Single fibre EMG findings in polyneuropathies of different aetiology.

Single fibre electromyography was carried out in patients with polyneuropathy due to uraemia, diabetes, and alcohol. In the two former groups the fibre density within the motor unit and the impulse transmission were mainly normal. In the latter group the fibre density was significantly increased as signs of reinnervation. Impulse transmission was impaired in a number of the action potential complexes, which is typical of active reinnervation. The results may indicate that the diabetic and uraemic polyneuropathies are characterized in the main by demyelination, whereas the alcoholic type is dominated by axonal lesion even at an early stage.