Laser injury of peripheral nerve: a model for focal endoneurial damage.

A model of endoneurial oedema is presented which produces localised nerve fibre injury including Wallerian degeneration, endoneurial oedema and increased endoneurial fluid pressure. A carbon dioxide laser was used to irradiate rat sciatic nerve and quantitative results were collected 2 days and 6 days after irradiation. The increase in endoneurial fluid pressure is compared with other models of Wallerian degeneration in which the entire fascicle was involved to aid in a comparative study of the role of oedema in neuropathy.