Lack of Accredited Clinical Training in Movement Disorders in Europe, Egypt, and Tunisia

Background: Little information is available on the official postgraduate and subspecialty training programs in movement disorders (MD) in Europe and North Africa. Objective: To survey the accessible MD clinical training in these regions. Methods: We designed a survey on clinical training in MD in different medical fields, at postgraduate and specialized levels. We assessed the characteristics of the participants and the facilities for MD care in their respective countries. We examined whether there are structured, or even accredited postgraduate, or subspecialty MD training programs in neurology, neurosurgery, internal medicine, geriatrics, neuroradiology, neuropediatrics, and general practice. Participants also shared their suggestions and needs. Results: The survey was completed in 31/49 countries. Structured postgraduate MD programs in neurology exist in 20 countries; structured neurology subspecialty training exists in 14 countries and is being developed in two additional countries. Certified neurology subspecialty training was reported to exist in 7 countries. Recommended reading lists, printed books, and other materials are the most popular educational tools, while courses, lectures, webinars, and case presentations are the most popular learning formats. Mandatory activities and skills to be certified were not defined in 15/31 countries. Most participants expressed their need for a mandatory postgraduate MD program and for certified MD sub-specialization programs in neurology. Conclusion: Certified postgraduate and subspecialty training exists only in a minority of European countries and was not found in the surveyed Egypt and Tunisia. MD training should be improved in many countries.Peer reviewe

Saccadic latency in hepatic encephalopathy: a pilot study

Hepatic encephalopathy is a common complication of cirrhosis. The degree of neuro-psychiatric impairment is highly variable and its clinical staging subjective. We investigated whether eye movement response times—saccadic latencies—could serve as an indicator of encephalopathy. We studied the association between saccadic latency, liver function and paper- and pencil tests in 70 patients with cirrhosis and 31 patients after liver transplantation. The tests included the porto-systemic encephalopathy (PSE-) test, critical flicker frequency, MELD score and ammonia concentration. A normal range for saccades was established in 31 control subjects. Clinical and biochemical parameters of liver, blood, and kidney function were also determined. Median saccadic latencies were significantly longer in patients with liver cirrhosis when compared to patients after liver transplantation (244 ms vs. 278 ms p < 0.001). Both patient groups had prolonged saccadic latency when compared to an age matched control group (175 ms). The reciprocal of median saccadic latency (μ) correlated with PSE tests, MELD score and critical flicker frequency. A significant correlation between the saccadic latency parameter early slope (σE) that represents the prevalence of early saccades and partial pressure of ammonia was also noted. Psychometric test performance, but not saccadic latency, correlated with blood urea and sodium concentrations. Saccadic latency represents an objective and quantitative parameter of hepatic encephalopathy. Unlike psychometric test performance, these ocular responses were unaffected by renal function and can be obtained clinically within a matter of minutes by non-trained personnel

The Unified Multiple System Atrophy Rating Scale: Status, Critique, and Recommendations

: The Unified Multiple System Atrophy (MSA) Rating Scale was developed to provide a surrogate marker of disease severity and clinical progression in patients with MSA. It is comprised of four subscales: UMSARS-I (12 items) rates patient-reported functional disability; UMSARS-II (14 items) assesses motor impairment based on a clinical examination; UMSARS-III records blood pressure and heart rate in the supine and standing positions; and UMSARS-IV (1 item) rates chore-based disability. Strengths of the UMSARS include its wide acceptance in the field, the comprehensive coverage of motor symptoms and its clinimetric properties (including reliability and validity). However, with its increasing use, potential areas of improvement in the UMSARS have become apparent. To address these limitations, a task force, involving clinicians, researchers, patient groups, and industry representatives, has recently been endorsed by the International Parkinson’s Disease and Movement Disorders Society. The present viewpoint summarizes strengths and weaknesses of the UMSARS and suggests a roadmap to develop an improved MSA clinical outcome assessment

Experimental and clinical studies in multiple system atrophy : paving the way towards interventional therapies

Multisystematrophie (MSA) ist eine rasch fortschreitende, neurodegenerative Erkrankung, die neuropathologisch durch krankheitsspezifische, -Synuklein positive Einschlusskörper gekennzeichnet ist. Diese Einschlusskörper werden von einem ausgedehnten Zellverlust begleitet, der vorwiegend die Basalganglien, das Kleinhirn und das Mittelhirn betrifft. Klinisch fällt eine variable Kombination aus autonomer Störung, Parkinsonismus, zerebellärer Dysfunktion und Pyramidenbahnzeichen auf. Die Erkrankung konnte in der Maus durch transgene Überexpression von -Synuklein nachgebildet werden. Trotz substantieller Fortschritte in der Forschung, stellt die MSA eine weiterhin unheilbare Erkrankung dar. Für die Entwicklung einer krankheitsmodifizierenden Therapie stellen vorhersagekräftige präklinische Krankheitsmodelle, sowie aussagekräftige Studiendesigns eine zentrale Voraussetzung dar. Dahingehend versuchte die vorliegende Dissertation die Aussagekraft eines MSA Mausmodells weiter zu stärken und die Validität und Anwendbarkeit von MSA-spezifischen Fragebögen zu verbessern. In dieser translationalen Arbeit konnte gezeigt werden, dass (1) ein MSA-typisches Symptom (der erhaltene Geruchssinn), welches die MSA von der häufigsten Differentialdiagnose dem Morbus Parkinson abgrenzt, im Mausmodell nachgebildet werden kann. (2) Die klinisch häufig angewandte „Unified MSA Rating Scale“ eine ausgezeichnete Intra-Rater Reliabilität aufweist und (3) die deutschsprachige Übersetzung eines MSA-spezifischen Lebensqualitätsfragebogens die psychometrischen Standardkriterien einer Summenskala erfüllt und eine Konstruktund kriterienbezogene Validität aufweist. Zusammengefasst konnte mit der vorliegenden kombiniert klinisch-experimentellen Dissertation, die Vorhersagekraft eines präklinischen MSA Modells gestärkt werden und die Verfügbarkeit und Anwendbarkeit von klinischen Bewertungsskalen, die für multinationale Forschungsvorhaben herangezogen werden können, erweitert werden.Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disorder of unknown aetiopathogenesis that is characterized by oligodendroglial, -synuclein immunoreactive inclusion bodies. A variable combination of autonomic failure, parkinsonism, cerebellar ataxia and pyramidal involvement portrays the clinical presentation. Neuropathology shows a cell loss within the basal ganglia, cerebellum and midbrain which is accompanied by reactive gliosis. At the preclinical level, MSA can be modelled in mice using transgenic -synuclein overexpression in oligodendrocytes. Despite significant advances in MSA research, the disease is still intractable. To overcome the current deadlock, reliable preclinical models and adequate trial methods are urgently required. To this end,the present thesis aimed at improving the face-validity of the PLP--synuclein MSA mouse model and at improving the validity and applicability of disease-specific rating scales. In summary, we were able to show that (1) a characteristic feature (i.e intact olfaction) that discriminate MSA from its most relevant differential diagnosis - Parkinsons disease - can be replicated in transgenic mice. (2) We were able to further substantiate the validity of the commonly used “Unified MSA Rating Scale“ by confirming its excellent intrarater reliability. (3) We successfully translated and validated a disease-specific health-related quality of life questionnaire by satisfying psychometric criteria of a summed rating instrument and confirming its face and construct validity. In conclusion, the present translational thesis improved the face-validity of a transgenic MSA mouse model and broadened the range of rating scales available for multinational clinical trials.eingereicht von Florian KrismerEnth. u.a. 4 Veröff. d. Verf. aus den Jahren 2012 - 2013 . - Zsfassung in dt. SpracheInnsbruck, Med. Univ., Diss., 2014OeBB(VLID)31726

Duty-Cycle Dependent Phase Shift Modulation of Dual Three-Phase Active Bridge Four-Port AC–DC/DC–AC Converter Eliminating Low Frequency Power Pulsations

A recently introduced Dual Three-Phase Active Bridge Converter (D3ABC) provides two three-phase ac ports (ac₁ and ac₂), two dc ports (dc₁ and dc₂), and galvanic isolation between the ports ac₁, dc₁ (primary side) and ac₂, dc₂ (secondary side). Previously documented studies confirm that the D3ABC is generally capable of transferring power between all four ports. However, it has been found challenging to operate the converter if ac voltages with different line frequencies, ⨍₁ ≠ ⨍₂, are present at the ports ac₁ and ac₂. Such operation causes Low-Frequency (LF) power pulsations in the converter's dc links, leading to fluctuating dc link voltages and distorted phase currents. In this paper, a new duty-cycle dependent phase shift modulation scheme is proposed that eliminates such LF power pulsations and substantially increases the theoretical maximum transmittable power between primary and secondary sides compared to previous work. The new modulation scheme is developed on the basis of analytical considerations, which are supported by the results of numerical calculations, and verified by means of circuit simulations and experimental results. A hardware demonstrator originally designed for a rated power of 8 kW when operated from ac₁ to dc₂ at the European low-voltage ac mains ( V_ac,1 = 230V line-to-neutral rms, V_dc,1 = 800V , V_dc,1 = 400V ) is used for experimental verification. Since the operation with ⨍₁ ≠ ⨍₂ leads to an increase of the currents in the converter, the experimental verification is conducted at half voltages and for a reduced power of 2 kW that is transferred from ac₁ to ac₂ at substantially different primary-side and secondary-side line frequencies of ⨍₁ = 50 Hz and $f_{2} = \tex...ISSN:2644-131

Minimum Loss Operation and Optimal Design of High-Frequency Inductors for Defined Core and Litz Wire

This paper studies the loss-optimal design of a power inductor employed in a 2 kW, 400 V input DC-DC converter. The design of an inductor is subject to a large number of design parameters and the implications of the different design parameters on the losses are often not clearly traceable in a full optimization, e.g., different current ripple amplitudes can lead to designs with similar losses, as larger ripple amplitudes lead to increased AC core and winding losses but lower DC losses in the winding due to lower inductance values and/or numbers of turns. In an effort to achieve a comprehensible description of the implications of the key design parameters (switching frequency, f s , current ripple, r, number of turns, N) on the losses, the remaining parameters, e.g., core (E55/28/21 N87) and type of conductor (litz wire), are considered to be given. In a first step, the investigation is based on a simplified analytical model, which is refined in a step-by-step manner, e.g., to consider core saturation. In a second step, the implications of further critical aspects on the losses, e.g., temperatures of core and coil, are examined using a comprehensive semi-numerical model. Surprisingly, the evaluation of the losses calculated in the f s -r domain reveals that nearly minimum inductor losses are obtained for a current ripple that is inversely proportional to the frequency, i.e., for a constant inductance, within a wide frequency range, from 200 kHz to 1 MHz. Furthermore, the investigation reveals a decrease of the losses for increasing frequencies up to 375 kHz, e.g., from 4.32 W at 80 kHz (r = 110 %) to 2.37 W at 375 kHz (r = 18 %). The detailed analysis related to these results enables the compilation of a simple two-equation guide for the design of an inductor that achieves close to minimum losses. In a next step, interesting trade-offs are identified based on a study of the design space diversity, e.g., with respect to low cost and increased partial-load efficiency. The findings of this work are experimentally verified, i.e., the losses of three different inductors are measured with an accurate calorimetric method and at four different frequencies, ranging from 150 kHz to 700 kHz.ISSN:2644-131