The Pathology of Wobbly Hedgehog Syndrome

Abstract

Wobbly hedgehog syndrome (WHS) is a leading cause of neurologic disease in African pygmy hedgehogs (APHs;Atelerix albi-ventris). This study describes the signalment, clinical signs, gross, microscopic, and ultrastructural lesions of WHS in a cohort of 12pet APHs. Microscopically, lesions consisted of status spongiosus of the white matter, typically bilateral and symmetrical, withmyelin degeneration and loss that was accompanied by neuronal/axonal degeneration plus reactive microgliosis and mild, focalastrocytosis and astrogliosis. Lesions were most severe in the cerebellum and medulla oblongata, as well as cervical and thoracicspinal cord. Less affected areas were the corona radiata, corpus callosum, corpus striatum, internal capsule, and the mesence-phalon. Ultrastructurally, the lesions consisted of splitting of the myelin sheath at the intraperiod line with subsequent focalexpansion, resulting in status spongiosus, disruption, dilatation, rhexis, and phagocytosis. Based on these results, WHS is bestdescribed as a “spongy myelinopathy” with widespread central nervous system involvement.