Trichromatic critical flicker frequency as potential visual test in cataract and macula disease patients.

PURPOSE: To investigate the capacity of critical flicker frequency (CFF) in discriminating cataract eyes with or without macula disease using trichromatic flickers, and to develop a model to predict postoperative best corrected visual acuity (BCVA). METHODS: Patients were divided into two groups based on the presence or absence of macular disease. CFF threshold measurements of red (R-CFF), green (G-CFF), and yellow (Y-CFF) flickers were conducted both preoperatively and postoperatively. A generalized estimating equations model (GEE) was employed to examine the relationship between CFF threshold and 3-month postoperative BCVA. RESULTS: A total of 115 eyes were enrolled, with 59 eyes in the cataract alone group and 56 eyes in the cataract with macular disease group completing the follow-up. R-CFF was found to be consistent before and after cataract removal (P = 0.06), even in cases where OCT was not performed successfully (P > 0.05). Y-CFF showed the highest AUC (0.798) for differentiating ocular comorbidities. According to the GEE model, in patients with a CFF threshold below 26 Hz, the odds ratios for achieving a postoperative VA of 20/40 or better were 34.8% for R-CFF, 26.0% for G-CFF, and 24.5% for Y-CFF. CONCLUSION: CFF emerges as a promising tool for predicting postoperative BCVA, providing valuable supplementary insights when fundus examination is obstructed. R-CFF demonstrates the best resistance to cataracts, while Y-CFF exhibits the highest sensitivity both in identifying macular diseases and predicting postoperative BCVA of 20/40 or better.

Performance of EncephalApp Stroop Test in Cirrhotic Patients for Evaluating Covert Hepatic Encephalopathy.

BACKGROUND: Covert hepatic encephalopathy (HE) is the mildest HE spectrum that is difficult to detect, but associated with significant decrease in quality of life. Currently, there is no gold standard to detect covert HE. EncephalApp Stroop Test as a newer diagnostic tool is easier, faster and its ease of availability in various health institutions is expected to be applied in Indonesia for covert HE detection. This study aimed to validate and test the reliability and diagnostic ability of EncephalApp Stroop Test to diagnose covert HE, compared to the Psychometric Hepatic Encephalopathy Score (PHES) and critical flicker frequency (CFF). METHODS: This study is a cross-sectional test, conducted from August to September 2018, targeted at patient with cirrhosis in Jakarta, to obtain Area Under The Curve (AUC), sensitivity, specificity, cut-off point, predictive value, likelihood ratio, and post-test probability of the EncephalApp Stroop Test, compared to PHES and CFF. The Validity and reliability tests were done before diagnostic study. Translation of the EncephalApp Stroop Test were first carried out using WHO protocol. All patients first underwent a Mini Mental State Examination and Ishihara Test to rule out color blindness. RESULTS: Thirty subjects participated in validity and reliability tests, and eighty in diagnostic tests. The translated application showed excellent internal consistency (Chronbach's Alpha of 0.942) and correlation coefficient of 0.82. The diagnostic study showed OnTime + OffTime as the best parameter (AUC: 0.897 (95% CI: 82.9% - 96.5%); sensitivity: 88.6%; specificity: 80%; positive predictive value (PPV): 0.77; negative predictive value (NPV): 0.9; positive likelihood ratio (LK+): 4.4; negative likelihood ratio (LK-): 1.4; positive post-test probability: 0,775; negative post-test probability: 0,1; and cut-off point ≥ 188.8 seconds. CONCLUSION: The EncephalApp Stroop Test is valid and reliable, with good AUC value, sensitivity, specificity, PPV, NPV and likelihood ratio in diagnosing covert hepatic encephalopathy in patients with cirrhosis in Indonesia.

Predicting overt hepatic encephalopathy after TIPS: Value of three minimal hepatic encephalopathy tests.

Background & Aims: Hepatic encephalopathy (HE) is a frequent and severe complication in patients after transjugular intrahepatic portosystemic shunt (TIPS) insertion. However, risk factors for post-TIPS HE remain poorly defined. Minimal HE (mHE) is a well-known risk factor for overt HE in patients with cirrhosis without TIPS. We aimed to evaluate three tools frequently used for diagnosing mHE for their dynamic changes and their predictive value for overt HE after TIPS. Methods: We prospectively recruited 84 consecutive patients before TIPS insertion and monitored them for 180 days for post-TIPS HE. Before TIPS insertion, the patients underwent the portosystemic encephalopathy (PSE) syndrome test, the animal naming test (ANT), and the critical flicker frequency (CFF). Patients were retested after TIPS insertion. Results: The majority of patients were male (67.9%), and the predominant indication for TIPS was refractory ascites (75%). Median age was 59 years, model for end-stage liver disease score was 12, and 66.3%, 64.6%, and 28.4% patients had evidence for mHE according to the PSE syndrome test, ANT, and CFF, respectively. Overall, 25 patients developed post-TIPS HE within 180 days after TIPS insertion. Post-TIPS incidence of overt HE was 22.2, 28.6, 45.5, and 55.6% in those with no, one, two, and three pathological tests at baseline, respectively. However, none of the three tests was significantly associated with post-TIPS HE. Of note, mean performance in all tests remained stable over time after TIPS insertion. Conclusions: PSE syndrome test, ANT and CFF, which are frequently used for diagnosing mHE have limited value for predicting HE after TIPS insertion. We could not find evidence that TIPS insertion leads to a psychometric decline in the long term. Impact and implications: This prospective observational study compared three diagnostic tests for mHE and showed the limited value of these tests for predicting overt HE in patients with cirrhosis undergoing TIPS insertion. In addition, the results suggest that cognitive performance generally remains stable after TIPS insertion. These results are important for physicians and researchers involved in the management of patients with cirrhosis undergoing TIPS procedures. The study's findings serve as a starting point for further investigations on the development of more effective strategies for predicting and managing post-TIPS HE. Clinical trial number: ClinicalTrials.gov NCT04801290.

Development and validation of the AMMON-OHE model to predict risk of overt hepatic encephalopathy occurrence in outpatients with cirrhosis.

BACKGROUND & AIMS: Neuropsychological and psychophysical tests are recommended to assess the risk of overt hepatic encephalopathy (OHE), but their accuracy is limited. Hyperammonaemia is central in the pathogenesis of OHE, but its predictive utility is unknown. In this study, we aimed to determine the role of neuropsychological or psychophysical tests and ammonia, and to develop a model (AMMON-OHE) to stratify the risk of subsequent OHE development in outpatients with cirrhosis. METHODS: This observational, prospective study included 426 outpatients without previous OHE from three liver units followed for a median of 2.5 years. Psychometric hepatic encephalopathy score (PHES) <-4 or critical flicker frequency (CFF) <39 was considered abnormal. Ammonia was normalized to upper limit of normal (AMM-ULN) at the respective reference laboratory. Multivariable frailty competing risk and random survival forest analyses were performed to predict future OHE and to develop the AMMON-OHE model. External validation was carried out using 267 and 381 patients from two independent units. RESULTS: Significant differences were found in time-to-OHE (log-rank p <0.001) according to PHES or CFF and ammonia, with the highest risk in patients with abnormal PHES plus high AMM-ULN (hazard ratio 4.4; 95% CI 2.4-8.1; p <0.001 compared with normal PHES and AMM-ULN). On multivariable analysis, AMM-ULN but not PHES or CFF was an independent predictor of the development of OHE (hazard ratio 1.4; 95% CI 1.1-1.9; p = 0.015). The AMMON-OHE model (sex, diabetes, albumin, creatinine and AMM-ULN) showed a C-index of 0.844 and 0.728 for the prediction of a first episode of OHE in two external validation cohorts. CONCLUSIONS: In this study, we developed and validated the AMMON-OHE model, comprising readily available clinical and biochemical variables that can be used to identify outpatients at the highest risk of developing a first episode of OHE. IMPACT AND IMPLICATIONS: In this study, we aimed to develop a model to predict which patients with cirrhosis are at risk of developing overt hepatic encephalopathy (OHE). Using data from three units and including 426 outpatients with cirrhosis, we developed the AMMON-OHE model - comprising sex, diabetes, albumin, creatinine and ammonia levels - which demonstrated good predictive ability. The AMMON-OHE model performs better than PHES and CFF to predict the first episode of OHE in outpatients with cirrhosis. This model was validated in 267 and 381 patients from two independent liver units. The AMMON-OHE model is available online for clinical use.

Current vision on diagnosis and comprehensive care in hepatic encephalopathy.

The first clinical guidelines on hepatic encephalopathy were published in 2009. Almost 14 years since that first publication, numerous advances in the field of diagnosis, treatment, and special condition care have been made. Therefore, as an initiative of the Asociación Mexicana de Gastroenterología A.C., we present a current view of those aspects. The manuscript described herein was formulated by 24 experts that participated in six working groups, analyzing, discussing, and summarizing the following topics: Definition of hepatic encephalopathy; recommended classifications; epidemiologic panorama, worldwide and in Mexico; diagnostic tools; conditions that merit a differential diagnosis; treatment; and primary and secondary prophylaxis. Likewise, these guidelines emphasize the management of certain special conditions, such as hepatic encephalopathy in acute liver failure and acute-on-chronic liver failure, as well as specific care in patients with hepatic encephalopathy, such as the use of medications and types of sedation, describing those that are permitted or recommended, and those that are not.

Peripheral Flicker Fusion at High Luminance: Beyond the Ferry-Porter Law.

The relationship between luminous intensity and the maximum frequency of flicker that can be detected defines the limits of the temporal-resolving ability of the human visual system, and characterizing it has important theoretical and practical applications; particularly for determining the optimal refresh rate for visual displays that would avoid the visibility of flicker and other temporal artifacts. Previous research has shown that this relationship is best described by the Ferry-Porter law, which states that critical flicker fusion (CFF) increases as a linear function of log retinal illuminance. The existing experimental data showed that this law holds for a wide range of stimuli and up to 10,000 Trolands; however, beyond this, it was not clear if the CFF continued to increase linearly or if the function saturated. Our aim was to extend the experimental data available to higher light intensities than previously reported in the literature. For this, we measured the peripheral CFF at a range of illuminances over six orders of magnitude. Our results showed that for up to 104 Trolands, the data conformed to the Ferry-Porter law with a similar slope, as previously established for this eccentricity; however, at higher intensities, the CFF function flattens and saturates at ~90 Hz for a target size of 5.7 degrees, and at ~100 Hz for a target of 10 degrees of angular size. These experimental results could prove valuable for the design of brighter visual displays and illumination sources that are temporally modulated.

J-difference GABA-edited MRS reveals altered cerebello-thalamo-cortical metabolism in patients with hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common neurological manifestation of liver cirrhosis and is characterized by an increase of ammonia in the brain accompanied by a disrupted neurotransmitter balance, including the GABAergic and glutamatergic systems. The aim of this study is to investigate metabolic abnormalities in the cerebello-thalamo-cortical system of HE patients using GABA-edited MRS and links between metabolite levels, disease severity, critical flicker frequency (CFF), motor performance scores, and blood ammonia levels. GABA-edited MRS was performed in 35 participants (16 controls, 19 HE patients) on a clinical 3 T MRI system. MRS voxels were placed in the right cerebellum, left thalamus, and left motor cortex. Levels of GABA+ and of other metabolites of interest (glutamine, glutamate, myo-inositol, glutathione, total choline, total NAA, and total creatine) were assessed. Group differences in metabolite levels and associations with clinical metrics were tested. GABA+ levels were significantly increased in the cerebellum of patients with HE. GABA+ levels in the motor cortex were significantly decreased in HE patients, and correlated with the CFF (r = 0.73; p < .05) and motor performance scores (r = -0.65; p < .05). Well-established HE-typical metabolite patterns (increased glutamine, decreased myo-inositol and total choline) were confirmed in all three regions and were closely linked to clinical metrics. In summary, our findings provide further evidence for alterations in the GABAergic system in the cerebellum and motor cortex in HE. These changes were accompanied by characteristic patterns of osmolytes and oxidative stress markers in the cerebello-thalamo-cortical system. These metabolic disturbances are a likely contributor to HE motor symptoms in HE. In patients with hepatic encephalopathy, GABA+ levels in the cerebello-thalamo-cortical loop are significantly increased in the cerebellum and significantly decreased in the motor cortex. GABA+ levels in the motor cortex strongly correlate with critical flicker frequency (CFF) and motor performance score (pegboard test tPEG), but not blood ammonia levels (NH3).

Efecto de la erradicación del VHC sobre la frecuencia crítica de parpadeo en pacientes coinfectados por VIH/VHC con cirrosis avanzada / Effect of HCV eradication on critical flicker frequency in HIV/HCV coinfected patients with advanced cirrhosis

Antecedentes La frecuencia crítica de parpadeo (FCP), definida como la frecuencia a la que un sujeto percibe una luz parpadeante como continua, se asocia directamente con el nivel de alerta del sistema nervioso central. Métodos Mediante el Hepatonorm analyzer (Medi-Business Freiburg GmGH, Germany) hemos estudiado la FCP en el momento basal y tras la erradicación del virus de la hepatitis C (VHC) en 47 pacientes coinfectados por virus de la inmunodeficiencia humana (VIH)/VHC y cirrosis. Los pacientes tenían una edad media de 52 años; el 81% eran varones y el 80% tenía antecedentes de consumo de drogas. Resultados Observamos un incremento en la FCP al final del tratamiento del VHC comparado con el momento basal (42,3 ± 8,5 Hz vs. 45,9 ± 7,8 Hz; p = 0,001), y una reducción en la proporción de pacientes con encefalopatía hepática subclínica (definida como una FCP < 39 Hz) desde 15 (32%) de los 47 pacientes al inicio a 7 (17%) de los 41 pacientes tras el tratamiento del VHC (p = 0,180). Conclusión La erradicación del VHC en pacientes coinfectados por VIH/VHC aumenta la FCP indicando una mejoría de la función hepática (AU)

Background Critical flicker frequency (CFF), defined as the frequency at which a subject perceives a flickering light as continuous, is directly associated with central nervous system alertness. Methods We studied CFF using the Hepatonorm analyzer (Medi-Business Freiburg GmGH, Germany) at baseline and after hepatitis C virus (HCV) eradication in 47 patients with human immunodeficiency virus (HIV)/HCV coinfection and cirrhosis. Patients had a mean age of 52 years, 81% were male, and 80% had a history of drug use. Results We observed an increase in the CFF at the end of HCV therapy compared to baseline (42.3 ± 8.5 Hz vs. 45.9 ± 7.8 Hz; p = 0.001), and a reduction in the proportion of patients with subclinical hepatic encephalopathy (defined as a CFF <39 Hz) from 15 (32%) of 47 patients at baseline to 7 (17%) of 41 patients after HCV therapy (p = 0.180). Conclusion HCV eradication in HIV/HCV coinfected patients increases CFF, indicating improved liver function (AU)

Effect of HCV eradication on critical flicker frequency in HIV/HCV coinfected patients with advanced cirrhosis.

BACKGROUND: Critical flicker frequency (CFF), defined as the frequency at which a subject perceives a flickering light as continuous, is directly associated with central nervous system alertness. METHODS: We studied CFF using the Hepatonorm analyzer (Medi-Business Freiburg GmGH, Germany) at baseline and after hepatitis C virus (HCV) eradication in 47 patients with human immunodeficiency virus (HIV)/HCV coinfection and cirrhosis. Patients had a mean age of 52 years, 81% were male, and 80% had a history of drug use. RESULTS: We observed an increase in the CFF at the end of HCV therapy compared to baseline (42.3 ±â€¯8.5 Hz vs. 45.9 ±â€¯7.8 Hz; p = 0.001), and a reduction in the proportion of patients with subclinical hepatic encephalopathy (defined as a CFF <39 Hz) from 15 (32%) of 47 patients at baseline to 7 (17%) of 41 patients after HCV therapy (p = 0.180). CONCLUSION: HCV eradication in HIV/HCV coinfected patients increases CFF, indicating improved liver function.

Evaluation of different diagnostic modalities of minimal hepatic encephalopathy in cirrhotic patients: case-control study.

INTRODUCTION: Minimal hepatic encephalopathy (MHE) represents one of the most overlooked complications of liver cirrhosis. AIM OF THE STUDY: To compare the utility and efficacy of different MHE diagnostic modalities. MATERIAL AND METHODS: This case-control study was conducted on hepatitis C virus (HCV)-related compensated cirrhotic patients. The Psychometric Hepatic Encephalopathy Score (PHES) was used to assign patients to MHE and controls. All patients were subjected to plasma ammonia, serum 3-nitrotyrosine (3-NT), critical flicker frequency (CFF), and the modified inhibitory control test (ICT). RESULTS: CFF was significantly lower in the control group (38.5, 40 Hz, p = 0.003). The unweighted lures on ICT were 8.7, 4.9 in MHE and controls (p < 0.001). Moreover, ammonia was higher in the MHE group (89, 61.5 µmol/l, p < 0.001). 3-NT was also higher in the MHE group (31.5, 13.7 nmol/l, p < 0.001) respectively. CFF at cutoff < 39 Hz had sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 57.5%, 77.5%, 71.9% and 64.6%, respectively; in modified ICT, at cutoff > 5 unweighted lures the values were 87.5%, 80%, 81.4% and 86.5%, respectively; in ammonia, at cutoff ≥ 76.45 µmol/l the values were 65%, 72.5%, 70.3% and 67.4%, respectively; for 3-NT at cutoff ≥ 14.15 nmol/l the values were 85%, 82.5%, 82.9% and 84.6%, respectively. The accuracy for MHE diagnosis was 67.5%, 83.3%, 68.8%, 83.8% relying on CFF, 3-NT, ammonia, and ICT respectively. On multivariate analysis, CFF < 39 Hz (OR = 10.2, p = 0.04), modified ICT > 5 unweighted lures (OR = 43.2, p = 0.002), and serum 3-NT levels ≥ 14.15 nmol/l (OR = 50.4, p < 0.001) were independent predictors of MHE. CONCLUSIONS: 3-NT and ICT are advantageous to reveal MHE in compensated liver cirrhosis, while CFF can be only used as adjuncts, with humble merits of ammonia.

Binasal hemianopia caused by bilateral optic perineuritis due to sarcoidosis.

•We describe the first case of binasal hemianopia due to bilateral optic perineuritis.•Bilateral optic perineuritis should be considered as a causative disease of binasal hemianopia.•Early diagnosis of optic perineuritis is crucial to avoid irreversible visual impairment.

Altered motor cortical plasticity in patients with hepatic encephalopathy: A paired associative stimulation study.

OBJECTIVE: Hepatic encephalopathy (HE) is a potentially reversible brain dysfunction caused by liver failure. Altered synaptic plasticity is supposed to play a major role in the pathophysiology of HE. Here, we used paired associative stimulation with an inter-stimulus interval of 25 ms (PAS25), a transcranial magnetic stimulation (TMS) protocol, to test synaptic plasticity of the motor cortex in patients with manifest HE. METHODS: 23 HE-patients and 23 healthy controls were enrolled in the study. Motor evoked potential (MEP) amplitudes were assessed as measure for cortical excitability. Time courses of MEP amplitude changes after the PAS25 intervention were compared between both groups. RESULTS: MEP-amplitudes increased after PAS25 in the control group, indicating PAS25-induced synaptic plasticity in healthy controls, as expected. In contrast, MEP-amplitudes within the HE group did not change and were lower than in the control group, indicating no induction of plasticity. CONCLUSIONS: Our study revealed reduced synaptic plasticity of the primary motor cortex in HE. SIGNIFICANCE: Reduced synaptic plasticity in HE provides a link between pathological changes on the molecular level and early clinical symptoms of the disease. This decrease may be caused by disturbances in the glutamatergic neurotransmission due to the known hyperammonemia in HE patients.

Prevalence of and Factors Associated with Sleep-Wake Abnormalities in Patients with Cirrhosis.

BACKGROUND & AIMS: Sleep-wake abnormalities [poor nighttime sleep and excessive daytime sleepiness (EDS)] are common in patients with cirrhosis. The aim of this study was to assess the prevalence of sleep-wake abnormalities and clinical factors associated with these abnormalities in a group of patients with cirrhosis. METHODS: 1098 patients with cirrhosis [Child Turcotte Pugh (CTP) class A, 22.2%; CTP class B, 29.2% and CTP class C, 48.6%], with either no ascites or mild ascites controlled on diuretics, and no history of or current overt hepatic encephalopathy were included in the study. RESULTS: Poor nighttime sleep and EDS were found in 569 (51.8%) and 489 (44.5%) patients respectively. On multivariate analysis, factors associated with poor nighttime sleep were CTP class C (vs. class A), presence of minimal hepatic encephalopathy (MHE), intermediate or evening type of diurnal preference category (vs. morning type), high risk for obstructive sleep apnea (OSA), diuretic use, presence of major depression, and presence of generalized anxiety disorder (GAD). Factors associated with EDS on multivariate analysis were CTP class B and C (vs. class A), intermediate or evening type of diurnal preference category (vs. morning type), high risk for OSA, presence of major depression, and presence of GAD. CONCLUSIONS: Sleep-wake abnormalities are common in patients with cirrhosis. CTP status, diurnal preference chronotype, risk of OSA, major depression and GAD are associated with both poor nighttime sleep and EDS. MHE and diuretic use are associated with poor nighttime sleep, but not with EDS.

Temporal vision: measures, mechanisms and meaning.

Time is largely a hidden variable in vision. It is the condition for seeing interesting things such as spatial forms and patterns, colours and movements in the external world, and yet is not meant to be noticed in itself. Temporal aspects of visual processing have received comparatively little attention in research. Temporal properties have been made explicit mainly in measurements of resolution and integration in simple tasks such as detection of spatially homogeneous flicker or light pulses of varying duration. Only through a mechanistic understanding of their basis in retinal photoreceptors and circuits can such measures guide modelling of natural vision in different species and illuminate functional and evolutionary trade-offs. Temporal vision research would benefit from bridging traditions that speak different languages. Towards that goal, I here review studies from the fields of human psychophysics, retinal physiology and neuroethology, with a focus on fundamental constraints set by early vision.

Determination of Turkish norms of psychometric tests for diagnosing minimal hepatic encephalopathy and proposal of a high sensitive screening test battery.

BACKGROUND: Psychometric hepatic encephalopathy score (PHES) needs local standardization. AIMS: This study aimed at standardizing PHES for Turkish patients and compare them with German norms; to determine minimal hepatic encephalopathy (mHE) prevalence with two different methods [PHES battery and Critical Flicker Frequency (CFF)] and to assess whether sub-tests of the battery can be used for screening for mHE. METHODS: Healthy volunteers (n = 816; 400 male) and cirrhotics (n = 124; 58 male) were included. For mHE diagnosis PHES score threshold was set at ≤ - 5 points and that of CFF at < 39 Hz. For comparing German and Turkish norms, datasets were combined. Multiple backward procedure was applied to assess effects of age, sex and education on single tests of the battery. Receiver operating characteristic (ROC) curves were created for assessing diagnostic capabilities of subtests of the battery. RESULTS: PHES norms for Turks were developed. MHE prevalence in compensated cirrhotics was 29.8% and 27.4% with PHES and CFF tests, respectively, with low compatibility (kappa coefficient 0.389); mHE prevalence decreased to 16% when both tests were combined. Turks performed worse vs Germans in the digit symbol (DS) and serial dotting (SD) subtests but performed better in other subtests. In ROC analyzes of subtests, the combination of DS + SD tests achieved an AUROC of 0.974 versus PHES. CONCLUSIONS: Use of two methods for diagnosing mHE is important for research purposes. From a clinical perspective, sensitivity with acceptable specificity may suffice for screening instruments for mHE. Combined use of DS and SD subtests of the PHES battery appears suitable for this purpose.

Minimal portosystemic encephalopathy: A new nosological entity in patients with hereditary haemorrhagic telangiectasia.

BACKGROUND: Portosystemic shunts in Hereditary Haemorrhagic Telangiectasia (HHT) are often overlooked by conventional imaging although they could reduce hepatic clearance of gut-derived toxins. AIMS: To evaluate, the presence of subclinical neurological alterations (SNAs), that we named "minimal portosystemic encephalopathy" (mPSE) in HHT patients without advanced liver disease (ALD). METHODS: In this cross sectional study, consecutive HHT outpatients were firstly screened by critical flicker frequency (CFF) test (abnormal ≤39Hz), and the simplified animal naming test (S-ANT1) (abnormal <15) was used to confirm the diagnosis of mPSE. Furthermore, we evaluated the effect of lactulose administration on mPSE. Multi-slice CT, cerebral dynamic magnetic resonance, laboratory analyses and transient elastography were also used. RESULTS: None of the 37 enrolled patients showed portosystemic shunts at imaging techniques. However, 33 patients had normal CFF values (CFF-) and 4 displayed CFF alterations (37.0±0.7Hz, CFF+). The S-ANT1 confirmed an impaired neurological performance (10.2±2.8) in CFF+ patients thus confirming the presence of mPSE. Noteworthy, lactulose administration determined a CFF increase (39.1±0.4Hz) and S-ANT1 normalization in these patients. Neither mPSE- nor mPSE+ patients had ALD and showed similar demographic, clinical and laboratory parameters. Finally, no mPSE+ patient showed radiologically-detectable brain vascular malformations or other brain abnormalities at imaging. CONCLUSIONS: HHT patients represent a human model of mPSE secondary to portosystemic shunts escaping radiological detection. mPSE evaluation should be incorporated in HHT surveillance protocols since it can affect both health-related/social aspects and pharmacokinetics of orally administered drugs with a narrow therapeutic index and high hepatic first-pass uptake.

Minimal Hepatic Encephalopathy in Patients with Alcohol Related and Non-alcoholic Steatohepatitis Related Cirrhosis by Psychometric Hepatic Cephalopathy Score and Critical Flicker Frequency.

BACKGROUND: alcohol may have additional neurotoxic ill-effects in patients with alcohol related cirrhosis apart from hepatic encephalopathy. We aimed to evaluate minimal hepatic encephalopathy (MHE) with Psychometric Hepatic Encephalopathy (PHES) score and Critical Flicker Frequency (CFF) in alcohol (ALD) and non-alcoholic steatohepatitis related (NASH) related cirrhosis. METHODS: 398 patients were screened between March 2016 and December 2018; of which 71 patients were included in ALD group and 69 in NASH group. All included patients underwent psychometric tests which included number connection test A and B (NCT-A and NCT-B), serial dot test (SDT), digit symbol test (DST), line tracing test (LTT) and CFF. MHE was diagnosed when their PHES was <-4. RESULTS: the prevalence of MHE was significantly higher in ALD group compared to NASH (69.01% vs 40.58%; P=0.007). The performance of individual psychometric tests was significantly poorer in ALD (P<0.05). Overall sensitivity and specificity of CFF was 76.62% (95%CI 65.59 - 85.52) and 46.03% (95%CI 33.39 - 59.06) respectively. Mean CFF was significantly lower in ALD than NASH (37.07 (SD 2.37) vs 39.05 (SD 2.40), P=0.001); also in presence of MHE (36.95 (SD 2.04) vs 37.96 (SD 1.87), P=0.033) and absence of MHE (37.34 (SD 3.01) vs 39.79 (SD 2.46), P=0.001). CONCLUSION: MHE is significantly more common in patients with ALD cirrhosis than NASH counterparts. Overall CFF values are less in alcohol related cirrhosis than NASH related cirrhosis, even in presence or absence of MHE. We recommend additional caution in managing MHE in ALD cirrhosis.

Evaluation of cerebral dysfunction in patients with chronic kidney disease using neuropsychometric and neurophysiological tests.

BACKGROUND: Uremic encephalopathy is defined as cerebral dysfunction due to toxin accumulation in patients with chronic kidney disease (CKD). This condition is characterized by subtle to florid symptoms, and its clinical course is always progressive when untreated but partially reversible with renal replacement therapy. While no test exists to measure subclinical uremic encephalopathy, two tests have been validated to measure minimal hepatic encephalopathy: the critical flicker frequency (CFF) test and the psychometric hepatic encephalopathy score (PHES). OBJECTIVE: To use CFF and PHES to measure the prevalence of cerebral dysfunction in individuals with CKD. METHODS: This cross-sectional study included a total of 69 patients with stage-5 CKD. Cutoff points for minimal encephalopathy were established using existing clinical guidelines: ≤39 Hz for CFF and < -4 for PHES. All participants were also screened for cognitive function and depression. RESULTS: Eighteen cases (26.1%) of cerebral dysfunction linked to uremic encephalopathy were detected with CFF, while twelve (17.4%) were detected by PHES; only six cases (8.7%) were diagnosed by both methods. Half of the cases (50%) had diabetes, and 61% were on hemodialysis. Cognitive function scores did not differ significantly between those receiving dialysis, hemodialysis, or no renal replacement therapy. CONCLUSIONS: It is essential to identify cerebral dysfunction when uremic encephalopathy is in early subclinical stages to reduce preventable events as traffic and work accidents.

Role of Brain Biomarkers S-100-Beta and Neuron-Specific Enolase for Detection and Follow-Up of Hepatic Encephalopathy in Cirrhosis before, during and after Treatment with L-Ornithine-L-Aspartate.

INTRODUCTION: Hepatic encephalopathy (HE), in the context of liver cirrhosis, seems to result from low-grade cerebral edema of the astrocytes. Serum brain biomarkers S-100-beta und neuron-specific enolase (NSE) are often elevated in brain injury. We hypothesized that neuromarkers S-100-beta and NSE can be used in the diagnosis of HE, compared with standardized diagnostic tools. MATERIAL AND METHODS: A prospective non-randomized intervention study was performed using L-ornithine-L-aspartate (LOLA) for HE treatment. Primary endpoint was the evaluation of neuromarkers S-100-beta and NSE for detection and diagnosis of follow-up of HE. As secondary endpoints, the efficacy of LOLA on the course of HE and the diagnostic role of Portosystemic-Encephalopathy-Syndrome score (PHES) and critical flicker frequency (CFF) were analyzed. For diagnosis of covert (CHE) and overt (OHE) HE, West-Haven criteria (WHC), PHES and CFF were assessed at study entry. LOLA was applied (20 g i.v.) for 6 days. At the end of the study, HE evaluation was repeated. S-100-beta, NSE and ammonia were assessed in each patient before, during and after therapy with LOLA. RESULTS: 30 patients were included. At study entry, CHE was diagnosed in 50% and OHE in 50% of all subjects. A total of 25 participants completed the study. After LOLA therapy, deterioration of HE occurred in <11%, while most patients showed improvement (e.g. improved CFF in 79%). No significant correlation with HE severity (as diagnosed by WHC, PHES and CFF) could be demonstrated for any biochemical parameter. In addition, there were no significant changes in brain biomarkers during the treatment period. DISCUSSION: While CFF as well as PHES showed good correlation with treatment response, S-100-beta and NSE did not significantly correlate with HE severity compared to proven diagnostic methods, and do not seem reliable biochemical markers for the follow-up under therapy.

INTRODUÇÃO: A encefalopatia hepática (EH) na cirrose é vista como o resultado de edema cerebral de baixo grau dos astrócitos. Biomarcadores cerebrais serológicos S-100-beta e enolase neurónio-específica (NSE) estão frequentemente elevados na lesão cerebral. A nossa hipótese é que os neuromarcadores S-100-beta e NSE podem ser usados no diagnóstico de EH, quando comparados com os meios diagnósticos standard. MATERIAL E MÉTODOS: Estudo prospectivo não randomizado foi realizado usando L-ornitina-L-aspartato (LOLA) no tratamento da EH. O endpoint primário foi a avaliação dos neuromarcadores S-100-beta e NSE para a deteção e vigilância da EH. Foram endpoints secundários a eficácia da LOLA no curso da EH e o papel diagnóstico do Portosystemic-Encephalopathy-Syndrome score (PHES) e do critical flicker frequency (CFF). Para o diagnóstico de EH oculta (EHO) ou declarada (EHD) foram avaliados os West-Haven criteria (WHC), PHES e CFF à entrada do estudo. LOLA foi administrada (20 g ev) por 6 dias. No fim do estudo os testes de EH foram repetidos. Os níveis de S-100-beta, NSE e amónia foram avaliados em todos os doentes antes, durante e após a terapêutica com LOLA. RESULTADOS: Foram incluídos 30 doentes no estudo. À entrada EHO foi diagnosticada em 50% e EHD nos restantes 50% dos participantes. Um total de 25 doentes completaram o estudo. Após a terapêutica com LOLA, verificou-se deterioração da EH em < 11%, enquanto a maioria dos doentes melhorou (melhoria CFF em 79%). Não se demonstrou nenhuma correlação significativa com a gravidade da EH (tendo em conta os WHC, PHES e CFF) para nenhum dos parâmetros bioquímicos. Para além disso, não se demonstraram variaões significativa nos biomarcadores cerebrais durante o período de tratamento. DISCUSSÃO: Apesar do CFF e do PHES apresentarem boa correlação com a resposta terapêutica, a S-100-beta e a NSE não se correlacionaram significativamente com a gravidade da EH quando comparado com os outros métodos diagnósticos standard, não parecendo ser marcadores bioquímicos úteos para a vigilância da resposta terapêutica.

Novel computerized psychometric tests as primary screening tools for the diagnosis of minimal hepatic encephalopathy.

Minimal hepatic encephalopathy (MHE) is a critical neurocognitive complication of decompensated liver cirrhosis and portosystemic shunting, which results in a wide range of cognitive deficits including impairments in working attention, psychomotor speed, and executive function. Current guidelines have recommended paper-and-pencil psychometric tests for the diagnosis of MHE. Most high-risk cirrhotic patients are required to be examined; however, paper-and-pencil psychometric tests are neither convenient nor rapid to perform in the clinic. Recently, novel computerized psychometric tests, including the inhibitory control test, EncephalApp Stroop App, and critical flicker frequency, have been proven to be rapid, effective, and convenient methods for screening MHE in clinical practice and for identifying high-risk cirrhotic patients for further validation using rigid neuropsychometric examinations. However, diagnostic accuracy of these tests is influenced by educational background, age, and cultural differences. This review summarizes clinical evidence of the application of novel computerized psychometric tests for screening MHE.