Substantia nigra hyperechogenicity and Parkinson's disease risk in patients with essential tremor.

Background: Several studies have reported an increased risk for patients with essential tremor to develop Parkinson's disease. In addition, hyperechogenicity in the area of the substantia nigra has been associated with a markedly increased risk for Parkinson's disease. The objective of this study was to evaluate the validity of substantia nigra hyperechogenicity in patients with essential tremor as a risk marker for Parkinson's disease.

Enteric nervous system α-synuclein immunoreactivity in idiopathic REM sleep behavior disorder.

Objective: To investigate the expression of α-synuclein in colonic biopsies of patients with idiopathic REM sleep behavior disorder (iRBD) and address if α-synuclein immunostaining of tissue obtained via colonic biopsies holds promise as a diagnostic biomarker for prodromal Parkinson disease (PD).

Methods: Patients with iRBD, patients with PD, and healthy controls were prospectively recruited to undergo colonic biopsies for comparison of α-synuclein immunoreactivity patterns between the groups by using 2 different antibodies.

Results: There was no difference in colonic mucosal and submucosal immunostaining between groups using the 15G7 α-synuclein antibody, which was found in almost all participants enrolled in this study.

Nonmotor symptoms in subjects without evidence of dopaminergic deficits.

Background: A subgroup of patients initially diagnosed with Parkinson's disease (PD) turn out to have normal dopamine transporter single-photon emission computed tomography imaging and have been labeled as subjects without evidence of dopaminergic deficit (SWEDDs). In this study, we sought to further characterize these patients and have analyzed the frequency of nonmotor symptoms (NMS) in SWEDDs, PD patients, and healthy controls.

Methods: We analyzed the baseline clinical data of 412 PD patients, 184 controls, and 62 SWEDDs included in the Parkinson's Progression Marker Initiative study on a variety of different NMS questionnaires.

Drug safety evaluation of rotigotine.

Introduction: Rotigotine, a non-ergolinic dopamine-receptor agonist, is currently approved as monotherapy in early idiopathic Parkinson's disease (IPD), in moderate to severe idiopathic restless legs syndrome (RLS) and as adjunct therapy to levodopa in advanced IPD. Randomized, double-blind, placebo-controlled, as well as open-label studies were conducted in IPD and RLS patients to evaluate the efficacy, tolerability and safety of rotigotine in dosages up to 16 mg/24 h. Overall, these trials have shown that rotigotine has a similar adverse event (AE) profile as other non-ergolinic dopamine agonists such as pramipexole or ropinirole, inducing typical dopaminergic effects like nausea, daytime somnolence, peripheral edema or impulse control disorders.