Patients with advanced Parkinson's disease (PD) who have surgery (deep brain stimulation) in addition to the best medical drug treatment have a better overall quality of life and more improvement in mobility and activities of daily living after 1 year than patients who receive the best medical drug treatment alone, according to the self-reported experience of patients. Despite patients who have surgery having a higher risk of serious adverse events, these results show that surgery is an important treatment option that should be offered to those people most likely to benefit, concludes an Article published Online first and in the June edition of The Lancet Neurology.
Recent advances in imaging have improved the accuracy of surgical interventions for PD, and particularly that of deep brain stimulation, in which electrical impulses are delivered into the brain to modulate areas that control movement. Surgery has become a widespread treatment when drug therapy is no longer providing relief from symptoms. However, few good quality randomised trials have compared the effects of surgery with other medical therapies.
To provide more evidence, researchers from the University of Birmingham and other UK colleagues conducted a randomised trial to examine the effects of deep brain stimulation and medical therapy on the lives of people with advanced PD. 366 patients from 13 neurosurgical centres in the UK were randomly assigned to receive surgery and best medical therapy (standard PD drug treatments, including apomorphine where appropriate) or best medical therapy alone. Patients completed self-reported scores on scales measuring quality of life (the 39-item Parkinson's disease questionnaire), functioning (unified Parkinson's disease rating scale), and cognitive status at 1 year after treatment.
Overall, results showed that deep brain stimulation improves quality of life more than medical therapy alone at 1 year (by 5•0 points in the surgery group vs 0•3 points in the medical therapy alone group; difference between groups, —4•7 points).
Additionally, compared with patients in the medical therapy alone group, patients in the surgery group experienced significant improvements in mobility (difference between groups: —8•9 points), activities of daily living (—12•4), and bodily discomfort (—7•5). Surgery also reduced problems with uncontrolled movements (dyskinesia) and off time (time when motor symptoms are not being adequately controlled).
Considerably more patients in the surgery group experienced serious adverse events than in the medical therapy group. 36 surgery patients (19%) had 43 surgery-related serious adverse events, the most common being infection, and one patient died as a result of the procedure. 20 surgery patients and 13 medical therapy patients experienced serious adverse events related to PD and drug treatment, the most common of which was worsening of PD symptoms or uncontrolled PD symptoms.
The authors conclude: "Surgery is likely to remain an important treatment option for patients with PD, especially if the way in which deep brain stimulation exerts its therapeutic benefits is better understood, if its use can be optimised by better electrode placement and settings, and if patients who would have the greatest benefit can be better identified."
In an accompanying Comment, Maria Rodriguez-Oroz from Clinica Universidad de Navarra in Spain says that this trial has advantages over previous studies, such as the larger number of patients and longer follow-up. However, she cautions that the study has some limitations, including that evaluators were not masked to treatment allocation.
Professor Keith Wheatley, University of Birmingham, Birmingham, UK.
T) +44 (0) 121 415 9119 (work)+44 (0)7702 990892 (mobile) E) k.wheatley@bham.ac.uk
Professor Adrian Williams, Queen Elizabeth Hospital, Birmingham, UK.
T) +44 (0) 121 627 2106 E) adrian.williams@uhb.nhs.uk
Ms Natalie Ives, University of Birmingham, Birmingham, UK.
T) +44 (0)121 415 9113 E) n.j.ives@bham.ac.uk
Dr Maria Rodriquez-Oroz, Clinica Universidad de Navarra, Pamplona, Spain.
T) +34 948 255 400 E) mcroroz@unav.es
For full Article and Comment, see: http://press.thelancet.com/tlnpddbs.pdf
Journal
The Lancet Neurology