Striatal Dopaminergic Function and Motor Slowing in Essential Tremor Plus.

Background: While previous imaging studies have generally shown normal striatal dopamine transporter (DAT) binding in essential tremor (ET), emerging evidence suggests a partial dopaminergic mechanism in this condition and an epidemiological link between ET and Parkinson's disease (PD). This link seems particularly meaningful in ET patients with additional neurological signs, such as slowness of movements, rigidity, or rest tremor (ET+).

Objectives: To investigate the potential dopaminergic pathophysiology of ET+ and to compare it to PD.

Environmental Risk Factors for Parkinson's Disease: A Critical Review and Policy Implications.

The age-standardized prevalence of Parkinson's disease (PD) has increased substantially over the years and is expected to increase further. This emphasizes the need to identify modifiable risk factors of PD, which could form a logical entry point for the prevention of PD. The World Health Organization (WHO) has recommended reducing exposure to specific environmental factors that have been reported to be associated with PD, in particular pesticides, trichloroethylene (TCE), and air pollution.

Rest Tremor in Parkinson's Disease Is Associated with Ipsilateral Striatal Dopamine Transporter Binding.

Background: The cardinal motor symptoms of Parkinson's disease (PD) include rigidity, bradykinesia, and rest tremor. Rigidity and bradykinesia correlate with contralateral nigrostriatal degeneration and striatal dopamine deficit, but association between striatal dopamine function and rest tremor has remained unclear.

Objective: The aim of this study was to investigate the possible link between dopamine function and rest tremor using Parkinson's Progression Markers Initiative dataset, the largest prospective neuroimaging cohort of patients with PD.

Multimodal neuroimaging to characterize symptom-specific networks in movement disorders.

Movement disorders, such as Parkinson's disease, essential tremor, and dystonia, are characterized by their predominant motor symptoms, yet diseases causing abnormal movement also encompass several other symptoms, including non-motor symptoms. Here we review recent advances from studies of brain lesions, neuroimaging, and neuromodulation that provide converging evidence on symptom-specific brain networks in movement disorders. Although movement disorders have traditionally been conceptualized as disorders of the basal ganglia, cumulative data from brain lesions causing parkinsonism, tremor and dystonia have now demonstrated that this view is incomplete.