EEG patterns and chronic fatigue syndrome

Abstract

This study examined the relationship between EEG recordings of 28 females with Chronic Fatigue Syndrome (CFS) and age matched controls of the same gender. CFS subjects' EEG recordings were also compared to their responses on the Profile of Fatigue Related Symptoms, and two questionnaires developed specifically for this study. EEG electrodes were placed in a monopolar arrangement (active lead at CZ, ground lead in the center of the forehead, and two reference electrodes clipped to the earlobes) according to the international 10–20 system, and impedance was kept below 6 kohms. The data were collected under two conditions: eyes closed and serial sevens (while the subjects silently counted backward from 900 by seven). CFS EEG microvolt levels were significantly higher in the 5–7 Hz range in both conditions and were significantly lower in the 9–11 Hz range during the serial sevens task. In the eyes closed condition, peak alpha (the frequency between 8 to 13 Hz at which the greatest amount of energy was observed) correlated negatively with the “fatigue today” rating and the peak frequency (the frequency between 4 to 20 Hz at which the greatest amount of energy was observed) correlated negatively with the theta to beta ratio and the total fatigue score. During the serial sevens task, peak frequency correlated negatively with the total cognitive difficulty rating. No EEG differences were found between employed and non-employed CFS subjects nor between CFS subjects who were taking antidepressant medications versus those who were not. Subjective symptom ratings and EEG comparisons suggest that CFS symptomology is displayed physiologically in the EEG. Implications are discussed. © 1997, Taylor & Francis Group, LLC.