Development and validation of the deep brain stimulation impairment scale (DBS-IS)

Franziska Maier; Catharine J Lewis; Carsten Eggers; Andrea A Kühn; Henriette Krug; Jens Volkmann; Anna D Kirsch; Lars Wojtecki; Alfons Schnitzler; Günther Deuschl; Joachim K Krauss; Christiane Woopen; Lars Timmermann

doi:10.1016/j.parkreldis.2017.01.002

Development and validation of the deep brain stimulation impairment scale (DBS-IS)

Parkinsonism Relat Disord. 2017 Mar:36:69-75. doi: 10.1016/j.parkreldis.2017.01.002. Epub 2017 Jan 6.

Authors

Affiliations

¹ Department of Neurology, University of Cologne, Cologne, Germany. Electronic address: franziska.maier@uk-koeln.de.
² Department of Neurology, University of Cologne, Cologne, Germany.
³ Department of Neurology, Movement Disorders Unit, Charité - University Medicine (CVK), Berlin, Germany.
⁴ Department of Neurology, University of Wuerzburg, Wuerzburg, Germany.
⁵ Department of Neurology, Movement Disorders and Neuromodulation, University Clinic Duesseldorf, Duesseldorf, Germany.
⁶ Department of Neurology, Christian-Albrecht-University, Kiel, Germany.
⁷ Department of Neurosurgery, Medical School Hannover, Hannover, Germany.
⁸ Research Unit Ethics, Institute for the History of Medicine and Medical Ethics, University of Cologne, Cologne, Germany.

PMID: 28089264
DOI: 10.1016/j.parkreldis.2017.01.002

Abstract

Background: Bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) has considerable influence on motor and non-motor symptoms in Parkinson's disease (PD). While improvements in motor functioning can be easily assessed with general quality of life questionnaires, the measurement of specific STN-DBS-associated impairments often remains insufficient. Hence, we aimed to develop a questionnaire that measures STN-DBS-related impairments.

Methods: The development of the (STN-)DBS Impairment Scale (DBS-IS) consisted of four steps. First, 30 semi-structured interviews before, three and twelve months after STN-DBS-surgery were performed to create 76 items that relate to motor and non-motor functioning in STN-DBS PD patients. Second, pilot-testing led to a rewording of the questions for better understanding. Third, a first multicentre survey was performed to reduce items by applying principal component analysis (PCA). Fourth, a second multicentre survey was conducted to examine factor structure, reliability (internal consistency) and validity.

Results: After the first survey (N = 215), the PCA lead to a reduction of 54 items. After the second survey (N = 391), exploratory factor analysis determined six factors with 22 items: 1. Postural instability and gait difficulties (5 items), 2. Cognitive impairment (5 items), 3. Speaking problems (3 items), 4. Apathy (3 items), 5. Impulsivity (3 items), and 6. Difficulties related to the DBS device (3 items). High reliability was reported for all subscales (Cronbach's alpha 0.71-0.90). Similarly, construct validity was high (r > 0.50, p < 0.001).

Conclusions: With this new questionnaire patients can be followed-up and STN-DBS-specific problems might be adequately measured. Also, comparisons between patients with and without STN-DBS might be possible.

Keywords: Deep brain stimulation; Factor analysis; Parkinson's disease; Patient outcome; Quality of life.

Publication types

Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Aged, 80 and over
Deep Brain Stimulation / adverse effects*
Female
Follow-Up Studies
Humans
Male
Middle Aged
Parkinson Disease / diagnosis*
Parkinson Disease / psychology
Parkinson Disease / surgery*
Pilot Projects
Postoperative Complications / diagnosis*
Postoperative Complications / psychology
Quality of Life*
Reproducibility of Results
Subthalamic Nucleus / surgery
Surveys and Questionnaires / standards*