Does Deep Brain Stimulation Improve Sexual Well-Being in Parkinson’s Disease?

Abstracts & Commentary

Synopsis: Deep brain stimulation of the subthalamic nucleus appears to affect sexual functioning in a small but positive way. Male patients with Parkinson’s Disease, especially when younger than 60, appeared more satisfied with their sexual well-being over a short-term follow-up period.

Source: Castelli L, et al. Sexual Well-Being in Parkinsonian Patients After Deep Brain Stimulation of the Subthalamic Nucleus. J Neurol Neurosurg Psychiatry. 2004;75:1260-1264.

Sexual function in people with Parkinson’s Disease (PD) is likely affected by a complex interplay of factors, including the disease itself, medication changes, and psychological and social effects. This report provides the first data concerning changes in sexual well-being in patients with advanced PD, after deep brain stimulation (DBS) targeting the subthalamic nucleus (STN). Improvements in motor function, as well as decreased medication requirements are well-documented results of this surgical intervention, but its effects on non-motor symptoms are less clear.1 Castelli and colleagues investigated a group of 31 patients with PD, complicated by severe motor fluctuations and drug-related dyskinesias. Twenty-one of the 31 patients were male, mean age was 61.7 years, and mean disease duration was 16.9 years. Sexual function was evaluated with the sexual functioning inventory (SFI), a newly abbreviated form of the Gollombok Rust inventory of sexual satisfaction (GRISS). The full form was found to be unacceptable for those patients in the study. Depression and anxiety were also measured using the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI-X1/X2). Subjects were interviewed 1 month prior to surgery, and 9-12 months after surgery. Total SFI scores were slightly lower after DBS in both men and women, but did not reach statistical significance. Analysis of subdomains revealed only 1 area of statistical significance: improvement in sexual dissatisfaction in male subjects. In the subgroup of men aged less than 60 years old (n = 7), improvements reached statistical significance in domains regarding infrequency of sexual intercourse, dissatisfaction, and avoidance. No correlation could be discerned between changes in sexual function and other variables, including Hoehn and Yahr stage, disease duration, or depression and anxiety.

Commentary

This is the first report to systematically address the issue of whether STN DBS may influence sexual well-being in PD. Castelli et al are to be commended for initiating this study, in an area notoriously challenging in terms of methodology. Sexual dysfunction in PD is common, as highlighted by Brown and colleagues.2 Despite its importance, there is scant, and sometimes conflicting, information concerning a complex relationship to disease severity and duration, associated autonomic dysfunction, depression, medication effects, and other factors such as hormonal changes, social, and cultural considerations. In this study, changes in SFI scores observed were positive, but for the most part small. It is tempting to ascribe any changes in sexual well-being to a non-specific consequence of overall improvement in physical function. No correlation between SFI score and Hoehn and Yahr stage of PD was revealed in this study, but scores reported do not take into account the full spectrum of severity of motor fluctuations and dyskinesias. Therefore, they may not reflect motor symptoms that interfere with sexual function, such as the degree of rigidity or abnormal involuntary movements. Overall, interpretation is limited given the small number of participants, along with use of a novel version of an established rating scale as primary outcome measure. Therefore, possible contributions of mood, medication reduction, and other factors influenced by DBS cannot be ruled out. Finally, little attention has been paid, to date, to effects of PD upon women’s sexuality, although they clearly exist.3 No significant improvement in women’s sexual well-being was demonstrated, but again this may be due to small numbers involved and difficulties in data collection. This emphasizes the need for further study of this complex area of patients’ lives, and should encourage physicians to communicate with their patients about sexual function. —Claire Henchcliffe

Claire Henchcliffe, MD is an Assistant Professor of the Department of Neurology at the Weill Medical College of Cornell University, New York, NY.

References

1. Limousin P, et al. N Engl J Med. 1998;339:1105-1111.

2. Brown RG, et al. J Neurol Neurosurg Psychiatry. 1990;53:4810-4816.

3. Welsh M, et al. Mov Disorders. 1997;12:923-927.