Robust sub-millihertz-level offset locking for transferring optical frequency accuracy and for atomic two-photon spectroscopy.

Robust sub-millihertz-level offset locking was achieved with a simple scheme, by which we were able to transfer the laser frequency stability and accuracy from either cesium-stabilized diode laser or comb laser to the other diode lasers who had serious frequency jitter previously. The offset lock developed in this paper played an important role in atomic two-photon spectroscopy with which record resolution and new determination on the hyperfine constants of cesium atom were achieved. A quantum-interference experiment was performed to show the improvement of light coherence as an extended design was implemented.

Different doses of recombinant tissue-type plasminogen activator for acute stroke in Chinese patients.

BACKGROUND AND PURPOSE: The relationship between the dose of recombinant tissue-type plasminogen activator (r-tPA) and its safety/efficacy for ischemic stroke has not been well evaluated in the East Asian population. We assessed the safety/efficacy of different doses of r-tPA for acute ischemic stroke in Chinese patients. METHODS: A total of 1004 eligible patients were classified according to the dose of r-tPA received for managing acute ischemic stroke: 0.9 mg/kg (n=422), 0.8 mg/kg (n=202), 0.7 mg/kg (n=199), and 0.6 mg/kg (n=181). The safety outcome was symptomatic intracerebral hemorrhage and death within 3 months. The efficacy outcome was good functional outcome (modified Rankin Scale ≤1) at 3 months. RESULTS: There was a significant trend for symptomatic intracerebral hemorrhage with age (P=0.002). With multivariate logistic regression analysis, a dose of 0.9 mg/kg was a predictor of symptomatic intracerebral hemorrhage (P=0.0109), and a dose ≤0.65 mg/kg was a predictor of good functional outcome (P=0.0369). In patients aged 71 to 80 years, there was a significant trend of increasing symptomatic intracerebral hemorrhage (P=0.0130) and less good functional outcome (P=0.0179) with increasing doses of r-tPA. There was also a trend of increasing mortality (P=0.0971) at 3 months in these patients. CONCLUSIONS: These results did not support the dose of 0.9 mg/kg of r-tPA being optimal for all patients in the East Asian population. In elderly patients (71-80 years), a lower dose of 0.6 mg/kg is associated with a better outcome. Confirmation of the results through randomized trial is required.

The interpretation of very high frequency band of instantaneous pulse rate variability during paced respiration.

BACKGROUND: Pulse rate (PR) indicates heart beat rhythm and contains various intrinsic characteristics of peripheral regulation. Pulse rate variability (PRV) is a reliable method to assess autonomic nervous system function quantitatively as an effective alternative to heart rate variability. However, the frequency range of PRV is limited by the temporal resolution of PR based on heart rate and it is further restricted the exploration of optimal autoregulation frequency based on spectral analysis. METHODS: Recently, a new novel method, called instantaneous PRV (iPRV), was proposed. iPRV breaks the limitation of temporal resolution and extends the frequency band. Moreover, iPRV provides a new frequency band, called very high frequency band (VHF; 0.4-0.9 Hz). RESULTS: The results showed that the VHF indicated the influences of respiratory maneuvers (paced respiration at 6-cycle and 30-cycle) and the nonstationary condition (head-up tilt; HUT). CONCLUSIONS: VHF is as a potential indication of autoregulation in higher frequency range and with peripheral regulation. It helps for the frequency exploration of cardiovascular autoregulation.

Differences between atrial fibrillation diagnosed before and after stroke: A large real-world cohort study.

The clinical characteristics and long-term outcomes of patients with ischemic stroke (IS) and atrial fibrillation detected after stroke (AFDAS) have not been clearly established. Previous studies evaluating patients with AFDAS were limited by the low prescription rates of anticoagulants and short follow-up periods. Consecutive patients hospitalized for IS between 2014 and 2017 were identified from a National Health Insurance Research Database. The included patients were categorized into three groups: (1) known diagnosis of AF (KAF) before the index stroke, (2) AFDAS, and (3) without AF (non-AF). Univariable and multivariable Cox regression analyses were performed to estimate the hazard ratio (HR) for independent variables and recurrent IS, hemorrhagic stroke, or all-cause mortality. We identified 158,909 patients with IS of whom 16,699 (10.5%) had KAF and 7,826 (4.9%) had AFDAS. The patients with AFDAS were younger, more often male, and had lower CHA2DS2-VASc scores (3.8 ± 1.9 versus 4.9 ± 1.8, p < 0.001) than the patients with KAF. Anticoagulant treatment significantly reduced the risks of all outcomes. The standardized mortality rates were 40.4, 28.6, and 18.4 (per 100 person-years) for the patients with KAF, AFDAS, and non-AF, respectively. Compared with AFDAS, KAF was associated with lower risks of recurrent IS [hazard ratio (HR): 0.91, 95% confidence interval (CI): 0.86-0.97, p < 0.01] and hemorrhagic stroke (HR: 0.88, 95% CI: 0.79-0.99, p < 0.01) and a higher risk of all-cause mortality (HR: 1.11, 95% CI: 1.07-1.16, p < 0.001). The risks of recurrent IS and hemorrhagic stroke were higher and of all-cause mortality was lower for patients with AFDAS than with KAF. There is a strong need to refine treatment modalities to reduce the high mortality in patients with KAF and AFDAS.

Jugular venous reflux and plasma endothelin-1 are associated with cough syncope: a case control pilot study.

BACKGROUND: Jugular venous reflux (JVR) has been reported to cause cough syncope via retrograde-transmitted venous hypertension and consequently decreased cerebral blood flow (CBF). Unmatched frequencies of JVR and cough syncope led us to postulate that there should be additional factors combined with JVR to exaggerate CBF decrement during cough, leading to syncope. The present pilot study tested the hypothesis that JVR, in addition to an increased level of plasma endothelin-1 (ET-1), a potent vasoconstrictor, is involved in the pathophysiology of cough syncope. METHODS: Seventeen patients with cough syncope or pre-syncope (Mean[SD] = 74.63(12.37) years; 15 males) and 51 age/gender-matched controls received color-coded duplex ultrasonography for JVR determination and plasma ET-1 level measurements. RESULTS: Multivariate logistic analysis showed that the presence of both-side JVR (odds ratio [OR] = 10.77, 95% confident interval [CI] = 2.40-48.35, p = 0.0019) and plasma ET-1 > 3.43 pg/ml (OR = 14.57, 95% CI = 2.95-71.59, p = 0.001) were independently associated with the presence of cough syncope/ pre-syncope respectively. There was less incidence of cough syncope/ pre-syncope in subjects with the absence of both-side JVR and a plasma ET-1 ≦3.43 pg/ml. Presence of both side JVR and plasma ET-1 level of > 3.43 pg/ml, increased risk for cough syncope/pre-syncope (p < 0.001). CONCLUSIONS: JVR and higher plasma levels of ET-1 are associated with cough syncope/ pre-syncope. Although sample size of this study was small, we showed a synergistic effect between JVR and plasma ET-1 levels on the occurrence of cough syncope/pre-syncope. Future studies should confirm our pilot findings.

Comparative proteomic analysis of rat aorta in a subtotal nephrectomy model.

Although accelerated atherosclerosis and arteriosclerosis are the main causes of cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients, the molecular pathogenesis remains largely obscure. Our study of the aortic function in a typical CKD model of subtotal nephrectomy (SNX) rats demonstrated phenotypes that resemble CKD patients with aortic stiffness. The 2-DE analysis of rat aortas followed by MS identified 29 up-regulated and 53 down-regulated proteins in SNX rats. Further Western blot and immunohistochemistry analyses validated the decreased HSP27 and increased milk fat globule epidermal growth factor-8 (MFG-E8) in SNX rats. Functional classification of differential protein profiles using KOGnitor revealed that the two major categories involved in aortic stiffness are posttranslational modification, protein turnover, chaperones (23%) and cytoskeleton (21%). Ingenuity Pathway Analysis highlighted cellular assembly and organization, and cardiovascular system development and function as the two most relevant pathways. Among the identified proteins, the clinical significance of the secreted protein MFG-E8 was confirmed in 50 CKD patients, showing that increased serum MFG-E8 level is positively related to aortic stiffness and renal function impairment. Drug interventions with an inhibitor of the angiotensin converting enzyme, enalapril, in SNX rats improved aortic stiffness and decreased MFG-E8 depositions. Together, our studies provide a repertoire of potential biomarkers related to the aortic stiffness in CKD.

Outcomes of thrombolytic therapy for acute ischemic stroke in Chinese patients: the Taiwan Thrombolytic Therapy for Acute Ischemic Stroke (TTT-AIS) study.

BACKGROUND AND PURPOSE: The safety and efficacy of alteplase for ischemic stroke has not been examined in Chinese patients. We assessed the safety and efficacy of alteplase for acute ischemic stroke in daily clinical practice in Taiwan. METHODS: A prospective, multicenter, observational study was conducted in Taiwan from December 2004 to July 2008. Eligible patients (241) receiving alteplase were recruited and divided into 2 groups: standard dose (0.90 + or - 0.02 mg/kg, n=125) and lower dose (0.72 + or - 0.07 mg/kg, n=116). Primary outcome measures were safety: symptomatic intracerebral hemorrhage and death within 3 months. The secondary outcome measure was efficacy a modified Rankin scale of 0 to 2 after 3 months. RESULTS: The standard-dose group had higher rates of symptomatic intracerebral hemorrhage using National Institute of Neurological Diseases and Stroke, European Cooperative Acute Stroke Study, and Safe Implementation of Thrombolysis in Stroke-Monitoring Study definitions (10.4% versus 5.2%, 8.0% versus 2.6%, and 5.6% versus 1.7%, respectively) and mortality within 3 months (12.8% versus 6.9%), twice that of the lower-dose group. This pattern was more prominent in older patients. Significantly higher rates of symptomatic intracerebral hemorrhage per European Cooperative Acute Stroke Study (15.4% versus 3.3%, P=0.0257) and mortality (21.1% versus 5.0%, P=0.0099) and significantly lower independence rate (32.6% versus 53.6%, P=0.0311) were observed among patients > or = 70 years old receiving the standard dose than those receiving the lower dose. CONCLUSIONS: This study suggests that the standard dose of 0.9 mg/kg alteplase may not be optimal for treating aged Chinese patients. However, the dose of recombinant tissue plasminogen activator for ischemic stroke in Chinese patients should be based on more broad and convincing evidences and randomized trials of lower versus higher doses are needed.

Jugular venous reflux affects ocular venous system in transient monocular blindness.

BACKGROUND: The frequency of jugular venous reflux (JVR) is higher in patients with transient monocular blindness (TMB). We hypothesize that JVR influences ocular venous outflow, and resulting disturbances in cerebral and ocular venous circulation might be a cause of TMB. To substantiate this hypothesis, we aimed to demonstrate that: (1) TMB patients have vasculature changes in their retinal venules, and (2) JVR could influence ocular venous outflow, as revealed by dilated retinal venules. METHODS: This study has 2 parts. The case-control study included 31 TMB patients and 31 age/gender-matched normal individuals, who all received fundus photography for retinal venule diameter comparisons. The Valsalva maneuver (VM) experiment included 30 healthy volunteers who received both color Doppler imaging of the internal jugular vein and fundus photography for retinal venule diameter measurement. RESULTS: In the case-control study, TMB patients had a wider retinal venule diameter (184.5 +/- 17.5 vs. 174.3 +/- 16.2 microm, right eye, p = 0.023; 194.20 +/- 24.6 vs. 176.6 +/- 19.5 microm, left eye, p = 0.017), especially TMB patients with JVR. The VM experiments showed that the presence of JVR was associated with a greater increase in retinal venule diameters during VM in the subjects' right eye (14.27 +/- 11.16 vs. 2.75 +/- 3.51%, JVR vs. non-JVR, p = 0.0002) and left eye (10.06 +/- 6.42 vs. 1.80 +/- 2.03%, p = 0.0003). CONCLUSIONS: These findings provide evidence that frequently occurring JVR associated with TMB impedes ocular venous outflow, and the subsequent disturbances in ocular venous circulation may be a cause of TMB.

Synthesis of selenophene derivatives as novel CHK1 inhibitors.

A series of selenophene derivatives 3 were synthesized as potential CHK1 inhibitors. The effects of substitution on the 4'- or 5'-position of selenophene moiety and shifting the hydroxyl group position on C6- phenolic ring of oxindole were explored. This study led to the discovery of the most potent CHK1 inhibitors 29-33 and 39-43, which had IC(50) values in the subnanomolar range.

Reflux of jugular and retrobulbar venous flow in transient monocular blindness.

OBJECTIVE: Transient monocular blindness (TMB) attacks may occur during straining activities that impede cerebral venous return. Disturbance of cerebral and orbital venous circulation may be involved in TMB. METHODS: Duplex ultrasonography and Doppler-flow measurement of jugular and retrobulbar veins were performed in 134 consecutive patients with TMB and 134 age- and sex-matched control subjects. All recruited patients received thorough examinations to screen for possible underlying causes. RESULTS: Of the 134 patients with TMB, 48 patients had ipsilateral carotid arterial lesion and 7 patients had TMB attack(s) caused by cardiac embolism. Of the remaining 79 patients with undetermined cause, 46 had 3 or more TMB attacks (undetermined-frequent group) and 33 had fewer than 3 attacks. In comparison with the control subjects, the TMB patients had greater frequencies of jugular venous reflux (57 vs 30%; p < 0.0001; odds ratio [OR]: 3.079, 95% confidence intervals [CI]: 1.861-5.096) and flow reversal in the superior ophthalmic vein (RSOV; 37 vs 9%; p < 0.0001; OR: 6.052, CI: 3.040-12.048). The undetermined-frequent group had the greatest frequencies of jugular venous reflux (74%, 34 patients; OR: 6.66, CI: 3.13-14.17) and RSOV (59%, 27 patients; OR: 6.51, CI: 3.12-13.58). Of the 50 patients with RSOV, 47 (94%) had RSOV on the side of the TMB attacks. INTERPRETATION: The increased incidences of jugular and orbital venous reflux in TMB patients suggest that disturbance of cerebral and orbital venous circulation is involved in the pathogenesis of TMB, especially among patients with frequent attacks of undetermined cause.

Transient Global Amnesia Linked to Impairment of Brain Venous Drainage: An Ultrasound Investigation.

Background: Previous neuroimaging and ultrasound studies suggested that compression and stenosis of the internal jugular vein (IJV) in patients with transient global amnesia (TGA) may impair IJV drainage, while a patent IJV releases intracranial pressure caused by the Valsalva maneuver (VM). Methods: Seventy-nine TGA patients with complete ultrasound examination data during admission were recruited prospectively to evaluate IJV drainage, which included the time-averaged mean velocity, and the cross-sectional lumen area of the IJV at the vein's middle (J2) and distal (J3) segments and the cross-sectional area during a 10-s VM to test for any retrograde or anti-grade flow. Forty-five TGA patients and 45 age- and sex-matched control subjects underwent complete contrast-enhanced magnetic resonance (MR) venous studies, which included time-resolved imaging of contrast kinetics, contrast-enhanced axial T1-weighted MR imaging, and phase-contrast-based non-contrast enhanced magnetic resonance venography (MRV). Results: In those subjects with complete MRV studies, the flow volumes exhibited at both the J2 and J3 segments of the left IJV and left vertebral vein (VV) were significantly lower in the TGA patients than in the control subjects. Although there was no significant difference in the flow volume of right IJV, the total of bilateral IJV, and VV flow volumes was still significantly lower in the TGA patients. As compared with the control subjects, the TGA patients exhibited significantly higher prevalence of completely blocked right IJV drainage at the J3 segment during the VM, but non-significantly higher for the left IJV at the J3 segment and for the right IJV at the J2 segment. Conclusion: Our results confirmed that the total venous flow decreases in the IJVs and VVs of the patients with TGA. This is consistent with the findings of previous MR imaging studies that have reported about compression and stenosis of the draining veins. We also found that IJV drainage is relatively compromised during the VM in the patients with TGA.

Reagentless pH-stat for microliter fluid specimens.

pH-stating is a common technique for monitoring kinetics of various biochemical reactions that involve the generation of hydrogen or hydroxyl ions. In this work, we describe a reagentless electrochemical micro-pH-stat where the titrant of acid or base is produced by water electrolysis on the rotating sample system (RSS) platform. RSS originated from the authors' laboratory as a convective platform to support different analytical techniques in microliter-sized samples. As water electrolysis induces no volume change and the current that generates the reagent can be precisely measured even at low levels, very small samples in the microliter range become accessible for pH-stating: a reduction of more than an order of magnitude in specimen size relative to the most sensitive conventional methods. Nearly 100% current efficiency has been achieved with this system using a 250 microm Pt minidisc working electrode for electrolysis. The developed micro-pH-stat has been validated by the determination of the activity of erythrocyte acetylcholinesterase as a function of substrate concentration and pH. The optimal pH and activity profile obtained are in good agreement with those determined with standard techniques. The micro-pH-stat has the potential for applications for enzyme assays, reagentless pH control, acidity/alkalinity, and buffer capacity measurements in very small samples of biomedical and environmental origin.

Reversible myelopathy on magnetic resonance imaging due to cobalamin deficiency.

Subacute combined degeneration (SCD) is known as myelopathy due to vitamin B12 deficiency. SCD always involves the posterior and lateral columns of the spinal cord, with the neuropathologic change showing vacuolation of the white matter. We describe 2 patients who presented with ataxic gait, impaired proprioception over limbs, and even mental change due to vitamin B12 deficiency. Magnetic resonance imaging (MRI) of the cervical spine showed increased signal intensity on T2-weighted imaging, and laboratory data showed low serum vitamin B12 level. The 2 patients were treated with vitamin B12 injection intramuscularly. There was clinical improvement after treatment along with normalization of the MRI.

Delayed reversible motor neuronopathy caused by electrical injury.

Electrical injury may cause central nervous system (CNS) complications and peripheral nerve disorders. Delayed neurologic complications are rarely reported. A case of delayed reversible motor neuronopathy caused by low-voltage electrical injury is reported due to its rarity. A 22-year-old female received an electric shock of 110 volts while pushing up a metal gate during a rainy morning on April 16, 2005. She initially suffered loss of consciousness for several hours, and then became quadriplegic, from which she completely recovered 10 days later. After return to work for 1 month, she developed weakness and numbness of bilateral upper limbs. Nerve conduction velocity study and bilateral median nerve somatosensory evoked potential were normal. Magnetic resonance imaging of the brain and cervical spine were also normal. Electromyography showed mild denervation, reduced interference and polyphasia over the upper arms, suggestive of anterior horn cell lesion. After rest and rehabilitation for 2 weeks, the patient completely recovered her muscle power over proximal upper limbs and partially over the distal upper limbs. Follow-up at the outpatient clinic 4 months later showed total recovery of muscle power. Low-voltage electrical current can cause acute transient quadriplegia and delayed motor neuronopathy. The mechanism of this patient's recovery from electric shock, followed by deterioration 1 month later, and then recovery after rest is unclear. We considered whether the mechanism of weakness after electric injury, with initial recovery followed later by the development of weakness, might be due to overuse, just like in post-poliomyelitis syndrome. This needs further investigation.

Altered retrobulbar hemodynamics in patients who have transient monocular blindness without carotid stenosis.

BACKGROUND AND PURPOSE: This study was to evaluate the retrobulbar hemodynamics in patients who have transient monocular blindness (TMB) without carotid stenosis. METHODS: Fifty-nine patients who have TMB without carotid stenosis were studied along with 59 age- and sex-matched controls. Color Doppler-imaging was used to study the retrobulbar hemodynamic by measuring the flow velocities (peak-systolic velocity, and end-diastolic velocity), vascular resistance indices (pulsatility index, and resistance index) in central retinal arteries, short posterior ciliary arteries, and ophthalmic arteries. The patients were divided into 2 groups according to the attack frequency: group 1 (occasional TMB, 2 or fewer attacks, 26 patients) and group 2 (frequent TMB, 3 or more attacks, 33 patients). RESULTS: The risk factors for atherosclerosis were similar between the cases and controls. The means of end-diastolic velocity were significantly lower in central retinal arteries and ophthalmic arteries, and the pulsatility index and resistance index were significantly higher in all the 3 retrobulbar vessels in TMB patients than for the controls. The differences between patients and controls were greater for the group-2 patients. CONCLUSIONS: Patients who have TMB without carotid stenosis had altered retrobulbar hemodynamics with a generalized increase in vascular resistance in the retrobulbar arteries. The role of venous hypertension as an etiology needs further study.

Transient global amnesia: cerebral venous outflow impairment-insight from the abnormal flow patterns of the internal jugular vein.

Cerebral venous reflux is found frequently in transient global amnesia (TGA) patients. The cerebral venous reflux mostly results from left brachiocephalic venous obstruction, and the level of reflux depends on different respiratory status. For further understanding of the role of venous outflow impairment in the pathogenesis of TGA, we used color duplex sonography to reveal the flow patterns in the internal jugular vein (IJV) and its branches (JB) under different respiratory conditions. We compared the frequency of abnormal venous flow of IJV and/or JB on color duplex sonography between 17 TGA patients and 17 age- and gender-matched normal individuals both at rest (regular breathing) and at deep inspiration. Further, these venous-flow abnormalities in IJV and JB were well described. Cranial 3-D time-of-flight magnetic resonance arteriography (MRA) were performed in all patients three to seven days after their TGA attacks and in all normal individuals to analyze the abnormal flow signals in the intracranial venous structures. In the result, abnormal flow-patterns in the left IJV and/or left JB during regular breathing were found more frequently in TGA patients than normal individuals (65% vs. 6%; p < 0.001). These abnormalities in TGA patients were (1) isolated reversed flow in the left JB, (2) segmental reversed flow in the left distal IJV and (3) continuous reversed flow in the left IJV and JB. The MRA study revealed that only the most severe reflux in the IJV causes intracranial venous reflux; six were in the group of continuous reversed flow in left IJV and one was in the group of segmental reversed flow in left distal IJV. These findings suggest that TGA might be one of the clinical manifestations of the "cerebral-type intermittent venous claudication," which stems from cerebral venous outflow impairment, insufficient venous collaterals and specific precipitating factors.

Flow volume in the jugular vein and related hemodynamics in the branches of the jugular vein.

Venous reflux in the internal jugular vein branches (JB) was found frequently in patients of certain neurologic disorders. We hypothesized that the retrograde-flow in JB is associated with retrograde hypertension transmitted from the internal jugular vein (IJV), which presumably underlies those neurologic disorders. In this study, we used color-Doppler imaging to evaluate the dynamic venous flow patterns in the IJV and its branches in 50 normal individuals (21 men, 29 women; mean age: 40.9 +/- 14.9 y, range: 22 to 70 y). The flow-direction of all detected JB (n = 100) was flowing into the IJV at baseline. During the Valsalva maneuver (VM), 38 JB (38%) had a retrograde-flow. Retrograde-flow in JB was significantly associated with IJV valve incompetence (OR = 7.6; 95% CI = 2.6 to 21.8; p = 0.0002) and greater IJV blood flow volume (blood flow volume >670 mL/min) (OR = 6.6; 95% CI = 1.8 to 24.5; p = 0.0052), both of which may reflect higher IJV pressure transmission during VM. The sonographic findings can be used in the future studies of diseases that are suspected to be related with retrograde cerebral venous hypertension due to an elevated IJV venous pressure.

Mechanisms of cough syncope as evaluated by valsalva maneuver.

Successful treatment of cough syncope depends on the correction of various pathogenetic mechanisms among different patients. The valsalva maneuver (VM), which elicits hemodynamic responses mimicking coughs, has potential for investigating the individual pathogenesis of cough syncope. Eighteen consecutive patients suffering from cough-induced syncope were examined. All patients were asked to cough and to perform VM several times under continuous cerebral blood-flow velocity and blood pressure (BP) monitoring by transcranial Doppler and finger plethysmography. Eight patients demonstrated abnormal VM characterized by the absent BP overshoot following the relief of straining. Patients demonstrating abnormal VM had delayed BP recovery after cough (median, 16.4; range, 8.7-25.6 seconds) compared to those demonstrating normal VM (2.6, 1.3-3.8 seconds, p < 0.001). Seven of the 10 patients exhibiting normal BP overshoot during VM had stenotic arterial lesions in the cerebral or coronary circulation, whereas only one of the eight patients demonstrating absent BP overshoot had coronary artery disease (70% vs. 12.5%, p = 0.025). Other clinical profiles, body mass index, frequency of obstructive pulmonary disease and valsalva ratio did not differ between patients featuring normal and absent BP overshoot. In conclusion, the pathogenesis of cough syncope could be different between patients with normal and abnormal VM responses. Patients who had no BP overshoot during VM sustained prolonged hypotension after cough. The VM helps in discriminating among pathogenic mechanisms and guiding investigation and treatment for cough syncope patients.

Ultrasound diagnosis of transverse sinus hypoplasia using flow profiles of the internal jugular vein.

Accurate diagnosis of subtypes of transverse sinus (TS) hypoplasia requires more expensive methods like magnetic resonance (MR) imaging. We hypothesized ultrasound findings of the internal jugular vein (IJV) can be surrogate indicators for diagnosis of TS hypoplasia. MR images were reviewed in 131 subjects to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction. Ultrasound parameters including the cross-sectional lumen area (CSA), time-average-mean velocity (TAMV), and flow volume (FV) at each IJV segment were also evaluated. Sixty-nine subjects had TS hypoplasia based on MRV criteria, of which 39 TS hypoplasia were considered a subtype of TS hypoplasia, which is secondary to the downstream venous compression/stenosis or left brachiocephalic vein. In the ultrasound study, the CSA of the IJV ipsilateral to TS hypoplasia was significantly smaller. Further, a contralateral/ipsilateral IJV CSA ratio >1.55 provided good sensitivity, specificity, and positive predictive value for discriminating TS hypoplasia.

Distribution of carotid arterial lesions in Chinese patients with transient monocular blindness.

BACKGROUND AND PURPOSE: Asian patients with cerebrovascular diseases have more intracranial atherosclerosis and less extracranial carotid artery stenosis compared with white patients. We systemically evaluated the distribution of carotid arterial lesions in Chinese patients with transient monocular blindness (TMB), which was rarely reported. METHODS: We prospectively evaluated 105 consecutive patients with TMB. All of the patients received ocular and physical examinations, blood tests for coagulation function and autoimmune diseases, and ultrasonography of cervical and intracranial arteries. All of the carotid lesions were confirmed by magnetic resonance angiography or cerebral angiography. RESULTS: Of the 36 (34.3%) patients with significant carotid stenosis (> or =50%), 16 (15.2%) had extracranial carotid stenosis; 17 (16.2%) had carotid siphon stenosis; and 3 (2.9%) had both. The duration, onset, and patterns of visual loss were not different between patients with and without carotid arterial lesion. CONCLUSIONS: This study signified the importance of carotid siphon stenosis as a probable underlying etiology for TMB in Chinese patients.