Parkinson's Disease: Impulsivity Does Not Cause Impulse Control Disorders but Boosts Their Severity.

Impulse control disorders (ICDs) are a common complication of Parkinson's disease (PD) receiving dopamine agonist (DAA) Impulsivity is considered an underlying mechanism but evidence of this relationship is scarce. To explore the relationship between impulsivity and the presence and severity of ICD in PD. Prospective cross-sectional study of consecutive PD outpatients.

Minor hallucinations occur in drug-naive Parkinson's disease patients, even from the premotor phase.

Objectives: The description of minor hallucinatory phenomena (presence, passage hallucinations) has widened the spectrum of psychosis in Parkinson's disease (PD). Minor hallucinatory phenomena seem to antedate the development of more severe hallucinations. Early detection of minor hallucinations may be useful for screening patients with more severe endophenotypes.

Alterations in cerebral white matter and neuropsychology in patients with cirrhosis and falls.

Background & Aim: Falls are frequent in patients with cirrhosis but underlying mechanisms are unknown. The aim was to determine the neuropsychological, neurological and brain alterations using magnetic resonance-diffusion tensor imaging (MR-DTI) in cirrhotic patients with falls.

Patients And Methods: Twelve patients with cirrhosis and falls in the previous year were compared to 9 cirrhotic patients without falls.

Apathy in Parkinson's disease: neurophysiological evidence of impaired incentive processing.

Apathy is one of the most common and debilitating nonmotor manifestations of Parkinson's disease (PD) and is characterized by diminished motivation, decreased goal-directed behavior, and flattened affect. Despite its high prevalence, its underlying mechanisms are still poorly understood, having been associated with executive dysfunction, and impaired emotional processing and decision making. Apathy, as a syndrome, has recently been associated with reduced activation in the ventral striatum, suggesting that early- to middle-stage Parkinson's disease patients with this manifestation may have a compromised mesocorticolimbic dopaminergic pathway and impaired incentive processing.

Secondary nonmotor negative symptoms in healthy volunteers after single doses of haloperidol and risperidone: a double-blind, crossover, placebo-controlled trial.

Objective: The effect of antipsychotics (APs) on negative symptoms is controversial. The present study assessed negative symptoms in healthy volunteers without any source of primary negative symptoms after single doses of haloperidol and risperidone.

Methods: Twenty-five healthy subjects were included in this randomized, placebo-controlled, single-dose (haloperidol 5 mg and risperidone 2.

Effect of CYP2D6 on risperidone pharmacokinetics and extrapyramidal symptoms in healthy volunteers: results from a pharmacogenetic clinical trial.

Aim: To elucidate the relationship between CYP2D6 genotype and risperidone pharmacokinetics and extrapyramidal symptoms we propose the APSEP pharmacogenetic clinical trial.

Materials & Methods: Twenty-five healthy subjects were included in this randomized, placebo-controlled, single dose (risperidone 2.5 mg) crossover and double-blind clinical trial.

Relationship between CYP2D6 genotype and haloperidol pharmacokinetics and extrapyramidal symptoms in healthy volunteers.

Aim: This study aimed to elucidate the relationship between CYP2D6 genotype and haloperidol pharmacokinetics and induced extrapyramidal symptoms (EPSs).

Materials & Methods: Twenty five healthy subjects were included in this randomized, placebo-controlled, single-dose (5 mg) crossover and double-blind clinical trial, selected according to their CYP2D6 genotype and classified as poor metabolizers (n = 8), extensive metabolizers (n = 10) and ultrarapid metabolizers (n = 7).

Results & Conclusion: We confirm that CYP2D6 genotype partially determines haloperidol metabolism and the rate of EPSs measured as wakefulness activity by actigraphy.

Parkinson's disease-cognitive rating scale: psychometrics for mild cognitive impairment.

Lack of validated data on cutoff scores for mild cognitive impairment (MCI) and sensitivity to change in predementia stages of Parkinson's disease (PD) limit the utility of instruments measuring global cognition as screening and outcome measures in therapeutic trials. Investigators who were blinded to PD-Cognitive Rating Scale (PD-CRS) scores classified a cohort of prospectively recruited, nondemented patients into a PD with normal cognition (PD-NC) group and a PD with MCI (PD-MCI) group using Clinical Dementia Rating (CDR) and the Mattis Dementia Rating Scale-2 (MDRS-2). The discriminative power of the PD-CRS for PD-MCI was examined in a representative sample of 234 patients (145 in the PD-NC group; 89 in the PD-MCI group) and in a control group of 98 healthy individuals.

Measuring functional impact of cognitive impairment: validation of the Parkinson's disease cognitive functional rating scale.

Background: Little is known on the impact of cognitive impairment on instrumental activities of daily living (IADL) in pre-dementia stages of Parkinson's disease (PD).

Objective: To investigate the clinimetric properties, applicability and responsiveness of a brief questionnaire (twelve-item; maximum score = 24) for rating functional abnormalities associated to cognitive impairment in non-demented PD patients (ND-PD).

Methods: Two studies were carried-out: (1) a clinimetric study validated the Parkinson's Disease-Cognitive Functional Rating Scale (PD-CFRS) against the Older Americans Resource Survey (OARS-IADL) in 53 ND-PD patients and 53 matched controls; (2) A prospective multicenter 6-month responsiveness study involving 120 ND-PD patients explored sensitivity to change.

Apathy in Parkinson's disease: more than just executive dysfunction.

Apathy is a frequent syndrome in Parkinson's disease (PD) usually associated with depression, cognitive impairment (CI), and dementia. Whereas executive dysfunction seems to play a major causative role in the development of apathy in PD, recent findings pointed for the possible participation of other underlying mechanisms in the development of clinically meaningful symptoms of apathy. By means of neuropsychological testing focused over global cognitive functioning, set-shifting, decision making, and cognitive effort, we compared to a control group, a carefully selected sample of PD patients presenting apathy as the only neuropsychiatric symptom and without clinically relevant signs of cognitive impairment.