Furuoka H, Okamoto R, Kitayama S, Asou S, Matsui T, Miyahara K
Department of Veterinary Pathology, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, Japan.
Acta Neuropathol. 1998 Oct;96(4):431-7. doi: 10.1007/s004010050916.
We have previously reported a pathological investigation of peripheral neuropathy in a horse with knuckling. This report describes details of the muscle and peripheral nerve lesions in two additional cases of light horse yearlings with knuckling. The skeletal muscles showed neurogenic atrophy characterized by scattered single angular fibers, fiber grouping, and fiber-type grouping. The severity of muscle lesions increased distally; that is, both fore- and hindleg muscles were affected more severely than cervical and dorsal muscles. In the peripheral nervous system, a number of Renaut bodies appeared to be common in the nerve fascicles. Pathological alterations indicating demyelination, remyelination and regeneration of nerve fibers were occasionally observed. The most common abnormality was myelin ovoids or myelin debris infiltrated by macrophages. Occasionally, myelinated axons were seen containing accumulations of organelles, often associated with buckling of the myelin. The myelin sheath occasionally formed axonal outpouching containing accumulations of mitochondria and dense lamellar bodies. Histochemically, intramuscular nerve fibers presented multiple arborization and collateral ramification, indicating relapsing denervation and reinnervation. Also seen were the fibers with myelin balloons or swollen segments considered as being degenerative processes. The distribution patterns of muscular lesions in the affected animals were indicative of systemic distal denervation atrophy. In addition, peripheral nervous lesions that selectively involve the distal parts of axons and an absence of abnormalities in neuronal cell bodies in the spinal cord suggest a dying-back neuropathy. It was concluded that this disease should be classified as a distal axonopathy.
我们之前报道过一匹患关节屈曲的马的周围神经病变的病理学研究。本报告描述了另外两例轻型一岁马驹患关节屈曲时肌肉和周围神经病变的详细情况。骨骼肌表现为神经源性萎缩，其特征为散在的单个角形纤维、纤维群组化和纤维类型群组化。肌肉病变的严重程度在远端增加；也就是说，前肢和后肢肌肉比颈部和背部肌肉受影响更严重。在周围神经系统中，许多雷诺体似乎在神经束中很常见。偶尔观察到神经纤维脱髓鞘、再髓鞘化和再生的病理改变。最常见的异常是被巨噬细胞浸润的髓鞘卵圆体或髓鞘碎片。偶尔可见有髓轴突含有细胞器聚集，常伴有髓鞘弯曲。髓鞘偶尔形成含有线粒体和致密板层小体聚集的轴突外突。组织化学上，肌内神经纤维呈现多分支和侧支分支，表明反复去神经支配和再支配。还可见到有髓鞘气球或肿胀节段的纤维，被认为是退行性过程。患病动物肌肉病变的分布模式表明为全身性远端去神经萎缩。此外，选择性累及轴突远端部分的周围神经病变以及脊髓神经元细胞体无异常提示为逆行性神经病。结论是这种疾病应归类为远端轴索性神经病。
