It most often results from high gut protein or acute metabolic stress eg, gastrointestinal bleeding, infection, electrolyte abnormality in a patient with portosystemic shunting. Pathogenesis of hepatic encephalopathy in acute liver failure. Medicines may help reduce the amount of ammonia and other toxins that your body absorbs. Current concepts in the pathophysiology of hepatic encephalopathy. Hepatic encephalopathy is a spectrum of potentially reversible neuropsychiatric abnormalities in patients with significant liver dysfunction and a complication of cld that significantly impairs quality of life. Background and definition of hepatic encephalopathy. Nitrogenous compounds produced by gut bacteria are normally transported to the liver via the portal circulation and enter the urea cycle, resulting in the generation of urea which is subsequently excreted through the urine. Hepatic encephalopathy pathogenesis and clinical features. Delay can result in the development of potentially life threatening complications, such as seizures and coma. It is defined as a spectrum of neuropsychiatric abnormalities in patients with liver dysfunction, when other known brain disease has been excluded. How to recognize and treat metabolic encephalopathy in neurology. Hepatic encephalopathy is a complex disorder that encompasses a spectrum or continuum of disease that ranges from a subtle condition with no outward signs or symptoms to a severe form that can cause serious, lifethreatening complications. Hepatic encephalopathy is a brain disorder that develops in some individuals with liver disease.
Hepatic encephalopathy in chronic liver disease external link opens in a new window vilstrup h, amodio p, bajaj j, et al. Simmons transplant institute, baylor university medical center, dallas, tx, usa abstract hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dys. Pathophysiology of he in cirrhosis is multifactorial, involving brain accumulation of ammonia and. It affects the quality of life of both patient and relatives2 and signifies a poor prognostic indicator for patients with cirrhosis, with a survival of only 23% at three. Despite the frequency of the condition, we lack a clear understanding of its pathogenesis. The major symptom of encephalopathy is an altered mental state.
Ammonia lowering strategies for the treatment of hepatic encephalopathy. The main pathogenesis is metabolic derangement of cell function and brain edema. Brain edema and intracranial hypertension are major causes of death in this syndrome. Diagnosis and management of hepatic encephalopathy core. Hepatic encephalopathy describes a broad range of neuropsychiatric abnormalities caused by advance hepatic insufficiency or portosystemic shunting. Hepatic encephalopathy he represents a broad continuum of neuropsychological dysfunction in patients with acute or chronic liver disease andor. Mechanisms, diagnosis and management of hepatic encephalopathy.
Hepatic encephalopathy he occurs through a combination of pathophysiologic mechanisms. Hepatic encephalopathy syndrome is divided into short and longterm, which are acute and chronic types of the condition the former is a sequel of acute viral hepatitis a and b, toxic hepatitis as a result of severe poisoning with hazardous substances or rapid blockage of the liver blood supply, while the latter one is an aftereffect. Following important aspects about pathophysiology of hepatic encephalopathy. It is brought on by chronic liver failure, particularly in alcoholics with cirrhosis. Wernickes encephalopathy may not be associ ated with the full clinical triad and that in the acute phase clinical symptoms may resolve with thiamine treatment. If your child does not have seizures now, there is a good chance he or she never will. Hepatic encephalopathy he describes a spectrum of potentially reversible neuropsychiatric abnormalities seen in patients with liver dysfunction after exclusion of unrelated neurologic andor metabolic abnormalities. The main pathogenesis is metabolic derangement of cell function and. Encephalopathy information page national institute of. Encephalopathy refers to a range of conditions that damage the brains structure or function. Chronic forms of the disorder often keep getting worse or continue to come back. The treatment of hepatic encephalopathy depends on the suspected underlying cause types a, b or c and the presence or absence of underlying causes. Encephalitis practice essential, pathophysiology, diagnosis. Encephalopathy is a general term that means brain disease, damage, or malfunction.
Etiology, pathogenesis, and clinical signs h epatic encephalopathy he is defined as an abnormal mental state with augmented neuronal inhibition in the central nervous system cns resulting from liver dysfunction. The term implies that altered brain function is due to metabolic abnormalities. The pathophysiology of this disease is quite complex, as it involves overproduction and reduced metabolism of various neurotoxins, particularly ammonia. Apr 04, 2019 hepatic encephalopathy is a syndrome observed in patients with cirrhosis. Neuropathology of hepatic encephalopathy he in cirrhosis is primarily astroglial in nature characterized by alzheimer type 2 astrocytosis together with activation of microglia indicative of neuroinflammation. Neonatal encephalopathy ne is a syndrome that involves depressed or disturbed neurological function, often caused by lack of oxygen to the baby during birth. Hepatic encephalopathy is a frequent and serious complication of liver cirrhosis. Abnormal levels and altered metabolism of ammonia play a central role. Hepatic encephalopathy or portalsystemic encephalopathy represents a reversible impairment of neuropsychiatric function associated with impaired hepatic function. There has been a lack of standardization of terminology used to define hepatic encephalopathy. Diagnosis of hepatic encephalopathy the diagnosis of he is based on evidence of hepatic dysfunction in a patient with neurologic deficits. Recent findings a stroop smartphone app has been developed to allow clinicians to test for covert. Sep 17, 2019 portosystemic encephalopathy pse or hepatic encephalopathy he is a neuropsychiatric syndrome associated with hepatocellular failure or portosystemic venous shunting. Both forms may result in irreversible coma and death.
Its a serious health problem that, without treatment, can cause temporary or permanent brain damage. This chapter focuses on acute and subacute encephalopathies, which are often challenging to the clinicians and require prompt inpatient. Hyperammonemia in hepatic encephalopathy sciencedirect. Diagnosis hepatic encephalopathy is a diagnosis of exclusion. The hallmark of the growing probability of hepatic encephalopathy is the elevated ammonia level in the bloodstream, together with impaired mental function. Hepatic encephalopathy he is defined as a metabolically induced, potentially reversible, functional disturbance of the brain that may occur in acute or chronic liver disease. Encephalopathy is not a single disease but a group of disorders with several causes. Current concepts in the pathophysiology and management of.
The complete pathophysiology of encephalopathy is unknown. In addition to significantly affecting the lives of patients and their caregivers, it is also associated with increased morbidity and. It represents a reversible decrease in neurologic function. Jun 22, 2016 hepatic encephalopathy is a syndrome observed in some patients with cirrhosis. Focal loss of neurons may also occur in the basal ganglia, thalamus and cerebellum. Jun 30, 2014 hepatic encephalopathy he is the term used to encapsulate the broad spectrum of neuropsychiatric disturbances associated with both acute and chronic liver failure alf and clf, respectively, as well as portosystemic bypass in the absence of hepatocellular disease. It is a clinical expression of a spectrum of potentially reversible neuropsychiatric abnormalities secondary to the accumulation of neurotoxic substances in brain tissue that is proportional to the synthetic function and functional reserve of the liver. Encephalopathy is a general term that describes a disease that damages your brain. Hepatic encephalopathy nord national organization for rare. Portosystemic encephalopathy hepatic and biliary disorders. Current concepts in the pathophysiology and management of hepatic encephalopathy r. The gut is the primary source of ammonia absorbed into the circulation through the portal venous system. There are two major types of metabolic encephalopathies, namely those due to lack of glucose, oxygen or metabolic cofactors which are usually vitaminderived and those due to peripheral organ dysfunction. A complete history and physical examination are key.
An update on the pathophysiology and therapeutic options article pdf available june 2017 with 103 reads how we measure reads. Hepatic encephalopathy is not an inherited condition, so an individual who has it cannot pass it on to hisher children. But if you are worried, be sure to ask your doctor. Pathophysiology of hepatic encephalopathy and future treatment. Hepatic encephalopathy is caused by derangement of neurotransmitter systems caused by defective metabolic processes in the liver. The causes of encephalopathy are numerous and varied. Disorders and conditions such as alcoholic liver disease, hepatitis c, hepatitis b, hemochromatosis, wilson disease, age above 50 years and male gender may lead to hepatic encephalopathy.
Hepatic encephalopathy is broadly classified as either overt. In these patients, the number of functional liver cells is reduced, and some blood is diverted. The immature brain is therefore less demanding for metabolic fuel, which is especially problematic during the period of hypoxia when anaerobic glycolysis prevails as there is failure to deliver enough energetic. The dominant view has been that gutderived nitrogenous toxins are not extracted by the diseased liver and thereby enter the brain. An update on the pathophysiology and therapeutic options saleh elwir and robert s. Nevertheless, decades of experience have suggested that an increase in ammonia. Hepatic encephalopathy he is a brain disorder caused by chronic liver failure, particularly in alcoholics with cirrhosis, which results in cognitive, psychiatric, and motor impairments. Hepatic encephalopathy in thioacetamideinduced acute liver failure in rats. Hepatic encephalopathy definition, pathogenesis and. Standardized nomenclature has been proposed but a standardized approach to the treatment, particularly of persistent, episodic and recurrent encephalopathy associated.
Acute hepatic encephalopathy referred to acute liver failure or acute. Hepatic encephalopathy he represents a broad continuum of neuropsychological dysfunction in patients with acute or chronic liver disease andor portosystemic shunting of blood flow. There are many causes of seizures, and static encephalopathy is only one of them. In the advanced stages it can result in a coma hepatic encephalopathy can occur in those with acute or chronic liver disease. Hepatic encephalopathy national institutes of health. Jul 11, 20 prognosis acute hepatic encephalopathy may be treatable. Definition it is a state of disordered cns function, resulting from failure of liver to detoxify toxic agents because of hepatic insufficiency and portosystemic shunt. Learn about some of the different types and causes of encephalopathy. While the exact pathophysiology of he has yet to be elucidated, a number of contributing factors have been described.
Encephalopathy is an acute intrapartum event sufficient to cause neuronal injury evidenced by. Ammonia is a byproduct of colonic bacterial catabolism of nitrogenous sources such as ingested protein and secreted urea nitrogen. Evidence for altered phenylalanine metabolism and comparison with hepatic encephalopathy. The brain dysfunction associated with liver failure can have diverse manifestations. Metabolic encephalopathy me represents a syndrome of temporary or permanent disturbance of brain. Brain edema and intracranial hypertension are major causes of death in. It is caused by the accumulation of toxic byproducts that have not been adequately metabolized by the liver. Other symptoms may include movement problems, changes in mood, or changes in personality.
While ne primarily affects the brain and nervous system, it can also affect other organ systems. Diagnosis and management of hepatic encephalopathy this is a pdf version of the following document. Hepatic encephalopathy can develop during acute hepatitis which is then called fulminant hepatic failure or during chronic liver disease. Hepatic encephalopathy is defined as a spectrum of neuropsychiatric abnormalities in patients with liver dysfunction, after exclusion of brain disease. Pathophysiology of hepatic encephalopathy and future. For mild hepatic encephalopathy, you may only need a lowprotein diet. Some people have seizures but do not have static encephalopathy. In this condition, your liver cant adequately remove toxins from your blood. Pathophysiology, diagnosis, and management of hepatic. Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dysfunction andor portosystemic. Hepatic encephalopathy he is a serious neuropsychiatric complication of acute and chronic liver disease inflammation and raised levels of ammonia in the blood owing to diminished clearance of ammonia by the liver underlie the pathogenesis of he some degree of cerebral edema is observed in all grades of he. There are few prospective studies on the epidemiology of this complication. Other potential causes of brain disease must be ruled out before making a diagnosis of he1,2 box 1.
Hyperammonemia plays the most important role in the pathogenesis of hepatic encephalopathy. Clinical and experimental aspects of hepatic encephalopathy. Portosystemic encephalopathy is a neuropsychiatric syndrome that can develop in patients with liver disease. It is caused by the accumulation of toxic byproducts that have not. Hepatic encephalopathy an overview sciencedirect topics. Encephalopathy due to hypoxicischemic injury hypoxicischemic encephalopathy hie is defined as brain injury caused by the combination of inadequate blood flow and oxygen delivery to the brain. Hepatic encephalopathy he presents in 3060% of patients with cirrhosis of the liver. Hepatic encephalopathy can be a serious complication of acute liver failure and chronic liver diseases, predominantly liver cirrhosis. Oct 10, 2014 hepatic encephalopathy he is a common complication of cirrhosis of the liver. Hepatic encephalopathy he is an altered level of consciousness as a result of liver failure. Metabolic encephalopathy symptoms, complications, causes.
The brainblood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, gabaergic or benzodiazepine pathway abnormalities, manganese. Encephalopathy the wiley handbook on the aging mind and brain. Mizock ba, sabelli hc, dublin a et al 1990 septic encephalopathy. Hepatic encephalopathy he in acute liver injury signifies a serious prognosis. Jun 14, 2018 hepatic encephalopathy is a decline in brain function that occurs as a result of severe liver disease. In this article, we look at the types, causes, symptoms. Hepatic encephalopathy guidelines bmj best practice.
The brainblood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, gabaergic or benzodiazepine pathway abnormalities. Non hepatic causes of encephalopathy are rarer and tend to present to a wide range of medical specialties with variable and episodic symptoms. Learn all about metabolic encephalopathy symptoms, complications, causes and treatment options. Hepatic encephalopathy due to liver cirrhosis the bmj. Current concepts in the assessment and treatment of hepatic. The pathophysiology of uremic encephalopathy up to now is uncertain, but several factors have been. If encephalopathy develops in acute liver failure type a, even in a mild form grade 12, it indicates that a liver transplant may be required, and transfer to a specialist centre is advised. Neuronal and glial marker proteins in encephalopathy associated with. It is important to mention that only arterial or venous blood have to be examined, the analysis of the specimens from an extremity may pervert the pattern. One of the most debilitating complications of cirrhosis, encephalopathy affects 3045% of cirrhotics.
A highprotein diet increases the amount of ammonia in your blood and may worsen the disease. Although there are many theories and possibilities regarding what exactly causes hepatic encephalopathy, it is thought that one of the main causes is the accumulation of ammonia in the. Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dysfunction andor portosystemic shunting. Encephalopathy may be caused by infectious agent bacteria, virus, or prion, metabolic or mitochondrial dysfunction, brain tumor or increased pressure in the skull, prolonged exposure to toxic elements including solvents, drugs, radiation, paints, industrial chemicals, and certain metals. You may be given medicine to increase bowel movements. Ammonialowering strategies for the treatment of hepatic encephalopathy.
Frederick is director of quality and clinical protocols for the hepatology and liver transplant program at california pacific medical center in san francisco, california. The precise mechanism underlying the neurotoxicity of hepatic encephalopathy he is remains unclear. Pdf neuropathology of hepatic encephalopathy he in cirrhosis is primarily astroglial in nature characterized by alzheimer type 2 astrocytosis. Encephalopathy is a term for any diffuse disease of the brain that alters brain function or structure.
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