Table 3.

Histopathological and histochemical findings from Congenital Tremor (CT) cases.

Country	Histopathological and histochemical findings	References
Germany	No significant findings in the central and peripheral nervous system, as well as skeletal muscles. Luxol fast blue staining revealed mildly reduced staining intensity accentuated in the lateral white matter of the spinal cord	(15)
Austria	Vacuoles in cerebellar white matter; moderate hypomyelination in the white matter of the cerebellum and thoracic spinal cord; detection of oligodendrocytes; and increased staining intensity	(3)
Brazil	Moderate vacuolization of the white matter of the cerebellum and brain stem. Luxol fast blue staining did not reveal a decrease in the amount of myelin in the cerebellum; however, mild myelin loss was noted in the white matter found in the spinal cord and sciatic nerve	(24)
Brazil	Luxol fast blue staining revealed evidence of myelin vacuolization with the formation of digestion chambers. These chambers were of different sizes, observed in the white matter of the cerebellum, brainstem, and spinal cord. Severe secondary demyelination, with either a complete absence or an inadequate amount of myelin, in areas in both the white and gray matter of the spinal cord and brainstem, with mild secondary demyelination in the cerebellum	(25)
China	No significant findings	(30)
Canada	Luxol fast blue staining revealed an important loss of myelin from the periphery of the thoracic spinal cord, more severe in the lateral and ventral funiculi	(26)
Brazil	Neuronal necrosis, gliosis, and neuronophagia with satellitosis particularly at the cerebral cortex and to a lesser extent at the spinal cord, white matter demyelination of the cerebrum and spinal cord, Wallerian degeneration of the spinal cord, and necrosis of Purkinje cells of the cerebellum. The immunohistochemistry revealed proliferation of glial fibrillary acidic protein (GFAP) cells and fibers were more severe and widespread in piglets infected by APPV	(36)