According to a study first published online by Archives of Neurology, patients with Parkinson’s disease (PD) who received implants that stimulate parts of the brain 10 years ago appear to maintain progress in motor function, despite part of the initial benefit deteriorating mostly due to progressive loss of benefit in other functions.

Background knowledge in the study indicates that a number of previous clinical investigations have revealed deep brain stimulation of the subthalamic nucleus (STN-DBS) for PD to be effective and safe. Investigations revealed the procedure, which stimulates a part of the brain involved in motor function, could have benefits in comparison with other medical treatments pertinent to controlling motor complications and improving quality of life.

The authors wrote,

“The motor improvement induced by STN stimulation has been reported to be sustained for up to five to eight years after surgery, although part of the initial benefit progressively deteriorates, mainly because of worsening axial signs. To date, studies with postoperative follow-up for longer than eight years are lacking.”

From the Università degli Studi di Perugia, Perugia, Italy, Anna Castrioto, M.D. and colleagues led a investigation between 1996 and 2000 of 18 patients with advanced PD who had received DBS implants. All motor assessments were videotaped and conducted before implantation and at one, five and ten years. Patients were evaluated without medication, without stimulation, without either and with both. At every evaluation, the investigators recorded each patient’s medications and dosages.

After one decade, the combination of medication and STN-DBS were linked with radically improved motor, resting and action tremor, bradykinesia (slowed movement) and rigidity scores. In comparison with baseline, the scores also displayed reductions in the medication and no medication conditions, the dyskinesia (difficulty controlling movement) and motor fluctuation scores and the levadopa-equivalent daily dose. Axial signs, (such as posture, gait and balance) however displayed a greater advancing decline in stimulation and medication response.

The authors conclude:

“Our findings further support the long-term response to STN stimulation in patients with advanced PD, showing a prolonged motor improvement up to 10 years.”

Written by Petra Rattue