Although the spectrum of side effects of DBS in Parkinson's disease is large these are not very severe and can be prevented/addressed.

Intra-operative: Intraoperative complications are usually due to stimulation of structures close to the target (Subthalamic nucleus/globus pallidus). Occasionally the electrode placement may not be accurate and they can stimulate structures such as internal capsule, thalamus etc. In such cases, the patient can develop facial twitching, numbness, dystonia on OT table. They may also develop psychiatric side effects such as delirium on table.

Immediate post operative: Wound infection is always a risk after DBS and compared to other elective neurosurgical procedures, the post operative wound infection is common in DBS surgeries.

Stimulation related: It includes side effects related to too high stimulations which may result in severe dyskinesia.

Other side effects may include weight gain, euphoria/mania, depression, gait abnormalities. However these adverse effects can be managed by proper programming of the DBS parameters.

Hi Wenchong

Check out the publication by Prof Lynn Rochester (expert in gait and Parkinson's disease) which you may find useful:

Rochester L, Chastin SFM, Lord S, Baker K, Burn DJ. Understanding the impact of deep brain stimulation on ambulatory activity in advanced Parkinson's disease. Journal of Neurology 2012, 259(6), 1081-1086.

Prof Rochester is here in RG if you want to check out her other work.

Dear Zhang,

There are a lot of side effects. Such as for example:

Suicide, worsening of mobility, motor fluctuations, dyskinesia, psychosis or hallucinations, anxiety, impulse control disorder, depression, cardiac disorder, injury, respiratory or thoracic disorder..

Some can also be associated with surgry or device: 

Impaired wound healing, intracerebral abscess or edema, dislocation of device, reoperation necessary..

Dysphonia should not be overlooked, especially in the STN DBS im.plications.

If you want to see this article:

Matias CM1, Mehanna R, Cooper SE, Amit A, Lempka SF, Silva D, Carlotti CG Jr, Butler RS, Machado AG. Correlation among anatomic landmarks, location of subthalamic deep brain stimulation electrodes, stimulation parameters, and side effects during programming monopolar review. Neurosurgery. 2015 Mar;11 Suppl 2:99-108; discussion 108-9. doi: 10.1227/NEU.0000000000000645.

Best Regards,

Dr Mehmet

Dear Zhang,

DBS is available commercially for 30 years. DBS is considered in movement disorders,  epilepsy, and psychiatric patients. Infection in the area of the implantable pulse generator (subcutaneous pouch under clavicle) is a concern. Maximum battery duration is 3 or 4 years, and implant changes increase the risk of infection (1).

Voon et al wrote an interesting review of suicide, mania, and other severe psychiatric side-effects (2), always cited in the literature about DBS.

1 Thrane JF et al. Increasing infection rate in multiple implanted pulse generator changes in movement disorder patients treated with deep brain stimulation. Stereotact Funct Neurosurg. 2014;92(6):360-4. doi: 10.1159/000365576.

2 Voon V et al. Psychiatric considerations in deep brain stimulation for Parkinson's disease. Handb Clin Neurol. 2013;116:147-54.

Thank you very much for all of your kindly help!

Overall if patient and target selection are done properly, DBS is highly effective (OR disks to be considered a part from the surgeon). 

If you are a clinician directly involved in programming the patients, you might be interesse in this one:

Movement disorders induced by deep brain stimulation. Baizabal-Carvallo JF, Jankovic J. Parkinsonism Relat Disord. 2016 Jan 14.

Dear  Mr Zhang,

As you can read in the comments, your question addresses an important subject in the DBS field. As mentioned by others, it is important to realise that the benefits of DBS outweigh the adverse events in most patients, especially after careful selection. For further reading I would recommend another interesting paper focussed on the adverse effects: Patel DM et al. Adverse events associated with deep brain stimulation for movement disorders: analysis of 510 consecutive cases. Neurosurgery. 2015;11 Suppl 2:190-9.

Kind regards

Dear Mr Zhang, 

The above commenters have given great answers. I would also like to add that the therapeutic mechanisms of DBS are not yet fully understood (though there are many good theories). Just last year at the annual Neuromodulation symposium in Minnesota, some of the leading experts in the field were discussing the importance of this question, and how a better understanding of therapeutic pathways could lead to better therapy and less unwanted side-effects. 

Below are some studies looking into DBS side-effects:

Ardouin, C. et al. Acute Psychotropic Effects of Bilateral Subthalamic Nucleus Stimulation and Levodopa in Parkinson ’ s Disease. 18, 524–530 (2003).

Mandat, T. S., Hurwitz, T. & Honey, C. R. Hypomania as an adverse effect of subthalamic nucleus stimulation: report of two cases. Acta Neurochir. (Wien). 148, 895–7; discussion 898 (2006).

Stypulkowski, P. H., Stanslaski, S. R., Denison, T. J. & Giftakis, J. E. Chronic evaluation of a clinical system for deep brain stimulation and recording of neural network activity. Stereotact. Funct. Neurosurg. 91, 220–232 (2013).

Deep brain stimulation involves creating small holes in the skull to implant the electrodes, and surgery to implant the device that contains the batteries under the skin in the chest. Complications of surgery may include:

Bleeding in the brain

Stroke

Infection

Breathing problems

Nausea

Heart problems

Seizures

Possible side effects after surgery

Side effects associated with deep brain stimulation may include:

Seizure

Infection

Headache

Confusion

Stroke

Hardware complications, such as an eroded lead wire

Temporary pain and swelling at the implantation site

A few weeks after the surgery, the device will be turned on and the process of finding the best settings for you begins. Some settings may cause side effects, but these often improve with further adjustments of your device.

Possible side effects of stimulation

Numbness or tingling sensations

Muscle tightness of the face or arm

Speech problems

Balance problems

Lightheadedness

Unwanted mood changes, such as mania and depression

reffer:http://www.mayoclinic.org/tests-procedures/deep-brain-stimulation/details/risks/cmc-20156104