Immunohistochemical studies were performed on muscle biopsy specimens of polymyalgia rheumatica (PMR) to evaluate the extent of muscle and peripheral nerve involvement. The routine histochemistry revealed a mild variation of fiber size, type 2 fiber atrophy and type 2A or 2B fiber deficiency. In 63% of the PMR cases small angular fibers, pyknotic nuclear clumps or target-targetoid fibers were observed, suggesting neurogenic changes, although abnormalities were mild in degree. In immunocytochemical studies, neither major histocompatibility complex (MHC) class 1 nor class 2 products were expressed on the muscle surface membrane of PMR. But regarding intramuscular vessels, MHC class 2 products were distinctly visualized. On serial sections, combined deposits of IgG and Clq in perimysial arteries were seen in 38% of PMR. These results suggest that arteries of small caliber might be involved in immunopathological processes, causing muscle and peripheral nerve damage.

Aged↗

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Progressive bulbar dysfunction caused by a predominantly venous vascular malformation of the medulla oblongata.

We describe a 58-year-old patient with a rare predominantly venous vascular malformation of the medulla oblongata, which caused a progressive bulbar dysfunction consisting of hiccoughs, dysphagia, hoarseness, dysarthria, gait ataxia and dysuria over a period of 11 months. On autopsy, a large dilated vein with focal marked intimal fibroelastic thickening was present on the ventral surface of the medulla. Microscopically, moderate proliferation of capillaries and veins was observed which was confined primarily to the medulla. The veins displayed abnormal dilatation and tortuosity; prominent thickening of vessel walls was also present in the veins and capillaries. The venous abnormalities were prominent in the parenchyma of the medulla, but much less apparent in its subarachnoid space. Multifocal neuronal loss and gliosis were observed, most prominently in the inferior olives, hypoglossal, dorsal vagal and ambiguus nuclei. The histopathologic findings suggested that abnormal venous drainage within the parenchyma of the medulla was the most critical factor for the pathogenesis of this patient's neurologic symptomatology.

Autonomic Nervous System Diseases↗