Can the NuFace Microcurrent hand held device be used on areas that have been injected with botox?

Is it necessary to avoid areas that were injected with botox (specifically, crow's feet & wrinkle between brows) when using the NuFace Microcurrent device? It seems that toning or stimulating these wrinkle producing muscles after they have been paralyzed with botox would be counter productive and certainly not cost effective. Thanks