Long-term outcome of 50 consecutive Parkinson’s disease patients treated with subthalamic deep brain stimulation.
Wider C, Pollo C, Bloch J, Burkhard PR, Vingerhoets FJ. (2007) Long-term outcome of 50 consecutive Parkinson’s disease patients treated with subthalamic deep brain stimulation. , Parkinsonism Relat Disord. 2007 Sep 5 [Epub ahead of print]
The authors of this study from Switzerland present the long term data (5 year follow-up) of 50 patients with Parkinson’s disease that underwent DBS-STN. It is notable that the patients in this study, as compared to others in the literature, were older (age = 64.9). All patient data was evaluated and 34% of the original 50 patients had died by the five year mark. The causes of death were infection (not directly related to the surgery), cancer, heart attack, embolism, anaphylactic shock, and suicide. All of the patients that died had good motor outcome from their surgery and did not generally differ from the remaining participants. The remaining patients also had improvement with their motor functioning with the stimulator on in the areas of dyskinesias, reduced “off” time, and tremor. Specific details regarding changes (good and bad) were included in the article. The results were less positive in regards to motor testing without medication, suggesting that disease progression continues and that the stimulator may not be as protective as originally thought. For many of the patients, there was also a reduced need for medications throughout the 5 years as compared to what they took prior to the surgery. It is notable that almost 30% of the patients did not take any PD medication after their surgery. The authors found that patients required more stimulation changes immediately after surgery than they did within the five years and the stimulation voltage increased across time. Patients typically had battery changes around 4 years after surgery. Adverse events immediately after the surgery included acute confusion (22%), seizure (2%), and hyperventilation during surgery (2%). Later adverse events were also well documented in the article and included; orthopedic injury (48%; fractures/arthritis; thought to be due to PD vs. the surgery itself), dementia (30%), depression (22%), misplacement of electrodes (8%), infection (8%), and seizure (2%). It should be noted that there was no specific discussion of speech testing or change within this study, which is important as other studies are finding changes in that area. The authors concluded that DBS-STN was beneficial and efficacious in motor testing at the 5 year follow-up but that the disease still progressed and caused patient symptoms to worsen over time. This study is important for patient’s considering as well as have undergone the DBS-STN procedure to allow the PWP to make informed choices about their medical conditions. Studies from the United States will soon be coming up, which will be interesting to see if similar results are found.