Accurate Detection of Parkinson`s Disease in Tremor Syndromes Using Olfactory Testing

When analysing volcanic seismicity and volcanic events, it is often interesting to focus on tremor, which is a signal of long duration. This is because not much is known about tremor. Unlike earthquakes, sources of tremor are difficult to locate due to them not having any clear onsets in the seismic signal. Different location methods can be used to attempt to locate tremor sources, one of which incorporates correlation of seismic signals between two different recording stations. This method is sensitive to the frequency content in the signal, and will not operate correctly if the signal consists of non-tremor signals, e.g. earthquakes. Earthquakes generally contain higher frequencies than tremor, and if these are present in the signals being correlated, this will affect the location method negatively. Therefore, it is desirable to try to detect these events containing other frequencies, to be able to remove them from the data and improve the location method. Constructing this method is the objective of the study, and is done using the programming language Matlab. The method uses correlation between the amplitude spectra of short adjacent time intervals of the bigger time series, in an attempt to detect when the spectral signature of the time series radically changes. An outlier is deemed to exist when the correlation coefficient from the comparison falls beneath a pragmatically chosen multiple of standard deviation from the mean of coefficient values. The objective of the study has been achieved, by constructing a method using correlation between time intervals to detect sudden fluctuations in the spectral shape of the time series. The method does seem promising, however, the accuracy of the method now needs to be rigorously tested. Time has not allowed for this to be done in this study, and is left for future research. / När man analyserar vulkaniska händelser och seismik är det ofta intressant att fokusera på tremor, vilket är långvariga händelser. Detta är p.g.a. att inte mycket är känt om des-sa. Till skillnad från jordbävningar, så är orsaken till tremor svår att lokalisera eftersom dom inte har en tydlig början i den seismiska signalen. Olika lokaliseringsmetoder kan användas för att försöka lokalisera dessa orsaker, varav en är en metod som använder sig av korrelationen mellan den seismiska signalen för två olika mätstationer. Denna metod är känslig för innehållet av frekvens i signalen som används i jämförelsen, och kommer inte fungera lika bra om signalerna innehåller annat än endast tremor, t.ex. jordbävningar. Jordbävningar innehåller generellt högre frekvenser än tremor, och ifall dessa är närvarande i signalerna som används i jämförelsen kommer detta påverka metoden negativt. Därför är det önskvärt att försöka hitta dessa händelser som ger upphov till andra frekvenser, för att sedan kunna avlägsna dessa och förbättra lokaliseringsmetoden. Målet med detta projekt är därmed att konstruera denna metod, och detta genomförs i programmeringspråket Matlab. Metoden använder sig av korrelation mellan amplitudspektrum av korta närliggande tidsintervall från den större tidsserien, för att försöka detektera när frekvensinnehållet i signalen ändras radikalt. Ett interval anses vara en avvikelse närkorrelationskoefficienten från jämförelsen faller under en pragmatiskt vald multipel av standardavvikelsen av medelvärdet av korrelationskoefficienterna.Målet med projektet har uppfyllts, genom att konstruera en metod som använderkorrelation mellan tidsintervall för att detektera plötsliga fluktuationer av dom frekvensersignalen innehåller. Metoden verkar lovande, men noggrannheten av den behöver nu testas rigoröst. Tyvärr kunde inte detta utföras inom tidsgränserna av detta projekt, och får lämnas som framtida forskning.

This study seeks to understand upper limb tremor in subjects with essential tremor (ET). A thorough understanding of tremor distribution will allow for the more effective development of tremor suppression devices, which offer an alternative to current treatments. Previous studies primarily focused on tremor in the hand only. This study seeks to characterize the distribution of tremor throughout the upper limb.We measured tremor in 25 subjects diagnosed with ET using motion capture, which provided displacement information of the limb during multiple postural and kinetic tasks. Inverse kinematics allowed us to analyze the motion capture data in the 7 major degrees of freedom (DOF) of the upper limb. The power spectral density estimate was used to determine: relative tremor magnitude throughout the DOFs, tremor variation between tasks, variation between subjects, and frequency variations between DOFs. Data analysis revealed that tremor increase is roughly proximal to distal. We also show that tremor magnitude in kinetic tasks is significantly higher than in postural tasks. Although we found some variation in tremor distribution between subjects, the roughly proximal to distal increase in tremor severity holds for several subsets of the study population. Finally, we found that tremor frequency doesnt vary significantly (< 1 Hz) between DOFs, in subjects with severe tremor. Our study shows that tremor distribution is quite stereotyped between subjects with ET. Furthermore, we have shown that tremor is greatest in the distal DOFs. This provides a compelling starting point for the development of future tremor suppression devices.

Deep tectonic tremor has been observed in major subduction zones, strike-slip faults, inland faulting systems, and arc-continent collision environments around the Pacific Rim. However, detailed space-time evolution of its source locations remains enigmatic because of difficulties in detecting and locating tremor accurately. In 2011, we installed two dense, small-aperture seismic arrays aiming to detect ambient tremor source beneath southern Central Range in Taiwan. We recorded continuous waveforms for a total of 134 days, including tremor triggered by the great 2011 Mw9.0 Tohoku earthquake. We use the broadband frequency-wavenumber beamforming and the moving-window grid-search methods to compute array parameters for detecting seismic signals. The obtained array parameters closely match both relocated local earthquakes and triggered tremor bursts located by an envelope cross-correlations method, indicating the robustness of our array technique. We identify tremor signals with coherent waveforms and deep incidence angles and detect tremor for 44 days among the 134-day study period. The total duration is 1,481-minute, which is 3-6 times more than that detected by the envelope cross-correlations method. In some cases, we observe rapid tremor migration with a speed at the order of 40-50 km/hour that is similar to the speed of fast tremor migration along-dip on narrow streaks in Japan and Cascadia. Our results suggest that dense array techniques are capable of capturing detailed spatiotemporal evolutions of tremor behaviors in southern Taiwan.

The pathophysiology of essential tremor (ET) is not clearly understood but is thought to involve multiple brain regions. The purpose of this study was to describe in greater detail head tremor in ET and to investigate the possible relationship between head and hand tremor. Ten ET subjects were recruited (1 male, 9 female) and compared to three control subjects (1 male, 2 female). Head and hand tremors were recorded simultaneously with surface electromyography (EMG) of the wrist extensors and various neck muscles, laser displacement sensors (hand tremor), a load cell (hand tremor) and an accelerometer (head tremor). While seated, subjects performed four tasks: 1) constant force (10% maximum) wrist extensions (with and without visual feedback); maintenance of the hands in a horizontal posture against gravity while 2) seated upright in a chair, 3) seated in a reclined chair (20° backward, head not supported); and 4) seated upright in a chair and producing steady submaximal hip adduction forces. Head tremor spectral peaks were found between 3.5 and 7 Hz in neck muscle EMG and the accelerometer signal. Wrist tremor (EMG and kinematic data) was slightly higher in frequency with a range of 4 -10 Hz. Of the ten ET subjects recruited for this study, 60% (n = 6) demonstrated significant levels of coherence (p < 0.05) in at least one neck-wrist muscle comparison at the fundamental frequency of their tremor. The results demonstrated an obvious bias of the trapezius descendens (TD) muscles over the more axial neck muscles to demonstrate significant coherence with the extensor carpi radialis (ECR) muscles. Of the six neck muscles investigated, the SPLs and the SCMs were commonly driven at the same frequencies (change in frequency < 0.5), although this seldom resulted in coherence. There is indication that the oscillatory activity driving more distal muscles is different from that in the SPL and the SCM. Due to the multifunctional nature of the TD, it may be the recipient of two descending neural commands. These commands may each be of a different oscillatory frequency originating from different central oscillators. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2008-10-29 10:03:22.354

Zugl.: Düsseldorf, Univ., Diss., 2008 u.d.T.: Reck, Christiane: Charakterisierung oszillatorischer Aktivität im Nucleus subthalamicus und Nucleus ventralis intermedius thalami bei Patienten mit Bewegungsstörungen / Hergestellt on demand

Würzburg, Univ., Diss., 2009. / Zsfassung in dt. Sprache.

Made available in DSpace on 2015-12-06T22:59:16Z (GMT). No. of bitstreams: 0 Previous issue date: 1997 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O envelhecimento da populacao mundial vem causando grande impacto na vida socio-economica dos paises. Por outro lado, varios estudos neuroquimicos e comportamentais em animais e humanos tem revelado mudancas relacionadas a idade. Sabendo-se que poucos estudos tem investigado a resposta farmacologica de agentes que atuam no sistema colinergico em funcao da idade, este trabalho investigou as respostas central e periferica a oxotremorina (OXO) entre ratos jovens (3-6 meses) e idosos (24-30 meses). Os ratos idosos apresentaram respostas farmacologicas mais intensas, tanto a nivel periferico (cromodacriorreia) como a nivel central (tremor), apos tratamento com OXO 0,25 a 1,0 mg/kg (ip.). Tais dados sugerem alteracoes farmacocineticas e/ou alteracoes na funcionalidade e mostram ainda que, possivelmente, os sistemas colinergico periferico e central sao igualmente afetados com a idade. Ratos idosos mostraram um retardo na aprendizagem de uma tarefa no labirinto em T. Todavia, apos aprendida a tarefa, nao se observaram diferencas entre os grupos, apesar do tratamento dos animais com OXO 0,1 mg/kg / BV UNIFESP: Teses e dissertações

Background/Aims: The diagnostic value of olfactory testing for the discrimination of tremor-dominant Parkinson’s disease (PD) from other tremor disorders remains enigmatic. We evaluated whether olfactory testing can accurately detect PD in tremor patients. Methods: A retrospective analysis of 299 consecutive subjects referred for the differential diagnosis of a tremor disorder was done. Olfactory testing was performed using ‘Sniffin’ Sticks’, resulting in a composite TDI score of odor threshold (T), discrimination (D), and identification (I). Receiver operating curve (ROC) plots were used to calculate sensitivity/specificity for the detection of PD. Results: Of all subjects, 167 (55.9%) had PD and 85 (28.4%) had essential tremor (ET). The mean TDI score in PD was significantly reduced compared to those in ET and other tremor disorders with no differences between ET and other tremor disorders. ROC analysis revealed strong correlations of TDI scores with PD [area under the curve: 0.85 (95% CI: 0.80–0.89); p < 0.001]. The highest Youden index was observed for a TDI score <25 (Youden index: 0.58). Using this cutoff score and that generated from normative data of healthy controls, the TDI score provided high sensitivity (negative predictive value) and specificity (positive predictive value) of approximately 80% for detecting PD. Conclusion: Olfactory testing is a useful, easily applied and inexpensive diagnostic test which is helpful to detect PD among tremor patients.

Der essentielle Tremor (ET) ist eine der häufigsten Bewegungsstörungen, welcher lange Zeit als rein motorische Störung angesehen wurde. Aufgrund zunehmender Belege über nicht-motorisch Begleitsymptome wandelte sich dieses Bild jedoch in den letzten Jahren zunehmend. In der vorliegenden Arbeit untersuchten wir 113 Probanden aus der Allgemeinbevölkerung mit klinisch definitiven oder wahrscheinlichen ET anhand einer breiten Batterie neuro-psychologischer Testverfahren. Es gelang hierbei signifikante Unterschiede im Vergleich zu gesunden Eichstichproben im Hinblick auf neuro-psychologische Charakteristika, wie Apathie, Ängstlichkeit und exekutive Dysfunktion, sowie deren negativen Einfluss auf die Lebensqualität der Probanden darzustellen. Bisher werden im klinischen Alltag nicht-motorische Begleitphänomene beim ET nicht regelhaft erfasst; aufgrund unserer Ergebnisse und der Relevanz vor allem im Hinblick auf die Lebensqualität des Einzelnen halten wir jedoch die Erfassung und gegebenenfalls Behandlung dieser Symptome für ebenso relevant. / Essential tremor (ET) is one of the most common movement disorders, which was previously considered a purely motor disorder. Due to increasing evidence of non-motor symptoms, however, this picture has changed recently. In the present study we investigated 113 subjects from the general population with clinically definite or probable ET using a broad battery of neuro-psychological screening tools. Thereby, significant differences in neuro-psychological characteristics, such as apathy, anxiety and executive dysfunction, as well as their negative impact on the quality of life of the subjects could be demonstrated in comparison to healthy samples. Up to now, non-motor symptoms in ET are generally not been recorded in the clinical routine; however, based on our findings and the relevance to the individual's quality of life in particular, we consider the assessment and, where appropriate, treatment of these symptoms to be equally relevant.