Impulse control disorders in Parkinson disease: a multicenter case--control study.

OBJECTIVE: To assess factors associated with impulse control disorders (ICDs) in Parkinson disease (PD) using a multicenter case--control design. METHODS: Patients enrolled in the DOMINION study, a multicenter study assessing the cross-sectional frequency of ICDs in PD, were eligible to participate in the case--control study. PD patients with and without an ICD (n = 282 each) (compulsive gambling, buying, sexual behavior, and eating) were matched individually on age, gender, and dopamine agonist treatment. Subjects were assessed with a comprehensive neurological, psychiatric, and cognitive assessment battery. RESULTS: ICD patients reported more functional impairment (p < 0.001); greater depressive (p < 0.0001), state (p < 0.0001), and trait (p < 0.0001) anxiety; greater obsessive-compulsive symptoms (p < 0.0001); higher novelty-seeking (p < 0.001) and impulsivity (p < 0.001); and differences in reward preference reflecting greater choice impulsivity (p < 0.05). Patients with multiple ICDs had greater dyskinesia scores compared to those with single ICDs. INTERPRETATION: ICDs in PD are associated with multiple psychiatric and cognitive impairments, including affective and anxiety symptoms, as well as elevated obsessionality, novelty seeking, and impulsivity. These results highlight the importance of assessing multiple mental health domains in individuals with PD and ICDs, and suggest possible pathophysiological mechanisms and risk indicators for these disorders.

Evaluation of painful sensory symptoms in restless legs syndrome: experience from two clinical trials.

BACKGROUND: Although "uncomfortable and unpleasant" limb sensations are a core symptom of restless legs syndrome (RLS), change in sensory symptomatology is usually not evaluated as a treatment outcome. METHODS: In two double-blind trials, patients with idiopathic RLS (n=357 in trial 615 and 398 in trial 604) were randomized to placebo or pramipexole (optimized at 0.125, 0.25, 0.50, or 0.75 mg/day). For entry, trial 604 also required at least moderate mood disturbance. In both trials, 12-week change in RLS-related limb pain was assessed using a 100-mm visual analogue scale (VAS). RESULTS: At baseline, approximately 75% of patients had limb-pain scores >30. Treatment with pramipexole yielded significant score reduction as early as day 5. At week 12, median score reduction for pramipexole relative to placebo was -33.5 vs. -11.0 (p<0.0001) in trial 615 and -31.0 vs. -11.0 (p<0.0001) in trial 604. CONCLUSIONS: Painful sensations may be more frequent in RLS than has previously been appreciated, and their amelioration may be a facet of pramipexole's benefit even in patients with concurrent mood disturbance. Limb pain assessment, e.g., by a VAS, is a useful measure of change in RLS symptom severity.

Amantadine use associated with impulse control disorders in Parkinson disease in cross-sectional study.

A recent controlled clinical trial suggested a role for amantadine as a treatment for pathological gambling in patients with Parkinson disease (PD). Analyzing data from a large cross-sectional study of impulse control disorders (ICDs) in PD, amantadine use (n = 728), vs no amantadine use (n = 2,357), was positively associated with a diagnosis of any ICD (17.6% vs 12.4%, p < 0.001) and compulsive gambling specifically (7.4% vs 4.2%, p < 0.001). This amantadine association remained after controlling for covariates of amantadine use, including both dopamine agonist use and levodopa dosage. Further research, including larger clinical trials, is needed to assess the role of amantadine in the development and treatment of ICDs in PD.

Efficacy, safety, and tolerability of overnight switching from immediate- to once daily extended-release pramipexole in early Parkinson's disease.

The aim of this article is to test the feasibility, in early Parkinson's disease (PD), of an overnight switch from immediate-release (IR) pramipexole to a new once-daily extended-release (ER) formulation. Nonfluctuating patients on pramipexole IR three-times daily, alone or with levodopa, for early PD were randomly switched overnight to double-blind IR three-times daily (N = 52) or ER once-daily (N = 104) at initially unchanged daily dosage. Successful switching (defined as no worsening >15% of baseline UPDRS II+III score and no drug-related adverse event withdrawal) was assessed at 9 weeks, after optional dosage adjustments (primary endpoint), and at 4 weeks, before adjustment. Other secondary endpoints included adjusted mean changes from baseline in UPDRS scores and proportion of responders based on Clinical or Patient Global Impression (CGI/PGI). Absolute difference between percentage of successful switch to ER versus IR was tested for ER noninferiority, defined as a 95% confidence-interval lower bound not exceeding -15%. At 9 weeks, 84.5% of the ER group had been successfully switched, versus 94.2% for IR. Noninferiority was not demonstrated, with a difference of -9.76% (95% CI: [-18.81%, +1.66%]). At 4 weeks, 81.6% of the ER group had been successfully switched, versus 92.3% for IR, a difference of -10.75% (95% CI: [-20.51%, +1.48%]). UPDRS changes and CGI/PGI analyses showed no differences between the groups. Both formulations were safe and well tolerated. Pramipexole ER was not equivalent to IR, but the difference was marginal. The fact that >80% of the patients successfully switched overnight at unchanged dosage shows that this practice was feasible in most patients.

Effect of pramipexole on RLS symptoms and sleep: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Patients with Restless Legs Syndrome (RLS) often seek treatment because of sleep problems related to nocturnal symptoms. Our goal was to test the ability of pramipexole to improve sleep in RLS patients and to reconfirm its efficacy for primary RLS symptoms. METHODS: Adults with moderate or severe RLS were randomized to receive placebo or pramipexole (flexibly titrated from 0.25 to 0.75mg), 2-3h before bedtime for 12 weeks. The co-primary outcome measures were change in Medical Outcomes Study (MOS) sleep disturbance score and International RLS Study Group Rating Scale (IRLS) score at 12 weeks. RESULTS: The intent-to-treat population included 357 patients: 178 received pramipexole and 179 received placebo. At 12 weeks, the adjusted mean change from baseline was greater for pramipexole (vs. placebo) for IRLS score (-13.4+/-0.7 vs. -9.6+/-0.7) and MOS sleep disturbance score (-25.3+/-1.5 vs. -16.8+/-1.5) (p

Working memory specific activity in auditory cortex: potential correlates of sequential processing and maintenance.

Working memory (WM) tasks involve several interrelated processes during which past information must be transiently maintained, recalled, and compared with test items according to previously instructed rules. It is not clear whether the rule-specific comparisons of perceptual with memorized items are only performed in previously identified frontal and parietal WM areas or whether these areas orchestrate such comparisons by feedback to sensory cortex. We tested the latter hypothesis by focusing on auditory cortex (AC) areas with low-noise functional magnetic resonance imaging in a 2-back WM task involving frequency-modulated (FM) tones. The control condition was a 0-back task on the same stimuli. Analysis of the group data identified an area on right planum temporale equally activated by both tasks and an area on the left planum temporale specifically involved in the 2-back task. A region of interest analysis in each individual revealed that activation on the left planum temporale in the 2-back task positively correlated with the task performance of the subjects. This strongly suggests a prominent role of the AC in 2-back WM tasks. In conjunction with previous findings on FM processing, the left lateralized effect presumably reflects the complex sequential processing demand of the 2-back matching to sample task.