All other edits I make in LR5 carry over to PS when I use the "Edit In" to move the PS to do additional edits, except edits that I made with the spot removal brush. Why?
Lightroom 5 uses the equivalent of ACR 8.x and the Latest ACR Plugin available for PS CS5 is version 6.7.
When you use the "edit in function" from Lightroom you should be getting a warning dialog that offers the choice of "Render using Lightroom" or "open anyway". If you wish all the edits done in Lightroom you need to choose "render using Lightroom" if you choose "open anyway" then ACR 6.x may not be able to apply all the edits done by Lightroom.
If you do not see the missmatch warning it is because it was turned off in a previous session. From the Lightroom main menu bar go to ""Edit >Preferences >General tab > under Prompts select Reset all warning dialogs""