Perspectives in Medicine最新文献

Background

Optic Neuritis (ONe) is common in Multiple Sclerosis (MS). The aim of this study was to evaluate the Optic Nerve (ONr) and its vascularisation in MS patients with and without previous ONe and in Healthy Controls (HC).

Methods

We performed high-resolution echo-color ultrasound examination in 50 subjects (29 MS patients and 21 HC). By a suprabulbar approach we measured the ONr diameter at 3 mm from the retinal plane and at another unfixed point. We assessed the flow velocities of Ophthalmic Artery (OA), Central Retinal Artery (CRA) and Central Retinal Vein (CRV) measuring the Peak Systolic Velocity (PSV) and the End Diastolic Velocity (EDV) for the arteries and the Maximal Velocity (MaxV), Minimal Velocity (MinV) and mean Velocity (mV) for the veins. The Pulsatility Index (PI) and the Resistive Index (RI) were also calculated.

Results

No significant variation for OA supply was found as well as no significant variation for CRA supply, while significant higher PI in the CRV of non-ONe MS eyes vs. both HC and ONe MS eyes was measured. We found that ONr diameter was decreased significantly from HC to non-ONe MS eyes and ONe MS eyes.

Conclusions

Ultrasound examination of ONr and its vascularisation is feasible and can demonstrate ON atrophy. The increase of CRV PI in unaffected eyes of MS patients is intriguing and seems not associated to ONr atrophy. Larger studies are needed to confirm these results.

Purpose

To demonstrate the capabilities of 4D ultrasound calf muscle imaging in patients with genetic types of distal myopathies (DMs).

Methods

Three patients with DM were studied: a 58-year-old man with Vocal Cord and Pharyngeal Weakness Distal Myopathy (VCPDM), a 36-year-old woman with Tibial Muscular Dystrophy (TMD) and a 27-year-old woman with Hereditary Inclusion Body Myopathy Type 2 (HIBM2). Their calf muscles were evaluated in rest and during maximal plantar flexion using 3D/4D ultrasound imaging. The results were compared to myosonograms of healthy controls.

Results

All patients had myopathic syndrome due to advanced muscular dystrophy. In comparison to controls abnormal calf muscle architectonics, reduced muscle contractility and a combination of spot-like hypo- and hyperechoic areas were established on 4D ultrasound imaging. The changes were associated with the degree of muscle atrophy, fat and fibrous tissue infiltration.

Conclusions

Four-dimensional myosonology gives additional information for muscle architectonics in patients with genetic types of DM. Further studies are needed to evaluate if the described findings are typical for specific genetic types of myopathy.

Several experimental studies have shown that noble gases can have neuroprotective effects in cerebral ischemia. The exact mechanism is unknown; increased cerebral blood flow may play a role. In order to investigate this concept we performed a n = 1 trial measuring cerebral blood flow velocity by means of transcranial Doppler (TCD) in a healthy young woman inhaling air or heliox. Peak systolic velocity, mean flow velocity and pulsatility index were measured in the right middle cerebral artery, and oxygen saturation and heart rate were measured with pulse oximetry. After a baseline of 3 min breathing normal air, heliox (79% helium, 21% oxygen) was inhaled though an oral nasal mask for 5 min, followed by a washout period of 5 min breathing normal air. This protocol was repeated four times. No significant changes were observed in hemodynamic parameters, except for a small increase in pulsatility index during heliox inhalation (from 0.91 to 0.95; p = 0.01).

In conclusion, inhalation of heliox does not influence cerebral blood flow in a healthy young person. Any beneficial effects of helium in stroke patients are more likely due to other neuroprotective effects than to hemodynamic changes.

Background

Sickle cell disease (SCD) may impair intellectual activity; 25% of SCD patients have a significant cognitive deficit. Our aim was to verify in a cohort of children with HbSS if the presence of silent strokes or altered Time Averaged Mean velocities of Maximum blood flow (TAMM) detected by Transcranial Color Doppler (TCD) Sonography are indicators of impaired intellectual ability.

Methods

Thirty-five consecutive SCD patients (17 males; mean age: 8.6 ± 3.22) were subdivided into two groups according to neuro-psycological deficits. Cognitive function was assessed by WISC III (for the children aged 6–16 years) and WPPSI (for the children aged 4–6 years). All patients underwent a TCD scan of the main intracranial arteries, in order to detect any increase of TAMM velocities (normal <170 cm/s; altered >170 cm/s) and a cerebral MRI to reveal any silent stokes.

Results

According to the neuro-psycological evaluation, 29/35 (82.8%) patients (Group 1) had a “normal” Total Intelligence Quotient (TIQ ≥70), while 6/35 (17.2%) patients (Group 2) were defined intellectually impaired (TIQ <69).

TCD detected altered velocities in 8/35 (22.8%) patients. No significant differences were found in the percentage of altered TAMM velocities between the two groups (Fisher's exact test: p = 0.42).

MRI detected silent ischemic lesions in 14/35 patients (40.0%). No significant differences were found in silent stroke frequencies (Fisher's exact test: p = 0.25) between Group 1 and Group 2.

Conclusion

With the limitations of the study sample, according to our results, altered TAMM values and silent strokes do not seem to be indicators of impaired intellectual ability in SCD patients.

Neurological deterioration can occur in 13–38% of patients with acute ischemic stroke due to hemodynamic and non-hemodynamic causes. Several non-hemodynamic mechanisms can lead to ischemic lesion extension and subsequent neurological worsening, including infections, cerebral edema, hemorrhagic conversion of infarction and metabolic disorders. The most common hemodynamic causes related to infarct expansion, leading to neurologic deterioration in the setting of acute cerebral ischemia are the following: (i) cardiac complications, (ii) arterial reocclusion, (iii) intracranial arterial steal phenomenon, and (iv) cerebral microembolization. The present review aims to address the underlying mechanisms and potential clinical implications of the hemodynamic causes of neurological deterioration in patients with acute cerebral ischemia. The contribution of neurosonology in detection of changes in cerebral hemodynamics in real-time are also going to be discussed. Finally, potential treatment strategies for specific causes of hemodynamic deterioration in acute ischemic stroke patients are reported.

Background

The aim of the study was to evaluate correlation of breath holding index (BHI) as functional parameter for intracranial subclinical atherosclerotic changes – we have shown in our previous works and arterial stiffness (AS – functional parameter for extracranial subclinical atherosclerotic changes) in diabetic patients with well and poor controlled glucose blood values in correlation with healthy population.

Patients and methods

We included 60 volunteers divided into 3 aged standardized groups – healthy volunteers, patients with well controlled diabetes and patients with poor controlled diabetes. We excluded individuals with moderate and severe carotid stenosis.

Results

There was decreasing trend in BHI values and increasing trend in AS values in diabetic patients, especially with poor regulated blood glucose values (r = −0.14 and 1.42; p < 0.05).

Conclusion

These results show that decline in BHI as parameter for intracranial microvessel dysfunction is in good correlation with increase of AS as functional parameter of extracranial vascular aging in diabetic patients.

Intravenous tissue plasminogen activator (tPA) remains the only approved, fastest and widely feasible treatment of acute ischemic stroke. Systemic tPA induces recanalization of an occluded vessel, the process thought to lead to neurological recovery. Augmentation of this fibrinolytic activity can be safely achieved with diagnostic ultrasound frequencies and intensities. Ultrasound delivers mechanical pressure waves to thrombi exposing more thrombus surface to circulating drug. International multi-center CLOTBUST trial showed that patients with acute stroke treated with sonothrombolysis (tPA+2 MHz TCD) had more dramatic clinical recovery coupled with arterial recanalization (25% vs 8%) at no increase in the risk of symptomatic intracerebral hemorrhage (sICH). Based on this trial and subsequent phase I–II studies of a novel operator-independent device for delivery of the CLOBUST levels of ultrasound energy, a phase III efficacy trial of sonothrombolysis (named CLOTBUSTER) is being launched in Europe and North America.

Major cardio- and cerebrovascular events often occur in individuals without known preexisting cardiovascular disease. The prevention of such events, including the accurate identification of those at risk, remains a serious public health challenge. Scoring equations to predict those at increased risk have been developed using cardiovascular risk factors, but they tend to overestimate the risk in low-risk populations and underestimate it in high-risk populations. This overview discusses the possible role of ultrasound for an optimized prevention of stroke and focusses on (1) the importance of embolic signals in asymptomatic carotid stenosis, (2) the detection of unstable carotid plaques using duplex ultrasonography, and (3) the role of the ankle–brachial index for the stroke risk prediction in the acute stage and for secondary prevention.

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's tumor, is a rare, generally considered a non neoplastic vascular lesion, caused by an abnormal endovascular proliferation of endothelial cells.

We describe, as far as we know, the first case of this lesion, localized at the origin of the internal carotid artery, which was responsible for an ischemic stroke. Although this entity is very rare, it is important for the clinician to become familiar with this lesion, since the complete removal of the lesion is the only treatment of choice. A partial removal may lead to further clinical events.

Background

Saddle thrombosis is less frequently detected in carotid arteries than in peripheral arterial embolism. The clot and the distal vessel patency have to be promptly recognized in these cases, because if the carotid vessel is open distally, chances may arise for successful emergent surgical procedures to remove the thrombus. At conventional static imaging, mobile floating thrombi may be difficult to differentiate from thrombosis on carotid complicated lesions of atherosclerotic origin. High-resolution ultrasound (US), with its unique capability of real-time imaging, adds fundamental data for interpretation of the findings.

Methods

Carotid ultrasound has been performed in acute stroke patients with high-resolution probes. Real-time clips are analyzed and imaging is presented.

Results

Saddle carotid bifurcation thrombosis of cardiac origin has been identified in 2 patients with acute homolateral ischemic stroke, with prompt successful surgical removal in one case. Moreover, an example of a thrombus attached on the ruptured surface of a complicated atherosclerotic plaque in an acute symptomatic stroke patient that was successfully operated in emergency is presented.

Conclusions

Early high-resolution ultrasound with real-time imaging can easily identify peculiar characteristics of carotid vulnerable diseases in acute stroke phase. Different clinical implications result from the early identification of these different conditions, modifying the therapeutical strategies.