The Deep Brain Stimulation Impairment Scale: A useful complement in assessment of well-being and functioning in DBS-patients - Results from a large multicentre survey in patients with Parkinson's disease

Background: Deep Brain Stimulation (DBS) has been proven to alleviate motor symptoms in Parkinson's Disease (PD). Regarding non-motor symptoms, however, inconsistencies have been reported, on whether DBS causes reductions in well-being and functioning. To assess motor and non-motor impairment in DBS-patients, the Deep Brain Stimulation Impairment Scale (DBS-IS) has been developed. Yet, the extent to which the DBS-IS detects impairment in DBS-patients and thus could serve as a useful tool that complements the PDQ-39 (gold standard) in assessment of well-being and functioning in PD-patients has not been shown. Objectives: By comparing DBS and non-DBS-patients we aimed to identify DBS-specific symptoms. We thereby aimed to show in how far the DBS-IS complements the PDQ-39 in assessing well-being and functioning in PD patients under DBS. Methods: In a cross-sectional study, 186 DBS-patients were matched (for age, disease duration and sex) to 186 non-DBS-patients (N = 372) and the two groups were compared regarding well-being and functioning: Impairment was assessed via DBS-IS and overall Quality of Life (QoL) was assessed via PDQ-39. Additionally, we analyzed differences in impairment between age and disease duration clusters. Results: DBS-patients showed significantly higher total impairment (DBS-IS) and significantly higher impairment on the subscales Postural Instability and Gait difficulties and speaking difficulties than non-DBS-patients. Impairment increased with age and disease duration and, overall, differences in impairment rose by age. Overall QoL (PDQ-39) was non-significantly lower in DBS-patients. Conclusion: Since there is evidence that the PDQ-39 misses some DBS-specific symptoms, the DBS-IS is recom-mended to complement the PDQ-39 when assessing DBS-patients.

Automated summary

By comparing DBS and non-DBS patients, this study found that DBS patients had higher impairment in postural instability, gait difficulties, and speaking difficulties. Age and disease duration were found to affect the level of impairment, with greater differences observed with increasing age. Overall quality of life was lower but not significantly different in DBS patients. Therefore, it is recommended to use the DBS-IS in addition to the PDQ-39 when evaluating DBS patients.