Bilateral cerebellar activation in unilaterally challenged essential tremor.

Background: Essential tremor (ET) is one of the most common hyperkinetic movement disorders. Previous research into the pathophysiology of ET suggested underlying cerebellar abnormalities.

Objective: In this study, we added electromyography as an index of tremor intensity to functional Magnetic Resonance Imaging (EMG-fMRI) to study a group of ET patients selected according to strict criteria to achieve maximal homogeneity.

Motor network disruption in essential tremor: a functional and effective connectivity study.

Although involvement of the cerebello-thalamo-cortical network has often been suggested in essential tremor, the source of oscillatory activity remains largely unknown. To elucidate mechanisms of tremor generation, it is of crucial importance to study the dynamics within the cerebello-thalamo-cortical network. Using a combination of electromyography and functional magnetic resonance imaging, it is possible to record the peripheral manifestation of tremor simultaneously with brain activity related to tremor generation.

Functional (psychogenic) movement disorders associated with normal scores in psychological questionnaires: A case control study.

Objective: Functional movement disorders (FMDs) fall within the broader category called functional neurological symptom disorder (FNSD). New DSM-5 criteria for FNSD no longer require the presence of a 'psychological conflict' suggesting that some patients with FMD may not have obvious psychological comorbidity. We studied patients with FMD in comparison to patients with a neurological movement disorder (MD) and healthy controls (HC) to identify whether there is a subgroup of patients with FMD who have normal psychological test scores.