Gender-specific outcomes of deep brain stimulation for Parkinson’s disease — results from a single movement disorder center

Abstract

Introduction and goal The investigation of gender differences in treatment response is crucial for effective personalized therapies. With only 30%, women are underrepresented in trials for deep brain stimulation (DBS) in Parkinson’s disease (PD). It is therefore important to evaluate gender-specific outcomes of DBS in PD in order to improve therapeutic counseling. Methods We analyzed clinical outcome parameters of 203 patients with PD that underwent DBS surgery targeting the subthalamic nucleus (STN) at our movement disorder center. A total of 27.6% of patients were female and 72.4% male. Motor and non-motor scores were compared before and 1 year after DBS surgery (1y FU) using Wilcoxon signed-rank tests and gender specific outcomes were analyzed with chi-square tests. Results At 1y FU, we found significant improvement in UPDRS II, UPDRS III (35.78 ± 36.14% MedOFF vs. StimON-MedOFF), UPDRS IV, depression (BDI-II), and health-related disability as (ADL) that showed no gender-specific differences. No significant change was revealed for UPDRS I, QUIP, and DemTect for the entire cohort. However, when analyzing both groups separately, only women improved in general cognition (plus 1.26 ± 3.03 DemTect points, p = 0.014*), whereas only men ameliorated in depression (minus 1.97 ± 6.92 BDI-II points, p = 0.002**) and impulsivity (minus 2.80 ± 7.27 QUIP points, p = 0.004**). Chi-square tests, however, revealed no significant differences between genders. Conclusion and outlook STN-DBS is a highly effective treatment for motor and non-motor symptoms of PD for both women and men but our study hints towards gender-specific outcomes in non-motor-domains like cognition, depressive symptoms, and impulsivity. To explore this in more detail, larger cohorts need to be investigated in multicenter trials.

Gender discrepancies and differences in motor and non-motor symptoms, cognition, and psychological outcomes in the treatment of Parkinson’s disease with subthalamic deep brain stimulation

“…STN-DBS improves the non-motor symptoms as measured by the Non-Motor Symptoms Scale (NMSS) total score ( 16 , 45 ), regardless of gender, but women improved significantly on the questions on attention and memory and men on the questions on mood and apathy and perceptual problems and hallucinations ( 16 ). However, when looking at non-motor symptoms as measured by UPDRS part I, two studies found no significant improvement for neither men nor women after STN-DBS ( 24 , 26 ).…”

“…Although it is known that STN-DBS does not lead to a decline in general cognitive abilities ( 38 , 39 ), one study found that male gender was a predictive factor for the development of dementia after STN-DBS ( 40 ). In addition, another study found that only women showed significant improvement on cognitive tests after STN-DBS ( 26 ). While one study reported improvement in the cognitive domain of the quality of life scale PDQ-39 after STN-DBS ( 28 ), another study found no difference in the cognitive domain of the PDQ-39 between genders ( 16 ).…”

“…Regarding depression, a total of seven studies were reviewed ( 24–27 , 32 , 41 , 42 ), with one study reporting greater improvement in depression in female patients ( 41 ) and one study reporting greater improvement in depression in male patients after STN-DBS ( 26 ). Furthermore, a longitudinal study reported that women had more depressive symptoms in all phases of STN-DBS surgery and LEDD was positively correlated with depressive symptoms only in women ( 27 ).…”

“…With regard to impulsivity and impulsive disorders, a total of three studies were analysed, one of which found an improvement in impulsivity only in men with PD after STN-DBS ( 26 ), and two reporting an increase in impulsivity behaviour in women. Namely, a study examining impulse control behaviours (ICB) after STN-DBS, reported that more women developed new-onset ICB than men, resulting in a higher prevalence of ICB in women ( 43 ).…”

“…However, these pre-surgical lower LEDD values in combination with less improvement in women was only seen in one study ( 24 ). Regarding cognition, the effect of DBS seems to be uncertain, but men may be more susceptible to cognitive decline ( 40 ), while women show more frequent improvement in cognitive functioning ( 26 ). In general, women seem to outperform men in cognitive tests ( 13 ), but this does not necessarily explain a possible gender-specific difference in improvement after STN-DBS.…”