Changes in periodic and isolated leg and neck muscle activity in SWS after VMPJ lesion. An increase in periodic and isolated leg and neck muscle activity in SWS was seen by day 7 and day 3 after VMPJ lesion and continued for the entire 4-months period. The change in the index of periodic leg (PLMI, bottom right) and neck (PNMI, top right) muscle activity, as well as isolated leg (ILMI, bottom left) and neck (INMI, top left) muscle activity reached a plateau level at 14 days after VMPJ lesion. The Y-axis represents the index of INM, PNM, ILM, and PLM.