Sodium Bromate中毒後にみられたAcute Uremic Neuropathy患者の回復期における腓腹神経の微細構造

ULTRASTRUCTURAL STUDY OF A BIOPSIED NERVE IN ACUTE UREMIC NEUROPATHY DUE TO SODIUM BROMATE INTOXICATION IN THE CONVALESCENT STAGE

はじめに

　尿毒症に末梢神経障害の合併することが明らかにされたのは比較的近年のことである^1）。

　その病理所見については，Asbury^2），Forno^3）Dayan^4）らの報告があるが，その詳細な検討は数少ない。また電顕的に観察した報告はいまだ見られない。

An electron microscopic study of the biopsied sural nerve of a 22-year-old female with acute renal failure due to sodium bromate intoxication was made in its convalescent stage.

In the light microscopic study, myelinated large fibers were decreased moderately in number, and onion bulb formation and increase of endoneurial nuclei were also observed.

According to the ultrastructural study, myelin sheath is occassionally destructed without any abnormalities of axons, this finding seems to be coincident with segmental demyelination. In addi-tion cavity formations were found in axons of both myelinated and unmyelinated nerve fibers. The ultrastructural study confirmed the presence of an initial phase of onion bulb formation surrounded by only one or two processes of Schwann cells.

As to unmyelinated fibers and Schwann cells, cluster formation by Schwann cells and unmyelinated fibers and spiralling mesoaxons were interpreted as their regenerating courses. At the same time the findings suggesting degeneration, which were re-presented by incomplete mesoaxon formation or extruded unmyelinated axons from Schwann cell processes and degeneration of Schwann cells, were observed.

Osmiophilic rod like structures (0.05μ-0. 2μ in width and 1.1 μ-1.4μ in length), were occasionally observed in Schwann cell cytoplasm, but their origin and meaning are unknown.

Perineurial vessels were surrounded by numerous basement membrane like structures located between endothelial cells and smooth muscle layers. This abnormality is not reported in any toxic neuropathies.

Many cases of ultrastructural study about acute uremic neuropathy must be accumulated in future.