Myers R R, Powell H C
Ann Neurol. 1984 Nov;16(5):587-94. doi: 10.1002/ana.410160510.
Peripheral neuropathy induced by galactose feeding results in endoneurial edema with increased tissue pressure and ultimate demyelination of nerve fibers. To assess the role of ischemia in the pathogenesis of this neuropathy, nerve blood flow was measured 6 months after the start of galactose ingestion, between the onset of edema and nerve fiber changes. Measurement was carried out by a noninvasive technique involving the use of [14C]iodoantipyrine as a radioactive tracer of tissue perfusion. A significant decline in nerve blood flow was found, which correlated positively with increased nerve water content as quantified by a microgravimetric technique. We sought to establish the pathogenic role of nerve edema in the development of schwannopathy and demyelination by morphological examination. It was found that Schwann cells appeared normal in areas of the peripheral nervous system in which edema does not occur, such as spinal ganglia and roots, whereas in regions in which there was edema, massive glycogen accumulation in Schwann cells and demyelination occurred. These findings suggest that edema, rather than hyperactivity in the sorbitol pathway, is responsible for the pathological changes in galactosemic neuropathy and that ischemia resulting from edema and increased endoneurial fluid pressure is the mechanism responsible for fiber injury.
由喂食半乳糖引起的周围神经病变会导致神经内膜水肿，组织压力增加，最终神经纤维发生脱髓鞘。为了评估缺血在这种神经病变发病机制中的作用，在摄入半乳糖开始6个月后，即在水肿开始和神经纤维变化之间，测量神经血流。测量采用非侵入性技术，使用[14C]碘安替比林作为组织灌注的放射性示踪剂。结果发现神经血流显著下降，这与通过微量重力技术量化的神经含水量增加呈正相关。我们试图通过形态学检查确定神经水肿在施万细胞病变和脱髓鞘发展中的致病作用。结果发现，在周围神经系统中未发生水肿的区域，如脊神经节和神经根，施万细胞看起来正常，而在有水肿的区域，施万细胞出现大量糖原积累并发生脱髓鞘。这些发现表明，水肿而非山梨醇途径的活性过高是半乳糖血症性神经病变病理变化的原因，并且由水肿和神经内膜液压升高导致的缺血是纤维损伤的机制。
