Teased fibre studies in leprous neuropathy.

Nerve biopsies were taken from four cases of leprosy, which included borderline tuberculoid, borderline and lepromatous types. They were examined in 1-micron resin sections and in teased preparations. The most common finding in teased fibres from each leprosy type was paranodal demyelination affecting successive internodes. In transverse sections some fibres showed changes associated with axonal atrophy. Together, these findings suggest that demyelination in some cases may be secondary to axonal changes. In addition, there was evidence of focal areas of demyelination affecting whole internodes of many fibres at the same level across the nerve and which was possibly caused by local factors.