Cactus spike-like protrusions found extending outward from the surface of the dendrite or cell body of Purkinje cells are called “cactus” formations. Changes such as this have been described in Menkes kinky hair disease and generally represent changes of Purkinje cells that exhibit degeneration and loss of cerebellar granule cells. They appear as short, light-colored, dendritic formations with H&E staining and are more clearly visualized with Bodian silver staining.
