Abstract
The term minimal hepatic encephalopathy refers to the subtle changes in cognitive function, electrophysiological parameters, cerebral neurochemical/neurotransmitter homeostasis, cerebral blood flow, metabolism, and fluid homeostasis that can be observed in patients with cirrhosis who have no clinical evidence of hepatic encephalopathy. Use of this term emphasizes the fact that the entity of hepatic encephalopathy is a single syndrome with quantitatively distinct features relating to severity. The absence of clinical evidence of hepatic encephalopathy is key to the diagnosis and can only be determined by a detailed assessment of the patients' history and a comprehensive neurological assessment of consciousness, cognitive, and motor function. The neuropsychological features of minimal hepatic encephalopathy point to a disorder of executive functioning, particularly selective attention and psychomotor speed, but other abnormalities may be observed. Alterations in electrophysiological variables have been described; endogenous evoked potentials are, in principle, more likely to reflect the presence of minimal hepatic encephalopathy, since they reflect cognitive phenomena rather than mere stimulus conduction but the specificity of the changes observed is unclear at present. Changes have also been described in the execution of diadochokinetic movements and in the capacity to discriminate flickering light, both of which may have diagnostic potential. The changes observed in cerebral blood flow and metabolism in SPET, PET, and 1H and 31P MRS studies reflect the pathogenic process that underlies the condition rather than providing diagnostic information. Similarly, the morphological brain abnormalities identified in this population, including mild brain oedema, hyperintensity of the globus pallidus and other subcortical nuclei observed in cerebral MR studies, and the central and cortical atrophy observed in neural imaging studies, are unlikely to have diagnostic utility. The presence of minimal hepatic encephalopathy is not without clinical consequence; it has a detrimental effect on health-related quality of life, the ability to perform complex tasks such as driving, and on outcome.
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REFERENCES
Amodio, P., Del Piccolo, F., Marchetti, P., Angeli, P., Iemmolo, R., Caregaro, L., Merkel, C., Gerunda, G., and Gatta, A. (1999a). Clinical features and survival of cirrhotic patients with subclinical cognitive alterations detected by the number connection test and computerized psychometric tests. Hepatology 29:1662–1667.
Amodio, P., Del Piccolo, F., Pettenò, E., Mapelli, D., Angeli, P., Iemmolo, R., Muraca, M., Musto, C., Gerunda, G., Rizzo, C., Merkel, C., and Gatta, A. (2001). Prevalence and prognostic value of quantified electroencephalo-gram (EEG) alterations in cirrhotic patients. J. Hepatol. 35:37–45.
Amodio, P., Marchetti, P., Del Piccolo, F., Beghi, A., Comacchio, F., Carraro, P., Campo, G., Baruzzo, L., Marchiori, C., and Gatta, A. (1997). The effect of flumazenil on subclinical psychometric or neurophysio-logical alterations in cirrhotic patients: A double-blind placebo-controlled study. Clin. Physiol. 17:533–539.
Amodio, P., Marchetti, P., Del Piccolo, F., Campo, G., Rizzo, C., Iemmolo, R.M., Gerunda, G., Caregaro, L., Merkel, C., and Gatta, A. (1998). Visual attention in cirrhotic patients: A study on covert visual attention orienting. Hepatology 27:1517–1523.
Amodio, P., Marchetti, P., Del Piccolo, F., de Tourtchaninoff, M., Varghese, P., Zuliani, C., Campo, G., Gatta, A., and Guérit, J.M. (1999b). Spectral versus visual EEG analysis in mild hepatic encephalopathy. Clin. Neuro-physiol. 110:1334–1344.
Amodio, P., Marchetti, P., Del Piccolo, F., Sartori, G., Prior, M., Merkel, C., and Gatta, A. (1995). Visual attention orienting in liver cirrhosis without overt hepatic encephalopathy. Metab. Brain Dis. 10:335–345.
Amodio, P., Pellegrini, A., Amistà, P., Luise, S., Del Piccolo, F., Mapelli, D., Montagnese, S., Musto, C., Valenti, P., and Gatta, A. (2003). Neuropsychological–neurophysiological alterations and brain atrophy in cirrhotic patients. Metab. Brain Dis. 18:63–78.
Amodio, P., Quero, J.C., Del Piccolo, F., Gatta, A., and Schalm, S.W. (1996). Diagnostic tools for the detection of subclinical hepatic encephalopathy: Comparison of standard and computerized psychometric tests with spectral-EEG. Metab. Brain Dis. 11:315–327.
Amodio, P., Wenin, H., Del Piccolo, F., Mapelli, D., Montagnese, S., Pellegrini, A., Musto, C., Gatta, A., and Umiltà, C. (2002). Variability of trail making test, symbol digit test and line trait test in normal people. A normative study taking into account age-dependent decline and sociobiological variables. Ageing: Clin. Exp. Res. 14:117–131.
Begleiter, H., Porjesz, B., and Chou, C.L. (1981). Auditory brainstem potentials in chronic alcoholics. Science 211:1064–1066.
Bernthal, P., Hays, A., Tarter, R.E., Van Thiel, D., Lecky, J., and Hegedus, A. (1987). Cerebral CT scan abnormal-ities in cholestatic and hepatocellular disease and their relationship to neuropsychologic test performance. Hepatology 7:107–114.
Blei, A.T., and Córdoba, J. (1996). Subclinical encephalopathy. Dig. Dis. Sci. 14(Suppl. 1):2–11.
Blei, A.T., and Córdoba, J. (2001). Hepatic encephalopathy. Am. J. Gastroenterol. 96:1968–1976.
Burra, P., Dam, M., Chierichetti, F., Tedeschi, U., Senzolo, M., Sale, E., Cagnin, A., Ori, C., Naccarato, R., Ferlin, G., and Pizzolato, G. (1999). 18F-fluorodeoxyglucose positron emission tomography study of brain metabolism in cirrhosis: Effect of liver transplantation. Transplant. Proc. 31:418–420.
Burra, P., Pizzolato, G., Orlando, F., Rossato, A., Chierichetti, F., Tedeschi, U., Rossaro, L., Salvagnini, N., Ermani, M., and Dam, M. (1994). Single-photon emission computed tomography with 99mTC-hexamethyl-propyleneamineoxide in cirrhotic patients before and after liver transplantation. Transplant. Proc. 26:3677–3678.
Butterworth, R.F. (1996). The neurobiology of hepatic encephalopathy. Semin. Liver Dis. 16:235–244.
Cadranel, J.F., Lebiez, E., Di Martino, V., Bernard, B., El Koury, S., Tourbah, A., Pidoux, B., Valla, D., and Opolon, P. (2001). Focal neurological signs in hepatic encephalopathy in cirrhotic patients: An underestimated entity? Am. J. Gastroenterol. 96:515–518.
Carpenter, P.A., Just, M.A., and Reichle, E.D. (2000). Working memory and executive function: Evidence from neuroimaging. Curr. Opin. Neurobiol. 10:195–199.
Chu, N.S., Yang, S.S., and Liaw, Y.F. (1997). Evoked potentials in liver diseases. J. Gastroenterol. Hepatol. 12:S288–S293.
Churchill's Medical Dictionary (1994). Churchill Livingstone, New York.
Conn, H.O., Leevy, C.M., Vlahcevic, Z.R., Rodgers, J.B., Maddrey, W.C., Seeff, L., and Levy, L.L. (1977). Comparison of lactulose and neomycin in the treatment of chronic portal–systemic encephalopathy. A double blind controlled trial. Gastroenterology 72:573–583.
Córdoba, J., Sanpedro, F., Alonso, J., and Rovira, A. (2002). 1H magnetic resonance in the study of hepatic encephalopathy in humans. Metab. Brain Dis. 17:415–429.
Dam, M., Burra, P., Tedeschi, U., Cagnin, A., Chierichetti, F., Ermani, M., Ferlin, G., Naccarato, R., and Pizzolato, G. (1998). Regional cerebral blood flow changes in patients with cirrhosis assessed with 99mTc-HM-PAO single-photon emission computed tomography: Effect of liver transplantation. J. Hepatol. 29:78–84.
Das, A., Dhiman, R.K., Saraswat, V.A., Verma, M., and Naik, S.R. (2001). Prevalence and natural history of subclinical hepatic encephalopathy in cirrhosis. J. Gastroenterol. Hepatol. 16:531–535.
Davidson, E.A., and Summerskill, W.H.J. (1956). Psychiatric aspects of liver disease. Postgrad. Med. J. 32:487–494.
Desmedt, J.E. (1980). P300 in serial tasks: An essential post-decision closure mechanism. Prog. Brain Res. 54:682–686.
Donchin, E., and Isreal, J.B. (1980). Event-related potentials and psychological theory. Prog. Brain Res. 54:697–715.
Douglass, A., Al Mardini, H., and Record, C. (2001). Amino acid challenge in patients with cirrhosis: A model for the assessment of treatments for hepatic encephalopathy. J. Hepatol. 34:658–664.
Eckstein, A.K., Reichenbach, A., Jacobi, P., Weber, P., Gregor, M., and Zrenner, E. (1997). Hepatic retinopathia. Changes in retinal function. Visi on Res. 37:1699–1706.
Elsass, P., Christensen, S.E., Mortensen, E.L., and Vilstrup, H. (1985). Discrimination between organic and hepatic encephalopathy by means of continuous reaction times. Liver 5:29–34.
Elsass, P., Lund, Y., and Ranek, L. (1978). Encephalopathy in patients with cirrhosis of the liver. A neuropsycho-logical study. Scand. J. Gastroenterol. 13:241–247.
Epstein, C.M., Riether, A.M., Henderson, R.M., and Cotsonis, G.A. (1992). EEG in liver transplantation: Visual and computerized analysis. Electroencephalogr. Clin. Neurophysiol. 83:367–371.
Ferenci, P., Lockwood, A., Mullen, K., Tarter, R., Weissenborn, K., and Blei, A.T. (2002). Hepatic encephalopathy– definition, nomenclature, diagnosis, and quantification: Final report of the working party at the 11th World Congresses of Gastroenterology, Vienna, 1998. Hepatology 35:716–721.
Folstein, M.F., Folstein, S.E., and McHugh, P.R. (1975). "Mini-mental state." A practical method for grading the cognitive state of patients for the clinician. J. Psychiatr. Res. 12:189–198.
Forton, D.M., Taylor-Robinson, S.D., and Thomas, H.C. (2003). Cerebral dysfunction in chronic hepatitis C infection. J. Viral Hepat. 10:81–86.
Forton, D.M., Thomas, H.C., Murphy, C.A., Allsop, J.M., Foster, G.R., Main, J., Wesnes, K.A., and Taylor-Robinson, S.D. (2002). Hepatitis C and cognitive impairment in a cohort of patients with mild liver disease. Hepatology 35:433–439.
Gilberstadt, S.J., Gilberstadt, H., Zieve, L., Buegel, B., Collier, R.O., Jr., and McClain, C.J. (1980). Psychomo-tor performance defects in cirrhotic patients without overt encephalopathy. Arch. Intern. Med. 140:519–521.
Groeneweg, M., Moerland, W., Quero, J.C., Hop, W.C., Krabbe, P.F., and Schalm, S.W. (2000). Screening of subclinical hepatic encephalopathy. J. Hepatol. 32:748–753.
Groeneweg, M., Quero, J.C., De Bruijn, I., Hartmann, I.J., Essink-bot, M.L., Hop, W.C., and Schalm, S.W. (1998). Subclinical hepatic encephalopathy impairs daily functioning. Hepatology 28:45–49.
Guérit, J.M., Amodio, P., Hafner, H., Litscher, G., and Van Huffelen, A.C. (2000). Neuromonitoring in the operating room and intensive care unit: An update. Clin. Neurophysiol. 5 3(Suppl.):61–71.
Hartmann, I.J., Groeneweg, M., Quero, J.C., Beijeman, S.J., de Man, R.A., Hop, W.C., and Schalm, S.W. (2000). The prognostic significance of subclinical hepatic encephalopathy. Am. J. Gastroenterol. 95:2029–2034.
Häussinger, D., Kircheis, G., Fischer, R., Schliess, F., and von Dahl, S. (2000). Hepatic encephalopathy in chronic liver disease: A clinical manifestation of astrocyte swelling and low-grade cerebral edema? J. Hepatol. 32:1035–1038.
Hilsabeck, R.C., Perry, W., and Hassanein, T.I. (2002). Neuropsychological impairment in patients with chronic hepatitis C. Hepatology 35:440–446.
Joebges, E.M., Heidemann, M., Schimke, N., Hecker, H., Ennen, J.C., and Weissenborn, K. (2003). Bradykinesia in minimal hepatic encephalopathy is due to disturbances in movement initiation. J. Hepatol. 38:273–280.
Jover, R., Compañy, L., Gutiérrez, A., Zapater, P., Pérez-Serra, J., Girona, E., Aparicio, J.R., and Pérez-Mateo, M. (2003). Minimal hepatic encephalopathy and extrapyramidal signs in patients with cirrhosis. Am. J. Gastroenterol. 98:1599–1604.
Kircheis, G., Wettstein, M., Timmermann, L., Schnitzler, A., and Häussinger, D. (2002). Critical flicker frequency for quantification of low-grade hepatic encephalopathy. Hepatology 35:357–366.
Kono, I., Ueda, Y., Nakajima, K., Araki, K., Kagawa, K., and Kashima, K. (1994). Subcortical impairment in subclinical hepatic encephalopathy. J. Neurol. Sci. 126:162–167.
Kramer, L., Bauer, E., Funk, G., Hofer, H., Jessner, W., Steindl-Munda, P., Wrba, F., Madl, C., Gangl, A., and Ferenci, P. (2002a). Subclinical impairment of brain function in chronic hepatitis C infection. J. Hepatol. 37:349–354.
Kramer, L., Bauer, E., Gendo, A., Funk, G., Madl, C., Pidlich, J., and Gangl, A. (2002b). Neurophysiological evidence of cognitive impairment in patients without hepatic encephalopathy after transjugular intrahepatic portosystemic shunts. Am. J. Gastroenterol. 97:162–166.
Krieger, S., Jauss, M., Jansen, O., Theilmann, L., Geissler, M., and Krieger, D. (1996). Neuropsychiatric profile and hyperintense globus pallidus on T1-weighted magnetic resonance images in liver cirrhosis. Gastroenterology 111:147–155.
Kügler, C.F., Lotterer, E., Petter, J., Wensing, G., Taghavy, A., Hahn, E.G., and Fleig, W.E. (1992). Visual event-related P300 potentials in early portosystemic encephalopathy. Gastroenterology 103:302–310.
Kügler, C.F., Petter, J., Taghavy, A., Lotterer, E., Wensing, G., Hahn, E.G., and Fleig, W.E. (1994). Dynamics of cognitive brain dysfunction in patients with cirrhotic liver disease: An event-related P300 potential perspective. Electroencephalogr. Clin. Neurophysiol. 91:33–41.
Kullmann, F., Hollerbach, S., Holstege, A., and Schölmerich, J. (1995). Subclinical hepatic encephalopathy: The diagnostic value of evoked potentials. J. Hepatol. 22:101–110.
Levy, L.J., Bolton, R.P., and Losowsky, M.S. (1987). The use of the visual evoked potential (VEP) in delineating a state of subclinical encephalopathy. A comparison with the number connection test (NCT). J. Hepatol. 5:211–217.
Lockwood, A.H. (2000). "What's in a name?" Improving the care of cirrhotics. J. Hepatol. 32:859–861.
Lockwood, A.H., Murphy, B.W., Donnelly, K.Z., Mahl, T.C., and Perini, S. (1993). Positron-emission tomo-graphic localization of abnormalities of brain metabolism in patients with minimal hepatic encephalopathy.Hepatology 18:1061–1068.
Lockwood, A.H., Weissenborn, K., Bokemeyer, M., Tietge, U., and Burchert, W. (2002). Correlations between cerebral glucose metabolism and neuropsychological test performance in nonalcoholic cirrhotics. Metab. Brain Dis. 17:29–40.
Marchesini, G., Bianchi, G., Amodio, P., Salerno, F., Merli, M., Panella, C., Loguercio, C., Apolone, G., Niero, M., and Abbiati, R. (2001). Factors associated with poor health-related quality of life of patients with cirrhosis. Gastroenterology 120:170–178.
McCrea, M., Córdoba, J., Vessey, G., Blei, A.T., and Randolph, C. (1996). Neuropsychological characterization and detection of subclinical hepatic encephalopathy. Arch. Neurol. 53:758–763.
Mehndiratta, M.M., Sood, G.K., Sarin, S.K., and Gupta, M. (1990). Comparative evaluation of visual, somatosen-sory, and auditory evoked potentials in the detection of subclinical hepatic encephalopathy in patients with nonalcoholic cirrhosis. Am. J. Gastroenterol. 85:799–803.
Messenheimer, J.A., Greenwood, R.S., Tennison, M.B., Brickley, J.J., and Ball, C.J. (1984). Reversible visual evoked potential abnormalities in vitamin E deficiency. Ann. Neurol. 15:499–501.
Moore, J.W., Dunk, A.A., Crawford, J.R., Deans, H., Besson, J.A., De Lacey, G., Sinclair, T.S., Mowat, N.A., and Brunt, P.W. (1989). Neuropsychological deficits and morphological MRI brain scan abnormalities in apparently healthy non-encephalopathic patients with cirrhosis. A controlled study. J. Hepatol. 9:319–325.
Niedermeyer, E. (1999). Metabolic central nervous system disorders. In (E. Niedermeyer and F. Lopes Da Silva, eds.), Electroencephalography. Basic Principles, Clinical Applications, and Related Fields, 4th edn., Williams & Wilkins, Baltimore, pp. 416–431.
Norenberg, M.D., and Bruce-Gregorios, J. (1997). Nervous system manifestation of systemic disease. In (R.L. Davies and D.M. Robertson, eds.), Textbook of Neuropathology, Williams & Wilkins, Baltimore, pp. 547–625.
O'Carroll, R.E., Hayes, P.C., Ebmeier, K.P., Dougall, N., Murray, C., Best, J.J., Bouchier, I.A., and Goodwin, G.M. (1991). Regional cerebral blood flow and cognitive function in patients with chronic liver disease. Lancet 337:1250–1253.
Parsons-Smith, B.G., Summerskill, W.H.J., Dawson, A.M., and Sherlock, S. (1957). The electroencephalograph in liver disease. Lancet 2:867–871.
Porjesz, B., and Begleiter, H. (1981). Human evoked brain potentials and alcohol. Alcohol: Clin. Exp. Res. 5:304–317.
Posner, M.I., and Petersen, S.E. (1990). The attention system of the human brain. Annu. Rev. Neurosci. 13:25–42.
Pritchard, W.S. (1981). Psychophysiology of P300. Psychol. Bull. 89:506–540.
Pujol, A., Pujol, J., Graus, F., Rimola, A., Peri, J., Mercader, J.M., Garcia-Pagan, J.C., Bosch, J., Rodés, J., and Tolosa, E. (1993). Hyperintense globus pallidus on T1-weighted MRI in cirrhotic patients is associated with severity of liver failure. Neurology 43:65–69.
Quero, J.C., Hartmann, I.J., Meulstee, J., Hop, W.C., and Schalm, S.W. (1996). The diagnosis of subclinical hepatic encephalopathy in patients with cirrhosis using neuropsychological tests and automated electroen-cephalogram analysis. Hepatology 24:556–560.
Quero, J.C., and Schalm, S.W. (1996). Subclinical hepatic encephalopathy. Semin. Liver Dis. 16:321–328.
Rehnström, S., Simert, G., Hansson, J.A., Johnson, G., and Vang, J. (1977). Chronic hepatic encephalopathy. A psychometrical study. Scand. J. Gastroenterol. 12:305–311.
Reitan, R.M. (1955). The relation of the trail making test to organic brain damage. J. Consult. Psychol. 19:393–394.
Rikkers, L., Jenko, P., Rudman, D., and Freides, D. (1978). Subclinical hepatic encephalopathy: Detection, prevalence, and relationship to nitrogen metabolism. Gastroenterology 75:462–469.
Ross, B.D., Danielsen, E.R., and Bluml, S. (1996). Proton magnetic resonance spectroscopy: The new gold standard for diagnosis of clinical and subclinical hepatic encephalopathy? Dig. Dis. Sci. 14(Suppl. 1):30–39.
Ross, B.D., Jacobson, S., Villamil, F., Korula, J., Kreis, R., Ernst, T., Shonk, T., and Moats, R.A. (1994). Subclinical hepatic encephalopathy: Proton MR spectroscopic abnormalities. Radiology 193:457–463.
Sagalés, T., Gimeno, V., de la Calzada, M.D., Casellas, F., Dolors Mascià, M., and Villar Soriano, M. (1990). Brain mapping analysis in patients with hepatic encephalopathy. Brain Topogr. 2:221–228.
Sandford, N.L., and Saul, R.E. (1988). Assessment of hepatic encephalopathy with visual evoked potentials compared with conventional methods. Hepatology 8:1094–1098.
Saxena, N., Bhatia, M., Joshi, Y.K., Garg, P.K., Dwivedi, S.N., and Tandon, R.K. (2002). Electrophysiological and neuropsychological tests for the diagnosis of subclinical hepatic encephalopathy and prediction of overt encephalopathy. Liver 22:190–197.
Saxena, N., Bhatia, M., Joshi, Y.K., Garg, P.K., and Tandon, R.K. (2001). Auditory P300 event-related potentials and number connection test for evaluation of subclinical hepatic encephalopathy in patients with cirrhosis of the liver: A follow-up study. J. Gastroenterol. Hepatol. 16:322–327.
Schomerus, H., and Hamster, W. (1998). Neuropsychological aspects of portal–systemic encephalopathy. Metab. Brain Dis. 13:361–377.
Schomerus, H., and Hamster, W. (2001). Quality of life in cirrhotics with minimal hepatic encephalopathy. Metab. Brain Dis. 16:37–41.
Schomerus, H., Hamster, W., Blunck, H., Reinhard, U., Mayer, K., and Dolle, W. (1981). Latent portasystemic encephalopathy. I. Nature of cerebral functional defects and their effect on fitness to drive. Dig. Dis. Sci. 26:622–630.
Srivastava, A., Mehta, R., Rothke, S.P., Rademaker, A.W., and Blei, A.T. (1994). Fitness to drive in patients with cirrhosis and portal–systemic shunting: A pilot study evaluating driving performance. J. Hepatol. 21:1023–1028.
Suzuki, C., Ozaki, I., Tanosaki, M., Suda, T., Baba, M., and Matsunaga, M. (2000). Peripheral and central conduction abnormalities in diabetes mellitus. Neurology 54:1932–1937.
Tarter, R.E., Arria, A.M., Carra, J., and Van Thiel, D.H. (1987a). Memory impairments concomitant with nonalcoholic cirrhosis. Int. J. Neurosci. 32:853–859.
Tarter, R.E., Carra, J., Switala, J., and Van Thiel, D.H. (1987b). Sequential concept formation capacity in subclinical (latent) portal–systemic encephalopathy. Int. J. Neurosci. 32:891–894.
Tarter, R.E., Hegedus, A.M., Van Thiel, D.H., Schade, R.R., Gavaler, J.S., and Starzl, T.E. (1984). Non-alcoholic cirrhosis associated with neuropsychological dysfunction in the absence of overt evidence of hepatic encephalopathy. Gastroenterology 86:1421–1427.
Taylor-Robinson, S.D., Sargentoni, J., Mallalieu, R.J., Bell, J.D., Bryant, D.J., Coutts, G.A., and Morgan, M.Y. (1994). Cerebral phosphorus-31 magnetic resonance spectroscopy in patients with chronic hepatic encephalopathy. Hepatology 20:1173–1178.
Teasdale, G., and Jennett, B. (1974). Assessment of coma and impaired consciousness. A practical scale. Lancet 2:81–84.
Thuluvath, P.J., Edwin, D., Yue, N.C., deVilliers, C., Hochman, S., and Klein, A. (1995). Increased signals seen in globus pallidus in T1-weighted magnetic resonance imaging in cirrhotics are not suggestive of chronic hepatic encephalopathy. Hepatology 21:440–442.
Trzepacz, P.T., Tarter, R.E., Shah, A., Tringali, R., Faett, D.G., and Van Thiel, D.H. (1994). SPECT scan and cognitive findings in subclinical hepatic encephalopathy. J. Neuropsychiatry Clin. Neurosci. 6:170–175.
Van der Rijt, C.C., and Schalm, S.W. (1992). Quantitative EEG analysis and evoked potentials to measure (latent) hepatic encephalopathy. J. Hepatol. 14:141–142.
Van der Rijt, C.C., Schalm, S.W., De Groot, G.H., and de Vlieger, M. (1984). Objective measurement of hepatic encephalopathy by means of automated EEG analysis. Electroencephalogr. Clin. Neurophysiol. 57:423–426.
Victor, M., Adams, R.D., and Cole, M. (1965). The acquired (non Wilsonian) type of chronic hepatocerebral degeneration. Medicine 44:345–396.
Virtaniemi, J., Kuusisto, J., Karjalainen, L., Karjalainen, S., and Laakso, M. (1995). Improvement of metabolic control does not normalize auditory brainstem latencies in subjects with insulin-dependent diabetes mellitus. Am. J. Otolaryngol. 16:172–176.
Weissenborn, K. (1998). Diagnosis of encephalopathy. Digestion 5 9(Suppl. 2):22–24.
Weissenborn, K., Ennen, J.C., Schomerus, H., Rückert, N., and Hecker, H. (2001). Neuopsychological character-ization of hepatic encephalopathy. J. Hepatol. 34:768–773.
Weissenborn, K., Heidenreich, S., Giewekemeyer, K., Rückert, N., and Hecker, H. (2003). Memory function in early hepatic encephalopathy. J. Hepatol. 39:320–325.
Weissenborn, K., Rückert, N., Hecker, H., and Manns, M.P. (1998). The number connection tests A and B: Interindividual variability and use for the assessment of early hepatic encephalopathy. J. Hepatol. 28:646–653.
Weissenborn, K., Scholz, M., Hinrichs, H., Wiltfang, J., Schmidt, F.W., and Kunkel, H. (1990). Neurophysiological assessment of early hepatic encephalopathy. Electroencephalogr. Clin. Neurophysiol. 75:289–295.
Yang, S.S., Wu, C.H., Chiang, T.R., and Chen, D.S. (1998). Somatosensory evoked potentials in subclinical portosystemic encephalopathy: A comparison with psychometric tests. Hepatology 27:357–361.
Yen, C.L., and Liaw, Y.F. (1990). Somatosensory evoked potentials and number connection test in the detection of subclinical hepatic encephalopathy. Hepatogastroenterology 37:332–334.
Zeegen, R., Drinkwater, J.E., and Dawson, A.M. (1970). Method for measuring cerebral dysfunction in patients with liver disease. BMJ 2:633–636.
Zeneroli, M.L., Cioni, G., Vezzelli, C., Grandi, S., Crisi, G., Luzietti, R., and Ventura, E. (1987). Prevalence of brain atrophy in liver cirrhosis patients with chronic persistent encephalopathy. Evaluation by computed tomography. J. Hepatol. 4:283–292.
Zeneroli, M.L., Pinelli, G., Gollini, G., Penne, A., Messori, E., Zani, G., and Ventura, E. (1984). Visual evoked potential: A diagnostic tool for the assessment of hepatic encephalopathy. Gut 25:291–299.
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Amodio, P., Montagnese, S., Gatta, A. et al. Characteristics of Minimal Hepatic Encephalopathy. Metab Brain Dis 19, 253–267 (2004). https://doi.org/10.1023/B:MEBR.0000043975.01841.de
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DOI: https://doi.org/10.1023/B:MEBR.0000043975.01841.de