The diagnosis of subclinical hepatic encephalopathy in patients with cirrhosis using neuropsychological tests and automated electroencephalogram analysis

✍ Scribed by J C Quero; I J Hartmann; J Meulstee; W C Hop; S W Schalm

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 216 KB
• Volume: 24
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.510240316

✦ Synopsis

Hepatic encephalopathy (HE) is a serious complication of Neuropsychological tests used for the assessment of advanced liver disease and refers to neuropsychiatric abnorsubclinical hepatic encephalopathy (SHE) may overdimalities (such as disorders of personality, altered levels of agnose SHE because scores are usually not corrected for consciousness, impairment of intellectual function), and neuage. The aim of this study was to estimate the prevalence romuscular dysfunction (asterixis) because of liver insuffiof SHE using two easy administrable psychometric tests ciency. 1 Traditionally HE is graded into four clinical stages (Number Connection Test part A [NCT-A], Symbol Digit of severity, ranging from abnormal behavior to coma. 2 In ad-Test [SDT]) with age-related normal values. In addition, dition to the clinical grading of HE, a subclinical stage has spectral electroencephalogram (EEG) was used, which been described, in which patients with cirrhosis, regardless of is the in-house electrophysiological method for quantifyits cause, show a number of quantifiable neuropsychological ing encephalopathy.

defects, yet have a normal mental and neurological status on One hundred and thirty-seven consecutive patients global clinical examination. [3][4][5][6][7][8][9][10][11][12][13] The prevalence of this subclin-(mean age 49 years, range 17-77) with cirrhosis without ical hepatic encephalopathy (SHE) has been reported to vary any clinical signs of encephalopathy, were screened for from 30% 13 to 84%, 11 depending on the tests and population SHE. In addition, the Child-Pugh score and the arterial used. blood ammonia were determined. Patients with concur-

The neuropsychological defects found in SHE may have a rent use of alcohol, benzodiazepines or anti-epileptics negative effect on patients' daily life. 6,14 In addition, these were excluded.

defects are considered to be a preclinical stage of clinical Fifty percent of the patients had an abnormal NCT manifest HE. 4,9,15 In view of the reported high incidence of according to the standard recommended procedure, in SHE in patients with cirrhosis and its possible impact on contrast only 7% of the patients had an abnormal NCT daily life, routine assessment of early stages of HE is recomwhen scores corrected for age were used. Combining the mended, 4,6,9,16 as this syndrome may be fully reversible with results of the spectral EEG and the psychometric tests treatment. 4,[17][18][19][20] However, the extensive neuropsychological corrected for age yielded a higher prevalence of SHE test batteries used in most studies (up to 21 different psycho-(23%) than when each test method was used alone (17% metric tests! 9 ), are not suitable for a fast routine screening vs. 10% abnormal, respectively). Severity of liver disease in an outpatient clinic. Conn 21 suggested to use the Number correlated with the presence of SHE, because the preva-Connection Test (NCT) as a sole psychometric test for quantilence of abnormal tests increased from 14% in Childfying HE. Other investigators 4,9,12,13,22 have proposed to use a Pugh grade A to 45% in Child-Pugh grade B or C. Age combination of two to three psychometric tests as a diagnostic above 40 years and an elevated blood ammonia level screen for SHE. As neuropsychological performance is known were significant determinants related to an abnormal to be influenced by age, 23,24 education, 24 and repetitive test-EEG. We conclude that the NCT uncorrected for age ing, 21 several investigators have used neurophysiological markedly overdiagnoses SHE and, therefore, should not tools such as evoked potentials 15,25,26 or quantitative electrobe used as a test for the screening of SHE. Using a combiencephalogram (EEG) analysis 27 for the diagnosis of SHE. nation of spectral EEG and two psychometric tests with However, controversy exists in literature whether these neuage-corrected normal values a low prevalence of SHE rophysiological methods are as sensitive as psychometric in patients with Child A liver cirrhosis is found. Older tests. 28,29 patients with an elevated arterial ammonia are more

The aim of the present study was to determine the prevaprone to develop SHE than younger patients with an lence of neuropsychological and neurophysiological defects equal arterial ammonia concentration. (HEPATOLOGY in stable cirrhotic patients attending a university hospital 1996;24:556-560.) outpatient clinic. Two psychometric tests with age-corrected normal values (NCT part A, 30 Symbol Digit Test 31 ) were selected to be used as a neuropsychological screen. These two tests are easy to administer, have a reported high sensitivity in detecting SHE,