Probable rapid eye movement (REM) sleep behavior disorder (RBD) prior to subthalamic deep brain stimulation (STN-DBS) is not associated with worse quality of life (QoL) or poorer motor and non-motor outcomes at 1 year after surgery in patients with Parkinson disease (PD), study findings published in Neurology suggest.
Patients with PD and RBD may have a more severe phenotype, characterized by greater motor disabilities, cognitive impairment, and axial symptoms. Despite the efficacy of STN-DBS for severe PD, the researchers noted that some patients who undergo the procedure experience worsening of motor and nonmotor symptoms.
In the study, researchers performed an ancillary analysis of data collected from the ongoing, French multicentric prospective study PREDISTIM. The goal of the study is to assess the predictive factors of treatment response to STN-DBS on long-term QoL. For their analysis, the researchers focused on the preoperative clinical profile of 448 patients (mean age, 63.3±7.4 years) with PD (mean disease duration, 11.0±4.3 years) from the French study, according to the absence or presence of probable RBD assessed with the RBD Single Question and RBD Screening Questionnaire.
All patients in the study had 12 months’ worth of follow-up after STN-DBS. Researchers compared patients with preoperative RBD (n=242) vs those without probable preoperative RBD (n=206) in terms of motor, cognitive, psycho-behavioral profile, and QoL outcomes.
Patients with preoperative RBD were significantly older (61±7.2 vs 59.5±7.7 years; P =.02), had less motor impairment (Movement Disorder’s Society Unified PD Rating Scale [MDS-UPDRS] III Off: 38.7±16.2 vs 43.4±7.1; P=.03), more nonmotor symptoms on daily living activities (MDS-UPDRS I: 12.6±5.5 vs 10.7±5.3; P<.001), more psycho-behavioral manifestations (Ardouin Scale of Behavior in PD total: 7.7±5.1 vs 5.1±0.4; P =.003), and significantly worse QoL (PD QoL 39 scale: 33±12 vs 29±12; P =.03).
After surgery, both patients with vs without preoperative RBD had significant reductions in MDS-UPDRS IV score (-37% and -33%, respectively; between group comparisons of variation: P =.43), MDS-UPDRS III “MedOff/StimOn” score (-52% and -54%; between group comparisons of variation: P =.28), and dopaminergic treatment (-52% and -49%; between group comparisons of variation: P =.22). Additionally, the researchers reported no significant between group differences for cognitive and global QoL outcomes.
Both groups experienced significant decreases in “activities of daily living” and “stigma” subscores, while subscores for “cognition” and “communication” only significantly decreased in patients with preoperative RBD (P <.01). None of the variations in the cognition and communication subscores significantly differed between groups (P =.20 and P =.19, respectively). While the QoL subscore of “bodily discomfort” significantly decreased more in patients with preoperative RBD (P =.04), this subscore decreased significantly in both groups.
The lack of polysomnography confirmed RBD diagnoses in the study may have led to misclassification of some patients with PD, the researchers stated.
Despite this limitation, they stated “the presence of RBD has been previously reported to be associated with a more severe phenotype of PD, it does not seem to constitute a marker of risk of poor outcome after surgery in PD patients eligible to STN-DBS.”
Long-term outcomes require further assessment in additional studies, particularly studies that include 3- to 5-year follow-up data after surgery, as this may “improve our comprehension of the specific prognosis associated with the presence of RBD in PD candidates to STN-DBS,” the researchers concluded.
Besse-Pinot E, Pereira B, Durif F, et al. Preoperative REM sleep behavior disorder and subthalamic deep brain stimulation outcome in Parkinson disease 1 year after surgery. Neurology. Published online October 19, 2021. doi:10.1212/WNL.0000000000012862