Neurologic manifestations of acute and chronic liver disease

Absence of Pupillary Reflexes in Pediatric Acute Liver Failure and Neurological Outcome After Liver Transplantation

BACKGROUND

Pediatric Acute Liver Failure (PALF) frequently requires liver transplantation (LTx). The neurological condition can deteriorate rapidly, but the difficulty in assessing the (ir)reversibility of neurological symptoms can hamper therapeutic decision-making, including transplantation. We aimed to determine the association between pupillary reflexes (PR), brain stem reflexes (BSR), radiological signs of brain herniation, and subsequent neurological outcome.

METHODS

We analyzed a retrospective, observational cohort of PALF patients with severe hepatic encephalopathy (grade III-IV), admitted to our national pediatric liver transplantation center between 1993 and 2023. We subdivided the patients into groups with PR present or PR absent. We compared the two groups for pre-treatment neurological and neuro-radiological parameters and related the findings to neurological outcomes.

RESULTS

Survival rate in patients with PR present was higher compared to patients with PR absent [70% (26/37) and 29% (4/14); resp., p = 0.008]. In the absence of PR, neurological outcome could still be favorable after LTx (n = 3/6). Presence or absence of BSR was not related to the outcome in terms of survival or death. Radiologically proven brain herniation was associated with mortality (6/7) or minimally conscious state (1/7), irrespective of undergoing a LTx or not.

CONCLUSIONS

Although absence of PR is associated with a poor prognosis, the neurological outcome can still be favorable after LTx. Radiological signs of brain herniation are strongly associated with mortality or severe neurological outcomes, irrespective of subsequent transplantation. We therefore advocate that absence of PR should be an indication for radiological imaging to assess brain herniation before making major treatment decisions.

Nonconvulsive status epilepticus disguising as hepatic encephalopathy

Nonconvulsive status epilepticus has become an important issue in modern neurology and epileptology. This is based on difficulty in definitively elucidating the condition and its various clinical phenomena and on our inadequate insight into the intrinsic pathophysiological processes. Despite nonconvulsive status epilepticus being a situation that requires immediate treatment, this disorder may not be appreciated as the cause of mental status impairment. Although the pathophysiology of nonconvulsive status epilepticus remains unknown, this disorder is thought to lead to neuronal damage, so its identification and treatment are important. Nonconvulsive status epilepticus should be considered in the differential diagnosis of patients with liver cirrhosis presenting an altered mental status. We report a case of a 52-year-old male with liver cirrhosis presenting an altered mental status. He was initially diagnosed with hepatic encephalopathy but ultimately diagnosed with nonconvulsive status epilepticus by electroencephalogram.

Neurologic Manifestations of Chronic Liver Disease and Liver Cirrhosis

The normal functioning of brain is intimately as well as intricately interrelated with normal functioning of the liver. Liver plays a critical role of not only providing vital nutrients to the brain but also of detoxifying the splanchnic blood. Compromised liver function leads to insufficient detoxification thus allowing neurotoxins (such as ammonia, manganese, and other chemicals) to enter the cerebral circulation. In addition, portosystemic shunts, which are common accompaniments of advanced liver disease, facilitate free passage of neurotoxins into the cerebral circulation. The problem is compounded further by additional variables such as gastrointestinal tract bleeding, malnutrition, and concurrent renal failure, which are often associated with liver cirrhosis. Neurologic damage in chronic liver disease and liver cirrhosis seems to be multifactorial primarily attributable to the following: brain accumulation of ammonia, manganese, and lactate; altered permeability of the blood-brain barrier; recruitment of monocytes after microglial activation; and neuroinflammation, that is, direct effects of circulating systemic proinflammatory cytokines such as tumor necrosis factor, IL-1β, and IL-6. Radiologist should be aware of the conundrum of neurologic complications that can be encountered in liver disease, which include hepatic encephalopathy, hepatocerebral degeneration, hepatic myelopathy, cirrhosis-related parkinsonism, cerebral infections, hemorrhage, and osmotic demyelination. In addition, neurologic complications can be exclusive to certain disorders, for example, Wilson disease, alcoholism (Wernicke encephalopathy, alcoholic cerebellar degeneration, Marchiafava-Bignami disease, etc). Radiologist should be aware of their varied clinical presentation and radiological appearances as the diagnosis is not always straightforward.