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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The standing steadiness and postural tremor of seven male volunteers were examined during slow and rapid induction of hypoxia. Spectrum analysis of position coordinates and tremor data generated from a quartz multicomponent force measuring platform and a tremor transducer showed that postural tremor (pt) and anteroposterior sway (ay) increased significantly during hypoxia. Rate of onset of hypoxia, however, did not affect the development of the increased tremor, whereas rapid-onset hypoxia consistently induced a greater anteroposterior sway than slow-onset hypoxia. Lateral sway (ax) was not affected by either slow- or rapid-onset hypoxia; however, it was significantly greater when eyes were closed compared to when they were opened. Anteroposterior sway (ay) was also significantly greater when visual cues were eliminated during both slow- and rapid-onset hypoxia. Heart rate (HR) and cardiac index (CI) of subjects increased significantly during both conditions of hypoxia.
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PMID:Postural stability during slow-onset and rapid-onset hypoxia. 711 52

In relation to static work, an experiment has been made with intention to examine the influence of maintaining standing posture for a long time on human body. The results are as follows: 1) Fluctuation waves of the body weight were classified into two types: type A, a higher amplitude with slow waves, and type B, a lower amplitude with rapid waves. 2) Spectrum analysis on the fluctuation waves of the body weight indicated that type A showed a gradual lowering in relative power in proportion to the wave frequency with the lapse of time, but type B showed a peak in power at around 10 Hz and it increased with the lapse ot time. 3) Action potentials from the left and right gastrocnemium muscles decreased almost simultaneously with the lapse of time in type A with a significant correlation between the left and right, while in type B there was no certain relation between the left and right as well as with the lapse of time. 4) The body weight tended to concentrate on the heel of the dominant foot with the lapse of time. 5) The brain alpha waves increased with the lapse of time, accompanying with a periodical change. 6) In the relationship between the brain alpha waves and the action potential from the gastrocnemius muscle, there was the same cycle at about 1.5 Hz and no change was seen with the lapse of time. 7) There was no significant change in the function of maintaining concentration (TAF). These results suggest that: 1) Besides the reflex mechanism existed as physiological tremor through the stretch reflex loop in maintaining a standing posture, there is a regulation mechanism working to keep balance of the body through the visual organ. 2) The standing posture itself is not always a big stress factor to human body. 3) On the stress by monotonous work, it is necessary to analyse the physiological and psychological load on human body.
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PMID:[Studies on physiological changes due to prolonged standing posture (author's transl)]. 731 53

The MPEG-1 Layer 3 compression schema of audio signal, or commonly known as mp3, has caused a great impact in recent years as it has reached high compression rates while also conserving a high sound quality. Previous listening tests have shown that music and speech samples compressed at high bitrates are virtually indistinguishable from the original samples, but very little is known about how compression acoustically affects the voice signal. In Experiment 1 the spectral composition of original and compressed speech signals were analyzed by means of the Long-Term Average Spectrum using the Computerized Speech Laboratory (Kay Elemetrics Corp. (Pine Brook, NJ, USA)). In Experiment 2 a set of 29 voice parameters extracted by using the Multidimensional Voice Program of Kay are compared between original and compressed voices at different bitrates. Results show a high fidelity at high-bitrate compressions (128 and 160 kbit per second (kbps)) both in voice parameters and the amplitude-frequency spectrum. Compressions at 64 kbps or lower bitrates introduces substantial modifications in the voice signal, seriously altering parameters related with tremor, amplitude perturbation, noise, subharmonics and voice irregularities, likewise the signal spectrum is altered in its high frequency region.
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PMID:The effect of MPEG audio compression on multidimensional set of voice parameters. 1182

This paper introduces the Hilbert Analysis (HA), which is a novel digital signal processing technique, for the investigation of tremor. The HA is formed by two complementary tools, i.e. the Empirical Mode Decomposition (EMD) and the Hilbert Spectrum (HS). In this work we show that the EMD can automatically detect and isolate tremulous and voluntary movements from experimental signals collected from 31 patients with different conditions. Our results also suggest that the tremor may be described by a new class of mathematical functions defined in the HA framework. In a further study, the HS was employed for visualization of the energy activities of signals. This tool introduces the concept of instantaneous frequency in the field of tremor. In addition, it could provide, in a time-frequency-energy plot, a clear visualization of local activities of tremor energy over the time. The HA demonstrated to be very useful to perform objective measurements of any kind of tremor and can therefore be used to perform functional assessment.
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PMID:Application of EMD as a novel technique for the study of tremor time series. 1795 45

The fragile X mental retardation 1 gene (FMR1), which codes for the fragile X mental retardation 1 protein (FMRP), is located at Xp27.3. The normal allele of the FMR1 gene typically has 5 to 40 CGG repeats in the 5' untranslated region; abnormal alleles of dynamic mutations include the full mutation (> 200 CGG repeats), premutation (55-200 CGG repeats) and the gray zone mutation (45-54 CGG repeats). Premutation carriers are common in the general population with approximately 1 in 130-250 females and 1 in 250-810 males, whereas the full mutation and Fragile X syndrome (FXS) occur in approximately 1 in 4000 to 1 in 7000. FMR1 mutations account for a variety of phenotypes including the most common monogenetic cause of inherited intellectual disability (ID) and autism (FXS), the most common genetic form of ovarian failure, the fragile X-associated primary ovarian insufficiency (FXPOI, premutation); and fragile X-associated tremor/ataxia syndrome (FXTAS, premutation). The premutation can also cause developmental problems including ASD and ADHD especially in boys and psychopathology including anxiety and depression in children and adults. Some premutation carriers can have a deficit of FMRP and some unmethylated full mutation individuals can have elevated FMR1 mRNA that is considered a premutation problem. Therefore the term "Fragile X Spectrum Disorder" (FXSD) should be used to include the wide range of overlapping phenotypes observed in affected individuals with FMR1 mutations. In this review we focus on the phenotypes and genotypes of children with FXSD.
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PMID:Fragile X spectrum disorders. 2560 63

Behavioral symptoms and traits have been proposed as early markers in neurodegenerative diseases. The aim of this study was to evaluate social anxiety and autism in FMR1 premutation carriers using the Social Phobia Inventory (SPIN) and the Autism-Spectrum Quotient (AQ) questionnaires. Fifty-nine premutation carriers were compared with 50 controls. The SPIN test showed statistically significant differences between female but not male carriers. The AQ questionnaire found statistically significant differences between premutation carriers and controls in the total AQ as well as in the social skills and attention switching subdomains. A gender effect was only observed for the social skills subdomain. Spearman's correlation analysis revealed a moderately positive correlation with the total AQ scores as well as the social skills and communication subdomains. Our results show that fragile X-associated tremor/ataxia syndrome (FXTAS) patients have higher AQ scores. Moreover, this is the first study to find statistically significant differences between FXTAS and no-FXTAS premutation carriers in the communication and the imagination subdomains, suggesting that FXTAS patients present a broader autistic phenotype than premutation carriers without FXTAS. Based on our results, a wide range of behavioral/psychiatric traits should be included within the broader phenotypic presentation of individuals with the FMR1 premutation.
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PMID:Social anxiety and autism spectrum traits among adult FMR1 premutation carriers. 2710 23

The authors describe the case of a 3-year-old boy with a giant congenital vertex hemangioma who underwent presurgical embolization with Onyx (ethylene-vinyl alcohol copolymer dissolved in dimethyl sulfoxide) and Glubran ( N-butyl-2-cyanoacrylate). This vascular tumor had no intracranial vascular communication as assessed by pre-embolization MRI and catheter angiography. All embolizations were performed by direct percutaneous injection. One week following the last embolization procedure the child presented with a 24-hour history of ataxia and extrapyramidal tremor. He was diagnosed with a possible immune-mediated reaction to Onyx or Glubran, which was treated with an urgent surgical excision of the hemangioma followed by intravenous administration of immunoglobulin and steroids. To the authors' knowledge, this is the first case of possible immune-mediated toxicity secondary to either Onyx or Glubran administration. This case highlights the need for awareness of potential toxic reactions to these embolic agents in the treatment of hemangiomas in the pediatric patient.
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PMID:Possible toxicity following embolization of congenital giant vertex hemangioma: case report. 2793 67

Direct puncture and embolization of the transverse sinus (TS) for treatment of dural arteriovenous fistula (DAVF) is typically performed with coils with or without glue. We report a case of DAVF at the left TS that was treated with Onyx embolization via direct puncture of the TS. A 75-year-old woman presented with tremor, festinating gait, and dysarthria. A left TS-DAVF with retrograde superior sagittal sinus and cortical venous reflux (Cognard type IIa+b) was identified on cerebral angiography, and both TSs were occluded with thrombi. We considered that achieving complete cure by transvenous embolization via the femoral vein or transarterial embolization via occipital feeders would be difficult. Thus, we performed a small craniotomy at the occipital bone to puncture the TS. The midportion of the TS was directly punctured with a 21-G microneedle under fluoroscopic guidance. We inserted a 5-F sheath into the TS. A microcatheter was then navigated into the affected sinus. Coils were placed through the microcatheter to support Onyx formation by reducing the pressure of shunting flow. Onyx embolization was performed with the same microcatheter. The DAVF was almost completely occluded except for the presence of minimal shunting flow to the proximal TS. After 1 week, time-of-flight magnetic resonance angiography showed complete resolution of DAVF. The patient showed resolved tremor and markedly improved mental status at 1-month follow up. Direct puncture and embolization of the TS using coils and Onyx is effective and feasible method for the treatment of DAVF when other approaches seem difficult.
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PMID:Feasibility and Effectiveness of Direct Puncture and Onyx Embolization for Transverse Sinus Dural Arteriovenous Fistula. 3163 95

The disabilities affecting the peripheral regions of the body can be often as a result of cerebellar damage. Tremor, poor and inaccurate coordination, and irregular movements associated with gait, balance and speech are some of the manifestations. Conventionally expert opinion determines severity of Cerebellar Ataxia (CA) and the assessment is likely to be inherently subjective. The automated versions of two commonly used tests: Finger to Nose test (FNT) and Heel to Shin Test (HST), are investigated in this paper for evaluating disability and movement deficits due to CA. Limb movements are measured using Inertial Measurement Units (IMU) that captures the disability related information, using kinematic parameters such as acceleration and angular velocity considered in both time and frequency domain. Using the Singular Spectrum Analysis (SSA), the collective dominance in the data distributions of the underlying features were observed. The dominant features were combined to substantiate the correlation with the expert clinical assessments through Linear Discriminant and Regression analysis where the classifier performance was also verified by means of cross-validation. This study found that IMU features captured characteristic movements as intention tremor in FNT and not in HST. In FNT predominantly consisting of translational movements, the rotation was a dominant feature whereas acceleration were observed to be more dominant for the case of HST.
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PMID:Quantitative Assessment of Cerebella Ataxia, through Automated Limb-Coordination tests. 3194 14