Neurocognitive-neurological complications of liver transplantation: a review

Cognitive impairment in recipients of liver transplantation and relation to hepatic encephalopathy

Background

Liver transplantation (LT) helped to save the life of end stage liver disease (ESLD) patients; however, there is a debate on the persistence of cognitive impairment. The study aimed to evaluate cognitive functions in patients with ESLD before and after liver transplantation and to assess its relation to hepatic encephalopathy (HE). Thirty recipients 47.6 ± 11 years undergone living donor liver transplantation at the transplantation center of both Ain Shams Center for Organ Transplant and Egypt air organ transplant unit were prospectively assessed by Trail Making Test, Wechsler Memory Scale–Revised, Benton Visual Retention—for the evaluation of cognitive functions before and 3 months after transplantation.

Results

The mean age of the patients was 47.6 ± 11 years, 17 males and 13 females. Eight out of 30 (26.7%) had past history of hepatic encephalopathy. The study reported significant improvement in the post-operative 3 months scores of Trail Making Test part (A), the digit span forward test, digit span backward test and the correct score difference of the Benton Visual Retention, as p value was (0.02), (0.01) (0.02), and (0.01) respectively, compared to the pre-operative scores. However, there was no difference in the scores of part (B), verbal association I, II, information subtest of WMS. Cognitive performance showed no significant difference between patients with or without history of HE.

Conclusions

Patients with ESLD have significant cognitive impairment that showed improvement after LT; HE did not correlate with cognitive function. Hence, transplantation has a favorable outcome on the cognitive impairment.

[Importance of cognitive disorders in internal medicine: Pathophysiology, diagnosis, management. The example of systemic lupus erythematosus]

Systemic diseases, which are in France mainly monitored in internal medicine, affect multiple organs or tissues. While cutaneous or articular manifestations are the most common, neurological involvement is often associated with severity. Diagnosis of peripheral (e.g, neuropathies) or central (e.g, myelitis) nervous disorders is quite easy through clinical examination and dedicated complementary tests. However, neuropsychological manifestations that affect cognition, including memory, attention, executive functions or reasoning, are difficult to diagnose, sometimes trivialized by practitioners. Their causes are often numerous and interrelated. Nevertheless, these cognitive manifestations are closely related to patients' quality of life, affecting their social life, family dynamics and professional integration but also the treatment adherence. The purpose of this review, focused on the example of systemic lupus erythematosus, is to raise awareness of cognitive dysfunction in systemic diseases including their management from diagnosis to treatments. The final aim is to go further into setting up research groups and care programs for patients with cognitive impairment followed in internal medicine.

Bile-duct ligation renders the brain susceptible to hypotension-induced neuronal degeneration: Implications of ammonia

Hepatic encephalopathy (HE) is a debilitating neurological complication of cirrhosis. By definition, HE is considered a reversible disorder, and therefore HE should resolve following liver transplantation (LT). However, persisting neurological complications are observed in as many as 47% of LT recipients. LT is an invasive surgical procedure accompanied by various perioperative factors such as blood loss and hypotension which could influence outcomes post-LT. We hypothesize that minimal HE (MHE) renders the brain frail and susceptible to hypotension-induced neuronal cell death. Six-week bile duct-ligated (BDL) rats with MHE and respective SHAM-controls were used. Several degrees of hypotension (mean arterial pressure of 30, 60 and 90 mm Hg) were induced via blood withdrawal from the femoral artery and maintained for 120 min. Brains were collected for neuronal cell count and apoptotic analysis. In a separate group, BDL rats were treated for MHE with the ammonia-lowering strategy ornithine phenylacetate (OP; MNK-6105), administered orally (1 g/kg) for 3 weeks before induction of hypotension. Hypotension 30 and 60 mm Hg (not 90 mm Hg) significantly decreased neuronal marker expression (NeuN) and cresyl violet staining in the frontal cortex compared to respective hypotensive SHAM-operated controls as well as non-hypotensive BDL rats. Neuronal degeneration was associated with an increase in cleaved caspase-3, suggesting the mechanism of cell death was apoptotic. OP treatment attenuated hyperammonaemia, improved anxiety and activity, and protected the brain against hypotension-induced neuronal cell death. Our findings demonstrate that rats with chronic liver disease and MHE are more susceptible to hypotension-induced neuronal cell degeneration. This highlights MHE at the time of LT is a risk factor for poor neurological outcome post-transplant and that treating for MHE pre-LT might reduce this risk.

Adolescents with solid organ transplant: Using the BRIEF2 parent-report and self-report to measure parent-child agreement and everyday executive function

Agreement between parent and adolescent ratings of executive function (EF) is not known in adolescents with solid organ transplant (SOT), even though pressing concerns about EF deficits are being raised in this population. The current study investigated EF in adolescents with SOT using parent and self report. Twenty-five adolescents (M = 15.51 years) with SOT and their parent completed a behavior rating scale assessing EF within everyday context using the Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2). Parents and their adolescents demonstrated moderate to excellent agreement across the BRIEF2 clinical and index scores, higher than previous research with a typical sample. Adolescent males had higher agreement with their parents than female adolescents. Both parents and adolescents reported significantly higher mean T scores on various BRIEF2 indices and domains, in addition to higher rates of clinically elevated executive dysfunction than their peers. Assessment of EF and targeting specific EF domains for intervention may be useful in this population.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Cognitive Function in Liver Transplantation

PURPOSE OF REVIEW

Liver transplantation (LT) remains the only way to cure patients with severe liver diseases. Important questions about neurological sequelae and quality of life after LT have emerged. In this review, we discuss the neurocognitive changes associated with LT and we conclude with recommendations in this regard for patients, caregivers, and physicians.

RECENT FINDINGS

Compared with other solid organ recipients, LT patients tend to have a higher incidence (up to 30%) of neurological complications post-LT. Even in absence of previous episodes of hepatic encephalopathy (HE), some patients display new onset of neurological symptoms post-LT, raising the concern about the role of other factors that may have a direct impact on cognitive function.

SUMMARY

Different mechanisms have been postulated to explain these postoperative neurological symptoms. They include sequelae of HE, persistent impairment of cognitive function due to cirrhosis, or postoperative decompensation of an unknown or undiagnosed neurodegenerative disorder.

Hepatic Encephalopathy Is Reversible in the Long Term After Liver Transplantation

Cognitive dysfunction caused by hepatic encephalopathy (HE) improves within the first year after liver transplantation (LT). However, cognitive restitution seems to be incomplete in a subset of patients and after LT a new-onset cognitive decline was described. Data about the longterm development of cognitive function after liver transplantation (LT) are sparse. This prospective study analyzed whether a history of hepatic encephalopathy (HE) before LT had an impact on the longterm outcome of cognitive function after LT and if patients who underwent LT 5 years earlier showed worse cognitive function than healthy controls. The cognitive function of 34 patients was assessed before LT and at 1 year and 5 years after LT by psychometric tests, including the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the portosystemic encephalopathy syndrome test, which provides the psychometric hepatic encephalopathy score (PHES). Furthermore, patients completed surveys to assess health-related quality of life (HRQOL). An 22 additional patients were included after LT. Patients were subdivided by having a history of HE before LT. The control group consisted of 55 healthy patients adjusted for age and education. Before LT, patients performed significantly worse than controls in the psychometric tests: RBANS Total Scale (TS), mean ± standard deviation (SD), 92.6 ± 13.3 versus 99.9 ± 12.0, P = 0.01; and PHES, median (interquartile range [IQR]), 0 (-3 to 1) versus 1 (0-2), P < 0.001. At 1 year after LT, patients with a history of HE still showed cognitive impairment compared with controls: RBANS TS, mean ± SD, 89.8 ± 15.1 versus 99.9 ± 12.0, P < 0.01; and PHES, median (IQR), 0 (-2 to 1.25) versus 1 (0-2), P = 0.03. At 5 years after LT, patients with and without a history of HE showed normal cognitive function and improved HRQOL. In conclusion, HE-associated cognitive impairment seems to be reversible within 5 years after LT.

Recent Topics on The Mechanisms of Immunosuppressive Therapy-Related Neurotoxicities

Although transplantation procedures have been developed for patients with end-stage hepatic insufficiency or other diseases, allograft rejection still threatens patient health and lifespan. Over the last few decades, the emergence of immunosuppressive agents such as calcineurin inhibitors (CNIs) and mammalian target of rapamycin (mTOR) inhibitors have strikingly increased graft survival. Unfortunately, immunosuppressive agent-related neurotoxicity commonly occurs in clinical practice, with the majority of neurotoxicity cases caused by CNIs. The possible mechanisms through which CNIs cause neurotoxicity include increasing the permeability or injury of the blood–brain barrier, alterations of mitochondrial function, and alterations in the electrophysiological state. Other immunosuppressants can also induce neuropsychiatric complications. For example, mTOR inhibitors induce seizures, mycophenolate mofetil induces depression and headaches, methotrexate affects the central nervous system, the mouse monoclonal immunoglobulin G2 antibody (used against the cluster of differentiation 3) also induces headaches, and patients using corticosteroids usually experience cognitive alteration. Therapeutic drug monitoring, individual therapy based on pharmacogenetics, and early recognition of symptoms help reduce neurotoxic events considerably. Once neurotoxicity occurs, a reduction in the drug dosage, switching to other immunosuppressants, combination therapy with drugs used to treat the neuropsychiatric manifestation, or blood purification therapy have proven to be effective against neurotoxicity. In this review, we summarize recent topics on the mechanisms of immunosuppressive drug-related neurotoxicity. In addition, information about the neuroprotective effects of several immunosuppressants is also discussed.

Neurological Recovery After Recovery From Acute Liver Failure: Is it Complete?

Neurologic dysfunction characterised by Hepatic Encephalopathy (HE) and cerebral oedema are the most dramatic presentations of Acute Liver Failure (ALF) and signify poor outcome. Improved critical care and wider availability of emergency Liver Transplantation (LT) has improved survivability in ALF. In most cases absence of clinically overt encephalopathy after spontaneous recovery from ALF or after LT is thought to indicate complete neurologic recovery. Recent data suggests that neurologic recovery may not always be complete. Instances of persistent neurologic dysfunction as well as neuropsychiatric abnormalities are now being recognised and warrant active follow up of these patients. Although evidences irreversible neurologic damage is uncommon after ALF, neuropsychiatric disturbances are not uncommon. Complex pathogenesis is involved in neurocognitive disorders seen after many other conditions including LT that require critical care. Structural damage and persistent neurological abnormalities seen after ALF are more likely to be related to cerebral edema, raised intracranial tension and cerebral hypoxemia, while neurocognitive dysfunctions may be a part of a wider spectrum of disorders commonly seen among those who recover from any critical illness.

Brain Integrity Changes Underlying Cognitive and Functional Recovery Postliver Transplant Continue to Evolve Over 1 Year

BACKGROUND

There is evidence of brain recovery on brain magnetic resonance imaging (MRI) early postliver transplant (LT), but the longer-term impact is unclear. The aim of this study was to determine the change in brain MRI parameters, cognition, and health-related quality of life (HRQOL) between 6 and 12 months post-LT.

METHODS

Listed cirrhotics underwent cognitive, HRQOL and brain MRI pre-LT, 6 months (post-LT1), and 1-year (post-LT2) post-LT. Assessment of MRI changes between visits was performed for ammonia-associated metabolite changes using magnetic resonance spectroscopy, white matter changes using tract-based spatial statistics analysis on diffusion tensor imaging data and grey matter changes using voxel-based morphometry analysis on 3D high resolution T1-weighted images.

RESULTS

Forty-five patients were included, of which 23 were tested at all visits. Cognitive and HRQOL scores improved between all visits compared with pre-LT values. This trend continued on magnetic resonance spectroscopy with reduced glutamine + glutamate and higher myoinositol, choline between pre-LT/post-LT1 but lower degrees of improvement between post-LT1/post-LT2. On diffusion tensor imaging, mean diffusivity, linear diffusivity and mode of anisotropy continued to increase in the posterior internal capsule at both post-LT visits. On voxel-based morphometry, a continued increase was seen in basal ganglia grey matter between both post-LT visits was seen.

CONCLUSIONS

HRQOL and cognition continue to improve compared with pre-LT values up to 1 year post-LT, although the rate of improvement slows down after 6 months. Grey matter increase is steady over time at 1 year although changes in ammonia-related metabolites and white matter integrity improve at a slower pace at 1 year post-LT.

Self-management in liver transplantation

BACKGROUND

Self-management is crucial for liver transplant (LT) recipients to maintain transplants and optimize health outcomes. However, previous literature has been primarily limited to examining medication adherence; there is a knowledge gap regarding self-management in the LT population.

AIM

The aims of this study were to 1) comprehensively describe self-management behaviors and activities in LT recipients, 2) explore levels of overall self-management, and 3) explore the relationships of self-efficacy, cognition, and health information seeking behavior with self-management.

METHODS

Adult LT recipients (n = 113) who had a functioning transplant for at least 6 months participated in this cross-sectional, descriptive study. Participants were asked to identify self-management behaviors and rate their performance of those behaviors, including symptom management and medication adherence. They also completed a cognitive assessment and questionnaires measuring self-efficacy and health information seeking behavior. Descriptive statistics, latent profile analysis, and probit model for path analysis were used for the data analysis.

RESULTS

LT recipients acknowledged engaging in various self-management behaviors including symptom management, physical activity, maintenance of positive attitudes, and communication with healthcare providers. Three levels of self-management (i.e., low, medium, and high) were found; a high level of self-management was related to self-efficacy and health information seeking behavior.

CONCLUSIONS

The findings indicate that self-management may be improved with interventions aimed at increasing self-efficacy and health information seeking behavior. Findings from this study will inform future interventions, to improve self-management and subsequent health outcomes in this population. Future longitudinal studies are necessary to confirm the causality of the identified relationships.

Intellectual and academic outcomes after pediatric liver transplantation: Relationship with transplant-related factors

As survival rates for pediatric liver transplant continue to increase, research attention is turning toward long-term functional consequences, with particular interest in whether medical and transplant-related factors are implicated in neurocognitive outcomes. The relative importance of different factors is unclear, due to a lack of methodological uniformity, inclusion of differing primary diagnoses, varying transplant policies, and organ availability in different jurisdictions. This cross-sectional, single-site study sought to address various methodological limitations in the literature and the paucity of studies conducted outside of North America and Western Europe by examining the intellectual and academic outcomes of Australian pediatric liver transplant recipients (N = 40). Participants displayed significantly poorer intellectual and mathematical abilities compared with the normative population. Greater time on the transplant waitlist was a significant predictor of poorer verbal intelligence, working memory, mathematical abilities, and reading but only when considering the subgroup of children with biliary atresia. These findings support reducing the time children wait for a transplant as a priority.

The short-term effect of liver transplantation on the low-frequency fluctuation of brain activity in cirrhotic patients with and without overt hepatic encephalopathy

Previous neuropsychological studies have demonstrated that liver transplantation (LT) is an effective method for improving the cognitive function of cirrhotic patients. However, the neural basis underlying the effects of LT is still unclear. Neuroimaging studies investigating changes in brain structures or functional networks mainly focus on patients without overt hepatic encephalopathy (HE). In this study, we recruited patients with and without overt HE and studied alterations in resting-state brain activity by quantizing the amplitude of low-frequency fluctuation (ALFF) before and 1 month after LT to study the short-term effect of LT in each group. Neuropsychological analyses indicated significant improvement of cognitive function in both groups. ALFF analysis showed that the brain activity in regions regulating motor function, vision, attention, and working memory were restored in both groups, reflecting the neuroplasticity of the brain. However, some persistent impairments and new-onset impairments in other regions related to these cognitive functions were observed in each group. Between-group comparison showed that although cognitive performance improved in both groups, the specific neural basis of LT in each group was different. The significant correlations of altered brain activity in regions showing LT and group effect with altered performance in neuropsychological and biochemical tests suggest a possible neuroimaging marker for the monitoring of short-term recovery of HE and the difference in individual recovery of cognitive performance. The findings in the present study help us further understand the neural effect of LT in patients with and without overt HE.

Alterations in gut microbial function following liver transplant

Liver transplantation (LT) improves daily function and ameliorates gut microbial composition. However, the effect of LT on microbial functionality, which can be related to overall patient benefit, is unclear and could affect the post-LT course. The aims were to determine the effect of LT on gut microbial functionality focusing on endotoxemia, bile acid (BA), ammonia metabolism, and lipidomics. We enrolled outpatient patients with cirrhosis on the LT list and followed them until 6 months after LT. Microbiota composition (Shannon diversity and individual taxa) and function analysis (serum endotoxin, urinary metabolomics and serum lipidomics, and stool BA profile) and cognitive tests were performed at both visits. We enrolled 40 patients (age, 56 ± 7 years; mean Model for End-Stage Liver Disease score, 22.6). They received LT 6 ± 3 months after enrollment and were re-evaluated 7 ± 3 months after LT with a stable course. A significant improvement in cognition with increase in microbial diversity, increase in autochthonous and decrease in potentially pathogenic taxa, and reduced endotoxemia were seen after LT compared with baseline. Stool BAs increased significantly after LT, and there was evidence of greater bacterial action (higher secondary, oxo and iso-BAs) after LT although the levels of conjugated BAs remained similar. There was a reduced serum ammonia and corresponding rise in urinary phenylacetylglutamine after LT. There was an increase in urinary trimethylamine-N-oxide, which was correlated with specific changes in serum lipids related to cell membrane products. The ultimate post-LT lipidomic profile appeared beneficial compared with the profile before LT. In conclusion, LT improves gut microbiota diversity and dysbiosis, which is accompanied by favorable changes in gut microbial functionality corresponding to BAs, ammonia, endotoxemia, lipidomic, and metabolomic profiles. Liver Transplantation 24 752-761 2018 AASLD.

Preliminary Experience in Combined Somatic and Cerebral Oximetry Monitoring in Liver Transplantation

OBJECTIVE

The use of cerebral near-infrared spectroscopy (NIRS) has become widespread in cardiac surgery after research demonstrated an association between perioperative cerebral desaturations and postoperative complications. Somatic NIRS desaturation also is associated with an increased risk of postoperative complications and mortality. The objective of this study was to explore the trends of both somatic and cerebral NIRS during liver transplantation.

DESIGN

A prospective, single-site, observational case series.

SETTING

Tertiary care center.

PARTICIPANTS

The study comprised 10 patients undergoing liver transplantation.

INTERVENTIONS

NIRS sensors were placed on the forehead (cerebral regional oxygen saturation [rSO₂]) and on the right arm and right leg (somatic rSO₂) to measure tissue perfusion. Desaturation was defined as a 20% decrease of baseline values for 15 seconds.

MEASUREMENTS AND MAIN RESULTS

In all patients, parallel changes in both cerebral and somatic rSO₂ values were observed during phlebotomy, bleeding, transfusion, portal vein clamping, and the use of vasoactive agents. Induction of anesthesia increased cerebral rSO₂ more than it did somatic values. However, ascites removal, abdominal manipulation, and clamping of the inferior vena cava (IVC) were associated with nonparallel changes in cerebral and somatic rSO₂. Ascites removal was associated with increased somatic leg rSO₂, and IVC clamping and abdominal hypertension were associated with a significant reduction in somatic leg rSO₂. Somatic leg desaturation instead of arm or cerebral desaturation was associated with more postoperative complications.

CONCLUSIONS

The use of combined NIRS monitoring allows for the identification of the source of somatic or cerebral desaturation. Compromised venous flow from the IVC from clamping or abdominal compartment syndrome typically is associated with the appearance of more pronounced leg than arm desaturation.

Immediate postoperative management and complications on the intensive care unit

The postoperative management of patients immediately after liver transplantation requires knowledge of this complex surgery and the physiology that accompanies liver failure. A multidisciplinary approach to the care of these patients is essential in order to reduce postoperative complications and preserve function in the transplanted organ. By their nature, patients undergoing liver transplantation have complicated medical problems before surgery which must be borne in mind when managing them after surgery. Haemorrhage, haemodynamic instability, acute renal failure, hepatic artery thrombosis and primary graft non-function are some of the complications that clinicians must be prepared for in the first days after transplantation. Pre-empting complications and acting rapidly to overt them is likely to have a considerable positive impact in these patients.

Liver transplant modulates gut microbial dysbiosis and cognitive function in cirrhosis

Liver transplantation (LT) improves daily function and cognition in patients with cirrhosis, but a subset of patients can remain impaired. Unfavorable microbiota or dysbiosis is observed in patients with cirrhosis, but the effect of LT on microbial composition, especially with poor post-LT cognition, is unclear. The aims were to determine the effect of LT on gut microbiota and to determine whether gut microbiota are associated with cognitive dysfunction after LT. We enrolled outpatient patients with cirrhosis on the LT list and followed them until 6 months after LT. Cognition (Psychometric Hepatic Encephalopathy score [PHES]), health-related quality of life (HRQOL), and stool microbiota (multitagged sequencing for diversity and taxa) tests were performed at both visits. Persistent cognitive impairment was defined as a stable/worsening PHES. Both pre-/post-LT data were compared with age-matched healthy controls. We enrolled 45 patients (56 ± 7 years, Model for End-Stage Liver Disease score 26 ± 8). They received LT 6 ± 3 months after enrollment and were re-evaluated 7 ± 2 months after LT with a stable course. A significantly improved HRQOL, PHES, with increase in microbial diversity, increase in autochthonous, and decrease in potentially pathogenic taxa were seen after LT compared with baseline. However, there was continued dysbiosis and HRQOL/cognitive impairment after LT compared with controls in 29% who did not improve PHES after LT. In these, Proteobacteria relative abundance was significantly higher and Firmicutes were lower after LT, whereas the reverse occurred in the group that improved. Delta PHES was negatively correlated with delta Proteobacteria and positively with delta Firmicutes. In conclusion, LT improves gut microbiota diversity and dysbiosis compared with pre-LT baseline but residual dysbiosis remains compared with controls. There is cognitive and HRQOL enhancement in general after LT, but a higher Proteobacteria relative abundance change is associated with posttransplant cognitive impairment. Liver Transplantation 23 907-914 2017 AASLD.

Modification of immunosuppressive therapy as risk factor for complications after liver transplantation

Management of complications post-liver transplantation (LT) includes immunosuppressive manipulations with the aim to reduce the overall burden of immunologic suppression and compensate for renal, cardiovascular, metabolic toxicities, and for the increased oncologic risk. Two approaches can be implemented to reduce immunosuppression-related adverse events: upfront schedules tailored to the pretransplant individual patient's risk profile versus downstream modifications in the event of immunosuppression-related complications. Upfront strategies are supported by evidence originating from prospective randomized trials and consist of triple/quadruple schedules whereby calcineurin inhibitors (CNI)-exposure is reduced with combination of anti-CD25 monoclonal antibodies, antimetabolites and corticosteroids. Quadruple regimens allow for staggering of CNI introduction and higher renal function in the early term, but their superiority in the long term has not yet been established. A more recent upfront schedule contemplates early (4 weeks) introduction of mammalian target of rapamycin inhibitor (mTORi) everolimus and allows for reduction of CNI up to 4 years posttransplantation. Incorporation of mTORi has the potential to prolong time to recurrence for patients with hepatocellular carcinoma. However, as suggested by the available evidence, downstream immunosuppressive manipulations are more frequently adopted in clinical practice. These encompass CNI replacement and immunosuppression withdrawal. Switching CNI to mTORi monotherapy is the option most commonly adopted to relieve renal function and compensate for posttransplant malignancies. Its impact is dependent on interval from transplantation and underlying severity of renal impairment. Introduction of mTORi is associated with longer overall survival for patients with extrahepatic posttransplant malignancies, but results are awaited for recurrences of hepatocellular carcinoma. Immunosuppression withdrawal seems feasible (70%) in very long term survivors (>10 years), but is not associated with reversal of immunosuppression-related complications. Awaiting novel immunosuppressive drug categories, integration of upfront strategies with the aim to reduce CNI-exposure and a low threshold for adjustment in the posttransplant course are both advisable to improve long-term outcomes of LT.

Neuropsychological functioning in preschool-aged children undergoing evaluation for organ transplant

OBJECTIVE

The purpose of this study was to review the current literature on neuropsychological functioning in two groups of children requiring organ transplants (liver or heart) and present recent clinical data collected through the liver and cardiac transplantation programs at a large pediatric academic medical center.

METHOD

Data included in this study came from 18 patients who completed evaluations for heart transplant (n = 8) or liver transplant (n = 10) between the ages of 2 and 6 years (inclusive). Measures examining neurocognitive, emotional-behavioral, and adaptive functioning were collected as part of standard pre-transplant clinical neuropsychological evaluations. Within each organ group, mean scores were calculated and compared with normative population mean scores using one sample t-tests. In addition, non-parametric binomial tests were calculated to examine whether the proportion of individuals falling more than one standard deviation below the population mean was significantly greater in the patient groups than the normative population base rate of 16%.

RESULTS

Patients in both groups performed below normative expectation in several neurocognitive and adaptive domains. However, neither group showed significant difficulties in behavioral or emotional regulation.

CONCLUSIONS

Results from this study document cognitive delays in preschool-aged children undergoing evaluations for liver transplant or heart transplant, highlighting the importance of intervention and long-term monitoring of these two patient populations, as well as the need for neuropsychologist involvement with transplant teams.

Liver transplantation significantly improves global functioning and cerebral processing

The functional basis of cognitive and quality of life changes after liver transplant is unclear. We aimed to evaluate the neurometabolic and functional brain changes as modulators of cognition and quality of life after transplant in patients with cirrhosis who were with/without pretransplant cognitive impairment and hepatic encephalopathy (HE). Patients with cirrhosis underwent detailed cognitive and quality of life assessment at enrollment and 6 months after transplant. A subset underwent brain magnetic resonance imaging (functional magnetic resonance imaging [fMRI], diffusion tensor imaging [DTI], and magnetic resonance spectroscopy [MRS]) before and after transplant. Changes before and after transplant were analyzed in all patients and by dividing groups in those with/without pretransplant cognitive impairment or with/without pretransplant HE. MRS evaluated ammonia-related metabolites; fMRI studied brain activation for correct lure inhibition on the inhibitory control test; and DTI studied white matter integrity. Sixty-six patients (mean Model for End-Stage Liver Disease score, 21.8; 38 HE patients and 24 cognitively impaired [CI] patients) were enrolled. Quality of life was significantly worse in CI and HE groups before transplant, which improved to a lesser extent in those with prior cognitive impairment. In the entire group after transplant, there was (1) significantly lower brain activation needed for lure inhibition (shown on fMRI); (2) reversal of pretransplant ammonia-associated changes (shown on MRS); and (3) improved white matter integrity (shown on DTI). Importantly, study findings suggest that pretransplant cognitive impairment serves as a marker for clinical outcomes. Regardless of pretransplant history of HE, it was the pretransplant cognitive impairment that was predictive of both posttransplant cognitive and psychosocial outcomes. Therefore, when working with patients and their families, a clinician may rely on the pretransplant cognitive profile to develop expectations regarding posttransplant neurobehavioral recovery. We conclude that functional brain changes after liver transplant depend on pretransplant cognitive impairment and are ultimately linked with posttransplant cognition and quality of life in cirrhosis. Liver Transplantation 22 1379-1390 2016 AASLD.

Comprehensive risk assessment for early neurologic complications after liver transplantation

AIM: To determine risk factors for early neurologic complications (NCs) after liver transplantation from perspective of recipient, donor, and surgeon.

METHODS: In all, 295 adult recipients were enrolled consecutively between August 2001 and February 2014 from a single medical center in Taiwan. Any NC in the first 30 d post-liver transplantation, and perioperative variables from multiple perspectives were collected and analyzed. The main outcome was a 30-d NC. Generalized additive models were used to detect the non-linear effect of continuous variables on outcome, and to determine cut-off values for categorizing risk. Risk factors were identified using multiple logistic regression analysis.

RESULTS: In all, 288 recipients were included, of whom 142 (49.3%) experienced at least one NC, with encephalopathy being the most common 106 (73%). NCs prolonged hospital stay (35.15 ± 43.80 d vs 20.88 ± 13.58 d, P < 0.001). Liver recipients’ age < 29 or ≥ 60 years, body mass index < 21.6 or > 27.6 kg/m², Child-Pugh class C, history of preoperative hepatoencephalopathy or mental disorders, day 7 tacrolimus level > 8.9 ng/mL, and postoperative intra-abdominal infection were more likely associated with NCs. Novel risk factors for NCs were donor age < 22 or ≥ 40 years, male-to-male gender matching, graft-recipient weight ratio 0.9%-1.9%, and sequence of transplantation between 31 and 174.

CONCLUSION: NCs post- liver transplantation occurs because of factors related to recipient, donor, and surgeon. Our results provide a basis of risk stratification for surgeon to minimize neurotoxic factors during transplantation.

Liver transplantation nearly normalizes brain spontaneous activity and cognitive function at 1 month: a resting-state functional MRI study

To investigate the short-term brain activity changes in cirrhotic patients with Liver transplantation (LT) using resting-state functional MRI (fMRI) with regional homogeneity (ReHo) method. Twenty-six cirrhotic patients as transplant candidates and 26 healthy controls were included in this study. The assessment was repeated for a sub-group of 12 patients 1 month after LT. ReHo values were calculated to evaluate spontaneous brain activity and whole brain voxel-wise analysis was carried to detect differences between groups. Correlation analyses were performed to explore the relationship between the change of ReHo with the change of clinical indexes pre- and post-LT. Compared to pre-LT, ReHo values increased in the bilateral inferior frontal gyrus (IFG), right inferior parietal lobule (IPL), right supplementary motor area (SMA), right STG and left middle frontal gyrus (MFG) in patients post-LT. Compared to controls, ReHo values of post-LT patients decreased in the right precuneus, right SMA and increased in bilateral temporal pole, left caudate, left MFG, and right STG. The changes of ReHo in the right SMA, STG and IFG were correlated with change of digit symbol test (DST) scores (P < 0.05 uncorrected). This study found that, at 1 month after LT, spontaneous brain activity of most brain regions with decreased ReHo in pre-LT was substantially improved and nearly normalized, while spontaneous brain activity of some brain regions with increased ReHo in pre-LT continuously increased. ReHo may provide information on the neural mechanisms of LT' effects on brain function.

Psychosocial functioning in patients with alcohol-related liver disease post liver transplantation

Emotional and role functioning difficulties are associated with chronic alcohol use and liver disease. Little is known about prospective changes in psychological and psychosocial functioning following orthotopic liver transplantation (OLT) amongst patients with alcoholic liver disease (ALD). We aimed to assess the functioning of this patient group post liver transplantation. Comprehensive psychosocial assessment of depression (Beck Depression Inventory [BDI]), anxiety (State-Trait Anxiety Inventory-Form X [STAI]) and psychosocial adjustment (Psychosocial Adjustment to Illness Scale-Self-Report version [PAIS-SR]) was conducted with 42 ALD patients available for pre and post OLT testing. Dependence severity was assessed by the Brief Michigan Alcoholism Screening Test (bMAST). Significant reductions in average anxiety and depression symptoms were observed 12-months post-OLT. Significant improvements in psychosocial adjustment to illness were also reported. Patients with higher levels of alcohol dependence severity pre transplant assessment improved comparably to those with lower levels of dependence. In summary, the study found that OLT contributed to reducing overall levels of mood and anxiety symptoms in ALD patients, approximating general (non-clinical) population norms. Psychosocial adjustment also improved significantly post liver transplantation.

Postoperative cognitive dysfunction after liver transplantation

OBJECTIVE

Postoperative cognitive dysfunction (POCD) in liver transplant (LT) recipients is defined as a "more than expected" postoperative deterioration in cognitive domains, including short-term and long-term memory, mood, consciousness and circadian rhythm. It is diagnosed, after exclusion of other neurological complications, by using specific neuropsychological tests that need preoperative baseline. The aim of this systematic review was to assess the prevalence of POCD after LT and to analyze patients' symptoms, type and timing of assessment used.

METHODS

PubMed, MEDLINE and The Cochrane Li-brary were searched up from January 1986 to August 2014. Study eligibility criteria are as follows: prospective and retrospective studies on human adult subjects describing prevalence of POCD and/or its sequelae after LT episodes were included.

RESULTS

Eighteen studies were identified. The timing of testing for POCD may vary between different studies and within the single study, ranging from 0.5 to 32 weeks. POCD occurs in up to 50% of LT recipient.

CONCLUSION

Future studies should be focused on detecting preoperative and intraoperative factors associated to POCD in order to carry out appropriate strategies aimed at reducing this disabling health condition. Relationship between POCD and long-term outcome needs to be investigated.

Central nervous system complications after liver transplantation: common but mostly transient phenomena

Although central nervous system complications (CNSCs) are common after orthotopic liver transplantation (OLT), standardized prospective studies are still lacking. This prospective study was aimed at determining the incidence of CNSCs, describing their clinical presentations, and establishing predicting factors. One hundred thirty-six adult patients who underwent OLT at Hannover Medical School between December 2008 and June 2011 were included. Weekly examinations were performed by a neurologist during the hospital stay after OLT. Patient data, donor data, and operative and postoperative variables were collected. Patients with cerebral dysfunction after OLT underwent a diagnostic work-up, which included brain imaging and, if necessary, cerebrospinal fluid analysis. Patients with central nervous system (CNS) symptoms but negative imaging and cerebrospinal fluid results and patients with pontine myelinolysis or posterior reversible encephalopathy syndrome were placed in a metabolic-toxic CNSC group, and patients with strokes, intracranial hemorrhaging, or CNS infections were placed in a nonmetabolic CNSC group. Multiple regression analysis was used to identify independent risk factors for the development of metabolic-toxic CNSCs. After excluding two patients that died after OLT without regaining consciousness, forty-four (32.8%) patients developed CNSCs: 37 of these patients (27.6%) had metabolic-toxic CNSCs, and 7 (5.2%) had nonmetabolic CNSCs. Acute-on-chronic liver failure, the number of subsequent surgeries, and primary sclerosing cholangitis were identified as independent predictors for the development of metabolic-toxic CNSCs. Metabolic-toxic CNSCs were associated with prolonged hospital stays, and nonmetabolic CNSCs were associated with higher mortality. In conclusion, CNSCs are common and relevant complications after OLT. Patients after OLT, especially with risk factors, should undergo a regular standardized neurological examination that would allow early detection of these complications.

Predictive factors of neurological complications and one-month mortality after liver transplantation

Background: Neurological complications are common after orthotopic liver transplantation (OLT). We aimed to characterize the risk factors associated with neurological complications and mortality among patients who underwent OLT in the post-model for end-stage liver disease (MELD) era.

Methods: In a retrospective review, we evaluated 227 consecutive patients at the Keck Hospital of the University of Southern California before and after OLT to define the type and frequency of and risk factors for neurological complications and mortality.

Results: Neurological complications were common (n = 98), with encephalopathy being most frequent (56.8%), followed by tremor (26.5%), hallucinations (11.2%), and seizure (8.2%). Factors associated with neurological complications after OLT included preoperative dialysis, hepatorenal syndrome, renal insufficiency, intra-operative dialysis, preoperative encephalopathy, preoperative mechanical ventilation, and infection. Preoperative infection was an independent predictor of neurological complications (OR 2.83, 1.47–5.44). One-month mortality was 8.8% and was independently associated with urgent re-transplant, preoperative intubation, and intra-operative arrhythmia.

Conclusion: Neurological complications are common in patients undergoing OLT in the post-MELD era, with encephalopathy being most frequent. An improved understanding of the risk factors related to both neurological complications and one-month mortality post-transplantation can better guide perioperative care and help improve outcomes among OLT patients.

Cognitive impairment and electroencephalographic alterations before and after liver transplantation: what is reversible?

The influence of liver transplantation (LT) on mental performance is debated, as is the role of pretransplant overt hepatic encephalopathy (OHE). The aim of this study was to evaluate the time course of the neuropsychological and electroencephalogram (EEG) features of patients with cirrhosis before and after LT with respect to prior OHE. The study population included 65 patients with cirrhosis on the transplant waiting list; 23 had a history of OHE. Each patient underwent an extensive psychometric assessment (10 tests, including paper and pencil tests and a computerized test) and an EEG before and 9 to 12 months after LT. For a subgroup of 11 patients, the assessment was also performed 3 and 6 months after LT. EEGs were analyzed spectrally, and the mean dominant frequencies were obtained. Both psychometric tests and EEGs improved 9 to 12 months after LT. Patients with a history of OHE before LT had worse cognitive performances (P < 0.001) and EEG performances in comparison with their counterparts with a negative history. They also showed greater cognitive improvement after LT (P < 0.01); however, their global cognitive performance remained slightly impaired (P < 0.01). After LT, EEGs normalized for 98% of the patients (P < 0.01), regardless of any history of OHE. In the subgroup of patients evaluated every 3 months, psychometric and EEG findings showed deterioration at 3 months and subsequently steady improvements from 6 months onward. In conclusion, both neuropsychological and EEG performances had significantly improved 1 year after LT. Patients with a history of OHE showed greater improvements after LT than patients with a negative history, but their global cognitive function remained slightly worse; in contrast, EEGs normalized in both groups.

Risk factors for neurological complications and their correlation with survival following pediatric liver transplantation

Despite the improved outcomes of LT, post-operative NCs remain a significant cause of morbidity and mortality. The aim of the study was to identify the incidence of and risk factors for NCs in children who underwent LT. The medical records of pediatric patients who underwent LT at Asan Medical Center Children's Hospital between January 1994 and December 2010 were retrospectively analyzed. The onset and types of NC and pretransplant variables associated with NC were evaluated. We identified 190 children (85 boys [44.7%], 105 girls [55.3%]) of mean age 4.1 ± 4.7 yr, who underwent LT. Forty-six NCs occurred in 41 (21.6%) patients after LT, the most common being seizures (n = 13, 28.3%) and encephalopathy (n = 10, 21.7%). Of the 46 NCs, 24 (52.2%) occurred within three months after LT. Multivariate analysis showed that primary liver disease, preoperative neurological problems, preoperatively higher serum creatinine concentration, and graft failure were significant risk factors for NCs. The survival rate was significantly lower for patients with NCs than for those without (p < 0.001). NCs after pediatric LTs were common and associated with a higher mortality rate in our study. Close monitoring and appropriate risk management may improve the long-term outcomes of pediatric patients who undergo LT.

Neurological complications prevalence and long-term survival after liver transplantation

INTRODUCTION

Neurological postsurgical complications are a significant cause of morbidity and mortality occur in transplant recipients impacting their survival.

METHODS

We analyzed the medical records of 269 patients who underwent transplantation between 2000 and 2011, after application of the exclusion criteria Neurological complications were examined according to the period in which they appeared: immediate (1-30 day) early (31-180 days), and late (after 180 days). The survival analysis was based on the first complication.

RESULTS

The majority of transplant recipients were males (73.2%) and white (97.1%) with an overall median age of 49 (range, 18-73) years. Regarding the etiology for transplantation, the most common causes were hepatitis C virus (56.5%) and alcohol (33.1%). Complications, appearing in 29.4% (immediate), 31.5% (early), and 39.1% (late) cases, were encephalopathy, confusion, tremors, headache, and stroke. Patients who had the first complication between 1 and 6 months showed greater mortality than those who had one after 6 months.

CONCLUSIONS

Neurological complications led to longer hospital stays with greater early morbidity and mortality. Knowledge of these complications appears to be extremely important for the multidisciplinary transplantation team to decrease its prevalence as well as to diagnose and treat early.

Minimal hepatic encephalopathy: follow-up 10 years after successful liver transplantation

BACKGROUND

The long-term effect of liver transplantation (LT) on cognitive functions and the complete reversibility of minimal hepatic encephalopathy are poorly documented. Much evidence indicates that spatial attention improves starting from the immediate period after LT. However, at least in the first 2 years, some cognitive defects seem to persist to some degree, especially for supramodal nonverbal cognitive functions. The aim of this study is to investigate (i) whether the improvements observed in the perioperative period fluctuate or remain stable 10 years after LT and (ii) whether the functions that have been found defective also improve.

METHODS

We called patients previously included in a prospective study (Mattarozzi et al., Arch Neurol 2004; 61: 242) for a further neuropsychological evaluation. We compared the cognitive evaluation after 7 to 10 years with previous data gathered 6 and 18 months after LT.

RESULTS

The improvements obtained in the first 2 years after transplantation remain stable during the 7 to 10 years thereafter, especially for visuospatial attention, F(12,96) 1.70; P=0.04 and selective attention, F(6,66) 3.51; P=0.005. Furthermore, these findings also seem to suggest an improvement in supramodal cognitive functions, such as spatial planning intelligence, measured by the Elithorn Maze Test, F(3,33) 7.42; P=0.002. Verbal short-term memory, F(3,33) 3.69; P=0.038, and visuospatial short-term memory, F(6,64) 2.97; P=0.013, show a more fluctuating trend over time.

CONCLUSIONS

Despite the risk of surgery, the neurotoxicity of immunosuppression therapy, and the effects of aging and related comorbidities, our data indicate that LT is able to significantly improve patients' cognitive functions in the long term.

Neurological complications following pediatric liver transplant

OBJECTIVE

We studied neurological complications (NCs) after liver transplantation (LT) in children.

METHODS

We performed an institutional review board-approved retrospective review of patients with LT ≤21 years during a period of 30 years (1980-2010). NCs were classified as early (within 3 months post-LT) and delayed (beyond 3 months post-LT).

RESULTS

Of 65 children with LT, 20 (30.7%) had NCs; 16 were girls. Mean age was 11.8±5.9 years. Early NCs were found in 13.8% (9/65) of the patients: seizures in 7 and encephalopathy in 2. Abnormal neuroimaging findings were posterior reversible leukoencephalopathy syndrome (1), intracranial hemorrhage (1), mild cerebral edema (1), and bilateral basal ganglia T1W hyperintensities in magnetic resonance imaging (1). On follow-up, there were 3 deaths (unrelated to NCs). One with intracranial hemorrhage had residual hemiparesis and was taking a long-term antiepileptic drug. Late NCs are found in 16.9% (11/65) of the patients: seizures in 4, headache in 4, encephalopathy in 3 (1 had seizures in addition), and paresthesias caused by possible small-fiber neuropathy in 1. Abnormal neuroimaging findings were hypoxic-ischemic encephalopathy (1), encephalomalacia caused by old hemorrhage (1), and hyperintensity of the posterior periventricular white matter in magnetic resonance imaging (1). On follow-up, all of the patients survived; 1 had papilledema with secondary optic atrophy requiring optic nerve sheath fenestration and 1 needed long-term antiepileptic drug.

CONCLUSIONS

NCs are common in children after LT, seizures being the most common. In contrary to the previous studies, we found delayed complications more often than early complications. Early detection and appropriate management of NCs is important.

Neuropsychological functioning in patients with alcohol-related liver disease before and after liver transplantation

BACKGROUND

Cognitive dysfunction is common in both end-stage liver disease and chronic alcohol misuse. The impact of orthotopic liver transplantation (OLT) on neuropsychological function is poorly documented. This prospective study examined changes in cognitive function pre- and post-OLT in patients with alcohol-related liver disease (ALD).

METHODS

Comprehensive neuropsychological assessment was conducted with 92 abstinent patients with ALD scheduled for OLT. Forty-two patients were available for reassessment 12 months post-OLT.

RESULTS

Posttransplantation, cognitive performance on all measures fell within normal limits. Greatest improvement occurred in visuomotor speed, complex visual attention processes, and the ability to solve visually presented problems. Performance on memory assessment tasks also improved posttransplantation. Applying a more robust assessment of change (Reliable Change Index), approximately half improved reliably on overall cognitive function. One quarter improved in memory performance. With the exception of the Full-Scale Intelligence Quotient scales, discriminant analysis was unable to successfully predict which patients reliably improved.

CONCLUSIONS

Overall improvement in cognitive function occurs after liver transplantation in ALD. It was not possible to identify which patient characteristics were associated with reliable change.

Changing picture of central nervous system complications in liver transplant recipients

Central nervous system (CNS) complications are common after liver transplantation (LT). According to the literature, the most common causes are infections and the neurotoxicity of immunosuppressive drugs (cyclosporine and tacrolimus). The aim of this study was to evaluate the incidence, clinical presentations, etiologies, and outcomes of CNS complications in a series of 395 consecutive LT recipients whose immunosuppression regimen was designed for low tacrolimus blood levels. An analysis of the 12-hour trough concentrations of tacrolimus in the study population showed that the target drug levels, which were designed to maintain minimal immunosuppression, were usually achieved. In all, 64 patients (16.2%) developed major neurological symptoms (37 within 30 days of LT). None of the observed CNS complications were caused by infections (viral, bacterial, or fungal), and only 3 of the 395 patients (0.8%) received a diagnosis of tacrolimus-related leukoencephalopathy. Cerebrovascular disease was identified in 15 patients (3.8%; 8 had cerebral hemorrhages, 5 had ischemic strokes, and 2 had subdural hemorrhages). Pontine myelinolysis was found in 2 patients (0.5%). Notably, no clear cause was identified for the remaining 44 cases (11.1%): brain imaging was negative for 22 cases, and diffuse hypoxic changes were present for the other 22. CNS complications were significantly associated with a reduction in 3-month patient survival (88.8% versus 95.4%) and 5-year patient survival (57.3% versus 84.1%). Among the pretransplant variables that were analyzed, the incidence of portosystemic encephalopathy, the peak serum bilirubin levels, and the lowest serum total cholesterol levels were significantly different between the 64-patient group with CNS complications and the asymptomatic group of 331 patients.

Intensive care management of liver transplanted patients

Advances in pre-transplant treatment of cirrhosis-related organ dysfunction, intraoperative patient management, and improvements in the treatment of rejection and infections have made human liver transplantation an effective and valuable option for patients with end stage liver disease. However, many important factors, related both to an increasing "marginality" of the implanted graft and unexpected perioperative complications still make immediate post-operative care challenging and the early outcome unpredictable. In recent years sicker patients with multiple comorbidities and organ dysfunction have been undergoing Liver transplantation; appropriate critical care management is required to support prompt graft recovery and prevent systemic complications. Early post-operative management is highly demanding as significant changes may occur in both the allograft and the "distant" organs. A functioning transplanted liver is almost always associated with organ system recovery, resulting in a new life for the patient. However, in the unfortunate event of graft dysfunction, the unavoidable development of multi-organ failure will require an enhanced level of critical care support and a prolonged ICU stay. Strict monitoring and sustainment of cardiorespiratory function, frequent assessment of graft performance, timely recognition of unexpected complications and the institution of prophylactic measures to prevent extrahepatic organ system dysfunction are mandatory in the immediate post-operative period. A reduced rate of complications and satisfactory outcomes have been obtained from multidisciplinary, collaborative efforts, skillful vigilance, and a thorough knowledge of pathophysiologic characteristics of the transplanted liver.

Progressive multifocal leukoencephalopathy in liver transplant recipients: a case report and review of the literature

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the reactivation of the JC polyomavirus in immunocompromised patients. We report a case of PML in a liver transplant recipient and review the other published cases. The clinical course of PML is characterised by a rapid progressive neurological decline coinciding with the presence of white matter lesions on magnetic resonance images. There is no direct antiviral therapy available against the JC polyomavirus. Restoration of the immune response achieved by tapering or terminating the immunosuppressive regimen is the mainstay of treatment at present in transplanted patients. The prognosis remains, however, extremely poor regardless of treatment.