VIENNA — The same brief, Web-based neuropsychologic test used by all National Football League teams to assess players for the effects of concussion appears to be advantageous for the diagnosis of minimal hepatic encephalopathy.
The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT v4.0) is a well-validated, computer-based neuropsychologic test that takes about 10 minutes. It's available in 13 languages, can be administered by anybody in the office, and produces immediate results without need of a clinical neuropsychologist to interpret the scores, Dr. Michel H. Mendler explained at the congress, sponsored by the European Association for the Study of the Liver.
“ImPACT could become a new standard for minimal hepatic encephalopathy testing, both in routine clinical practice and to evaluate treatments,” said Dr. Mendler, a gastroenterologist at Loma Linda (Calif.) University.
Minimal hepatic encephalopathy (MHE) is a greatly underdiagnosed neurocognitive disorder present in 60%-80% of patients with cirrhosis. It results in impaired quality of life, increased work disability, and impaired driving. If unchecked, MHE can progress to overt hepatic encephalopathy, a more serious neuropsychiatric syndrome characterized by cognitive and motor deficits that often require hospitalization.
MHE includes deficits in mental processing speed, fine motor skills, memory, complex attention, constructive abilities, and visual-spatial orientation. These deficits are subtle and require neuropsychologic testing for diagnosis.
Conventional neuropsychologic testing is complex, lengthy, and requires interpretation by a specialist Dr. Mendler said. A widely used alternative is paper-and-pencil testing using several psychometric tests, such as Digit Symbol and Number Connection tests A and B. But the results of these tests are confounded by the substantial practice effect with repeated testing.
In contrast, ImPACT (www.impacttest.com
He compared ImPACT with paper-and-pencil testing in 90 cirrhotic patients with no history of overt hepatic encephalopathy and 131 matched healthy controls. ImPACT scores identified 25 of 90 cirrhosis patients as having abnormal results consistent with MHE; paper-and-pencil testing identified 16, only 10 of whom were also ImPACT-positive.
In addition, ImPACT identified 12 of 74 paper-and-pencil test-negative patients as having MHE. Seven of 131 healthy controls were ImPACT-positive, a significantly lower false-positive rate than with paper-and-pencil testing, which was positive in 19 controls.
In a separate study presented at the congress, Dr. Arun Sanyal reported that the severity of chronic cognitive impairment is cumulative with the number of acute episodes of overt hepatic encephalopathy (OHE), underscoring the importance of early detection, prompt treatment, and preventive therapy.
Fifty cirrhosis patients were followed for a mean of 13 months after their first hospitalization for OHE. The severity of their deficits in working memory, attention, psychomotor speed, and response inhibition was highly correlated with the number of OHE episodes.
The implication is that the metabolic derangements that cause OHE might also induce chronic neurologic injuries that aren't readily reversible, according to Dr. Sanyal, professor of medicine and chairman of the division of gastroenterology, hepatology, and nutrition at Virginia Commonwealth University, Richmond.
Disclosures: Dr. Mendler's study was funded by a research grant from Salix Pharmaceuticals Ltd. He has no other financial relationship with the company nor any financial interest in the ImPACT test. Dr. Sanyal is a consultant to Salix.
Cognitive impairment is cumulative with the number of acute episodes of overt hepatic encephalopathy.
Source DR. SANYAL