Alterations of Quantitative EEG and Mini-Mental State Examination in Interferon-α-Treated Hepatitis C

Abstract

We have recently observed a diffuse slowing of brain waves using serial quantitative electroencephalographic (qEEG) examinations in interferon (IFN)-α-treated chronic hepatitis C patients. However, it remains unclear how this alteration could be assessed. We evaluated the correlation between the qEEG changes and three tests of mental status, including the Mini-Mental State Examination (MMSE), in such patients. This is the first study to undertake a clinical evaluation of the adverse effects on brain function due to IFN. We undertook blind, prospective and serial qEEG examinations on 56 chronic hepatitis C patients at three independent hospitals. IFN-α was administered intramuscularly at a dose of 9 × 10⁶ IU daily for the first 4 weeks and then 3 times/week for the next 20 weeks. Serial EEGs were obtained before, at 2 and 4 weeks of treatment, and after the IFN-α treatment. The absolute power values of each frequency band in each patient at different stages of treatment were recorded by qEEG. Each patient was assessed by the MMSE, Hamilton Rating Scale for Depression (HSD), and Hamilton Rating Scale for Anxiety (HSA). We statistically evaluated the correlations between the changes in power values and alterations of scores on the mental status tests during IFN-α treatment. The decreased scores observed on the MMSE ranged from 2 to 5 points at both 2 and 4 weeks of IFN-α treatment. There were no significant differences in age distribution for each decreased score on the MMSE. As the alteration in MMSE score during IFN treatment increased, the alteration in absolute power values for the slow waves during IFN treatment increased significantly, while that for the alpha 2 and fast waves during treatment decreased significantly. However, the changes in the HDS and HSA revealed no significant correlations. The alteration of the qEEG was reversible after the treatment. MMSE scores represent one screening method for the clinical assessment of IFN-α-induced alterations of brain function.

Relationship between Quantitative Electroencephalogram and Interferon-α-Induced Depression in Chronic Hepatitis C Patients

“…EEG recordings and qEEG analyses employed in the present study have been described in previous studies [6,7,8,9]. Briefly, EEG recordings (directly after checking for α-blocking) were obtained from each patient during a resting awake condition with their eyes closed.…”

“…Previously, we reported diffuse EEG slowing in patients with IFN-α-treated chronic hepatitis C using quantitative EEG (qEEG) techniques [6]. Additionally, we reported that the qEEG change in IFN-α-treated chronic hepatitis C was related to Mini-Mental State Examination score [7], patient age [8], and the severity of chronic hepatitis C based on liver biopsy [9]. However, no study has assessed the relationship between IFN-induced depression and EEG changes using a quantitative approach.…”

Quantitative Electroencephalographic Analysis in Patients with Chronic Hepatitis C Treated with Interferon-α: A Review Article

“…Although these previous studies assessed the relationship between IFNα treatment in chronic hepatitis C and EEG changes in patients using quantitative EEG (qEEG), the number of patients studied was small. In this review article, we describe (1) qEEG changes in IFNα-treated chronic hepatitis C patients [7], (2) the relationship between qEEG changes and patient age [8], (3) the severity of the disease [9] and (4) the Mini-Mental State Examination (MMSE) [10] score [11], and (5) IFNα-induced depression [12]. These results provide the first evaluation of qEEG findings assessed in a large number of IFNα-treated chronic hepatitis C patients.…”

<b>Cognitive impairment with interferon treatment in patients with chronic hepatitis</b><b> C </b>

“…Other studies have reported that electrophysiological changes, as shown on quantitative electroencephalograms, were associated with cognitive impairment during IFN treatment (7,8,14). Thus electrophysiological assessments may be sensitive to changes in cognitive impairment.…”

“…ment (9,10,12). In addition, it has been suggested that physiological alterations occurring among patients receiving IFN-α treatment are associated with cognitive impairment (8). However, in the Hepatitis C Antiviral Long-term Treatment Against Cirrhosis Trial (HALT-C) study, Fontana et al showed that the frequency of cognitive impairment for patients with CHC did not increase at week 24 compared with baseline, suggesting that the cognitive function of patients with CHC did not worsen with peg IFN and ribavirin retreatment (3).…”