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.

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

Cuff inflation time significantly affects blood flow recorded with venous occlusion plethysmography

© 2019, The Author(s). Purpose: We tested whether the values of limb blood flow calculated with strain-gauge venous occlusion plethysmography (VOP) differ when venous occlusion is achieved by automated, or manual inflation, so providing rapid and slower inflation, respectively. Method: In 9 subjects (20–30 years), we calculated forearm blood flows (FBF) values at rest and following isometric handgrip at 70% maximum voluntary contraction (MVC) when rapid, or slower inflation was used. Result: Rapid and slower cuff inflation took 0.23 ± 0.01 (mean ± SEM) and 0.92 ± 0.02 s, respectively, reflecting the range reported in published studies. At rest, FBF calculated from the 1st cardiac cycle after rapid and slower inflation gave similar values: 10.5 ± 1.4 vs. 9.6 ± 1.3 ml dl − 1  min − 1 , respectively (P > 0.05). However, immediately post-contraction, FBF was ~ 40% lower with slower inflation: 54.6 ± 5.1 vs. 33.8 ± 4.2 ml dl − 1  min − 1 (P < 0.01). The latter value was similar to that calculated over the 3rd cardiac cycle following rapid inflation: 2nd cardiac cycle: 40.5 ± 4.5; 3rd cycle: 32.6 ± 4.5 ml dl − 1  min − 1 . Regression analyses of FBFs recorded at intervals post-contraction showed those calculated over the 1st, 2nd, or 3rd cardiac cycles with rapid inflation correlated well with those from the 1st cardiac cycle with manual inflation (r = 0.79, 0.82, 0.79; P < 0.01). However, only the slope for the 3rd cycle with rapid inflation vs. slower inflation was close to unity (2.07, 1.34, and 0.94, respectively). Conclusion: These findings confirm that the 1st cardiac cycle following venous occlusion should be used when calculating FBF using VOP and, but importantly, indicate that cuff inflation should be almost instantaneous; just ≥ 0.9 s leads to substantial underestimation, especially at high flows

Effect of a home based, low intensity, physical exercise program in older adults dialysis patients: A secondary analysis of the EXCITE trial

Background: Older adults dialysis patients represent the frailest subgroup of the End Stage Renal Disease (ESRD) population and physical exercise program may mitigate the age-related decline in muscle mass and function. Methods: Dialysis patients of the EXCITE trial aged > 65 years (n = 115, active arm, n = 53; control arm, n = 62) were submitted in random order to a home based, low intensity physical exercise program. At baseline and 6 months after exercise training 6-min walking distance (6MWD) and 5-time sit-to-stand test (5STS) were performed, and quality of life (QoL) was tested. Results: The training program improved both the 6MWD (6-months: 327 \ub1 86 m versus baseline: 294 \ub1 74 m; P < 0.001) and the 5STS time (6-months: 19.8 \ub1 5.6 s versus baseline: 22.5 \ub1 5.1 s; P < 0.001) in the exercise group whereas they did not change in the control group (P = 0.98 and 0.25, respectively). The between-arms differences (6 months-baseline) in the 6MWD (+ 34.0 m, 95% CI: 14.4 to 53.5 m) and in the 5STS time changes (- 1.9 s, 95% CI: -3.6 to - 0.3 s) were both statistically significant (P = 0.001 and P = 0.024, respectively). The cognitive function dimension of QoL significantly reduced in the control arm (P = 0.04) while it remained unchanged in the active arm (P = 0.78) (between groups difference P = 0.05). No patient died during the trial and the training program was well tolerated. Conclusions: This secondary analysis of the EXCITE trial shows that a home-based, exercise program improves physical performance and is well tolerated in elderly ESRD patients. Trial registration: The trial was registered in ClinicalTrials.Gov (Clinicaltrials.gov identifier: NCT01255969) on December 8, 2010