Subthamalmic nucleus vs. globus pallidus interna deep brain stimulation, the rematch: will pallidal deep brain stimulation make a triumphant return
Archives of Neurology
Okun MS, Foote KD Subthamalmic nucleus vs. globus pallidus interna deep brain stimulation, the rematch: will pallidal deep brain stimulation make a triumphant return Archives of Neurology, 2005 Apr;62(4):554-60
This is an editorial by Okun et al., in response to the recently reviewed article (see Outcomes of DBS June on the DBS-STN website) by Anderson et al. (2005). These authors overview the treatment of PD and tremors from the very beginning (1909) up to current treatments. They also reviewed the results reported by Anderson et. al (2005). They discuss that there is a significant size difference between the GPi and STN (GPi>STN). Due to the size differences stimulation of the GPi requires a higher charge than the STN. They discuss the benefits as well as possible adverse events associated with the size of the stimulation target. They noted that both GPi and STN stimulation reduce dyskinesia and dystonia but may do so by different mechanisms. Both GPi and STN DBS also improve other features of Parkinson’s (tremor, rigidity, bradykinesia, and gait disturbances) but they added that the studies that have looked at these features have methodological differences and in some instances it is relatively unknown why there is a difference between the two sites and levels of improvement. They also discuss the differences in medication reduction between the two DBS sites. Interestingly, there are few studies that discuss the cognitive, behavioral, and mood symptom changes between DBS-GPi and STN, which may be the information that patients are most interested in, outside of general motor improvement. The authors also point out several important areas that need to be addressed with clinical trials that look at DBS-STN vs. DBS-GPi (e.g. electrode placement, technique, equipment, microelectrode recording, and patient selection criteria). The authors also discuss the risk-benefit ratio that will be important for patients as well as physicians to make informed decisions about DBS-GPi or DBS-STN. The general take home point from this editorial is that there isn’t a lot of clinical data comparing GPi vs. STN and that we need to do more controlled research to evaluate which type of stimulation has the best motor improvement with the least adverse effects. They note that it is too early to tell which method is the best but suggest that physicians should be open to upcoming changes and the possibility that the best choice may be based on individual patient needs combined with the strengths and weaknesses of individual targets.