Top-down and bottom-up processes in the extrastriate cortex of cirrhotic patients: an ERP study.

OBJECTIVE: This study aims to evaluate the efficiency of top-down and bottom-up processes in the extrastriate cortex of cirrhotic patients without overt hepatic encephalopathy (HE). METHODS: Reaction times (RTs), accuracy and event-related potentials (ERPs) were recorded during the execution of a visual Simon task in 17 cirrhotic patients and 10 healthy controls. Amplitude and latency of the P1 and N1 (indexes of bottom-up processes) and of the N2pc (index of top-down processes) were measured. RESULTS: Patients were slower than controls, and patients with minimal HE (MHE) were slower than patients without MHE. The distribution analysis of RTs showed that the Simon effect decays with slower RTs in all the groups and that the shape of the distribution was different in MHE patients. No differences were found between cirrhotic patients and controls for P1 and N1 amplitude and latency. In contrast, N2pc latency was delayed in cirrhotic patients compared to controls independently of MHE. CONCLUSIONS: In the extrastriate cortex of cirrhotic patients without HE, top-down processes are altered whereas bottom-up processes are preserved. SIGNIFICANCE: The analysis of exogenous and endogenous visual components of ERPs provides a model to study the functional dissociation between top-down and bottom-up processes inside the extrastriate cortex.     

Effect of Blood Ammonia Elevation Following Oral Glutamine Load on the Psychometric Performance of Cirrhotic Patients

Oral glutamine challenge is a method to increase blood ammonia and may be used to study the ammonia lowering effect of drugs potentially useful in hepatic encephalopathy (HE). We tested its influence on the psychometric performance of 18 cirrhotic patients without HE. Twelve nonencephalopatic cirrhotic patients were studied before and after glutamine load (20 g in 100 mL tap water) and six patients before and after placebo (100 mL tap water) by using the Number Connection Test (NCT), the Covert Visual Attention Orienting Test (CVAOT), and the Scan Test (SCT). Blood ammonia increased significantly after glutamine (from 79 ± 34 to 211 ± 66 g/dL) but not after placebo (from 94 ± 41 to 88 ± 26). No difference in the NCT was found before and after glutamine load or placebo. The CVAOT was similar after glutamine challenge and placebo, nor any interaction between Loads (glutamine or placebo) × Cue position was found, suggesting that glutamine load did not influence attention-orienting. SCT results were also similar after glutamine and placebo, suggesting a lack of influence on the working memory. Glutamine challenge is a safe method to induce hyperammonemia in nonencephalopatic cirrhotic patients and, therefore, to study the efficacy of ammonia lowering treatments.     

Hepatitis C virus infection and health-related quality of life

Hepatitis C virus (HCV) hepatitis and other diseases related to HCV, such as cryoglobulinemia, lymphoma and renal failure, impair health-related quality of life (HRQoL). In addition, HCV per se might directly influence HRQoL via colonization of microglia in the brain or, indirectly, via the effect of systemic inflammatory cytokines which, in turn, can trigger brain interleukin production. The treatment of HCV-related disorders with interferon (IFN) has an effect on HRQoL. Initially, IFN causes a transient deterioration of HRQoL, due to the induction of depression and other side effects of treatment. Subsequently, the subjects who obtain a sustained virologic response experience an improvement in HRQoL. Only rarely does interferon treatment causes permanent detrimental effects on HRQoL, due to residual psychiatric or neurologic side effects. Liver transplantation is the only treatment for end-stage HCV-related liver disease. HRQoL generally improves massively a few months after transplantation, except in the case of serious complications of the transplant procedure. Furthermore, high levels of anxiety and neuroticism pre-transplant are associated with lower HRQoL one year after transplant. Additionally, six months after transplant, patients with HCV who experience virologic recurrence show significantly greater depression, anxiety, phobic anxiety, and paranoid ideation than anti-HCV-negative patients. In conclusion, optimal care for the overall well-being of patients with HCV infection requires adequate knowledge of their neurological and psychological status.     

Neuropsychological tools in hepatology: a survival guide for the clinician

Neuropsychological assessment has three main applications in clinical hepatology: (i) to detect, grade and monitor liver failure-related cognitive alterations in end-stage liver disease (hepatic encephalopathy), (ii) to substantiate complaints of attention or concentration difficulties in patients with non-cirrhotic chronic hepatitis C viral infection, and (iii) to screen patients who are being considered for liver transplantation for early signs of dementia. However, there is limited agreement on how cognitive assessment should be conducted in these patients, and how results should be interpreted and used to implement clinical decisions. In this review, we summarize the available literature on neuropsychological dysfunction in patients with cirrhosis and with chronic hepatitis C viral infection and provide some guidance on how to utilize neuropsychological assessment in practice.     

Simple tools for complex syndromes: A three-level difficulty test for hepatic encephalopathy

Background

Despite the impact of hepatic encephalopathy on quality of life and prognosis, easily administered tests for its diagnosis are still lacking.

Aim

To assess the usefulness of the Scan package, a three-level-difficulty computerised reaction time test, to diagnose varying degrees of hepatic encephalopathy.

Methods

Sixty-one cirrhotic patients underwent clinical evaluation, paper-and-pencil psychometry and the Scan package; 32 healthy controls served as reference.

Results

Twenty-nine patients were classified as unimpaired, 15 as having minimal and 17 as having overt hepatic encephalopathy. All healthy controls were able to complete the Scan package; in contrast, the number of patients who were able to complete three/two/one part decreased in parallel with the degree of encephalopathy (χ² = 17, p = 0.01). Reaction times in all three parts increased significantly with the severity of encephalopathy. However, the profile of increase was different [group: F(3,77) = 26, p < 0.0001; test: F(2,154) = 277, p < 0.0001; group × test: F(6,154) = 7, p < 0.0001], with different parts being more/less sensitive to varying degrees of encephalopathy.

Conclusions

The Scan package seems useful for the diagnosis of hepatic encephalopathy and covers a considerable portion of its spectrum of severity.     

How to mimic a type A intramural hematoma: A case of IgG4-related aortitis associated with cerebral hemorrhage

IgG4-related aortitis is an inflammatory condition of the aorta, characterized by aortic wall thickening and periaortic soft-tissue involvement. Therefore, this condition can mimic an aortic intramural hematoma (IMH), due to similar radiological findings. We hereby report the case of an IgG4-related aortitis misdiagnosed as an IMH, associated with cerebral hemorrhage, possibly due to cerebral vascular system involvement.