Poster Session C, Sunday, March 24, 5:00 – 7:00 pm, Pacific Concourse
Stopping natural desires: defining the hypersexuality network in impulse control disorders in Parkinson’s disease
Ignacio Obeso1, José Ángel Pineda-Pardo1, Lydia Vela1, Fernando Alonso1, Jose A. Obeso1; 1CINAC
Humans are prone to approach natural stimuli with positive connotation such as food or sex. Impulse control disorders (ICD) is a side-effect of dopamine agonist medication to treat motor symptoms in Parkinson´s disease (PD) whereby desire towards natural rewards increases and uncontrolled actions occur as a result. Male PD+ICD (n=18), PD-ICD patients (n=16) performed the task while on and off medicated (after overnight withdrawal) and compared to healthy male controls (n=16). The erotic stop-signal task inside the fMRI presented participants either an erotic or non-erotic image (1s), followed by a go signal sometimes replaced with a stop signal (33%). Behaviorally, PD+ICD patients while medicated were slower to inhibit actions that followed an erotic image as compared to unmedicated conditions. Failed inhibition under erotic stimuli influence produced BOLD increment in PD+ICD (while medicated) in the left caudate [-4 12 6; z = 433; p = .005]. When stopping was successful in the erotic condition, however, PD+ICD significantly activated while medicated (compared to off medication) the left caudate [-6 0 16; z = 487; p = .001] in addition to cortical regions such as the right pre-SMA [7 22 43; z = 387; p = .005] and ACC [4 24 20; z = 399; p = .005]. Connectivity analysis during successful stops revealed that PD+ICD patients recruit the caudate in combined forces with pre-SMA and contralateral caudate (left side). Hypersexual ICD seems to be driven by overrepresentation of limbic activity combined with reduced top-down control.
Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control