Table 6 Proportion of reported symptoms in prevalent cases, according to study case definitionsa
Current symptoms | All cases (n = 265) | CDC-1994 (n = 258) | Canadian (n = 142) | ECD (n = 43) | |
|---|---|---|---|---|---|
Sleep dysfunction | Unrefreshing sleep | 97.4 | 97.3 | 100.0 | 97.7 |
| Â | Sleep problems | 84.9 | 85.3 | 94.4 | 73.0 |
Neurological/Cognitive manifestations | Memory/concentration problems | 94.3 | 95.3 | 98.0 | 95.3 |
| Â | Difficulty thinking | 81.5 | 82.0 | 93.0 | 74.4 |
| Â | Unexplained muscle weakness | 75.1 | 74.8 | 88.0 | 70.0 |
| Â | Light/noise sensitivity | 65.7 | 66.0 | 82.4 | 65.1 |
| Â | Difficulty in understanding things | 58.1 | 59.3 | 76.1 | 48.8 |
| Â | Confusion or disorientation | 54.7 | 55.0 | 78.2 | 44.2 |
Pain | Pain in two or more joints | 89.8 | 91.1 | 94.4 | 76.7 |
| Â | Muscle pain | 88.9 | 89.5 | 95.1 | 74.4 |
| Â | Muscle discomfort | 86.8 | 88.0 | 94.4 | 76.7 |
| Â | Migratory joint pain | 75.8 | 76.4 | 85.2 | 53.5 |
| Â | Headaches | 64.5 | 65.5 | 74.6 | 60.5 |
| Â | Migraine | 28.3 | 28.3 | 36.6 | 25.6 |
Fatigue/tiredness | Fatigue after exercise (> 24 hours) | 81.1 | 80.6 | 100.0 | 90.7 |
| Â | Intolerance to exercise | 71.7 | 71.7 | 85.2 | 81.4 |
| Â | Malaise after exertion (> 24 hours) | 69.1 | 69.4 | 85.9 | 86.0 |
Psychological | Anxiety | 70.9 | 72.5 | 83.1 | 39.5 |
| Â | Depression | 55.8 | 56.2 | 67.6 | 11.6 |
Autonomic | Sweatiness/cold hands and feet | 66.4 | 67.4 | 88.0 | 55.8 |
| Â | Intolerance to be on your feet | 61.1 | 60.8 | 79.6 | 55.8 |
Immunological | Sore throat | 57.0 | 56.7 | 71.8 | 60.5 |
| Â | Tender glands in the neck/armpits | 57.0 | 57.7 | 74.6 | 55.8 |
| Â | Mild fever or chills | 52.8 | 52.7 | 75.3 | 46.5 |