Hepatic encephalopathy: lack of changes of gamma-aminobutyric acid content in plasma and cerebrospinal fluid

The aim of the study was to verify the role of gamma-aminobutyric acid in the pathogenesis of hepatic encephalopathy occurring in cirrhotic patients by attempting to correlate plasma and cerebrospinal fluid content of authentic gamma-aminobutyric acid with the neurological manifestations of hepatic encephalopathy. For this purpose, plasma and cerebrospinal fluid gamma-aminobutyric acid levels were measured by means of mass fragmentography in 17 cirrhotic patients with hepatic encephalopathy and in 6 cirrhotics without neurological symptoms. Moreover, in all patients, a second sample was obtained during the clinical course of hepatic encephalopathy. The mean plasma and cerebrospinal fluid gamma-aminobutyric acid levels were not different in patients with or without hepatic encephalopathy and did not change during the evolution of the neurological symptoms. The lack of changes in the gamma-aminobutyric acid content in plasma and cerebrospinal fluid during hepatic encephalopathy is in contrast with the hypothesized importance of increased entry into the brain of gamma-aminobutyric acid in the pathogenesis of hepatic encephalopathy.     

Plasma and CSF Benzodiazepine Receptor Ligand Concentrations in Cirrhotic Patients with Hepatic Encephalopathy: Relationship to Severity of Encephalopathy and to Pharmaceutical Benzodiazepine Intake

Increased plasma and CSF concentrations of substances which bind to brain benzodiazepine receptors have previously been reported in cirrhotic patients with hepatic encephalopathy (HE). However, their relationship to previous intake of pharmaceutical benzodiazepines has not been clearly established. In the present study, plasma levels of benzodiazepine receptor ligands (BZRLs) were measured using a sensitive radioreceptor assay in 12 control subjects with no evidence of hepatic, neurological or psychiatric illness, 11 cirrhotic patients without HE, 24 cirrhotic patients with moderate (grade I-II) HE and in 45 cirrhotic patients with severe (grade II-IV) HE. In addition, CSF concentrations of BZRLs were measured in 8 cirrhotic patients with HE and an equal number of age-matched controls. Recent intake (within 10 days) of pharmaceutical benzodiazepines was assessed by detailed review of medical files, and interviews with the patient, at least one family member as well as the pharmacist. Significantly increased plasma concentrations of BZRLs were observed in cirrhotic patients with severe encephalopathy (p<0.02) compared to controls and to cirrhotic patients without (or with mild) neurological impairment. Increased plasma BZRLs could be accounted for by prior exposure to benzodiazepine medication in all cases. CSF concentrations of BZRLs in cirrhotic patients were not significantly different from control values. These findings do not support a role for endogenous benzodiazepines in the pathogenesis of HE in chronic liver disease but suggest that pharmaceutic benzodiazepines administered to cirrhotic patients as sedatives or as part of endoscopic work-up could have contributed to the neurological impairment in some patients.     

Intracortical inhibitory and excitatory circuits in subjects with minimal hepatic encephalopathy: a TMS study

Minimal hepatic encephalopathy (MHE) is the earliest form of hepatic encephalopathy (HE) and affects up to 80 % of patients with liver cirrhosis. By definition, MHE is characterized by psychomotor slowing and subtle cognitive deficits,  but obvious clinical manifestations are lacking. Given its covert nature, MHE is often underdiagnosed. This study was aimed at detecting neurophysiological changes, as assessed by means of transcranial magnetic stimulation (TMS), involved in the early pathogenesis of the HE. We investigated motor cortex excitability in 15 patients with MHE and in 15 age-matched age-matched cirrhotic patients without MHE; the resting motor threshold, the short-interval intracortical inhibition (SICI) and the intracortical facilitation (ICF) were examined. Paired-pulse TMS revealed significant increased SICI and reduced ICF in the patients with MHE. These findings may reflect abnormalities in intrinsic brain activity and altered organization of functional connectivity networks. In particular, the results suggest a shift in the balance between intracortical inhibitory and excitatory mechanisms towards a net increase of inhibitory neurotransmission. Together with other neurophysiological (in particular EEG) and neuroimaging techniques, TMS may thus provide early markers of cerebral dysfunction in cirrhotic patients with MHE.     

Aromatic and branched-chain amino acids in autopsied brain tissue from cirrhotic patients with hepatic encephalopathy

Concentrations of the branched-chain amino acids (BCAAs) valine, leucine, and isoleucine and the aromatic amino acids (AAAs) phenylalanine and tyrosine were measured in three areas of dissected brain tissue obtained at autopsy from nine cirrhotic patients who died in hepatic encephalopathy. The controls were an equal number of subjects free from neurological, psychiatric or hepatic diseases, matched for age and time interval from death to freezing of autopsied brain samples. Amino acids were measured using high-performance liquid chromatography with fluorimetric detection. In brain tissue of cirrhotic patients, no changes in BCAA concentrations were observed compared with controls. On the other hand, phenylalanine levels were found to be increased 141% in prefrontal cortex, 86% in frontal cortex and 26% in caudate nucleus, and tyrosine content was increased by 71% in prefrontal cortex and 28% in frontal cortex with no significant increase in caudate nucleus. Alterations in the concentration of AAAs may lead to disturbances of monoamine neurotransmitters in brain. Such changes could play a role in the pathogenesis of hepatic encephalopathy resulting from chronic liver disease in man.     

Proton magnetic resonance spectroscopy (1H-MRS) findings for the brain in patients with liver cirrhosis reflect the hepatic functional reserve

OBJECTIVE: Proton magnetic resonance spectroscopy (1H-MRS) has been used to assess the metabolic changes in the brain in patients with liver cirrhosis. Decreased myo-inositol and increased glutamine levels were noted to be the most sensitive spectroscopic markers for cirrhotic patients with hepatic encephalopathy (HE). The purpose of this study was to assess how the abnormalities seen on the 1H-MRS of the brain in patients with liver cirrhosis are related to clinical and laboratory parameters. METHODS: In a prospective study, localized 1H-MRS was performed in the basal ganglia and parietal white matter regions in liver cirrhosis patients with (n = 48) and without (n = 52) HE and chronic hepatitis (CH) (n = 15), and in normal controls (n = 20). RESULTS: Among cirrhotic patients, the myo-inositol levels were significantly lower (p < 0.01) and the glutamine levels were higher (p < 0.05) for patients with HE than for those without HE. The myo-inositol and glutamine levels, respectively, were inversely (r = -0.50; p < 0.001) and linearly (r = 0.50; p < 0.001) related to the Child-Pugh score. However, by subgroup analysis of Child-Pugh class C patients, there were no significant differences in the myo-inositol and glutamine levels between cirrhotic patients with (n = 40) and without HE (n = 24). A follow-up study of eight cirrhotic patients with HE showed no significant differences in the myo-inositol and glutamine levels after clinical improvement of HE. CONCLUSIONS: The abnormalities seen on the 1H-MRS of the brain of patients with liver cirrhosis are not likely to reflect the severity of HE or acute alteration in the level of consciousness. Rather, we believe they represent the chronic metabolic derangement of the brain associated with hepatic functional reserve.     

肝性脑病脑组织乙型肝炎病毒标志物免疫组化染色观察

目的 肝性脑病至今仍以血液检查所见的生化代谢异常来解释,因不能圆满解释全面情况,需进一步探讨。方法 不加选择收集70例肝硬变死亡者脑组织,分别作HE和免疫组化检查,观察病理改变和HBsAg、HBeAg表达。结果 在70例脑组织标本内免疫组化染色HBsAg、HBeAg阳性者计30例,阳性率42.3％,临床上有肝性脑病表现者阳性率明显高于无表现者,脑组织病理改变较明显者,阳性率亦明显高于较轻者。结论 肝硬变脑组织内出现HBsAg和HBeAg表达,而且阳性率与脑组织病理改变和是否出现临床表现密切相关,提示HBV侵及脑组织,导致病理形态改变可能是肝性脑病的病理基础,生化代谢异常可能仅是肝衰的表现。     

Zinc and other trace elements in liver cirrhosis.

Alterations in trace element concentrations may be observed in patients with chronic liver disease. Notably, selenium and zinc levels are reduced both in serum and in liver tissue of cirrhotic patients. Low selenium levels have been involved in the pathogenesis of liver damage as this element is important in controlling the levels of toxic oxygen radicals in the cells. Zinc deficiency has been involved in the pathogenesis of a number of clinical findings in chronic liver disease. These include the possible role of zinc deficiency in the pathogenesis of hepatic encephalopathy, by inducing alterations in urea metabolism. In CC14 cirrhotic rats oral zinc supplementation reduces ammonia levels and increases OCT activity in the liver. Oral zinc supplementation has been also proposed in the treatment of cirrhotic patients with chronic hepatic encephalopathy, the results however are not yet conclusive.     

Backflux of ammonia from brain to blood in human subjects with and without hepatic encephalopathy

In patients with hepatic encephalopathy (HE) the blood concentration of ammonia is usually highly elevated. Ammonia readily enters brain cells from the blood, and toxic effects of ammonia on brain metabolism and neurotransmission are believed to play a key role in the pathogenesis of HE. It has, however, been a matter of great controversy whether backflux of unmetabolized ammonia (NH₃ + NH₄ ⁺) from brain cells to the blood occurs in man. In the present analysis of data from a dynamic PET study of brain ¹³N–ammonia metabolism in healthy subjects and cirrhotic patients with and without HE, we provide the first unambiguous evidence for backflux of ammonia from brain cells to the blood in man. The high temporal and spatial resolution of modern PET technology was employed to distinguish between unidirectional blood-brain transport of ammonia and subsequent metabolism of the ammonia in the brain. In all 16 subjects, clearance of the unidirectional transport of ¹³N–ammonia from the blood to brain cells (K₁) was higher than the metabolic clearance of ¹³N–ammonia from the blood (K_met=K₁ k₃/(k₂+k₃). This can only be explained by backflux (k₂) of ammonia from brain cells to the blood. In conclusion, backflux of ammonia from the brain to the blood does indeed occur in both healthy subjects and cirrhotic patients with and without hepatic encephalopathy.     

Inflammation:A novel target of current therapies for hepatic encephalopathy in liver cirrhosis

Hepatic encephalopathy(HE) is a severe neuropsychiatric syndrome that most commonly occurs in decompensated liver cirrhosis and incorporates a spectrumof manifestations that ranges from mild cognitive impairment to coma. Although the etiology of HE is not completely understood, it is believed that multiple underlying mechanisms are involved in the pathogenesis of HE, and one of the main factors is thought to be ammonia; however, the ammonia hypothesis in the pathogenesis of HE is incomplete. Recently, it has been increasingly demonstrated that inflammation, including systemic inflammation, neuroinflammation and endotoxemia, acts in concert with ammonia in the pathogenesis of HE in cirrhotic patients. Meanwhile, a good number of studies have found that current therapies for HE, such as lactulose, rifaximin, probiotics and the molecular adsorbent recirculating system, could inhibit different types of inflammation, thereby improving the neuropsychiatric manifestations and preventing the progression of HE in cirrhotic patients. The antiinflammatory effects of these current therapies provide a novel therapeutic approach for cirrhotic patients with HE. The purpose of this review is to describe the inflammatory mechanisms behind the etiology of HE in cirrhosis and discuss the current therapies that target the inflammatory pathogenesis of HE.     

Hepatic encephalopathy: from pathophysiology to treatment

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome due to hepatic dysfunction and porto-systemic shunting of the intestinal blood. Cirrhosis is the most frequent liver disease causing HE. On most occasions, HE appears due to a superimposed precipitating factor (gastrointestinal bleeding, infections, renal and electrolyte disturbances, etc.). Ammonia produced in colon by intestinal bacteria is the main toxic substance implicated in the pathogenesis of HE. Other mechanisms, such as changes in the GABA-benzodiazepine system, accumulation of manganese into the basal ganglia of the brain, changes in blood-brain barrier and neurotransmission disturbances are also present. Clinical manifestations of HE may vary widely, from minimal neurologic changes, only detected with specific tests, to deep coma. Treatment of HE should be directed to controlling the precipitating factors, as well as therapies aimed at correcting the above-mentioned pathophysiological changes, mainly reduction of blood ammonia levels. Artificial liver support systems may play a role in the future. Liver transplantation should be evaluated as a definitive therapy in all cases of HE.     

Increased Brain Concentrations of Endogenous (Non-benzodiazepine) GABA-A Receptor Ligands in Human Hepatic Encephalopathy

It has been suggested that alterations of GABAergic neurotransmission are implicated in the pathophysiology of hepatic encephalopathy (HE). Increased concentrations of endogenous benzodiazepines with positive allosteric modulatory properties at the GABA-A receptor complex were proposed as a pathophysiological mechanism to explain increased GABAergic tone in HE. However, results of controlled trials with benzodiazepine receptor antagonists have yielded equivocal results and increases in benzodiazepine levels in body fluids of cirrhotic patients were suggested to be largely accounted for by previous pharmaceutical benzodiazepine intake. In the present study the issue of benzodiazepine receptor ligands in brains of cirrhotic patients, and their contribution to alterations of GABA-A receptor complex in HE are addressed. "Benzodiazepine-like" ligands were present in trace amounts in autopsied brain tissue from control subjects (0.2 +/- 0.2 ng/g tissue), and from cirrhotic patients not previously exposed to benzodiazepine medication (0.8 +/- 0.4 ng/g tissue). In contrast, these ligands accumulate in brain extracts from cirrhotic patients previously exposed to benzodiazepines by up to 200-fold (161.5 +/- 93.2 DE ng/g tissue). Brain extracts from cirrhotic patients increased the binding of the GABA-A receptor agonist [3H]muscimol. This increase was minimal with brain extracts from controls (6.8 +/- 2.8%), but was significant with brain extracts from cirrhotic patients without (29.4 +/- 2.7%), or with (55.1 +/- 7.6%) previous exposure to benzodiazepines. Addition of flumazenil, a selective benzodiazepine receptor antagonist did not significantly modify the increase of [3H]muscimol binding by brain extracts from patients without prior exposure to benzodiazepines and only partially inhibited the increase of [3H]muscimol binding in presence of brain extracts from cirrhotic patients previously exposed to benzodiazepines. These findings suggest the presence of nonbenzodiazepine substances (possibly neurosteroids) with positive allosteric modulatory properties at the GABA-A receptor complex in brain in hepatic encephalopathy.     

Oral Tryptophan Challenge Studies in Cirrhotic Patients: No Evidence of Neuropsychiatric Changes

Hepatic encephalopathy is a frequent complication of cirrhosis. Abnormalities of5-hydroxytryptamine (5-HT) and its metabolites are recognized and may contribute to its pathogenesis. We therefore studied the effect of an oral tryptophan load (6–18 g) upon psychometric test scores and analyzed EEG's in alcoholic cirrhotic patients. Eight patients had had previous encephalopathic episodes related to variceal bleeds and one patient was awaiting a liver transplant. Five out of the 10 patients had at least one abnormal baseline psychometric test. Following tryptophan challenge there were no changes in blood ammonia but plasma tryptophan levels were elevated approximately 10-fold (p <0.01× 10^–7). Nevertheless, there were no statistically significant changes in psychometric testing or analyzed EEG frequency distribution. All patients reported nausea or vomiting while one patient developed a short-lived serotonin like syndrome. We conclude that in this group of patients, an oral tryptophan load does not induce or worsen subclinical hepatic encephalopathy. If the high blood levels of tryptophan seen in these studies are able to influence cerebral neurotransmitter synthesis, the results do not support a primary role for abnormalities of 5-HT neurotransmission in hepatic encephalopathy.     

幽门螺杆菌感染对高氨血症和肝性脑病发病的影响

目的了解幽门螺杆菌(Hp)感染和血氨水平、肝性脑病(HE)发病的关系,并探讨根除Hp对血氨水平和HE发生的影响。方法2003年7月-2005年1月在浙江省5个地区收集肝硬化住院患者,记录患者的一般资料、数字连接试验结果、Hp感染情况、肝功能Child-Pugh分级、血氨水平和HE情况。Hp(+)患者予“奥美拉唑+克拉霉素+替硝唑”1周根除治疗,1个月后查~(14)C尿素呼气试验,并记录患者的神经精神症状和血氨水平。结果(1)共收集肝硬化住院患者457例,Hp感染率60．6%,HE发生率47．5%。检出亚临床肝性脑病(SHE)患者55例,SHE占未发生HE肝硬化患者的47．0%(55/117)。(2)Hp(+)和Hp(-)肝硬化患者血氨浓度分别为(78．4±63．6)μmoL/L和(53．8±51．4)μmol/L(P＜0．01);根除Hp后血氨显著下降至(53．5±37．7)μmol/L(P＜0．01)。Hp(+)和Hp(-)肝硬化患者HE发生率差异有统计学意义(58．5%比30．6%,P＜0．01);根除Hp后HE发生率下降至34．1%(P＜0．01)。(3)HE、SHE和肝硬化患者的Hp感染率分别为74．4%、69．1%和53．2%(P＜0．05)。三组患者的血氨水平分别为(94．5±75．6)μmol/L、(59．9±49．2)μmol/L和(47．3±33．5)μmol/L(P＜0．05)。结论Hp感染是引起肝硬化高氨血症和并发HE的重要因素,根除Hp有利于治疗和预防HE的发生。     

肝性脑病的病因和防治探讨

肝性脑病至今仍以血液检查所见的生化代谢异常来解释，因不能圆满解释全面情况，需进一步探讨。不加选择收集70例肝硬化死亡者脑组织，分别作HE和免疫组化检查，观察病理改变和HBsAg、HBcAg表达。在70例脑组织标本中免疫组化染色HBsAg、HBcAg阳性者计30例，阳性率42.3%，临床上有肝性脑病表现者阳性率明显高于无表现者，脑组织病理改变较明显者，阳性率亦明显高于较轻者。肝硬化脑组织内出现HBsAg和HBcAg表达，而且阳性率与脑组织病理改变和是否出现临床表现密切有关。提示HBV侵及脑组织，导致病理形态改变可能是肝性脑病的病理基础，生化代谢异常可能仅是肝衰的表现。     

Increased Extracellular Brain Glutamate in Acute Liver Failure: Decreased Uptake or Increased Release?

Glutamatergic dysfunction has been suggested to play an important role in the pathogenesis of hepatic encephalopathy (HE) in acute liver failure (ALF). Increased extracellular brain glutamate concentrations have consistently been described in different experimental animal models of ALF and in patients with increased intracranial pressure due to ALF. High brain ammonia levels remain the leading candidate in the pathogenesis of HE in ALF and studies have demonstrated a correlation between ammonia and increased concentrations of extracellular brain glutamate both clinically and in experimental animal models of ALF. Inhibition of glutamate uptake or increased glutamate release from neurons and/or astrocytes could cause an increase in extracellular glutamate. This review analyses the effect of ammonia on glutamate release from (and uptake into) both neurons and astrocytes and how these pathophysiological mechanisms may be involved in the pathogenesis of HE in ALF.     

Hepatic encephalopathy in patients with liver cirrhosis：Is there a role of malnutrition？

Hepatic encephalopathy（HE） is a common complica-tion in patients with liver cirrhosis but its pathogenesis remains incompletely understood.Malnutrition is commonly encountered in patients with liver cirrhosis and it has been reported to affect the quality of life of this group of patients.Experimental studies suggest that low energy intake and poor nutritional status may facilitate the development of HE but there are scarce data on the potential role of malnutrition in HE in patients with liver cirrhosis.Two recently published studies have evaluated the potential role of malnutrition in the development of HE in cirrhotic patients with conflicting results.In this letter to the editor we briefly present the results of the two studies as well as potential reasons for the conflicting results reported.     

Neuroactive amino acids in hepatic encephalopathy

There is abundant evidence to suggest that alterations of excitatory and inhibitory amino acids play a significant role in the pathogenesis of hepatic encephalopathy (HE) in both acute and chronic liver diseases. Brain glutamate concentrations are reduced in patients who died in hepatic coma as well as in experimental HE, astrocytic reuptake of glutamate is compromised in liver failure and postsynaptic glutamate receptors (both NMDA and non-NMDA subclasses) are concomitantly reduced in density. Recent studies in experimental acute liver failure suggest reduced capacity of the astrocytic glutamate transporter in this condition. Together, this data suggests that neuron-astrocytic trafficking of glutamate is impaired in HE. Other significant alterations of neuroactive amino acids in HE include a loss of taurine from brain cells to extracellular space, a phenomenon which could relate both to HE and to brain edema in acute liver failure. Increased concentrations of benzodiazepine-like compounds have been reported in human and experimental HE. Clinical trials with the benzodiazepine antagonist flumazenil reveal a beneficial effect in some patients with HE; the mechanism responsible for this effect, however, remains to be determined.     

Critical flicker frequency for quantification of low-grade hepatic encephalopathy

Subclinical hepatic encephalopathy (SHE) is currently diagnosed by psychometric tests or neurophysiologic techniques. In view of its sociomedical relevance, simple and reproducible tests for routine diagnosis are required. This study evaluates critical flicker-frequency thresholds for quantification of low-grade hepatic encephalopathy. A total of 115 patients (92 with cirrhosis, 23 controls) were analyzed for HE severity (mental state, computerized psychometric tests), and the threshold frequencies at which light pulses are perceived as fused (fusion frequency) or flickering light (critical flicker frequency [CFF]). CFF was a highly reproducible parameter with little age, day-time, and training dependency. CFFs in cirrhotic patients without HE (HE 0) were not different from those found in noncirrhotic controls. Significantly lower CFFs were found in cirrhotic patients with subclinical or manifest HE, and the various HE groups separated from each other at a high level of significance (P <.01). By using a CFF cut-off value of 39 Hz, a 100% separation of patients with manifest HE from noncirrhotic controls and HE 0 cirrhotic patients was obtained. SHE patients separated from HE 0 cirrhotic patients with high sensitivity (55%) and specificity (100%). The HE severity-dependent differences were found in both, alcoholic and posthepatitic cirrhosis. Statistically significant correlations (P <.01) were found between CFFs and individual psychometric tests. Aggravation of preexisting HE after transjugular intrahepatic portosystemic stent shunt (TIPS) implantation was accompanied by a corresponding decrease of CFF, whereas improvement of HE increased CFF. In conclusion, CFF is a sensitive, simple, and reliable parameter for quantification of low-grade HE severity in cirrhotic patients and may be useful for the detection and monitoring of SHE.     

Changes in brain catecholamine levels in human cirrhotic hepatic encephalopathy

Hepatic encephalopathy (HE) is currently felt to be secondary to a disturbance in the metabolism of cerebral catecholamines with a decline in dopamine and noradrenaline and a rise in the false neurotransmitter octopamine. The aim of this study was to evaluate brain tissue levels of dopamine, noradrenaline, and octopamine in patients with cirrhosis and HE. This study includes 34 patients: 22 were cirrhotic, 12 were control subjects. Among the 22 cirrhotic patients, 19 had HE, three did not. Tissue specimens were obtained at necropsy from the locus niger, caudate nucleus, hypothalamus, thalamus and frontal cortex, and from the frontal cortex during neurosurgical procedures. Our results showed that (1) dopamine and noradrenaline levels are identical in cirrhotic patients with or without HE and in patients without liver disease (P < 0.05); (2) octopamine levels are higher in control subjects than in patients with cirrhosis and HE. In conclusion, there is no decline in dopamine and noradrenaline levels in the brain tissues of cirrhotic patients with HE, and this is in contradication with the animal findings; octopamine levels are not raised. Hepatic encephalopathy in human liver cirrhosis does not seem to be secondary to a disturbance in cerebral catecholamines.     

Natural endogenous ligands for benzodiazepine receptors in hepatic encephalopathy

Benzodiazepines of natural origin (NBZDs) have been found in human blood and brains as well as in medicinal plants and foods. In plasma and brain tissue there are i.e. diazepam and nordiazepam equal to commercial drugs but there are also other benzodiazepine-like compounds termed “endozepines”, which act as agonists at the benzodiazepine receptors of central type (CBR). A synthetic pathway for the production of NBZDs has not yet been found, but it has been suggested that micro-organisms may synthesize molecules with benzodiazepine-like structures. Hence NBZDs could be of both endogenous and exogenous source and be considered as natural anxyolitic and sedative. Interestingly there are also natural compounds, such as the polypeptide Diazepam Binding Inhibitor (DBI) acting as an “inversive agonist” implicated in fair and panic disorders. It has been suggested that NBZDs may play a role in the pathogenesis of hepatic encephalopathy (HE). Multidirectional studies evaluated NBZDs levels (1) in the blood of normal subjects, of cirrhotic with or without HE and in commercial benzodiazepine consumers; (2) in the blood of cirrhotic treated or not with a non-absorbable antibiotic; (3) in several constituents of our diet. In conclusion, NBZDs increase sometime in cirrhotics with or without HE but they reach concentrations not higher than those found in commercial benzodiazepines consumers. Hence NBZDs must be considered as occasional precipitating factor of HE and benzodiazepine antagonists only symptomatic drugs. The finding that NBZDs may be in part synthesized by intestinal bacterial flora and in part constituent of our diet underlines the importance to feed cirrhotic patients with selected food.