793 research outputs found
Cross-spectral analysis of physiological tremor and muscle activity. I. Theory and application to unsynchronized EMG
We investigate the relationship between the extensor electromyogram (EMG) and
tremor time series in physiological hand tremor by cross-spectral analysis.
Special attention is directed to the phase spectrum and the effects of
observational noise. We calculate the theoretical phase spectrum for a second
order linear stochastic process and compare the results to measured tremor data
recorded from subjects who did not show a synchronized EMG activity in the
corresponding extensor muscle. The results show that physiological tremor is
well described by the proposed model and that the measured EMG represents a
Newtonian force by which the muscle acts on the hand.Comment: 9 pages, 6 figures, to appear in Biological Cybernetic
Estimation of time delay by coherence analysis
Using coherence analysis (which is an extensively used method to study the
correlations in frequency domain, between two simultaneously measured signals)
we estimate the time delay between two signals. This method is suitable for
time delay estimation of narrow band coherence signals for which the
conventional methods cannot be reliably applied. We show by analysing coupled
R\"ossler attractors with a known delay, that the method yields satisfactory
results. Then, we apply this method to human pathologic tremor. The delay
between simultaneously measured traces of Electroencephalogram (EEG) and
Electromyogram (EMG) data of subjects with essential hand tremor is calculated.
We find that there is a delay of 11-27 milli-seconds () between the tremor
correlated parts (cortex) of the brain (EEG) and the trembling hand (EMG) which
is in agreement with the experimentally observed delay value of 15 for the
cortico-muscular conduction time. By surrogate analysis we calculate error-bars
of the estimated delay.Comment: 21 pages, 8 figures, elstart.cls file included. Accepted for
publication in Physica
The economic benefit of timely, adequate, and adherence to Parkinson's disease treatment: the Value of Treatment Project 2
Background: Parkinson's disease (PD) is a chronic progressive neurological disorder with a high psychosocial and economic burden. As part of the European Brain Council (EBC)-led Value of Treatment project, this study aimed to capture the economic benefit of timely, adequate, and adherence to PD treatment. Methods: The EBC Value of Treatment Initiative combined different stakeholders to identify unmet needs in the patients’ journey according to Rotterdam methodology. The economic evaluation focused on three major topics identified as major gaps: start of treatment; best treatment for advanced disease; and adherence to treatment. Two separate healthcare systems (Germany and the UK) were chosen. Cost-effectiveness was determined by using decision-analytical modelling approaches. Effectiveness was expressed as quality-adjusted life-years (QALYs) gained and incremental cost-effectiveness ratio (ICER). Results: Treatment intervention in PD was found to be cost-effective regardless of the initial health state of the patient receiving the treatment. Cost savings were between -€1000 and −€5400 with 0.10 QALY gain and -€1800 and -€7600 with 0.10 QALY gain for Germany and the UK, respectively. Treatment remains cost-effective within the National Institute for Health and Care Excellence thresholds. Availability of adequate treatment to more patients was also found to be cost-effective, with an ICER of €15,000–€32,600 across country settings. Achieving the target adherence to treatment would generate cost-savings of €239,000–€576,000 (Germany) and €917,000–€2,980.000 (UK) for every 1,000 patients treated adequately. Conclusions: The analyses confirmed that timely, adequate, and adherence to PD treatment will not only improve care of the patients but is also cost-effective across healthcare systems. Further studies with a distinct identification of gaps in care are necessary to develop better and affordable care
Antibody-related movement disorders - a comprehensive review of phenotype-autoantibody correlations and a guide to testing
Background: Over the past decade increasing scientific progress in the field of autoantibody–mediated
neurological diseases was achieved. Movement disorders are a frequent and often prominent feature in such
diseases which are potentially treatable.
Main body: Antibody-mediated movement disorders encompass a large clinical spectrum of diverse neurologic
disorders occurring either in isolation or accompanying more complex autoimmune encephalopathic diseases.
Since autoimmune movement disorders can easily be misdiagnosed as neurodegenerative or metabolic conditions,
appropriate immunotherapy can be delayed or even missed. Recognition of typical clinical patterns is important to
reach the correct diagnosis.
Conclusion: There is a growing number of newly discovered antibodies which can cause movement disorders.
Several antibodies can cause distinctive phenotypes of movement disorders which are important to be aware of.
Early diagnosis is important because immunotherapy can result in major improvement.
In this review article we summarize the current knowledge of autoimmune movement disorders from a point of
view focused on clinical syndromes. We discuss associated clinical phenomenology and antineuronal antibodies
together with alternative etiologies with the aim of providing a diagnostic framework for clinicians considering
underlying autoimmunity in patients with movement disorders
Progressive ataxia with oculo-palatal tremor and optic atrophy
The final publication is available at Springer via doi: 10.​1007/​s00415-013-7136-
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