“…The mechanisms underlying these types of LID are not well understood and, given the multiple effects of STN-HFS, it would not be surprising to find that STN-HFS has a direct effect on some types of LID, such as off-period dystonia, as suggested in a clinical study (Krack et al, 1999). By contrast, other types of LID, such as on-period dyskinesia, may be decreased essentially by the decrease in the daily dose of levodopa (Guridi et al, 2008) and still others, such as peak dose dyskinesia, may even increase, depending on stimulation status (Nutt et al, 2001). Thus, the improvement in LID mediated by chronic STN-HFS is probably multifactorial, resulting from both the stabilized functioning of the BG induced by STN-HFS and a decrease in the sensitization phenomenon caused by the chronic intermittent administration of high doses of levodopa (Bejjani et al, 2000).…”