Author:
L. Kramer and colleagues, Dept. Medicine IV, Univ. Vienna
|
[
Next Thread |
Previous Thread |
Next Message |
Previous Message
]
Date Posted: Sat, November 03 2001, 6:49:58 PST
In reply to:
H. Aaron Aronow,MD Neurology and Internal Medicine USC ..
's message, "Neurological manifestation of HCV" on Sat, May 19 2001, 10:27:06 PDT
Cognitive Brain Function Is Subclinically Impaired In Patients With Chronic Hepatitis C - Does Hepatitis C Affect The Brain?
http://www.medonscene.com/liverdisease/easl2000/
Cognitive Brain Function Is Subclinically Impaired In Patients With Chronic Hepatitis C - Does Hepatitis C Affect
The Brain? Primary author: L. Kramer and colleagues, Department of Medicine IV, University of Vienna, Austria Author interviewed: Petra Steindl-Munda, M.D.
In brief: Non-cirrhotic hepatitis C patients were found to have some subclinical impairment of cerebral function prior to combination therapy with interferon and ribavirin. After 16 weeks of therapy, one measure of cognitive function returned to normal range. Measures of health-related quality of life did not improve.
Besides affecting the liver, hepatitis C is known to affect the central nervous system more frequently than other liver diseases, causing depression and fatigue. Similarly, patients with hepatitis C show greater impairment of health-related quality of life measures than do patients with hepatitis B.
Because no correlation has been found between fatigue and ALT level or histologic severity of hepatitis, people have hypothesized that HCV may directly affect the brain. To examine this possibility, this study aimed to determine whether hepatitis C caused measurable but subclinical cognitive impairment by using a highly sensitive, quantitative measure of brain function. It also sought to determine whether treatment with combination therapy improved cognitive function.
The patient population consisted of 83 non-cirrhotic patients with chronic HCV infection treated at an Austrian hospital. Their mean age was 46 +/- 12 years (same as controls). The clinical diagnosis of HCV was made using serum HCV antibodies in an enzyme-linked immunoassay and confirmed by PCR of HCV RNA in the absence of other causes of liver disease.
The study protocol involved use of the SF-36 questionnaire to measure health-related quality of life. Fatigue was quantified by validated questionnaires. Cognitive processing was measured using P300 event-related potentials, a highly sensitive and objective test of cognitive function that measures the brain's response to an acute audio stimulus. (P300 latency is a measure of processing speed. P300 amplitude reflects the amount of attention given to the stimulus.)
At baseline, patients with HCV showed a slower reaction time and a lower amplitude than a control group of matched, healthy subjects. The results showed a marked prolongation in the P300 latency in hepatitis C patients of 359 milliseconds compared to 338 milliseconds for the control group. Additionally, the amplitude of response was lower in hepatitis C patients compared to the control group, as shown in the chart below.
P300 EVENT-RELATED POTENTIALS HCV PatientsControls Latency (milliseconds)359 +/- 37338 +/-16 Amplitude (microvolts)13 +/- 818 +/- 6
For purposes of comparison, measures of P300 potentials of HCV patients are listed in the table below with the potentials of patients with other diseases (as measured in other experiments). The effect of HCV infection was similar to several other diseases, and latency was worse than in patients with insulin dependent diabetes.
CEREBRAL DYSFUNCTION IN HCV INFECTION vs. OTHER MEDICAL CONDITIONS P300 Latency (milliseconds) P300 Amplitude (microvolts) Mean Age (yrs.) Insulin Dependent Diabetes3421941 HCV Infection3591346 Uremia3861243 Wilson's disease382936 Carotid artery stenosis3961467 COPD3901362
In the second phase of the experiment, hepatitis patients were given a standard regimen of interferon plus ribavirin combination therapy. Twenty patients who started a 38-week course of interferon plus ribavirin combination treatment had their P300 latencies measured at week 16. In that group, the P300 latency was 349 milliseconds in that group of patients returned to normal, to 336 in the majority of patients, according to Petra Steindl-Munda, M.D., one of the study investigators. Dr. Steindl-Munda is Professor of Medicine at the University of Vienna in Austria.
The study concluded that patients with chronic hepatitis C infection exhibit a sub-clinical neurophysiological dysfunction that tended to improve with antiviral combination treatment. But according to the data analyzed to date, no clear correlation emerged between measures of hepatitis activity and neurophysiological dysfunction.
Commentary
"The percentage of people with hepatitis C that complain about fatigue and quality of life is much higher than in other liver diseases," Dr.Steindl-Munda said. "The idea was to see whether there is a correlation between this fatigue and quality of life and [histologic] activity of hepatitis to an objective measurement such as the P300."
Commenting on the limitations of the study, Dr. Steindl-Munda said results were still being collected for the remaining 63 patients who are still under treatment. She noted that the majority of patients who received 16 weeks of antiviral treatment recorded a "normal." P300 latency of 336 [milliseconds]. "This was a significant difference," she said, comparing the scores to those of HCV patients prior to treatment.
More data, she noted, were also needed to see if this finding continues with the larger patient group. Additionally, the researchers will examine whether the P300 potential scores will correlate any better with quality of life measurements. "The results that we have already analyzed did not reveal any correlation between quality of life, prolongation of P300, and activity of hepatitis" she said. "But we will continue and see if there are any correlations that will come out."
Researchers will take P300 measurements at the end of combination therapy (week 38) to compare them to week 16 results. Additionally, the study will look at "whether the non-responder to treatment will return back to normal, or whether there are any changes after the end of therapy," Dr. Steindl-Munda said.
Disclosure
This study was independently funded without contributions from any drug company.
[
Next Thread |
Previous Thread |
Next Message |
Previous Message
]
|
Feedback: 