Correlation of single fibre EMG and muscle histochrmistry using an open biopsy recording technique.

Single fibre electromyographic (SFEMG) recordings were carried out during open muscle biopsy. Nine patients were studied, including 5 with Duchenne muscular dystrophy, 2 with spinal muscular atrophy and 1 each with limb-girdle dystrophy and myotonic dystrophy. Correlations were possible between the SFEMG fibre density determinations and histochemical evidence of grouping in some biopsies, particularly involving Type I fibres. This combined technique permits an improved assessment of the functional state of abnormal muscle.