Potential side effects of deep brain stimulation
Many side effects related to stimulation are transient and can be managed by adjusting the stimulation settings. Several follow-up visits may be necessary in order to find the right stimulation settings to optimize symptom control and minimize side effects.
DBS therapy has been proven to have a well-established long-term safety profile, particularly in younger patients under 70 -75 years. As with any surgery there are some risks associated with the procedure, but these are very low when DBS therapy is performed by an experienced team. For example, the literature indicates that 6 in every 1,000 people (0.6%) might experience a temporary surgical complication (such as a seizure or trauma to the brain tissue), while skin infections can affect 2 in every 100 patients (2%), same as after a total hip replacement . When complications do occur in DBS, they are generally mild, short-lived and normally resolve around 30–90 days after surgery. The risk of permanent health impairments is also low (1.0%), mainly caused by bleeding within the skull. Like with any other treatment, deaths can occur but again the risk is low (0.4%), the same as the risk of death associated with total hip replacement (0.41%),for example.
There seems to be an increased risk of gait disturbances and falls with DBS therapy. However, it is not certain whether DBS therapy increases gait disturbances or fall risk directly, or whether patients are at a higher risk because of the improvement in their overall function and greater activity level. What is clear is that gait, balance and postural stability can improve significantly 6 to 12 months following surgery. In addition, the increased risk of gait disturbances and falls does not seem to have a negative impact on quality of life. Nevertheless, it is essential that all patients are offered physiotherapy to manage any possible gait disturbances, and that they undergo careful assessment by a multidisciplinary team before and after surgery, especially during the first year after the operation.
DBS does not permanently change the thinking or personality of an individual. However, DBS - like antiparkinsonian medication - may have psychiatric side effects, that are more likely to occur in patients, who have been suffering from previous psychiatric conditions due to their Parkinson’s disease or drug treatment. The problems that may occur are emotional disorders, such as depression or mania, confusional states or apathy. They are overall rare and most often transient, if managed appropriately.
Neurologists with experience in DBS should discuss these issues fully with their patients as well as potential risks associated with untreated Parkinson's, anti-Parkinson drugs and other types of therapies. This information will enable patients to balance the potential benefits of DBS therapy against any possible risks, and ensure that they choose the right therapy that will most effectively manage their specific symptoms