Clinical and laboratory characteristics of the patients
| Patient No | |||||||
|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
| ND, not determined; −, negative or not present; +, present. EMG, electromyography; ESR, erythrocyte sedimentation rate; F, female; M, male; Myopathic, myopathic EMG with brief, small amplitude, polyphasic motor unit potentials; sp act, spontaneous activity at rest, including fibrillations and positive sharp waves. | |||||||
| Clinical features | |||||||
| Age at onset (years) | 32 | 35 | 48 | 46 | 39 | 70 | 66 |
| Sex | M | F | F | M | F | F | F |
| Weakness | |||||||
| Proximal > distal | + | + | + | + | + | + | + |
| Arms + legs | + | + | + | + | + | + | + |
| Maximum severity (% of normal strength) | 0% | 20% | 0% | 0% | 0% | 20% | 0% |
| Time to maximum severity (months) | 5 | 12 | 3 | 8 | 4 | 2 | 2 |
| Season of onset of weakness | Autumn | Autumn | Summer (August) | Autumn | Winter (January) | Autumn | Autumn |
| Muscle pain | + | + | − | + | − | − | + |
| Fatigue | + | + | + | + | + | − | − |
| Dysphagia | − | + | − | − | − | + | + |
| Skin rash | − | − | − | − | − | + | − |
| Dyspnoea | + | − | − | − | − | − | + |
| Palpitations | − | − | − | − | − | − | − |
| Weight loss | + | − | − | + | − | − | + |
| Steroid response | − | + | + | + | + | + | + |
| Laboratory data | |||||||
| Creatine kinase (maximum) (IU/l) | 6204 | 3064 | 24 972 | 8940 | 7406 | 25 000 | 15 034 |
| Aldolase (IU/l) | 55 | ND | ND | ND | 28.5 | 23 | 174 |
| ESR (mm/h) | 42 | 19 | 38 | 12 | 40 | 34 | 1 |
| Antinuclear antibody | − | − | − | − | − | 1:160 | − |
| EMG | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act |