Parkinson’s disease patients given deep brain stimulation witnessed a boost in driving proficiency, at times performing better than people without the neurological disease, according to a new study in the journal Neurology.

Deep brain stimulation (DBS) is a surgical procedure that aims to mimic the brain cells lost during Parkinson’s. A battery-powered electrode implanted in the damaged brain feeds pulses of electricity into remaining tissue. DBS only works for a subset of patients, namely ones without dementia, but when successful, it masks the debilitating symptoms of the disease for an extended period of time.

Example of a DBS success story
(Courtesy of Mount Sinai Hospital)

Driving joins a list of benefits seen with DBS therapy for Parkinson’s disease, which affects 7 million people worldwide.

"Up until now, we weren't sure how deep brain stimulation would affect driving," said study author Dr. Carsten Buhmann of University Medical Center Hamburg-Eppendorf in Hamburg, Germany. "On the one hand, it might enhance driving ability by improving the motor problems which occur with Parkinson's disease, but on the other hand, it might hamper driving because it potentially causes a decline in executive cognitive skills."

Buhmann and his colleagues had three groups of 20 individuals jump into a virtual driving simulator that mimicked a regular automatic car.

Two groups consisted of Parkinson’s patients, expect one was receiving deep brain stimulation, while the other did not. People without the disease made up the third group. Anytime a subject made a driving error in the simulator, the researchers made a note of it. Errors fell into three catergories: slight (ex. driving too slow), moderate (ex. false turning), and severe (ex. ignoring a stop sign or red light). Mistakes were judged by an official driving instructor.

Patients treated with DBS made fewer errors overall, with major difference in the number of slight errors. Indeed, they made fewer slight errors than those without the disease. Those with DBS averaged 3.8 slight driving errors, while controls and patients without DBS made 7.5 and 11.4 mistakes on average, respectively.

Further analysis showed that patients were better drivers with DBS compared to those only taking levodopa, the standard medication for Parkinson’s disease.

“In conclusion, regaining a better driving ability in Parkinson’s disease might be one aspect of improved quality of life with DBS in comparison to medical treatment alone,” the authors write. “Based on our data, we suggest handling driving permission for DBS-treated patients with Parkinson’s disease not more restrictively than permissions for patients with PD in general.”

Source: Buhmann C, Lea Maintz L, Hierling J, Vettorazzi E, et al. Effect of subthalamic nucleus deep brain stimulation on driving in Parkinson disease. Neurology. 2013.