signs of impending cerebral herniation.