Baseline QoL Predicts DBS Outcomes in Parkinson Disease With Early Motor Complications

Subjectively-identified impairments in quality of life is the most important predictor of benefit from deep brain stimulation in Parkinson disease with early motor complications.

Subjectively determined impaired quality of life (QoL), as assessed by the 39-item Parkinson Disease Questionnaire summary index (PDQ-39-SI), may be effective for predicting QoL improvements in patients with Parkinson disease (PD) and early motor complications, according to a study published in Neurology.

Investigators from the study performed a secondary analysis of the EARLYSTIM study, which compared subthalamic nucleus deep brain stimulation (STN-DBS; n=124) with best medical treatment (n=127) at 2-year follow-up.

The primary endpoint of the study included disease-specific QOL, as determined by the PDQ-39-SI.

Related Articles

Predictors of change in the PDQ-39-SI were evaluated in analyses adjusted for age, disease duration, duration of motor complications, and disease severity with the Unified Parkinson’s Disease Rating Scale (UPDRS; UPDRS-III, “off” and “on” medications; UPDRS-IV) at baseline.

In a regression model for each treatment, a correlation was found between the baseline PDQ-39-SI value and the change in QoL during the 2-year period (P <.001 for both). A stronger correlation was found in patients in the STN-DBS group vs patients in the medical control group (P =.0262).

According to the UPDRS-III, the change in QoL during follow-up was independent of the severity of parkinsonian motor signs in the condition “off” and “on” medications. In addition, the change in QoL was independent of the severity of levodopa-induced complications and the “off” time.

A limitation of the study includes its highly selected patient population, which may reduce the generalizability of the findings.

“The subjective individual suffering as measured with the PDQ-39-SI should be taken into account as a predictive factor for outcome when selecting patients with early motor complications for STN-DBS,” the researchers concluded.


Schuepbach WMM, Tonder L, Schnitzler A, et al; for the EARLYSTIM study group. Quality of life predicts outcome of deep brain stimulation in early Parkinson disease. Neurology. 2019;92(10):e1109-e1120.