Hypersexuality in Parkinson's Disease: Systematic Review and Report of 7 New Cases.

Hypersexuality (HS) was one of the earliest examples of an impulse control disorder (ICD) or behavior to be associated with treatment for Parkinson's disease (PD), with an estimated prevalence of approximately 3.5%. Here, we report on a systematic review of the published literature of HS in PD with a view to uncovering evidence as to whether it is distinct from other ICDs. In addition, we report on 7 new cases that had broad neuropsychological testing, including a gambling test, which taps into reward and inhibitory mechanisms. The review uncovered a number of case series and cohorts that comment on the prevalence of HS, but very few made systematic comparisons with other ICDs, although younger onset and male sex are usually noted. A few studies have begun to map out a neuropsychological profile for HS, and our own cases show particular deficits in learning from negative outcomes, but, overall, there are insufficient data to draw firm conclusions. Functional imaging has shown patterns of increased content-specific activation in response to sexual material and this might relate to increased dopamine release. We conclude with a brief survey of the neurobiology of sexuality, which suggests possible avenues for further research and treatment of HS.