A Dynamic Objective Evaluation of Peripheral Arterial Disease by Near-Infrared Spectroscopy

AbstractObjectivesNear-Infrared Spectroscopy (NIRS), suitable for dynamic measurements, is not routinely used for peripheral arterial disease (PAD). We propose a dynamic NIRS-based measurement to quantify variations in muscle metabolism in PAD.MethodSixty-seven consecutive PAD patients (males=56, age 71.6±8.7 years) and 28 healthy subjects (males=12, age 30.4±11.9 years) were studied. An echo-colour Doppler (ECD) was performed and the ankle–brachial index (ABI) was calculated. Participants performed an incremental treadmill test with NIRS probes on the gastrocnemius. Variations in oxygenated (HbO2), deoxygenated (HHb), total (tHb=HbO2+HHb), and differential (dHb=HbO2−HHb) haemoglobin were recorded and quantified as area-under-curve (AUC) within the range 1.7–3.0kmh−1. Heart rate was recorded, and the number of beats in the same interval was calculated (dHr).ResultsO2HbAUC, HHbAUC and dHbAUC differed between diseased and non-diseased legs (P<0.0001) and exhibited different patterns related to PAD severity according to the ABI value. A compensatory heart rate increase was observed in PAD patients. Compared with the ECD positivity for occlusions/stenoses or multiple plaques, only the receiver-operating characteristic (ROC) analysis of dHbAUC (area=0.932, P<0.0001) showed a sensitivity/specificity of 87.6/93.4 for values ≤−197 (LR+LR−: 13.36/0.13).ConclusionThe dynamic NIRS-based test, quantifying muscle metabolic response according to presence and degree of PAD, allows the evaluation of patients with walking disabilities

Chronic cerebrospinal venous insufficiency in patients with multiple sclerosis

BACKGROUND: The extracranial venous outflow routes in clinically defined multiple sclerosis (CDMS) have never been investigated. METHODS: Sixty-five patients affected by CDMS, and 235 controls composed, respectively, of healthy subjects, healthy subjects older than CDMS patients, patients affected by other neurological diseases, and older controls not affected by neurological diseases but scheduled for venography (HAV-C), blindly underwent a combined transcranial and extracranial Color-Doppler high-resolution examination (TCCS-ECD) aimed at detecting at least two of five parameters of anomalous venous outflow. According to the TCCS-ECD screening, patients and HAV-C further underwent selective venography of the azygous and jugular venous system with venous pressure measurement. RESULTS: CDMS and TCCS-ECD venous outflow anomalies were dramatically associated (OR 43, 95% CI 29-65, p<0.0001). Subsequently, venography demonstrated in CDMS, and not in controls, the presence of multiple severe extracranial stenosis, affecting the principal cerebrospinal venous segments; it configures a picture of chronic cerebrospinal venous insufficiency (CCSVI) with four different patterns of distribution of stenosis and substitute circle. Moreover, relapsing-remitting and secondary progressive courses were associated to CCSVI patterns significantly different from those of primary progressive (p<0.0001). Finally, the pressure gradient measured across the venous stenosies was slightly but significantly higher. CONCLUSION: CDMS is strongly associated with CCSVI, a picture never been described so far, characterized by abnormal venous haemodynamics determined by extracranial multiple venous strictures of unknown origin. The location of venous obstructions plays a key role in determining the clinical course of the disease

Calibrating the Mixing Length Parameter for a Red Giant Envelope

Two-dimensional hydrodynamical simulations were made to calibrate the mixing length parameter for modeling red giant's convective envelope. As was briefly reported in Asida & Tuchman (97), a comparison of simulations starting with models integrated with different values of the mixing length parameter, has been made. In this paper more results are presented, including tests of the spatial resolution and Large Eddy Simulation terms used by the numerical code. The consistent value of the mixing length parameter was found to be 1.4, for a red giant of mass 1.2 solar-mass, core mass of 0.96 solar-mass, luminosity of 200 solar-luminosities, and metallicity Z=0.001.Comment: 18 pages, 1 table, 13 figures. Accepted for publication in Ap.

Central venous pressure estimation from ultrasound assessment of the jugular venous pulse

OBJECTIVES: Acquiring central venous pressure (CVP), an important clinical parameter, requires an invasive procedure, which poses risk to patients. The aim of the study was to develop a non-invasive methodology for determining mean-CVP from ultrasound assessment of the jugular venous pulse. METHODS: In thirty-four adult patients (age = 60 ± 12 years; 10 males), CVP was measured using a central venous catheter, with internal jugular vein (IJV) cross-sectional area (CSA) variation along the cardiac beat acquired using ultrasound. The resultant CVP and IJV-CSA signals were synchronized with electrocardiogram (ECG) signals acquired from the patients. Autocorrelation signals were derived from the IJV-CSA signals using algorithms in R (open-source statistical software). The correlation r-values for successive lag intervals were extracted and used to build a linear regression model in which mean-CVP was the response variable and the lagging autocorrelation r-values and mean IJV-CSA, were the predictor variables. The optimum model was identified using the minimum AIC value and validated using 10-fold cross-validation. RESULTS: While the CVP and IJV-CSA signals were poorly correlated (mean r = -0.018, SD = 0.357) due to the IJV-CSA signal lagging behind the CVP signal, their autocorrelation counterparts were highly positively correlated (mean r = 0.725, SD = 0.215). Using the lagging autocorrelation r-values as predictors, mean-CVP was predicted with reasonable accuracy (r2 = 0.612), with a mean-absolute-error of 1.455 cmH2O, which rose to 2.436 cmH2O when cross-validation was performed. CONCLUSIONS: Mean-CVP can be estimated non-invasively by using the lagged autocorrelation r-values of the IJV-CSA signal. This new methodology may have considerable potential as a clinical monitoring and diagnostic tool

Spectral characteristics of the internal jugular vein and central venous pressure pulses: a proof of concept study

In this proof-of-concept study the impact of central venous pressure (CVP) on internal jugular veins cross-sectional area (CSA) and blood flow time-average velocity (TAV) was evaluated in eight subjects, with the aim of understanding the drivers of the jugular venous pulse. CVP was measured using a central venous catheter while CSA variation and TAV along a cardiac cycle were acquired using ultrasound. Analysis of CVP, CSA and TAV time-series signals revealed TAV and CSA to lag behind CVP by on average 0.129 s and 0.138 s, with an inverse correlation between CSA and TAV (r= –0.316). The respective autocorrelation signals were strongly correlated (mean r=0.729-0.764), with mean CSA periodicity being 1.062 Hz. Fourier analysis revealed the frequency spectrums of CVP, TAV and CSA signals to be dominated by frequencies at approximately 1 and 2 Hz, with those &gt;1 Hz greatly attenuated in the CSA signal. Because the autocorrelograms and periodograms of the respective signals were aligned and dominated by the same underlying frequencies, this suggested that they are more easily interpreted in the frequency domain rather than the time domain

Hypoperfusion of brain parenchyma is associated with the severity of chronic cerebrospinal venous insufficiency in patients with multiple sclerosis: a cross-sectional preliminary report

<p>Abstract</p> <p>Background</p> <p>Several studies have reported hypoperfusion of the brain parenchyma in multiple sclerosis (MS) patients. We hypothesized a possible relationship between abnormal perfusion in MS and hampered venous outflow at the extracranial level, a condition possibly associated with MS and known as chronic cerebrospinal venous insufficiency (CCSVI).</p> <p>Methods</p> <p>We investigated the relationship between CCSVI and cerebral perfusion in 16 CCSVI MS patients and 8 age- and sex-matched healthy controls. Subjects were scanned in a 3-T scanner using dynamic susceptibility, contrast-enhanced, perfusion-weighted imaging. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in the gray matter (GM), white matter (WM) and the subcortical GM (SGM). The severity of CCSVI was assessed according to the venous hemodynamic insufficiency severity score (VHISS) on the basis of the number of venous segments exhibiting flow abnormalities.</p> <p>Results</p> <p>There was a significant association between increased VHISS and decreased CBF in the majority of examined regions of the brain parenchyma in MS patients. The most robust correlations were observed for GM and WM (<it>r </it>= -0.70 to -0.71, <it>P </it>< 0.002 and <it>P </it>corrected = 0.022), and for the putamen, thalamus, pulvinar nucleus of thalamus, globus pallidus and hippocampus (<it>r </it>= -0.59 to -0.71, <it>P </it>< 0.01 and <it>P </it>corrected < 0.05). No results for correlation between VHISS and CBV or MTT survived multiple comparison correction.</p> <p>Conclusions</p> <p>This pilot study is the first to report a significant relationship between the severity of CCSVI and hypoperfusion in the brain parenchyma. These preliminary findings should be confirmed in a larger cohort of MS patients to ensure that they generalize to the MS population as a whole. Reduced perfusion could contribute to the known mechanisms of virtual hypoxia in degenerated axons.</p

Programa cognitivo-conductual para el control de los síntomas del tracto urinario inferior después de la prostatectomía radical: un ensayo clínico aleatorizado

Objetivo: avaliar a efetividade de um programa cognitivo-comportamental para controle de sintomas do trato urinário inferior pós-prostatectomia radical. Método: estudo de ensaio clínico randomizado, com 41 participantes aleatorizados em intervenção (n=20) e controle (n=21), durante três meses. O grupo intervenção recebeu o programa cognitivocomportamental, enquanto o grupo controle recebeu orientações de rotina do serviço. As variáveis desfechos foram intensidade da incontinência urinária e sintomas do trato urinário inferior, avaliados pelo Pad-Test e Urinary Incontinence Scale of Radical Prostatectomy e King’s Health Questionnaire. Resultados: ao final do estudo, o grupo intervenção apresentou menor intensidade da incontinência urinária (p≤0,001), e houve menos chances de apresentar alterações da frequência urinária (p≤0,001), urgência miccional (p≤0,001), noctúria (p=0,005), incontinência urinária de esforço (p≤0,001) e urge-incontinência (p≤0,045). Conclusão: o programa cognitivo-comportamental foi efetivo para a redução de sintomas do trato urinário inferior após a prostatectomia radical. Registro Brasileiro de Ensaios Clínicos: RBR-3sstqg.Objective: to assess the effectiveness of a cognitive-behavioral program to control lower urinary tract symptoms after radical prostatectomy. Methods: a randomized clinical trial study, with 41 participants randomized into intervention (n=20) and control (n=21), for three months. The intervention group received the cognitive-behavioral program, while the control group received routine guidance from the service. Outcome variables were urinary incontinence intensity and lower urinary tract symptoms, assessed by the Pad-Test and Urinary Incontinence Scale of Radical Prostatectomy and King’s Health Questionnaire. Results: at the end of the study, the intervention group had a lower urinary incontinence intensity (p≤0.001), and there were less chances of presenting changes in urinary frequency (p≤0.001), urinary urgency (p≤0.001), nocturia (p=0.005), stress urinary incontinence (p≤0.001) and urge incontinence (p≤0.045). Conclusion: the cognitive-behavioral program was effective in reducing lower urinary tract symptoms after radical prostatectomy. Brazilian Clinical Trial Registry: RBR-3sstqg.Objetivo: evaluar la efectividad de un programa cognitivo-conductual para controlar los síntomas del tracto urinario inferior después de la prostatectomía radical. Métodos: estudio de ensayo clínico aleatorizado, con 41 participantes aleatorizados en intervención (n=20) y control (n=21), durante tres meses. El grupo de intervención recibió el programa cognitivoconductual, mientras que el grupo control recibió orientación rutinaria del servicio. Las variables de resultado fueron la intensidad de la incontinencia urinaria y los síntomas del tracto urinario inferior, evaluados mediante Pad-Test y Urinary Incontinence Scale of Radical Prostatectomy y King’s Health Questionnaire. Resultados: al final del estudio, el grupo intervención presentó menor intensidad de incontinencia urinaria (p≤0,001), y hubo menos posibilidades de presentar cambios en la frecuencia urinaria (p≤0,001), urgencia urinaria (p≤0,001), nicturia (p=0,005), incontinencia urinaria de esfuerzo (p≤0,001) e incontinencia de urgencia (p≤0,045). Conclusión: el programa cognitivo-conductual fue eficaz para reducir los síntomas del tracto urinario inferior después de la prostatectomía radical. Registro Brasileño de Ensayos Clínicos: RBR-3sstqg

Efficacy and safety of extracranial vein angioplasty in multiple sclerosis: A randomized clinical trial

Importance: Chronic cerebrospinal venous insufficiency (CCSVI) is characterized by restricted venous outflow from the brain and spinal cord. Whether this condition is associated with multiple sclerosis (MS) and whether venous percutaneous transluminal angioplasty (PTA) is beneficial in persons with MS and CCSVI is controversial. Objective: To determine the efficacy and safety of venous PTA in patients with MS and CCSVI. Design, Setting, and Participants: We analyzed 177 patients with relapsing-remitting MS; 62 were ineligible, including 47 (26.6%) who did not have CCSVI on color Doppler ultrasonography screening. A total of 115 patients were recruited in the study timeframe. All patients underwent a randomized, double-blind, sham-controlled, parallel-group trial in 6MS centers in Italy. The trial began in August 2012 and concluded in March 2016; data were analyzed from April 2016 to September 2016. The analysis was intention to treat. Interventions: Patients were randomly allocated (2:1) to either venous PTA or catheter venography without venous angioplasty (sham). Main Outcomes and Measures: Two primary end pointswere assessed at 12 months: (1) a composite functional measure (ie, walking control, balance, manual dexterity, postvoid residual urine volume, and visual acuity) and (2) a measure of new combined brain lesions on magnetic resonance imaging, including the proportion of lesion-free patients. Combined lesions included T1 gadolinium-enhancing lesions plus new or enlarged T2 lesions. Results: Of the included 115 patients with relapsing-remitting MS, 76 were allocated to the PTA group (45 female [59%]; mean [SD] age, 40.0 [10.3] years) and 39 to the sham group (29 female [74%]; mean [SD] age, 37.5 [10.6] years); 112 (97.4%) completed follow-up. No serious adverse events occurred. Flow restoration was achieved in 38 of 71 patients (54%) in the PTA group. The functional composite measure did not differ between the PTA and sham groups (41.7%vs 48.7%; odds ratio, 0.75; 95%CI, 0.34-1.68; P = .49). The mean (SD) number of combined lesions on magnetic resonance imaging at 6 to 12 months were 0.47 (1.19) in the PTA group vs 1.27 (2.65) in the sham group (mean ratio, 0.37; 95%CI, 0.15-0.91; P = .03: adjusted P = .09) and were 1.40 (4.21) in the PTA group vs 1.95 (3.73) in the sham group at 0 to 12 months (mean ratio, 0.72; 95%CI, 0.32-1.63; P = .45; adjusted P = .45). At follow-up after 6 to 12 months, 58 of 70 patients (83%) in the PTA group and 22 of 33 (67%) in the sham group were free of new lesions on magnetic resonance imaging (odds ratio, 2.64; 95%CI, 1.11-6.28; P = .03; adjusted P = .09). At 0 to 12 months, 46 of 73 patients (63.0%) in the PTA group and 18 of 37 (49%) in the sham group were free of new lesions on magnetic resonance imaging (odds ratio, 1.80; 95%CI, 0.81-4.01; P = .15; adjusted P = .30). Conclusion and Relevance: Venous PTA has proven to be a safe but largely ineffective technique; the treatment cannot be recommended in patients with MS