Non-motor predictors of 36-month quality of life after subthalamic stimulation in Parkinson disease
Authors: Jost Stefanie T. , Visser-Vandewalle Veerle , Rizos Alexandra , Loehrer Philipp A. , Silverdale Monty , Evans Julian , Samuel Michael , Petry-Schmelzer Jan Niklas , Sauerbier Anna , Gronostay Alexandra , Barbe Michael T. , Fink Gereon R. , Ashkan Keyoumars , Antonini Angelo , Martinez-Martin Pablo , Chaudhuri K. Ray , Timmermann Lars , Dafsari Haidar S. ,   EUROPAR and the International Parkinson and Movement Disorders Society Non-Motor Parkinson’s Disease Study Group, Bhidayasiri Roongroj , Falup-Pecurariu Cristian , Jeon Beomseok , Leta Valentina , Borghammer Per , Odin Per , Schrag Anette , Storch Alexander , Violante Mayela Rodriguez , Weintraub Daniel , Adler Charles , Barone Paolo , Brooks David J. , Brown Richard , Cantillon Marc , Carroll Camille , Coelho Miguel , Henriksen Tove , Hu Michele , Jenner Peter , Kramberger Milica , Kumar Padma , Kurtis Mónica , Lewis Simon , Litvan Irene , Lyons Kelly , Martino Davide , Masellis Mario , Mochizuki Hideki , Morley James F. , Nirenberg Melissa , Pagonabarraga Javier , Panicker Jalesh , Pavese Nicola , Pekkonen Eero , Postuma Ron , Rosales Raymond , Schapira Anthony , Simuni Tanya , Stocchi Fabrizio , Subramanian Indu , Tagliati Michele , Tinazzi Michele , Toledo Jon , Tsuboi Yoshio , Walker Richard 
Published: June 2021

To identify predictors of 36-month follow-up quality of life (QoL) outcome after bilateral subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson’s disease (PD). In this ongoing, prospective, multicenter international study (Cologne, Manchester, London) including 73 patients undergoing STN-DBS, we assessed the following scales preoperatively and at 6-month and 36-month follow-up: PD Questionnaire-8 (PDQ-8), NMSScale (NMSS), Scales for Outcomes in PD (SCOPA)-motor examination, -activities of daily living, and -complications, and levodopa equivalent daily dose (LEDD). We analyzed factors associated with QoL improvement at 36-month follow-up based on (1) correlations between baseline test scores and QoL improvement, (2) step-wise linear regressions with baseline test scores as independent and QoL improvement as dependent variables, (3) logistic regressions and receiver operating characteristic curves using a dichotomized variable “QoL responders”/“non-responders”. At both follow-ups, NMSS total score, SCOPA-motor examination, and -complications improved and LEDD was reduced significantly. PDQ-8 improved at 6-month follow-up with subsequent decrements in gains at 36-month follow-up when 61.6% of patients were categorized as “QoL non-responders”. Correlations, linear, and logistic regression analyses found greater PDQ-8 improvements in patients with younger age, worse PDQ-8, and worse specific NMS at baseline, such as ‘difficulties experiencing pleasure’ and ‘problems sustaining concentration’. Baseline SCOPA scores were not associated with PDQ-8 changes. Our results provide evidence that 36-month QoL changes depend on baseline neuropsychological and neuropsychiatric non-motor symptoms burden. These findings highlight the need for an assessment of a wide range of non-motor and motor symptoms when advising and selecting individuals for DBS therapy.