To study the differential educational effects of a multimodal educational program on public stroke knowledge, we performed computer-assisted telephone surveys among a random sample of 500 members of ...the general public, before and immediately after an intense three-month educational campaign. The intervention comprised of poster advertisements, flyers, mail circular, slogans, stroke interest stories etc. in local newspapers, on television and radio, and public events. The main outcome measures were stroke knowledge, the intended behavior in acute stroke and the educational media remembered after the intervention. General knowledge of the nature of stroke (65.7% correct answers before versus 84.9 % after the campaign, p < 0.01) and the awareness of being at risk of stroke (32.7 % vs. 41.9%, p < 0.01) increased due to the campaign, especially in respondents of lower educational background. There was no significant effect on the number of patients who would seek emergency medical care after the intervention (81 % vs. 82 %) and hardly any effect on detailed knowledge of stroke warning signs or different risk factors.Mass media like newspapers, radio and television were most frequently reported as the main information source remembered (66.6 %). Our data indicate that educational programs do have differential effects on public stroke knowledge and individual stroke risk,which does not necessarily lead to a change in care-seeking behavior. Repeated information using short-tailored slogans and cues to action led to a gain in general stroke knowledge, especially in high-risk populations of lower educational background. Large educational campaigns seem unsuitable, however, for mediation of detailed information on stroke.
BACKGROUND AND PURPOSE—In patients who present with acute ischemic stroke while on treatment with non–vitamin K antagonist oral anticoagulants (NOACs), coagulation testing is necessary to confirm the ...eligibility for thrombolytic therapy. We evaluated the current use of coagulation testing in routine clinical practice in patients who were on NOAC treatment at the time of acute ischemic stroke.
METHODS—Prospective multicenter observational RASUNOA registry (Registry of Acute Stroke Under New Oral Anticoagulants; February 2012–2015). Results of locally performed nonspecific (international normalized ratio, activated partial thromboplastin time, and thrombin time) and specific (antifactor Xa tests, hemoclot assay) coagulation tests were documented. The implications of test results for thrombolysis decision-making were explored.
RESULTS—In the 290 patients enrolled, nonspecific coagulation tests were performed in ≥95% and specific coagulation tests in 26.9% of patients. Normal values of activated partial thromboplastin time and international normalized ratio did not reliably rule out peak drug levels at the time of the diagnostic tests (false-negative rates 11%–44% 95% confidence interval 1%–69%). Twelve percent of patients apparently failed to take the prescribed NOAC prior to the acute event. Only 5.7% (9/159) of patients in the 4.5-hour time window received thrombolysis, and NOAC treatment was documented as main reason for not administering thrombolysis in 52.7% (79/150) of patients.
CONCLUSIONS—NOAC treatment currently poses a significant barrier to thrombolysis in ischemic stroke. Because nonspecific coagulation test results within normal range have a high false-negative rate for detection of relevant drug concentrations, rapid drug-specific tests for thrombolysis decision-making should be established.
CLINICAL TRIAL REGISTRATION—URLhttp://www.clinicaltrials.gov. Unique identifierNCT01850797.
Vertebrobasilar ischemia has been attributed to a reduction of net vertebral artery flow volume, the product of mean flow velocity and the cross-sectional area of the vessel. It can be determined by ...duplex sonography. There are no reference values for vertebral artery flow volume in an age group representative of patients with cerebrovascular disease.
We examined 50 nonvascular neurological patients (age 55.8+/-14.0 years). Flow velocities and vessel diameters were recorded in the intertransverse (V2) segments bilaterally, and the flow volume was calculated according to the following equations: (1) Q1=time-averaged mean velocity times area and (2) Q2=(time-averaged maximum velocity/2)times area.
Flow velocities and vessel diameters tended to be lower on the right side, resulting in a lower flow volume. Flow volumes (according to Equation 1) were 77.2+/-29.8 mL/min on the right side, 105.3+/-46.4 mL/min on the left side, and 182.0+/-56.0 mL/min net. Side-to-side differences were not significant. Flow volumes calculated with the 2 equations did not differ significantly. An age dependence could not be shown, but vessel diameters and net vertebral artery flow volumes were significantly lower in women than in men. The normal range for net vertebral artery flow volume defined by the 5th to 95th percentiles is between 102.4 and 301.0 mL/min. This wide range is due to the high interindividual variability of the parameters.
On the basis of the reference values presented here, the association of decreased vertebral artery flow volume and vertebrobasilar ischemia should be reevaluated. Additional areas for investigation include the quantification of collateral flow in the vertebral arteries in carotid artery occlusive disease and their contribution to overall cerebral blood flow volume.
While transient global amnesia (TGA) is a clinically well defined disorder, its etiology is poorly understood. Cerebral venous hypertension and subsequent damage to hippocampal and diencephalic ...structures are among the discussed hypothetical causes. Using a direct method for the study of retrograde flow during a Valsalva maneuver, we determined whether jugular valve insufficiency contributes to cerebral venous hypertension in patients with TGA.
Jugular valve closure was assessed by duplex sonography in 20 patients with TGA and 20 age and gender matched controls. The diagnosis of valvular insufficiency was made on the basis of recently established criteria.
Valvular insufficiency (either left or right-sided, or bilateral) was identified in 85% of patients with TGA,and in 45% of controls (p = 0.008). All patients with involuntary Valsalva episodes immediately prior to TGA developed valvular insufficiency (n = 8; p = 0.13 compared with patients who did not recall such an event). The mean duration of the insufficiency jet did not differ significantly between patients with TGA (3.26 s) and controls (2.78 s; p = 0.315). However, patients with TGA who experienced a trigger event were characterized by significantly longer insufficiency reflux times (3.84 s) than those without (2.55 s; p = 0.03).
TGA is associated with an increase in the prevalence of jugular insufficiency. Valvular insufficiency may lead to increased venous pressure transmission during a Valsalva maneuver and thus contribute to venous ischemia in TGA. The association of valvular insufficiency and longer reflux times with the occurrence of a trigger event further suggests that cerebral venous congestion is an important etiological factor in transient global amnesia.
Swallowing disorders are common symptoms in many neurological diseases. The aim of this pilot-study was to analyse vertical laryngeal excursion during swallowing non-invasively using ultrasound ...sonographic techniques in patients with dysphagia compared with healthy volunteers.
Data were obtained from 42 healthy volunteers (mean age: 57 +/- 19 years) and 18 patients (mean age: 63 +/- 8 years) with dysphagia due to different neurological diseases using a 7.5 MHz linear array probe, which was placed in longitudinal position above the larynx. This allowed visualization of the contour and the acoustic shadow of the hyoid bone and the thyroid cartilage. The distance between the hyoid bone and the upper end of the thyroid cartilage during laryngeal elevation was readily assessed by video-mode function.
In healthy subjects we found a mean distance of 220 (+/- 30) mm at rest; the shortest distance during swallowing of 5 or 10 ml water was 85 (+/- 11) mm and represents a reduction of 61 % (+/- 3) under physiological conditions. The mean relative laryngeal elevation in the patients with neurogenic dysphagia was reduced to only 42 % (+/- 10) (p < 0.0001).
Ultrasound is a viable and non-invasive method in the investigation of laryngeal elevation during swallowing. It allows direct visualization of impaired laryngeal motion in patients with neurogenic dysphagia.
To compare the additive effect of a helium-oxygen mixture (Heliox) or racemic epinephrine (RE) on croup scores (CSs) in children with moderate to severe croup treated with humidified oxygen and ...steroids. Design. A prospective, randomized, double-blind trial.
Emergency department and pediatric intensive care unit of an urban level I trauma center.
Randomly assigned, consecutive children ages 6 months to 3 years presenting with moderate to severe croup (CS: >/=5). Interventions. After cool humidified oxygen and 0.6 mg/kg of intramuscular dexamethasone, patients were randomized to receive either Heliox or RE. Vital signs, oxygen saturation, and CSs were recorded at regular intervals. OUTCOME/ANALYSIS: Reductions in CSs were compared using repeated-measures analysis of variance.
Thirty-three patients were enrolled. Three were excluded because of protocol violations, and 1 was excluded because of lack of documentation, leaving 29 patients for final analysis. The average age was 24.2 months, 20 were male (68.8%). Both Heliox and RE were associated with improvement in CSs over time. There were no significant differences in mean CS, oxygen saturation, respiratory rate, or heart rate between groups at baseline or at the end of the treatment period.
In patients with moderate to severe croup, the administration of Heliox resulted in similar improvements in CS compared with patients given RE.
A 65-year-old man had an embolic stroke of both posterior cerebral arteries in 2002. Two years later he noted rapid improvement of the residual bilateral inferior quadrant anopia whenever he took ...25 mg sildenafil. The improvement of scotomas was verified by visual field examinations and persisted reproducibly for 3–7 days. An overlay of a subtraction of functional magnetic resonance imaging (MRI) during visual stimulation before and after medication onto a T
1
-weighted MRI of the patient revealed additional activations along the margins of the old cerebral infarctions. These findings and the additional results of a perfusion MRI suggest that phosphodiesterase 5 inhibitors may prove beneficial in the rehabilitative course after ischemic strokes.
As the clinical implications of altitude sickness are well known, the etiology of this potential life threatening disease is far from understood completely. We studied noninvasively by means of ...Neurosonography the effects of a rapid change of altitude in the alpine region on the cerebral volume flow and intracranial pressure.
We studied 36 participants (19 m, 17 w; mean age 52yrs) of the 55th. Conference of Clinical Neurophysiology and Adjacent Specialities, which took place in January 2016 in Gaschurn/Montafon/Austria. Participants were studied first in the conference hotel (altitude above sea level appr. 1000m) and with a maximum latency of 30min. to the first study a second time in a mountain station (altitude appr. 2000m). The primary question of this trial was to investigate a potential altitude change induced impact on the volume flow rate in the Common Carotid (CCA) and Internal Carotid Artery (ICA) as well as flow velocity changes in the Middle Cerebral Artery (MCA). Additionally the Optic Sheath Diameter (OSD) was determined to obtain data on intracranial pressure. The extracranial volume flow rate was determined by integrating vessel diameter and flow velocity information. Data were obtained by 2 portable color duplex systems (GE, Logiq e; 3–10 (Doppler 5) MHz linear array probe for extracranial applications and OSD measurements; a 1,7-4 (Doppler 2,5) MHz phased array probe was applied transcranially). Additionally, data on blood pressure, heart rate, facial skin temperature and endexpiratory CO2 were obtained.
As the volume flow rate in the CCA significantly dropped from 508 to 410ml/min.
Previous neurophysiological studies on altitude sickness as published from the Inselspital in Bern/Switzerland have focussed on extreme situations, mountaineers are exposed in extreme high altitude (including the Himalaya). We studied moderate, but rapid changes of altitude. The study set up was applied successfully and can also be used in future studies investigating bigger altitude changes. An altitude change of 1000m, which skiers and conventional European mountaineers are experiencing, has no impact on cerebral perfusion and intracranial pressure.
Ultrasound-accelerated thrombolysis is a promising approach toward acute stroke treatment. In previous in vitro studies, we demonstrated enhanced thrombus destruction induced by 20-kHz ultrasound. ...However, little is known about biological interactions of low-frequency ultrasound with brain tissue. The aim of this in vivo MRI study was to assess safety aspects of transcranial low-frequency ultrasound in rats.
The cranium of 33 male Wistar rats was sonificated for 20 minutes (20-kHz continuous wave). Power output was varied between 0 and 2.6 W/cm2. Tympanal and rectal temperature was monitored. Diffusion-weighted imaging and T2-weighted imaging was performed before and 4 hours, 24 hours, and 5 days after sonification. Apparent diffusion coefficients (ADCs) and T2 relaxation time (T2-RT) were measured in regions of interest in the cortex and the basal ganglia. The animals were euthanized for histological evaluation thereafter.
Tympanal temperature increased significantly during insonation with 1.1 and 2.6 W/cm2. ADCs decreased significantly at 0.5 and 1.1 W/cm2, indicating cytotoxic edema. T2-RT increased significantly in the 0.5 and 1.1 W/cm2 group, consistent with vasogenic edema. No changes were detectable in the low-power output group (0.2 W/cm2). After sonification with 2.6 W/cm2, a significant loss of neurons could be detected on histopathology. Furthermore, 3 animals developed circumscript cortical lesions that could be identified as parenchymal necrosis.
Low-frequency ultrasound caused vasogenic and cytotoxic brain edema and intracerebral necrosis in a dose-dependent fashion. This study indicates therapeutic low-frequency ultrasound as being potentially harmful and underlines the necessity of careful evaluation in further animal models.
Laser Doppler is widely used to evaluate sympathetic vasoconstrictor function. Continuous wave (cw)-Doppler of the radial artery may be an alternative but less expensive approach to quantify ...sympathetically induced resistance changes in the peripheral vascular system. In order to compare the power of both methods, this study was performed with simultaneous assessment of cw Doppler and laser Doppler flowmetry in volunteers. Twenty-five healthy subjects (median age years, range 20-27) rested in a relaxed supine position and were asked to perform a deep inspiratory gasp and a commanded cough (DIG + C). Radial artery blood flow was assessed with a standard cw Doppler device, arteriolar blood flow was assessed simultaneously employing a single point laser Doppler perfusion monitor at the fingertips. We quantified the latency between stimulus and onset of vasoconstriction, the latency to the maximum vasoconstriction and the duration of response. The decrease in flow velocities (cw Doppler) after stimulus was compared with the decrease in capillary flow (laser Doppler). While the flow profile as measured with laser Doppler remained monophasic after stimulation, cw Doppler showed biphasic flow (or absent diastolic flow) in all subjects after DIG + C. The latencies between stimulus and onset of reaction were significantly shorter when measured with laser Doppler (1.8 s vs. 2 s, p = 0.049), the latencies till the maximum extent of the reaction was reached did not differ significantly (3.2 vs. 3.3 s). The duration of the response was significantly shorter when measured by laser Doppler (12.0 vs. 14.5 s (p < 0.0001). While skin blood flow in the laser Doppler measurement decreased after stimulation from 654 flux units (FU) to 319 FU (-59%), mean flow velocities in the radial artery declined from 1.07 kHz to 0.14 kHz (-87%). This relative change was significantly different (p < 0.0001). The correlation between the decline of flux units as measured by laser Doppler and cw Doppler changes was r = 0.616 (p = 0.004). Both methods are feasible to monitor flow changes due to sympathetic stimulation. Latencies and relative quantitative changes were closely correlated.Thus, cw Doppler is a valid alternative approach to laser Doppler flowmetry in healthy volunteers.
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