Use of ImPACT to Diagnose Minimal Hepatic Encephalopathy: An Accurate, Practical, User-Friendly Internet-Based Neuropsychological Test Battery


Background and Aims

An effective, user-friendly neurocognitive test to diagnose minimal hepatic encephalopathy (MHE) is needed. Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) is a brief, validated, Web-based, neuropsychological test battery resulting in four composite scores [Verbal Memory (VrbM), Visual Memory, Visual Motor Speed (VMS), Reaction Time (RT)]. We compared ImPACT to traditional paper-and-pencil tests in patients at risk for MHE versus controls.


Ninety cirrhotic patients with no history of overt hepatic encephalopathy were compared with 131 controls on standard psychometric tests (SPT) [Trail Making Test-A, Trail Making Test-B, Digit Symbol Test], 4 ImPACT composite scores, and the Sickness Impact Profile (SIP). MHE+ was defined by a score 2 SD below the normative mean on at least one of the SPT. ImPACT (ImP+) scores of patients were defined as 2 SD from the control mean.


Cirrhotic patients scored more poorly than controls on 3/4 of ImPACT scores: VrbM (78.88 vs. 71.37, p < 0.001), VMS (26.47 vs. 22.68, p < 0.001) and RT (0.89 vs. 1.00, p < 0.01), as well as on all 3 SPT. Of the 90 cirrhotics, 16 (18 %) were MHE+, who performed more poorly (p < 0.001) than patients without MHE on VrbM (58.13 vs. 74.19), VMS (16.77 vs. 23.95) and RT (1.24 vs. 0.95). Of the 90 cirrhotics, 25 (27.8 %) were ImP+. MHE+ and ImP+ patients had increased SIP scores versus controls (p < 0.001).


Compared to paper-and-pencil testing, ImPACT provides a brief, user-friendly, neuropsychological evaluation of MHE. ImPACT could become a new standard for MHE diagnosis.

This is a preview of subscription content, log in to check access.



Acculturation rating scale for Mexican Americans-II


Digit symbol test


Immediate post-concussion assessment and cognitive testing


Model of end-stage liver disease


Minimal hepatic encephalopathy


Trail making test-A


Trail making test-B


Overt hepatic encephalopathy


Reaction time


Sickness impact profile


Standard psychometric tests


Visual memory


Visual motor speed


Verbal memory


  1. 1.

    Das A, Dhiman R, Saraswat V, et al. Prevalence and natural history of subclinical hepatic encephalopathy in cirrhosis. J Gastroenterol Hepatol. 2001;16:531–535.

    PubMed  Article  CAS  Google Scholar 

  2. 2.

    Groeneweg M, Moerland W, Quero JC, et al. Screening of subclinical hepatic encephalopathy. J Hepatol. 2000;32:748–753.

    PubMed  Article  CAS  Google Scholar 

  3. 3.

    Groeneweg M, Quero JC, De Bruj I, et al. Subclinical hepatic encephalopathy impairs daily functioning. Hepatology. 1998;28:45–49.

    PubMed  Article  CAS  Google Scholar 

  4. 4.

    Schomerus H, Hamster W. Quality of life in cirrhotics with minimal hepatic encephalopathy. Metab Brain Dis. 2001;16:37–41.

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Prasad S, Dhiman RK, Duseja A, et al. Lactulose improves cognitive functions and health-related quality of life in patients with cirrhosis who have minimal hepatic encephalopathy. Hepatology. 2007;45:549–559.

    PubMed  Article  Google Scholar 

  6. 6.

    Bao ZJ, Qui DK, Ma X, et al. Assessment of health-related quality of life in Chinese patients with minimal hepatic encephalopathy. World J Gastroenterol. 2007;13:3003–3008.

    PubMed  Google Scholar 

  7. 7.

    Wein C, Koch H, Popp B, et al. Minimal hepatic encephalopathy impairs fitness to drive. Hepatology. 2004;39:739–745.

    PubMed  Article  Google Scholar 

  8. 8.

    Bajaj JS, Hafeezullah M, Hoffmann RG, et al. Minimal hepatic encephalopathy: a vehicle for accidents and traffic violations. Am J Gastroenterol. 2007;102:1903–1909.

    PubMed  Article  Google Scholar 

  9. 9.

    Bajaj JS, Saeian K, Schubert CM, et al. Minimal hepatic encephalopathy is associated with motor vehicle crashes: the reality beyond the driving test. Hepatology. 2009;50:1175–1183.

    PubMed  Article  Google Scholar 

  10. 10.

    Romero-Gomez M, Boza F, Garcia-Valdecassas M, et al. Subclinical hepatic encephalopathy predicts the development of overt hepatic encephalopathy. Am J Gastroenterol. 2001;96:2718–2723.

    PubMed  CAS  Google Scholar 

  11. 11.

    Dhiman RK, Kurmi R, Thumburu KK, et al. Diagnosis and prognostic significance of minimal hepatic encephalopathy in patients with cirrhosis of liver. Dig Dis Sci. 2010;55:2381–2390.

    PubMed  Article  Google Scholar 

  12. 12.

    McCrea M, Cordoba J, Vessey G, et al. Neuropsychological characterization and detection of subclinical hepatic encephalopathy. Arch Neurol. 1996;53:758–763.

    PubMed  Article  CAS  Google Scholar 

  13. 13.

    Weissenborn K, Ennen JC, Schomerus H, et al. Neuropsychological characterization of hepatic encephalopathy. J Hepatol. 2001;34:768–773.

    PubMed  Article  CAS  Google Scholar 

  14. 14.

    Randolph C, Hilsabeck R, Kato A, et al. Neuropsychological assessment of hepatic encephalopathy: ISHEN practice guidelines. Liver Int. 2009;29:629–635.

    PubMed  Article  Google Scholar 

  15. 15.

    Crook TH, Kay GG, Larrabee GJ. Computer-based cognitive testing. In: Grant I, Adams KM, eds. Neuropsychological assessment of neuropsychiatric and neuromedical disorders. 3rd ed. New York: Oxford University Press; 2009:84–100.

    Google Scholar 

  16. 16.

    Bajaj JS, Saeian K, Verber MD, et al. Inhibitory control test is a simple method to diagnose minimal hepatic encephalopathy and predict development of overt hepatic encephalopathy. Am J Gastroenterol. 2007;102:754–760.

    PubMed  Article  Google Scholar 

  17. 17.

    Bajaj JS, Hafeezullah M, Franco J, et al. Inhibitory control test for the diagnosis of minimal hepatic encephalopathy. Gastroenterology. 2008;135:1591–1600.

    PubMed  Article  Google Scholar 

  18. 18.

    Mardini H, Saxby BK, Record CO. Computerized psychometric testing in minimal encephalopathy and modulation by nitrogen challenge and liver transplant. Gastroenterology. 2008;135:1582–1590.

    PubMed  Article  Google Scholar 

  19. 19.

    Lovell MR, Collins MW, Podell K, et al. Immediate Post-Concussion Assessment and Cognitive Testing. Pittsburgh, PA: NeuroHealth Systems, LLC; 2000.

    Google Scholar 

  20. 20.

    Schatz P, Pardini JE, Lovell MR, et al. Sensitivity and specificity of the ImPACT test battery for concussion in athletes. Arch Clin Neuropsychol. 2006;21:91–99.

    PubMed  Article  Google Scholar 

  21. 21.

    Ferenci P, Lockwood A, Mullen K, et al. Hepatic encephalopathy-definition, nomenclature, diagnosis, and quantification: final report of the Working Party at the 11th World Congresses of Gastroenterology, Vienna, 1998. J Hepatol. 2002;35:716–721.

    Article  Google Scholar 

  22. 22.

    Lovell MR. The ImPACT neuropsychological test battery. In: Echemendia RJ, ed. Sports Neuropsychology: Assessment and Management of Traumatic Brain Injury. New York: The Guilford Press; 2006:193–215.

  23. 23.

    Bergner M, Bobbitt RA, Cartner WB, et al. The sickness impact profile: development and final revision of a health status measure. Med Care. 1981;19:787–805.

    PubMed  Article  CAS  Google Scholar 

  24. 24.

    Dikmen S, McLean A, Temkin N. Neuropsychological and psychosocial consequences of minor head injury. J Neurol Neurosurg Psychiatry. 1986;49:1227–1232.

    PubMed  Article  CAS  Google Scholar 

  25. 25.

    Weissenborn K, Ruckert N, Hecker H, et al. The number connection tests A and B: interindividual variability and use for the assessment of early hepatic encephalopathy. J Hepat. 1998;28:641–653.

    Article  Google Scholar 

  26. 26.

    Wechsler D. Wechsler Adult Intelligence Scale-III. San Antonio, TX: Psychological Corporation; 1999.

    Google Scholar 

  27. 27.

    Ortiz M, Jacas C, Cordoba J. Minimal hepatic encephalopathy: diagnosis, clinical significance and recommendations. J Hepatol. 2005;42:S45–S53.

    PubMed  Article  Google Scholar 

  28. 28.

    Tan HH, Lee GH, Thia KTJ, et al. Minimal hepatic encephalopathy runs a fluctuating course: results from a three-year prospective cohort follow-up study. Singap Med J. 2009;50:255–260.

    CAS  Google Scholar 

  29. 29.

    Cuéllar I, Arnold B, Maldonado R. Acculturation rating scale for Mexican Americans-II: a revision of the original ARSMA scale. Hisp J Behav Sci. 1995;17:275–304.

    Article  Google Scholar 

  30. 30.

    Bianchini LJ, Greve KW, Glynn G. On the diagnosis of pain-related disability: lessons from cognitive malingering research. Spine J. 2005;5:404–417.

    PubMed  Article  Google Scholar 

  31. 31.

    Covassin T, Elbin RJ III, Stiller-Ostrowski JL, et al. Immediate post-concussion assessment and cognitive testing (ImPACT) practices of sports medicine professionals. J Athl Train. 2009;44:639–644.

    PubMed  Article  Google Scholar 

  32. 32.

    Bajaj JS, Estemadian A, Hafeezullah M, et al. Testing for minimal hepatic encephalopathy in the United States: an AASLD survey. Hepatology. 2007;45:833–834.

    PubMed  Article  Google Scholar 

  33. 33.

    Schatz P, Browndyke J. Applications of computer-based neuropsychological assessment. J Head Trauma Rehabil. 2002;17:395–410.

    PubMed  Article  Google Scholar 

  34. 34.

    Iduru S, Mullen KD. The demise of the pencil? New computer-assisted tests for minimal hepatic encephalopathy. Gastroenterology. 2008;135:1455–1456.

    PubMed  Article  Google Scholar 

  35. 35.

    Iverson GL, Lovell MR, Collins MW. The ImPACT test. Pittsburgh, PA: Authors; 2003.

    Google Scholar 

  36. 36.

    Llorente A, ed. Principles of Neuropsychological Assessment with Hispanics. Theoretical Foundations and Clinical Practice. New York: Springer; 2008.

    Google Scholar 

  37. 37.

    Tarter RE, Van Thiel DH. Neuropsychological dysfunction due to liver disease. In: Tarter RE, Butters M, Beers SR, eds. Medical Neuropsychology (2nd ed.). New York: Kluwer Academics/Plenum Publishers; 2001.

  38. 38.

    Weissenborn K, Heidenreich S, Giewekemeyer K, et al. Memory function in early hepatic encephalopathy. J Hepatol. 2003;39:320–325.

    PubMed  Article  Google Scholar 

  39. 39.

    Watanabe A, Sakai T, Sato S, et al. Clinical efficacy of lactulose in cirrhotic patients with and without subclinical hepatic encephalopathy. Hepatology. 1997;26:1410–1414.

    PubMed  Article  CAS  Google Scholar 

  40. 40.

    Dhiman RK, Sawhney I, Chawla Y, et al. Efficacy of lactulose in cirrhotic patients with subclinical hepatic encephalopathy. Dig Dis Sci. 2000;45:1549–1552.

    PubMed  Article  CAS  Google Scholar 

  41. 41.

    Liu Q, Duan ZP, Ha DK, et al. Symbiotic modulation of gut flora: effect on minimal hepatic encephalopathy in patients with cirrhosis. Hepatology. 2004;39:1441–1449.

    PubMed  Article  Google Scholar 

  42. 42.

    Malaguarnera M, Greco F, Barone G, et al. Bifidobacterium longum with fructo-oligosaccharide (FOS) treatment in minimal hepatic encephalopathy: a randomized, double-blind, placebo-controlled study. Dig Dis Sci. 2007;52:3259–3265.

    PubMed  Article  Google Scholar 

  43. 43.

    Sharma P, Sharma B, Puri V, et al. An open-label randomized controlled trial of lactulose and probiotics in the treatment of minimal hepatic encephalopathy. Eur J Gastroenterol Hepatol. 2008;20:506–511.

    PubMed  Article  CAS  Google Scholar 

  44. 44.

    Bajaj JS, Saeian K, Christensen K, et al. Probiotic yogurt for the treatment of minimal hepatic encephalopathy. Am J Gastroenterol. 2008;103:1707–1715.

    PubMed  Article  Google Scholar 

Download references


Investigator-initiated research grant from Salix Pharmaceuticals. Salix was not involved in protocol design and implementation, data collection, analysis, or interpretation of the study results.

Conflict of interest


Author information



Corresponding author

Correspondence to Michel Henry Mendler.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Tsushima, M., Tsushima, W., Tsushima, V. et al. Use of ImPACT to Diagnose Minimal Hepatic Encephalopathy: An Accurate, Practical, User-Friendly Internet-Based Neuropsychological Test Battery. Dig Dis Sci 58, 2673–2681 (2013).

Download citation


  • Cirrhosis
  • Minimal hepatic encephalopathy
  • ImPACT
  • Computer testing
  • Sickness impact profile