Nerve damage in leprosy-a teased fibre study of sciatic nerves in experimental mice

The extent of nerve damage was assessed in the sciatic nerves of CBA/J mice with experimental leprosy by the teased single fibre preparations. Morphological changes in the fibres were observed upto 15 months of infection and compared with control animals of the same age groups. During 4 to 9 months period, the fibres showed paranodal enlargements, widening of the Schmidt-Lantermann incisures, paranodal and whole segmental demyelination. In addition, fragmentation of axons with the formation of myelin ovoids in the schwann tubes was also observed in animals with 9 to 15 months of infection. While segmental demyelination was predominant early in infection, axonal degeneration was more evident in advanced infection. These findings may possibly, explain the underlying mechanism of nerve damage in human leprosy.