A role of the motor cortex in tremor generation essential (ET) is assumed, yet directionality corticomuscular coupling unknown. Our aim to clarify cortex. To this end we also study ‘familial cortical myoclonic with epilepsy’ (FCMTE) and slow repetitive voluntary movements a known drive. Directionality (EEG-EMG) was studied renormalized partial directed coherence (rPDC) during 25 ET patients, he...

lent than Parkinson’s disease in Arabic villagers in Israel (ET prevalence = 0.78% vs. PD prevalence = 1.44%) [12] ; however, those results are atypical. The incidence of ET has been examined in only 2 studies [13, 14] . The incidence rate reported for ET, based on a populationbased study (the NEDICES study) [13] , was substantially higher (6.3 per 1,000 person-years) than that reported in the ...

Although essential tremor (ET) has been well characterized since 1887, there is still considerable controversy about the definition of ET, and there is no agreement among the experts as to whether ET is a symptom, a syndrome, or a specific disease entity. Some experts, including my esteemed colleague, Dr. Elble, have concluded that ET “may not be a single entity.” As I agree with this view, the...

The changes in postural tremor of the hand produced by moderate cooling of the muscles of one forearm have been investigated in 16 normal subjects and in 16 patients with essential tremor. In both groups, cooling produced a profound long lasting decrease in tremor level of the ipsilateral hand. In normal subjects, although cooling reduced the tremor size, the EMG of the active muscle clearly in...

Structural changes in Purkinje cells have been identified in the essential tremor cerebellum, although the mechanisms that underlie these changes remain poorly understood. Climbing fibres provide one of the major excitatory inputs to Purkinje cells, and climbing fibre-Purkinje cell connections are essential for normal cerebellar-mediated motor control. The distribution of climbing fibre-Purkinj...

Detecting psychogenic tremors (PsychT) is often challenging. As there are no laboratory investigations or imaging techniques that can confirm the diagnosis, PsychT is identified on a clinical basis. We present a tree-based statistical algorithm derived from quantitative computerized tremor recordings as a novel method to help in the recognition of PsychT. The goal of this study was to show that...

In order to study the mode of action of beta-adrenoreceptor antagonists in essential tremor the efficacy of single oral doses of 2, 4 and 10 mg LI 32-468, a peripherally acting, selective beta-2 adrenoreceptor antagonist, was compared with a single oral dose of 120 mg propranolol in a randomised, double blind, placebo controlled trial. Both the lowest dose of LI and propranolol were shown to be...

One major challenge in neuroscience is the identification of interrelations between signals reflecting neural activity. When applying multivariate time series analysis techniques to neural signals, detection of directed relationships, which can be described in terms of Granger-causality, is of particular interest. Partial directed coherence has been introduced for a frequency domain analysis of...