Publications by authors named "R C G Helmich"

Tremor is defined as an oscillatory and rhythmical movement. By contrast, dystonia is defined by sustained or intermittent abnormal postures, repetitive movements, or both. Tremor and dystonia often coexist in the same individual.

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Objective: Parkinson's disease (PD) resting tremor is thought to be initiated in the basal ganglia and amplified in the cerebello-thalamo-cortical circuit. Because stress worsens tremor, the noradrenergic system may play a role in amplifying tremor. We tested if and how propranolol, a non-selective beta-adrenergic receptor antagonist, reduces PD tremor and whether or not this effect is specific to stressful conditions.

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Article Synopsis
  • Parkinson's disease (PD) symptoms, particularly tremor, evolve differently over time, with bradykinesia and rigidity worsening while positive tremor symptoms may decrease.
  • The study used MRI and clinical assessments over two years to analyze changes in 520 PD patients, focusing on the relationship between tremor and brain structural changes.
  • Findings revealed that while bradykinesia and rigidity worsen with PD progression, action tremors tend to stabilize or diminish, indicating complex relationships between motor symptoms and brain atrophy.
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Alterations in subcortical brain regions are linked to motor and non-motor symptoms in Parkinson's disease (PD). However, associations between clinical expression and regional morphological abnormalities of the basal ganglia, thalamus, amygdala and hippocampus are not well established. We analyzed 3D T1-weighted brain MRI and clinical data from 2525 individuals with PD and 1326 controls from 22 global sources in the ENIGMA-PD consortium.

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Long-term cognitive impairment is common in cardiac arrest survivors. Screening to identify patients at risk is recommended. Functional magnetic resonance brain imaging (fMRI) holds potential to contribute to prediction of cognitive outcomes.

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