What Do Patients Want from DBS for Parkinson’s Disease?

Patients’ stated goals for undergoing deep brain stimulation (DBS) for Parkinson’s disease (PD) are distinct from standard clinical research measures of DBS efficacy. So concludes a Cleveland Clinic study recently reported in Neurology, which also found these patient-defined goals were well met in the months following DBS surgery. The findings suggest that new and useful outcomes information can potentially be gained by systematically evaluating these patients’ self-defined goals.

“By asking patients up front about their goals for DBS and measuring changes related to those areas months after the procedure, we were able to discern how effective DBS was in meeting goals most important to patients,” says lead author Cynthia Kubu, PhD, ABPP-CN, a neuropsychologist with Cleveland Clinic’s Center for Neurological Restoration. “We found that DBS was even better in addressing the things that patients care most about than the standard measures used to determine DBS effectiveness.”

Study rationale and design

Potential differences between patients’ and physicians’ goals for DBS surgery were an important factor behind the study, Dr. Kubu explains. Such differences were suggested by prior studies in the literature that appeared to show significant disparities between patient satisfaction following DBS and appraisals by treating physicians.

To explore the extent of such differences, Dr. Kubu and colleagues recruited participants from a series of 59 consecutive patients scheduled to undergo DBS for treatment of PD at Cleveland Clinic. The 52 patients who agreed to participate (mean age, 61.3 years; 75 percent male) were asked to provide and rank in order of importance their top three symptom goals and top three behavioral goals for the procedure.

Symptom goal responses were sorted into the following categories: tremor, gait, rigidity, dyskinesias, medication side effects, nonmotor symptoms (e.g., fatigue, pain, sleep problems, psychiatric issues) and other motor symptoms (e.g., on/off fluctuations, bradykinesia, dystonia).

Behavioral goal responses were categorized as social/interpersonal, avocational pursuits, activities of daily living (ADLs), work, driving and “other.”

Patients rated the severity of their symptoms (or greatest limits to participation in their behavioral goals) on a 10-point visual analog scale prior to DBS surgery and at three and six months following surgery. Standard clinical research metrics for PD — i.e., the Parkinson’s Disease Questionnaire-39 and various scores from the Unified Parkinson’s Disease Rating Scale motor subscale (UPDRS-III) — were also collected, which generally focus on motor symptoms (tremor, gait and rigidity).

Key findings

Patients’ most common symptom goals were improvements in tremor, gait and nonmotor symptoms.

Their most common behavioral goals were avocational, followed by social/interpersonal and those related to work and ADLs.

Following DBS surgery, significant improvements were found for patient-identified symptom and behavioral goals as well as for the standard clinical research metrics. Severity ratings for most patient-identified measures were significantly correlated with each other but not with the standard clinical research measures. Effect sizes were especially strong for the UPDRS-III and for patient-identified primary symptom and behavioral goals.

How the study adds to current understanding

Dr. Kubu notes that this study did not find the so-called satisfaction gap between patients and their physicians (by way of the standard clinical metrics) suggested by previous research. She attributes this difference to the fact that the earlier papers were based on isolated cases while the present study was a systematic assessment of a consecutive patient series. She adds that this study is unique in that it assessed quantitative and qualitative measures of patient-identified goals.

While conceding that patients may be more attentive to their own goals and have higher expectations around those that they value most highly, Dr. Kubu says this possibility does not diminish the findings “but instead highlights the importance of understanding patient perspectives.”

Next steps in patient-centered research of DBS for PD

She emphasizes that direct assessment of patient goals and values before embarking on a therapy such as DBS — an elective procedure addressing quality of life — is imperative to help determine whether patient expectations are realistic.

“This study reflects Cleveland Clinic’s core mission of ‘patients first’ as well as the National Academy of Medicine’s manate of patient-centered care,” she says. “The patient perspective should not be the only outcome measured, but not incorporating it is not doing justice to patients.”

Dr. Kubu’s research interests focus on systematically analyzing patient experiences to identify gaps that can be improved in clinical practice. She plans further studies to explore personality changes following DBS from a patient and family perspective, another area in which effects reported in the literature are mixed.