title: Use of ImPACT to diagnose minimal hepatic encephalopathy: an accurate, practical, user-friendly internet-based neuropsychological test battery.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of GI and Liver Diseases, Loma Linda University Medical Center, Loma Linda, CA, USA. mtsushima@hawaii.rr.com
authors.forename: Matthew
authors.initials: M
authors.lastname: Tsushima
authors.forename: William
authors.initials: W
authors.lastname: Tsushima
authors.forename: Vincent
authors.initials: V
authors.lastname: Tsushima
authors.forename: Nelson
authors.initials: N
authors.lastname: Lim
authors.forename: Erika
authors.initials: E
authors.lastname: Madrigal
authors.forename: Christian
authors.initials: C
authors.lastname: Jackson
authors.forename: Michel Henry
authors.initials: MH
authors.lastname: Mendler
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D004522:Educational Status; D005260:Female; D006501:Hepatic Encephalopathy / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D020407:Internet; D008103:Liver Cirrhosis / Q000150:complications* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests