Differential diagnosis of limb girdle syndromes

The term limb girdle syndrome includes a variety of neuromuscular disorders like the scapulohumeral and pelvifemoral types of muscular dystrophy, quadriceps myopathy and Wohlfart-Kugelberg-Welander syndrome. There may be considerable difficulty in distinguishing between different types of limb girdle syndrome, even with the aid of electromyographic and muscle biopsy examinations. The aim of this investigation was to reestablish the clues for distinguishing between different types of limb girdle syndrome. Fifty-four patients with limb girdle syndromes took part in this investigation. They were subdivided into two groups according to EMG and muscle biopsy data. The first group consisted of 39 patients with limb-girdle type of muscular dystrophy and the second group consisted of 15 patients with juvenile type of spinal muscular atrophy. Our results revealed that neurological examination was not enough to distinguish the different types of limb girdle syndrome. The most important electromyographic findings in patients with muscular atrophy are the neurogenic action potentials and fasciculations. Fibrillations, positive sharp waves and bizzare discharges may be found also in some patients with muscular dystrophy. Myogenic action potentials are found in some patients with muscular atrophy and so may cause confusion. Muscle biopsy may also reveal some myogenic features in patients with muscular atrophy. In conclusion electromyography and muscle biopsy are useful in the differentiation of different types of limb girdle syndrome, as well as, in determining the exact pattern of muscle involvement.