Cerebral CT scan abnormalities in cholestatic and hepatocellular disease and their relationship to neuropsychologic test performance

Pitch Processing Can Indicate Cognitive Alterations in Chronic Liver Disease: An fNIRS Study

Early detection and evaluation of cognitive alteration in chronic liver disease is important for predicting the subsequent development of hepatic encephalopathy. While visuomotor tasks have been rigorously employed for cognitive evaluation in chronic liver disease, there is a paucity of auditory processing task. Here we focused on auditory perception and examined behavioral and haemodynamic responses to a melodic contour identification task (CIT) to compare cognitive abilities in patients with chronic liver disease (CLD, N = 30) and healthy controls (N = 25). Further, we used support vector machines to examine the optimal combination of channels of functional near-infrared spectroscopy that can classify cognitive alterations in CLD. Behavioral findings showed that CIT performance was significantly worse in the patient group and CIT significantly correlated with neurocognitive evaluation (i.e., number connection test, digit span test). The findings indicated that CIT can measure auditory cognitive capacity and its difference existing between patient group and healthy controls. Additionally, optimal subsets classified the 16-dimensional haemodynamic data with 78.35% classification accuracy, yielding markers of cognitive alterations in the prefrontal regions (CH6, CH7, CH10, CH13, CH14, and CH16). The results confirmed the potential use of behavioral as well as haemodynamic responses to music perception as an alternative or supplementary method for evaluating cognitive alterations in chronic liver disease.

Laboratory Abnormalities of Hepatic Encephalopathy

Currently, there is no gold standard serologic or imaging modality to detect hepatic encephalopathy (HE). It is a clinical diagnosis gathered from the history and physical. Imaging is nonspecific; however, PET and MRI have shown areas of utility, but are not widely available, cost-efficient, or necessary for diagnosis. Electroencephalogram has shown promise as it can be used in conjunction with the Portal Systemic Hepatic Encephalopathy Score test to diagnose minimal HE. Further research on these techniques would need to be performed to identify strict criteria and cutoffs for diagnosing HE as well as associated sensitivities and specificities.

Neurocritical care monitoring of encephalopathic children with acute liver failure: A systematic review

Research on non-invasive neuromonitoring specific to PALF is limited. This systematic review identifies and synthesis the existing literature on non-invasive approaches to monitoring for neurological sequelae in patients with PALF. A series of literature searches were performed to identify all publications pertaining to five different non-invasive neuromonitoring modalities, in line with PRISMA guidelines. Each modality was selected on the basis of its potential for direct or indirect measurement of cerebral perfusion; studies on electroencephalographic monitoring were therefore not sought. Data were recorded on study design, patient population, comparator groups, and outcomes. A preponderance of observational studies was observed, most with a small sample size. Few incorporated direct comparisons of different modalities; in particular, comparison to invasive intracranial pressure monitoring was largely lacking. The integration of current evidence is considered in the context of the clinically significant distinctions between pediatric and adult ALF, as well as the implications for planning of future investigations to best support the evidence-based clinical care of these patients.

Regional cerebral blood flow assessed by single photon emission computed tomography (SPECT) in dogs with congenital portosystemic shunt and hepatic encephalopathy

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a ^99mtechnetium-hexamethylpropylene amine oxime (^99mTc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain.

New Methods of Testing and Brain Imaging in Hepatic Encephalopathy: A Review

The diagnosis of hepatic encephalopathy is predominantly clinical, and the tests available assist in the diagnosis only by excluding other causes. Covert hepatic encephalopathy, which is defined as abnormal performance on psychometric tests when standard neurologic examination is completely normal, has gained widespread attention in recent years due to its effect on quality of life. This review focuses on the tests available to aid in the diagnosis of this significant complication of liver disease, and discusses the complex pathophysiologic mechanisms identified through new imaging techniques and their significance toward development of new therapeutic targets for this condition.

Quality of life and physical activity in liver transplantation patients: results of a case-control study in Italy

The aim of the study was to assess the quality of life (QOL) and the physical activity of liver transplant recipients compared with the general population. The case-controlled pilot study was accomplished through the administration of 2 questionnaires: 36-item Medical Outcomes Study, Short-Form General Health Survey (SF-36) for quality of life (10 scores) and International Physical Activity Questionnaire (IPAQ) to estimate the physical activity (metabolic equivalent score). Fifty-four patients who underwent liver transplantation using the piggyback technique and 108 controls from the general population at the orthopedic ambulatories were enrolled between 2002 and 2009. Participants had a mean age of 55 years (range, 41-73). The multivariate analysis showed significant differences for some scales of the SF-36: liver transplant recipients displayed lower values for "Mental Composite Score" (P = .043), "physical activity" (P = .001), "role limitations due to physical health" (P = .006), "role limitations due to the emotional state" (P = .006), and "mental health" (P = .010). The metabolic equivalent positively associated with all examined SF-36 scales. The present study focused on the QOL and physical activity of liver transplant recipients, demonstrating that transplant recipients scored lower than the general population. Liver transplantation may allow full recovery of health status, but the physical and social problems persist in some patients. Interventions aimed at improving rehabilitation programs, regular psychosocial support, and follow-up in all phases of treatment may give patients a more satisfying lifestyle after transplantation.

Multi-dimensional MR spectroscopy: towards a better understanding of hepatic encephalopathy

Hepatic encephalopathy (HE) is normally diagnosed by neuropsychological (NP) tests. The goals of this study were to quantify cerebral metabolites, separate glutamate (Glu) from glutamine (Gln) in patients with minimal hepatic encephalopathy (MHE) as well as healthy subjects using the prior-knowledge fitting (ProFit) algorithm on data acquired by two-dimensional (2D) localized correlated spectroscopy (L-COSY) on two different MR scanners, and to correlate the metabolite changes with neuropsychological (NP) tests. We studied 14 MHE patients and 18 healthy controls using a GE 1.5 T Signa MR scanner. Another group of 16 MHE patients and 18 healthy controls were studied using a Siemens 1.5 T Avanto MR scanner. The following parameters were used for L-COSY: TR/TE = 2 s/30 ms, 3 × 3 × 3 cm(3) voxel size, 96 Δt(1) increments with 8 averages per Δt(1). Using the ProFit algorithm, we were able to differentiate Gln from Glu on the GE 1.5 T data in the medial frontal white/gray matter. The ratios of myo-inositol (mI), Glu, total choline, scyllo-inositol (sI), phosphoethanolamine (PE), and total N-acetyl aspartate (NAA) showed statistically significant decline in HE patients compared to healthy controls, while the ratio of Gln was significantly increased. Similar trend was seen in the ProFit quantified Siemens 1.5 T data in the frontal and occipito-parietal white/gray regions. Among the NP domain scores, motor function, cognitive speed, executive function and the global scores showed significant differences. Excellent correlations between various NP domains and metabolite ratios were also observed. ProFit based cerebral metabolite quantitation enhances the understanding and basis of the current hypothesis of MHE.

Hepatic encephalopathy as a complication of liver cirrhosis: an Asian perspective

Hepatic encephalopathy is one of the most important clinical manifestations in decompensated liver cirrhosis. Accepted concepts regarding the pathophysiology of hepatic encephalopathy are that the endogenous neurotoxic substances, including ammonia: (i) escape from catabolism by the liver due both to the impaired function of the cirrhotic liver and also to the presence of portal systemic shunting; (ii) circulate at elevated concentrations in the systemic blood flow; (iii) reach the brain through the blood-brain barrier; and (iv) impair cerebral function leading to disturbances of consciousness. The majority of these toxic substances are produced in the intestine by the bacterial flora, and are absorbed into the portal venous flow. The epidemiology of liver cirrhosis depends particularly on its etiology, and shows a marked geographic difference worldwide between Western, and Asian countries. Hepatic encephalopathy developed at an annual rate of 8% in cirrhotics in Far Eastern studies. In Eastern and Far East countries, therapeutic options are similar to those in the western hemisphere, but pronounced application of dietary restriction, antimicrobial agents, disaccharides, shunt obliteration and branched chain amino acids is noted. In spite of improved therapeutic options for encephalopathy, the long-term survival is still low. Thus, hepatic encephalopathy remains a serious complication of liver cirrhosis. Establishment of truly effective prevention modalities and broader application of liver transplantation will help rescue patients suffering from this complication of liver cirrhosis in the near future.

Neuropsychiatric dysfunction in patients with chronic hepatitis and liver cirrhosis

AIM

The aim of this study is to clarify the cerebral functions in patients with chronic hepatitis (CH) as well as those with liver cirrhosis (LC).

METHODS

We studied 58 patients with CH (20 in fibrosis stage F1, 20 in F2, 18 in F3), 77 with LC (46 rated as Child-Pugh class A, 24 as B, 7 as C), and 20 healthy volunteers (HV). Computer-aided quantitative neuropsychiatric function test systems, including eight neuropsychiatric tests were performed.

RESULTS

Subjects with results over the cut-off value for healthy subjects ranged from 11.1-28.6% in CH and 19.5-36.4% in LC. The percentages with abnormality in at least one test in CH and LC were 72.4% and 80.6%, respectively, which were significantly higher than that in the HV group (35.0%) (P = 0.003, P = 0.0003, respectively). Among CH subjects, those with three or more abnormal results in the F1, F2 and F3 subgroups were 15.0%, 20.0% and 38.9%, respectively. Among LC subjects, those with three or more abnormal results in the Child-Pugh class A, B and C subgroups comprised 30.4%, 50.0% and 57.1%, respectively. The rate in the CH F3 subgroup (P = 0.011) and in all three LC subgroups (P = 0.023, P = 0.001, P = 0.002, respectively) were significantly higher than that in the HV group.

CONCLUSION

The percentage of patients with neuropsychiatric function impairment was high in both LC and CH, especially in stage F3. Neuropsychiatric dysfunction may initiate in CH in a considerable number of patients.

Type and etiology of liver cirrhosis are not related to the presence of hepatic encephalopathy or health-related quality of life: a cross-sectional study

BACKGROUND

Hepatic encephalopathy has a negative impact on health-related quality of life (QoL) in liver cirrhosis. There are scarce and conflicting data on whether type or etiology of liver cirrhosis could be related to hepatic encephalopathy in patients with cirrhosis. We aimed to determine the impact of cirrhosis etiology on hepatic encephalopathy and whether hepatic encephalopathy affects health-related QoL among patients with cirrhosis of different etiologies.

METHODS

A total of 156 cirrhotic patients were prospectively evaluated for the presence of hepatic encephalopathy according to the West-Haven criteria as well as by means of two psychometric tests. Patients with cryptogenic cirrhosis or cirrhosis due to mixed hepatocellular/cholestatic etiologies were excluded. Fasting plasma glucose levels were also measured. QoL was evaluated by means of a validated questionnaire (SF-36).

RESULTS

Diabetes mellitus was more common in patients with hepatocellular cirrhosis compared to those with cholestatic cirrhosis but the two groups did not differ in cirrhosis severity or the prevalence of hepatic encephalopathy (p > 0.05). The groups of patients with cirrhosis due to alcohol, hepatitis C, or cholestatic liver disease did not differ in severity of liver cirrhosis or the prevalence of hepatic encephalopathy (p > 0.05). Patients with cirrhosis of different etiologies did not differ in any SF-36 domain (p > 0.05). In multivariate analysis, performance at neuropsychological testing was independently related only to age, diabetes mellitus, and the Child-Pugh score whereas the SF-36 physical component summary only to the Child-Pugh score and hepatic encephalopathy.

CONCLUSION

Cirrhosis etiology does not seem to be related to hepatic encephalopathy or health-related QoL. Cognitive impairment is associated mainly with age, liver disease severity and diabetes mellitus.

Brain atrophy in alcoholics: relationship with alcohol intake; liver disease; nutritional status, and inflammation

OBJECTIVES

Brain atrophy is a common finding in alcoholics. Several mechanisms may be involved, including ethanol itself, malnutrition, liver failure, and, possibly, ethanol-induced hormone and cytokine changes. The aim of this study was to analyse the relation of brain atrophy-assessed by computerized tomography (CT) scan-and the aforementioned alterations.

METHODS

Serum insulin-like growth factor 1 (IGF-1), interleukin (IL)-6, IL-8, IL-10, TNF alpha, PTH, estradiol, free testosterone, and corticosterone were measured in 36 alcoholics, ten of them cirrhotics, who also underwent brain CT, which recorded the presence of cortical atrophy or cerebellar atrophy, Evan's, Huckmann's, cella media, bicaudate, cortical atrophy, bifrontal, and ventricular indices, and diameter of the third ventricle; subjective nutritional assessment, midarm anthropometry, and evaluation of liver function.

RESULTS

Patients showed marked alterations of all the CT indices compared with 12 controls, but poor relations between these indices and the other parameters analysed (IGF-1, handgrip strength and years of addiction with bifrontal index (P < 0.025 in all cases); PTH and Evan's index (r = 0.36, P = 0.032); mean corpuscular volume with cella index and cortical atrophy (P < 0.05). Cerebellar atrophy was associated with a greater daily ethanol consumption (t = 2.19, P = 0.034).

CONCLUSION

Brain atrophy is frequently observed in alcoholics, but relationships with liver function, cytokines, nutritional status, and hormone levels are poor.

Magnetic resonance images of the globus pallidus in patients with idiopathic portal hypertension: a quantitative analysis of the relationship between signal intensity and the grade of portosystemic shunt

BACKGROUND AND AIM

To elucidate a quantitative relationship between hyperintensity of the globus pallidus on T1-weighted magnetic resonance images (MRI) and portosystemic shunt (PSS) in portal hypertension.

METHODS

Fifteen patients with idiopathic portal hypertension (IPH) and 44 patients with liver cirrhosis (LC) underwent brain MRI to asses signal intensity at the globus pallidus and Doppler sonography to examine the blood flow volume of PSS. Blood manganese (Mn) levels were examined in 36 patients and neuropsychological tests were performed in 15 patients without overt hepatic encephalopathy.

RESULTS

Pallidal hyperintensity on MRI was more prominent in patients with IPH than in patients with LC. There was no correlation between MRI pallidal hyperintensity and the severity of liver dysfunction or hepatic encephalopathy. The grade of hyperintensity correlated well with the grade of PSS. The correlation was stronger in patients with IPH than in patients with LC. The plasma ammonia level and whole blood Mn level significantly correlated with MRI pallidal hyperintensity, but blood Mn level showed a stronger correlation than plasma ammonia.

CONCLUSION

Hyperintensity of the globus pallidus on T1-weighted MRI correlated with the development of PSS independent of liver cell function. This brain image should be an index of the grade of PSS rather than a landmark of chronic liver failure.

Hepatic encephalopathy: a neurochemical, neuroanatomical, and neuropsychological study

Hepatic encephalopathy (HE) is normally diagnosed by neuropsychological (NP) tests, which are not very specific and do not reveal the underlying pathology. Magnetic resonance imaging (MRI) and spectroscopy (MRS) of the brain offer alternative and possibly more specific markers for HE. These methods were applied in conjunction with NP testing in order to determine their usefulness in the identification of HE and to understand the pathogenesis of HE more clearly. MR imaging and spectroscopy examinations, in addition to a battery of 15 NP tests, were administered to investigate 31 patients awaiting liver transplantation and 23 healthy controls. MR image intensities from the globus pallidus region were calculated and normalized to those of the thalamus. Absolute concentrations and ratios with respect to creatine (Cr) of several metabolites were computed from MR spectra. The MR data were correlated with the results of NP tests. The patients showed impairment in NP tests of attention and visuospatial and verbal fluency. In T1-weighted MRI, the relative intensity of the globus pallidus with respect to that of the thalamus region was significantly elevated in patients and correlated(negatively) with three NP tests (Hooper, FAS, and Trails B). The absolute concentrations of myo-inositol (mI) and choline (Ch) were significantly reduced in three brain regions. In addition, the absolute concentrations of glutamine (Gln) and combined glutamate and glutamine (Glx) were increased in all three locations, with Gln increase being significant in all areas while that of Glx only in the occipital white matter. In summary, this study partially confirms a hypothesized mechanism of HE pathogenesis, an increased synthesis of glutamine by brain glutamate in astrocytes due to excessive blood ammonia, followed by a compensatory loss of myo-inositol to maintain astrocyte volume homeostasis. It also indicates that the hyperintensity observed in globus pallidus could be used as complementary to the NP test scores in evaluating the mental health of HE patients.

Diagnostic methods in hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome in patients with liver disease and/or portosystemic shunting that affects quality of life and prognosis. The diagnosis is primarily based on clinical criteria that classify HE into 5 grades of severity ranging from normal mental status (grade 0) to coma (grade 4). As this clinical classification is rather subjective, additional diagnostic methods are required. Biochemical diagnostic tests can be used to confirm or exclude the diagnosis and to monitor the effect of treatment. An elevated ammonia level plays a central role in the pathogenesis of HE and can be determined in arterial, venous and capillary blood. Neuropsychological and neurophysiological tests are more sensitive and objective in diagnosing HE than the clinical criteria. Neuropsychological tests are especially of great value because of their high sensitivity for the detection of minimal HE and their low costs. The more sophisticated diagnostic tests such as magnetic resonance spectroscopy or positron emission tomography are mainly used for investigational purposes. This review will highlight these different diagnostic methods and comment on its pitfalls, clinical significance and overall applicability.

Evaluation of two experimental models of hepatic encephalopathy in rats

The serious neuropsychological repercussions of hepatic encephalopathy have led to the creation of several experimental models in order to better understand the pathogenesis of the disease. In the present investigation, two possible causes of hepatic encephalopathy, cholestasis and portal hypertension, were chosen to study the behavioral impairments caused by the disease using an object recognition task. This working memory test is based on a paradigm of spontaneous delayed non-matching to sample and was performed 60 days after surgery. Male Wistar rats (225-250 g) were divided into three groups: two experimental groups, microsurgical cholestasis (N = 20) and extrahepatic portal hypertension (N = 20), and a control group (N = 20). A mild alteration of the recognition memory occurred in rats with cholestasis compared to control rats and portal hypertensive rats. The latter group showed the poorest performance on the basis of the behavioral indexes tested. In particular, only the control group spent significantly more time exploring novel objects compared to familiar ones (P < 0.001). In addition, the portal hypertension group spent the shortest time exploring both the novel and familiar objects (P < 0.001). These results suggest that the existence of portosystemic collateral circulation per se may be responsible for subclinical encephalopathy.

Characteristics of minimal hepatic encephalopathy

The term minimal hepatic encephalopathy refers to the subtle changes in cognitive function, electrophysiological parameters, cerebral neurochemical/neurotransmitter homeostasis, cerebral blood flow, metabolism, and fluid homeostasis that can be observed in patients with cirrhosis who have no clinical evidence of hepatic encephalopathy. Use of this term emphasizes the fact that the entity of hepatic encephalopathy is a single syndrome with quantitatively distinct features relating to severity. The absence of clinical evidence of hepatic encephalopathy is key to the diagnosis and can only be determined by a detailed assessment of the patients' history and a comprehensive neurological assessment of consciousness, cognitive, and motor function. The neuropsychological features of minimal hepatic encephalopathy point to a disorder of executive functioning, particularly selective attention and psychomotor speed, but other abnormalities may be observed. Alterations in electrophysiological variables have been described; endogenous evoked potentials are, in principle, more likely to reflect the presence of minimal hepatic encephalopathy, since they reflect cognitive phenomena rather than mere stimulus conduction but the specificity of the changes observed is unclear at present. Changes have also been described in the execution of diadochokinetic movements and in the capacity to discriminate flickering light, both of which may have diagnostic potential. The changes observed in cerebral blood flow and metabolism in SPET, PET, and 1H and 31P MRS studies reflect the pathogenic process that underlies the condition rather than providing diagnostic information. Similarly, the morphological brain abnormalities identified in this population, including mild brain oedema, hyperintensity of the globus pallidus and other subcortical nuclei observed in cerebral MR studies, and the central and cortical atrophy observed in neural imaging studies, are unlikely to have diagnostic utility. The presence of minimal hepatic encephalopathy is not without clinical consequence; it has a detrimental effect on health-related quality of life, the ability to perform complex tasks such as driving, and on outcome.

Does liver-disease aetiology have a role in cerebral blood-flow alterations in liver cirrhosis?

BACKGROUND

Studies using brain-imaging techniques have shown changes in regional blood flow (rCBF) in patients with liver cirrhosis. It remains unknown whether the aetiology of liver disease accounts for these changes.

AIMS

To evaluate whether the aetiology of liver cirrhosis is associated with different patterns of rCBF.

MATERIALS AND METHODS

A total of 50 patients with end-stage liver disease and no overt encephalopathy were studied. Thirteen age-matched subjects admitted to the neurology department for headache were used as controls. Exclusion criteria were focal brain lesions, severe brain atrophy and any abnormalities found on computed tomography scan suggesting other central nervous system diseases, alcohol intake or use of neuroactive drugs for at least 6 months. rCBF was assessed using single-positron-emission tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (99mTc-HM-PAO) as a tracer in all patients and controls. The Mann-Whitney U test was used for statistical analysis.

RESULTS

The liver-disease aetiology was as follows: alcoholic (A) in 19 patients; viral (V) (hepatitis B virus, hepatitis D virus, hepatitis C virus) in 14 patients; alcoholic with concomitant viral (A + V) in five patients; and cholestatic (C) (primary biliary cirrhosis, primary sclerosing cholangitis) in 12 patients. SPECT showed significantly lower rCBF in cirrhotic patients than in controls for most cortical and subcortical regions and in alcoholic and viral patients than in cholestatic liver disease patients for some cortical regions. When patients were grouped according to previous alcohol abuse (including cases with a concomitant viral aetiology), rCBF was significantly lower in the frontal superior, medial and temporal inferior regions in the alcoholic group.

CONCLUSIONS

Cerebral blood flow is significantly lower in patients with liver cirrhosis than in controls and, among cirrhotics, it is lower in alcoholic and viral cirrhosis than in cholestatic liver disease. In patients with previous alcohol abuse, cerebral blood flow was significantly more reduced in the frontal and temporal regions compared with patients without previous alcohol abuse.

Abnormally high resistive index of central retinal artery by ultrasound color Doppler in patients with viral chronic liver disease: correlation with worsening liver staging

Retrobulbar-ocular circulation provides an opportunity to assess the terminal circulation of the arterial cerebral tree. To evaluate whether retrobulbar circulation in patients with chronic liver disease is affected by adaptive mechanisms, we assessed by echo color Doppler, 1. The resistive-index of the central retinal artery, a terminal branch of the ophthalmic artery, and 2. the potential interrelationships with both liver staging and the most important splanchnic Doppler-parameters used to assess portal hypertension. The resistance index (RI) of the central retinal artery was obtained and compared with other classical Doppler parameters known to be affected by portal hypertension. The RI of the central retinal artery (CRA) was higher in cirrhotic patients than in controls or subjects with chronic hepatitis; it correlated with all the Doppler parameters of portal hypertension considered, with plasma renin-activity, and norepinephrine concentrations. Similarly to renal and splanchnic hemodynamics, retinal arterial circulation assessed by duplex Doppler seems to be affected by the histology of liver disease and by the overactivity of vasoconstrictor systems.

Hepatic encephalopathy--definition, nomenclature, diagnosis, and quantification: final report of the working party at the 11th World Congresses of Gastroenterology, Vienna, 1998

Research on hepatic encephalopathy is hampered by the imprecise definition of this disabling complication of liver disease. Under this light, the Organisation Mondiale de Gastroentérologie commissioned a Working Party to reach a consensus in this area and to present it at the 11th World Congress of Gastroenterology in Vienna (1998). The Working Party continued its work thereafter and now present their final report. In summary, the Working Party has suggested a modification of current nomenclature for clinical diagnosis of hepatic encephalopathy; proposed guidelines for the performance of future clinical trials in hepatic encephalopathy; and felt the need for a large study to redefine neuropsychiatric abnormalities in liver disease, which would allow the diagnosis of minimal (subclinical) encephalopathy to be made on firm statistical grounds. In the interim, it proposes the use of a psychometric hepatic encephalopathy score, based on the result of 5 neuropsychologic tests. Finally, the need for a careful evaluation of the newer neuroimaging modalities for the diagnosis of hepatic encephalopathy was stressed.

Chronic liver disease: relaxometry in the brain after liver transplantation

Relaxometry revealed changes in the basal ganglia in T(1) and T(2) relaxation times due to liver disease. Manganese is probably responsible for T(1) and T(2) shortening (as the concentration is known to be higher in both the liver and blood due to hepatic cirrhosis). The aim of this study was to follow possible recovery after liver transplantation by MR relaxometry. Together with a group of 20 healthy volunteers we scanned 53 patients before and after liver transplantation (some of them repeatedly). Both T(1) and T(2) values were evaluated in the basal ganglia, thalamus, and frontal white matter. T(1) relaxation time was shortened by approx. 20-25% compared to the control group, probably the result of manganese deposition in the brain caused by hepatic cirrhosis. After liver transplantation the relaxation time recovered gradually with almost normal values reached approx. 2 years after surgery. T(1) recovery was observed in all evaluated structures. Similar results were observed with T(2) relaxation in the basal ganglia and thalamus. In the white matter T(2) remained low even 2 years after surgery.

Health-related quality of life after liver transplantation: a meta-analysis

The goal of this study is to assess health-related quality of life (HRQL) after orthotopic liver transplantation (OLT). Structured MEDLINE and Embase literature searches identified 5473 potentially relevant articles. Thirty-two additional references were collected from the bibliographies. Of the 5505 identified articles, 49 studies reporting data on 3576 transplant recipients met our inclusion criteria, which were an assessment of quality of life (QOL) in adult patients reported as either pretransplantation and posttransplantation data or with a comparison group and written in English. We combined posttransplantation QOL scores from 15 studies that reported data from the same QOL scales to assess the magnitude of the effect of OLT on QOL scales. We also performed a sign test on the 49 studies to evaluate the direction (positive or negative) of the effect of transplantation on QOL. Transplantation resulted in an improvement of 32% in Karnofsky scores, 11% in Sickness Impact Profile scores, and 20% to 50% in the domains of the Nottingham Health Profile. The sign test showed significant improvement in posttransplantation physical health (P <.0004), sexual functioning (P <.008), daily activities (P <.02), general HRQL (P <.02), and social functioning (P <.05), but not psychological health (P <.08). In general, the HRQL of the 3576 patients was impaired pretransplantation and improved posttransplantation. Transplant recipients reported large gains in those aspects of QOL most affected by physical health and smaller improvements in areas affected by psychological functioning.

Cerebral magnetic resonance imaging in patients with chronic liver disease

Bilateral, symmetrical hyperintensity of the globus pallidus is observed in T1-weighted cerebral magnetic resonance images in from 52 to 100% of patients with chronic liver disease. No significant relationship exists between the presence of these cerebral changes in image signal intensity and the patients' neuropsychiatric status. However, their presence significantly relates to both the severity of the liver disease and the presence and degree of portal-systemic shunting of blood. This shortening of the T1-relaxation time is associated with pallidal deposition of manganese most likely reflecting the presence of an adaptive process designed to improve the efficacy of ammonia detoxification by astrocytes. Future studies employing magnetic resonance imaging techniques to obtain information on cerebral function or combined with magnetic resonance spectroscopy to obtain localized biochemical information might further our understanding of the pathogenesis of hepatic encephalopathy in cirrhotic patients.

Cerebral 1H MR spectroscopy and neuropsychologic status of patients with hepatic encephalopathy

OBJECTIVE

Our objective was to assess the metabolite levels (myo-inositol [ml], choline [Cho], creatine [Cr], glutamate or glutamine [Glx], and N-acetyl-L-aspartate [NAA]) visible on 1H MR spectroscopy in patients with subclinical and mild hepatic encephalopathy before and after liver transplantation and to correlate these data with the results of neuropsychiatric tests and related clinical findings.

SUBJECTS AND METHODS

A stimulated-echo sequence was used to localize a single voxel in the parietal region. Seventeen patients and 13 healthy volunteers were investigated. Nine of the 17 patients also were investigated after liver transplantation. A battery of neuropsychologic tests also was administered to patients to assess frontal, memory, and motor functions.

RESULTS

Before liver transplantation, significant reductions in mI:Cr (51%) and Cho:Cr (11%) and a significant increase in Glx:Cr (20%) were observed in patients compared with the respective ratios in healthy subjects. Patients also were significantly impaired on neuropsychologic tests measuring frontal and motor performance, but not memory. Impairment on the frontal index showed a significant correlation with mI:Cr levels; likewise, performance on the motor index showed a significant correlation with serum ammonia levels before transplantation. MR spectroscopy after liver transplantation showed changes in the metabolite ratios compared with the pretransplantation status. Even though the Glx:Cr ratios decreased after transplantation, the mI:Cr ratio remained lower than those of healthy subjects.

CONCLUSION

The relationship of changes in the metabolite ratios recorded from a voxel in the posteromedial parietal lobe to the neuropsychologic findings before and after liver transplantation is a major finding.

Portal systemic encephalopathy

The goal of this article is to update the status of Portal systemic encephalopathy (PSE) in the light of new data. First, PSE is the context of other types of hepatic encephalopathy. Subsequently, current views of the pathogenesis of the disorder are discussed, followed by an analysis of therapeutic options. Diagnosis will not be considered, as no major new developments have recently been documented in this area.

Hepatic encephalopathy in liver transplant recipients precipitated by benzodiazepines present in transfused blood

The observation that there are episodes of encephalopathy in liver cirrhosis patients after orthotopic liver transplantation, despite a well functioning graft and despite the lack of cerebral complications, prompted us to investigate the potential role of circulating benzodiazepine-like compounds in these episodes. The plasma levels of benzodiazepines were examined in 14 liver cirrhotic patients before and after transplantation. The benzodiazepines in the fluids infused during surgery and in individual bags of blood administered after surgery to 4 of these patients were also assayed. Herein we report that benzodiazepines accumulating in the blood of some transplanted patients appear to derive from blood transfusions utilized during surgery. The analysis of the types of benzodiazepines present in the blood utilized for transfusions suggests the use of commercial benzodiazepines by the donors. These compounds seem to be able to precipitate hepatic encephalopathy in patients with preexisting encephalopathy. Hence we suggest not using benzodiazepine consumers as blood donors, at least for patients with encephalopathy undergoing to liver transplantation.

Clinical evaluation of liver disease

The clinical history and examination is essential in the evaluation of patients with liver disease. This chapter details important points in the clinical history and examination allowing the physician to identify likely causes of liver damage and their investigation. The evaluation should allow the physician to differentiate acute and chronic liver diseases, and in the latter case separate those with obstructive or chronic parenchymal liver disease. It should also allow identification of important complications such as encephalopathy, ascites and portal hypertension. Identification of these main features or complications of liver disease by the clinical evaluation leads to a logical plan of investigation and prompt diagnosis and management of the liver disease.

Visual attention orienting in liver cirrhosis without overt hepatic encephalopathy

The attention system in patients with liver cirrhosis has not yet been fully investigated. We therefore studied visual attention orienting in cirrhotic patients without overt hepatic encephalopathy. Seventy cirrhotic patients without overt hepatic encephalopathy (aged 57 +/- 10 yr., mean +/- s.d.) and 55 controls (aged 49 +/- 12 yr.) were enrolled. Visual attention orienting was evaluated by a computerized neuropsychological test. The Reitan A test, commonly used to detect subclinical hepatic encephalopathy, was used to evaluate mental performance. Psychometric test scores were reduced in cirrhotics compared to controls (attention test: neutral condition = 495 +/- 149 vs. 401 +/- 98 msec; valid condition = 434 +/- 110 vs. 398 +/- 84 msec; invalid condition = 485 +/- 146 vs. 392 +/- 110 msec; p < 0.001; Reitan A test = 52 +/- 20 vs. 35 +/- 11 sec., p < 0.001). The attention effect of the cue was found both in controls and cirrhotics; however, it was significantly higher in cirrhotics than in controls (61 +/- 111 vs. 33 +/- 41 msec; p < 0.002). The attention effect was directly correlated with Reitan A test (r = 0.23, p = 0.05) in cirrhotics. In conclusion, in cirrhotic patients without overt hepatic encephalopathy, visual attention orienting was present and focusing to an indexed location had a higher effect on reaction time compared to controls, possibly because of reduced basal arousal.

Increased brain concentrations of polyamines in rats with encephalopathy due to a galactosamine-induced fulminant hepatic failure

Polyamine concentrations including putrescine, spermidine and spermine were documented in two brain areas of rats with mild and severe stages of hepatic encephalopathy (HE) due to fulminant hepatic failure induced by galactosamine HC1 injection (3 g kg-1 i.p.). In the mild stage of HE putrescine increased by 3-4 times whereas spermidine and spermine showed a slight increase. The scenario, however, was found to be changed going from the mild to the severe stage of HE, since in this last stage spermidine and spermine showed a further rise while putrescine was found to be significantly lower than in the mild stage of HE in both the brain areas studied. The changes in the ratio among the three polyamines with an enhanced prevalence in the severe stage of HE of spermidine and spermine are likely to be related to the exhaustion of the synthetic pathway of putrescine or to a reduction of the interconversion to this polyamine from spermidine and spermine. Considering that these last two polyamines potentiate the N-methyl-D-aspartate glutamate receptor mediated toxicity and that they might exert neurotoxic effects per se, there are clear reasons for suspecting an implication of the described changes of polyamines in the neurochemical mechanism which sustain HE and to surmise a potential therapeutic effect in this pathology of non-competitive antagonists of polyamine-site on N-methyl-D-aspartate glutamate receptors.

A quantitative evaluation of magnetic resonance image signal changes of the brain in chronic hepatic encephalopathy

Hyperintensity in the basal ganglia of patients with serious liver disease is a common finding on T1-weighted magnetic resonance images. In this study, we used optical densitometry to quantitatively evaluate the hyperintense magnetic resonance image signal changes in the various regions of the brain of patients with chronic hepatic encephalopathy. The incidence and morphological distribution of the magnetic resonance signal changes were evaluated from T1-weighted magnetic resonance images of the brain from seven non-alcoholic patients and six healthy controls. Significant differences (p < 0.05) between the patient group and controls were found in the limbic system (hippocampus, temporal lobe, cingulate gyrus, and fornix), extrapyramidal system and associated myelinated pathways (lentiform nucleus, tectum, tegmentum, cerebral peduncles, internal capsule and the corpus callosum). No measurable differences were observed in the frontal, parietal, and occipital cortex, or the dorsomedial thalamus. The presence of the high signal intensity changes on T1-weighted magnetic resonance image suggests that characteristics alterations occur in functional regions of the brain in chronic hepatic encephalopathy.

The psychiatric assessment of liver transplant patients with alcoholic liver disease: a review

Patients with severe alcoholic liver disease are receiving liver transplants in increasing numbers. Alcoholic liver transplant patients appear to have a good prognosis, yet alcoholic candidates may be rejected on psychiatric grounds alone. The role of the psychiatrist in the multidisciplinary assessment is discussed and the use of a number of predictors of outcome for alcoholic candidates considered. Studies examining these variables have many methodological limitations and it is therefore very difficult to draw any firm conclusions on their validity or reliability. Long-term prospective studies using appropriate measures of outcome should enable the liaison psychiatrist to provide more useful advice on the psychosocial outcome and treatment requirements of this growing group of patients.

Selective loss of pallidal dopamine D2 receptor density in hepatic encephalopathy

The binding parameters of [3H]SCH 23390 and [3H]spiperone (radioligands for dopamine D1 and D2 receptors, respectively) were investigated in autopsied frontal cortex, caudate nucleus and globus pallidus/putamen of cirrhotic patients who died in hepatic coma as well as in age- and sex-matched controls. Specific [3H]SCH 23390 binding site densities were unchanged in all regions; in contrast, specific [3H]spiperone binding site density was decreased (by 44%, P < 0.001) in the globus pallidus/putamen of patients with HE. Decreased densities of pallidal D2 binding sites could relate to the motor dysfunctions commonly encountered in human HE.

Positron-emission tomographic localization of abnormalities of brain metabolism in patients with minimal hepatic encephalopathy

Many patients with compensated cirrhosis without overt hepatic encephalopathy have deficits in visual-spatial perception, a condition we call minimal hepatic encephalopathy. Five patients with alcohol-induced cirrhosis and nine control subjects underwent positron-emission tomographic imaging of the brain with 18F-fluorodeoxyglucose. Patients also underwent neuropsychological and clinical chemistry tests. The patients had mild arterial hyperammonemia (62 +/- 13 mumol/L, range = 11 to 35 mumol/L) and other abnormalities typical of patients with cirrhosis. The patients' mean percentile scores on the digit symbol and block design subtests, from the Wechsler Adult Intelligence Scale (revised), and Purdue pegboard test were 11 +/- 7, 24 +/- 7 and 7 +/- 8 (right hand). Tests of vocabulary, memory, and new learning were normal. The technique of statistical parametric mapping was used to identify regions where cerebral 18F-fluorodeoxyglucose uptake and metabolism were abnormal. We noted significant reductions in the cingulate gyrus, a center mediating attention, target analysis and response formulation and significant increases in visual associative regions subserving motion and color perception and object orientation. We suggest that minimal hepatic encephalopathy is due to a deficit in the detection and formulation of responses to visual stimuli, a function of the cingulate, which is a part of the anterior attentional system of the brain. Increases in 18F-fluorodeoxyglucose metabolism may be compensatory. These studies show that brain regions differ in their sensitivity to the agents that cause hepatic encephalopathy and that positron-emission tomography is useful in studying the pathophysiology of this disorder.

Brain morphologic characteristics of cirrhotic alcoholics and cirrhotic nonalcoholics: an MRI study

Cirrhotic alcoholics, cirrhotic nonalcoholics, and normal controls were compared on planimetric and subjective ratings of the MRI of the brain. The results indicated that the cirrhotic alcoholics exhibited more gross pathology than the nonalcoholic cirrhotics on ratings of frontal, parietal, and cerebellar atrophy; however, these groups were more similar to each other than they were different on planimetric measurements. The results are discussed in terms of the etiology and localization of the neuropathologic sequelae found commonly among alcoholics.

Psychiatric aspects of liver disease

This paper reviews the literature on the effects of liver disease on mental health, a topic which has been relatively neglected in the recent psychiatric literature. It discusses both the encephalopathy which may be associated with liver disease of almost any type and the psychological consequences of specific liver disorders. Also considered are the effects of liver disease on sexual function; the relationship between alcohol and hepatic disorder in causing mental disturbance; the effects of childhood liver disease; psychiatric aspects of liver transplantation; and the use of psychotropic drugs in patients with hepatic dysfunction.

Regional cerebral blood flow and cognitive function in patients with chronic liver disease

Subtle impairments of cognitive function may be an important cause of occupational and psychosocial morbidity in patients with chronic liver disease. Correlation of structural brain abnormalities with cognitive deficits has yielded inconsistent results. 10 patients with cirrhotic liver disease were compared with 10 age, education, and intelligence matched control subjects. Neuropsychological assessment revealed significant overall cognitive impairments in cirrhotic patients compared with controls (p = 0.02). Regional cerebral blood flow was measured by single photon emission computed tomography (SPET or SPECT) and showed increased uptake of radiotracer in the right and left posterior parts of the basal ganglia and right occipital lobe, together with reduced uptake in the right anterior cingulate region. The degree of cognitive impairment was directly correlated with functional abnormalities in the basal ganglia and limbic cortex (p less than 0.05). Our results suggest that impaired cognitive status may be associated with abnormalities of regional brain function in patients with chronic liver disease. Since these deficits are clinically inapparent, our findings have important implications for identification and management of patients with chronic liver disease.

Globus pallidus alterations and brain atrophy in liver cirrhosis patients with encephalopathy: an MR imaging study

Brain magnetic resonance (MR) was performed in 29 liver cirrhosis patients without (N = 10) and with hepatic encephalopathy (HE) of chronic recurrent (N = 10) and of chronic persistent (N = 9) type. Sixty percent of the patients with chronic recurrent HE and 100% of the patients with chronic persistent HE showed a bilateral and symmetrical hyperintensity of the globus pallidus in the T1-weighted images while the T2-weighted images were normal, suggesting the possibility of the accumulation of a paramagnetic compound in this brain area during HE. Other findings of the study were evidence of brain atrophy of mild or moderate degree in 70% of patients with chronic recurrent HE and in 77% with chronic persistent HE and patients with liver cirrhosis without HE appeared normal on MR examination.

Supersensitivity of GABA-A receptors in hepatic encephalopathy

During the past decade a new approach to pathogenetic studies of hepatic encephalopathy has been undertaken to identify the neurochemical alterations which characterize the syndrome. Using animal models of hepatic encephalopathy electrophysiological, behavioral, pharmacological and biochemical evidence were provided of an increased functional activity of the GABA-A receptors, including the Benzodiazepine site. These demonstrations seem to explain the increased sensitivity of patients with acute or chronic liver disease to sedative administration. The described increased tone of the GABAergic receptor complex seems to play a key role in the generalized depression of the central nervous system which characterizes hepatic encephalopathy, but other factors seem to contribute to the neuronal derangement present in this syndrome leading to an imbalance between inhibitory and excitatory receptor systems in the brain. Based on these findings a new symptomatic treatment with anti-benzodiazepine compounds which seem temporarily to counteract the symptoms of hepatic encephalopathy, was introduced.

Neurotransmission in hepatic encephalopathy

After a careful characterization, a rat model of fulminant hepatic failure galactosamine-induced was utilized in order to evaluate the neurochemical changes and the histological alterations which occur during the developing of the encephalopathy. Following these studies, normal rats were treated with toxins claimed to be the primary agents of hepatic encephalopathy to recognize those which are able to mimic the behavioral, electrophysiological and neurochemical changes found in the rat model of fulminant hepatic failure. With the limit due to informations coming from an experimental model, the symptoms of HE seem to be attributable to neurotoxic agents such as ammonia. The toxicity of ammonia does not seem to be due to a mere decrease of general brain metabolism, but seems rather to be mediated by an increase, at least in some compartment, of neurotoxic amino acids such as glutamate. Both accumulation of ammonia and the neurotoxic effect of glutamate seem to be potentiated by the described zinc depletion (both in liver and in brain). Hence the final effect of these phenomena is the development of the symptoms of encephalopathy triggered by an imbalance between inhibitory and excitatory receptor systems in the brain associated with neuronal alterations which take place early and before the appearance of brain edema.

Neuropsychological deficits and morphological MRI brain scan abnormalities in apparently healthy non-encephalopathic patients with cirrhosis. A controlled study

By means of psychometric testing, we have determined the frequency of latent hepatic encephalopathy in a group of 19 cirrhotics with no clinical evidence of encephalopathy. Magnetic resonance imaging (MRI) of the brain was performed in order to determine whether morphological cerebral abnormalities were associated with latent encephalopathy. Nineteen age and educationally matched patients with normal liver function acted as controls. Significant differences (P less than 0.05) between cirrhotics and controls were found in tests of short-term visual memory and speed of reaction to light (cirrhotics 316 +/- 132 ms vs. controls 225 +/- 36 ms), sound (cirrhotics 361 +/- 152 ms vs. controls 236 +/- 52 ms) and choice (cirrhotics 651 +/- 190 ms vs. controls 406 +/- 101 ms) stimuli (all values mean +/- S.D.). Reitan trail test performance, however, was similar in both groups. (Trail A: cirrhotics 43 +/- 19 s vs. controls 35 +/- 13 s; Trail B: cirrhotics 105 +/- 66 s vs. controls 93 +/- 36 s.) In patients with cirrhosis, MRI revealed statistically significant increases in the maximum fissure width of right frontal sulci, right and left parietal sulci, inter-hemispheric fissure width and in bicaudate index. These changes, indicating cerebral atrophy, were largely confined to alcoholics. There was poor correlation between measurements of cerebral morphology and neuropsychological performance, only 10% of associations achieving statistical significance.

Cerebral blood flow and plasma free tryptophan in cirrhotics with and without hepatic encephalopathy

Cerebral blood flow (CBF), measured by the non-invasive 133-Xenon inhalation method, plasma levels of ammonia (NH3) and free tryptophan (fTRP) were determined in 30 cirrhotic patients without overt encephalopathy. Psychometric evaluation detected subclinical hepatic encephalopathy (SHE) in 20 of them, and was normal in the other 10. A significant CBF difference (p less than 0.05) was found between the SHE and the non-SHE patients. fTRP levels were significantly (p less than 0.05) higher in patients with SHE than in those without SHE, and a significant negative correlation (p = 0.003) was found between CBF values and fTRP in the whole group of patients. NH3 did not differ in the two subgroups and did not correlate with CBF values. It is concluded that CBF could have some implications in SHE, although its relevance is still unclear. The negative correlation between CBF and fTRP prompts further investigation concerning the relationships between plasma fTRP, brain serotonin, cerebral metabolism and blood flow in the development of brain derangement during cirrhosis.

Hepatic injury correlates with neuropsychologic impairment

Five liver injury measures (albumin, prothrombin time, gamma globulin, indocyanine green clearance and serum ammonia) were correlated with neuropsychologic test performance in a group of 79 nonalcoholic cirrhotic patients. Employing linear regression analysis techniques revealed that these five measures, particularly albumin and prothrombin time, could explain a significant amount of the variance on neuropsychological tests. The results indicate that functional liver status, even where there is no overt evidence of hepatic encephalopathy, is related to cognitive capacity.