a sonographic quantitative cutoff value of cerebral venous outflow in neurologic diseases a blinded study of 115 subjects

BACKGROUND AND PURPOSE: The autonomic nervous system maintains constant cerebral venous blood outflow in changing positions. Alterations in cerebral autoregulation can be revealed by postural changes at quantitative color Doppler sonography. The aim of this study was to reach an optimal cutoff value of the difference between the cerebral venous blood outflow in the supine and seated positions that can discriminate healthy controls from patients with multiple sclerosis and those with other neurologic diseases and to evaluate its specificity, sensitivity, and diagnostic accuracy. MATERIALS AND METHODS: One hundred fifteen subjects (54 with MS, 31 healthy controls, 30 with other neurologic diseases) underwent a blinded quantitative color Doppler sonography evaluation of cerebral venous blood outflow in the supine and sitting positions. An optimal difference value between the supine and sitting positions of the cerebral venous blood outflow cutoff value was sought. RESULTS: The difference value between supine and sitting positions of the cerebral venous blood outflow was ≤ 503.24 in 38/54 (70.37%) patients with MS, 9/31 (29.03%) healthy controls, and 13/30 (43.33%) subjects with other neurological diseases. A difference value between supine and sitting positions of the cerebral venous blood outflow at a 503.24 cutoff reached a sensitivity at 70.37%, a 70.96% specificity, a 80.85% positive predictive value, and a 57.89% negative predictive value; the quantitative color Doppler sonography parameters yielded significant differences. The difference value between supine and sitting positions of cerebral venous blood outflow ≤ 503.24 assessed the significant difference between MS versus other neurological diseases. CONCLUSIONS: Alteration of cerebral venous blood outflow discriminated MS versus other neurologic diseases and MS versus healthy controls. The difference value between supine and sitting positions of cerebral venous blood outflow ≤ 503.24 was statistically associated with MS

Experimental investigation of an atmospheric photoconductively switched high-voltage spark gap

We report on the experimental investigation of the photoconductively switched gas-filled spark gap. When the laser intensity of a femtosecond laser is high enough (around 1018 Wm-2), a plasma can be created that spans the complete distance between the electrodes. The gas-filled spark gap is then closed on a femtosecond timescale, similar to photoconductive switching of a semiconductor switch. Stochastic breakdown processes, such as avalanche and streamer formation that cause the breakdown in laser triggered spark gaps, are passed over, which results in faster risetime and less jitter. Measurements of the switched pulses as a function of laser energy were performed in a 1 mm gap at an applied voltage of 4.5 kV. A clear transition from triggering to switching was measured with increased laser energy. Measurements of the output pulses with the gap filled with nitrogen at 1 atm showed results very similar to measurements in air in the same gap. In the switching regime, the amplitude of the switched pulse did not depend strongly on the laser energy. Measurements at lower applied voltages but with the same gap distance showed that it was possible to switch voltages as low as 10% of the self-breakdown voltage. At low applied voltages, a significant difference between the applied voltage and the output voltage is measured. A possible explanation is given based on the dynamic behavior of the laser created plasma. The measured rise time and jitter of the switched pulses were both below the resolution of the measurement equipment, i.e., better than 100 ps and 15 ps, respectively

A Sonographic Quantitative Cutoff Value of Cerebral Venous Outflow in Neurologic Diseases: A Blinded Study of 115 Subjects

BACKGROUND AND PURPOSE: The autonomic nervous system maintains constant cerebral venous blood outflow in changing positions. Alterations in cerebral autoregulation can be revealed by postural changes at quantitative color Doppler sonography. The aim of this study was to reach an optimal cutoff value of the difference between the cerebral venous blood outflow in the supine and seated positions that can discriminate healthy controls from patients with multiple sclerosis and those with other neurologic diseases and to evaluate its specificity, sensitivity, and diagnostic accuracy. MATERIALS AND METHODS: One hundred fifteen subjects (54 with MS, 31 healthy controls, 30 with other neurologic diseases) underwent a blinded quantitative color Doppler sonography evaluation of cerebral venous blood outflow in the supine and sitting positions. An optimal difference value between the supine and sitting positions of the cerebral venous blood outflow cutoff value was sought. RESULTS: The difference value between supine and sitting positions of the cerebral venous blood outflow was ≤ 503.24 in 38/54 (70.37%) patients with MS, 9/31 (29.03%) healthy controls, and 13/30 (43.33%) subjects with other neurological diseases. A difference value between supine and sitting positions of the cerebral venous blood outflow at a 503.24 cutoff reached a sensitivity at 70.37%, a 70.96% specificity, a 80.85% positive predictive value, and a 57.89% negative predictive value; the quantitative color Doppler sonography parameters yielded significant differences. The difference value between supine and sitting positions of cerebral venous blood outflow ≤ 503.24 assessed the significant difference between MS versus other neurological diseases. CONCLUSIONS: Alteration of cerebral venous blood outflow discriminated MS versus other neurologic diseases and MS versus healthy controls. The difference value between supine and sitting positions of cerebral venous blood outflow ≤ 503.24 was statistically associated with MS

Manual thromboaspiration technique as a first approach for endovascular stroke treatment: A single-center experience

Background For intracranial large vessel occlusion in acute ischemic stroke (AIS), a high degree of revascularization in the minimal amount of time predicts good outcomes. Recently, different studies have shown that the direct aspiration first pass technique (ADAPT technique) for AIS obtains high recanalization rates, fast interventions and low costs when it works as first attempt. This study retrospectively describes revascularization efficacy, duration of procedure, intra and post-procedural complications, early and after 90-days clinical outcome in a group of patients who underwent ADAPT as the primary endovascular approach, eventually followed by stent retriever thrombectomy, for recanalization of large vessels in the anterior circulation. Materials and methods We analyzed clinical and procedural data of patients treated from April 2014 to August 2015. Recanalization was assessed according to the Thrombolysis in Cerebral Infarction score. Clinical outcome was evaluated at discharge and after 3 months (modified Rankin Scale, mRS). Results Overall, 71 patients (mean age of 69.7 years) were treated. Sites of occlusion were anterior circulation (including seven tandem extracranial-intracranial occlusions). In 39 patients i.v. rtPA was attempted. Recanalization of the target vessel was obtained in 87.3% of cases whereas direct aspiration alone was successful in 46/71cases (64.8%) with an average puncture-to-revascularization time of 43.1 minutes. Symptomatic intracranial hemorrhage occurred in 7.8% and embolization to new territories in 5.6%. In total, 38 patients (53.5%) had a good outcome at 90 days follow-up. Conclusions In our series, the manual thromboaspiration technique has been shown as fast and safe, with good rates of vessel revascularization in 87.3% of patients and neurological outcome <3 mRS in 53.5% of patients. © 2016 SAGE Publications

Transition to Homeownership Among Immigrant Groups and Natives in West Germany, 1984–2008

The present paper analyzes transitions to homeownership among immigrant groups and natives in West Germany over a 24–year period from 1984 to 2008. Using data from the German Socioeconomic Panel (GSOEP), we find that everything else being equal, Turks, ex-Yugoslavians, Southern Europeans and Eastern Europeans do not display any differences in transitions into homeownership. Immigrants from wealthy western countries and native Germans possess similar and higher transitions into homeownership. Factors exhibiting a positive effect on transitions to homeownership include years since migration, marital status, age, income and education