Concurrent subarachnoid haemorrhage and internal carotid artery dissection: a transcranial colour-coded sonography diagnosis

We report the case of a young woman affected by an aneurysmal subarachnoid haemorrhage (SAH) and numerous anatomic abnormalities. A Transcranial Colour-Coded Duplex Sonography, performed with the aim of monitoring the vasospasm, showed a non-pulsatile flow with loss of sharp systolic peak and lowering of mean flow velocities in the right extracranial Internal Carotid Artery (ICA) and all its intra-cranial branches. This event suggested a possible concomitant acute right ICA sub-occlusion with a lack of collateral circulation. This type of flow is typically found in systemic and brain arteries of patients undergoing to venous-arterial extracorporeal membrane oxygenation or to left ventricular assist devices. The absence of an adequate cerebral collateral circulation might be the explanation for this type of atypical flow. Aneurysms and arterial dissections contribute to SAH and ischemic stroke events, leading to long-term physical and cognitive disability. In our case, the prompt neurosonological diagnosis leaded to patient's good outcome.

A Single-Center Retrospective Analysis of 14 Head and Neck AVMs Cases Treated with a Single-Day Combined Endovascular and Surgical Approach

Arteriovenous malformations (AVMs) are rare congenital defects of vascular development whose treatment remains challenging. The paper presents a retrospective single-center study of 14 patients with AVMs of the head and neck region undergoing combined endovascular and surgical treatment in a single day. AVM architecture and therapeutic strategies were determined on the basis of angiographic studies, while the psychological involvement of each patient was assessed by means of a questionnaire. Most of the 14 patients achieved satisfactory clinical results with no recurrences, good aesthetic and functional results, and most patients reported improved quality of life. The combined endovascular and surgical approach is an effective treatment for AVMs of the head and neck and performing it on the same day is a possible option often accepted by patients which guarantees operative advantages for the surgeon.

Safety of intravenous thrombolysis and mechanical thrombectomy in bilateral posterior cerebral artery territory infarction

BACKGROUND

Acute bilateral blindness is an uncommon phenomenon, that requires immediate diagnosis and action. The emergent evaluation should concentrate on an early distinction between ocular, cortical, and psychogenic etiologies.

OBJECTIVE

To present a case of cortical blindness without anosognosia due to the embolic occlusion of both posterior cerebral arteries (PCAs) and treated by intravenous and mechanical thrombolysis.

CASE REPORT

A 67-year-old woman was admitted to the Stroke Unit due to cortical blindness without anosognosia. At the admission to the Hospital an emergent computed tomography scan of the brain ruled out intracranial acute hemorrhage and showed subtle changes consistent with hyperacute ischemia of the left occipital cortex, while a CT angiography demonstrated the occlusion of the P3 segment of both right and left posterior cerebral arteries. The patient was treated with combined thrombolysis (intravenous and mechanical thrombolysis), obtaining the complete revascularization and a significant clinical improvement.

CONCLUSION

Even if there is no randomized controlled trial to compare the effectiveness and safety of mechanical thrombectomy (MT) to intravenous thrombolysis in patients with posterior circulation occlusion, the good outcome of this case encourages combined stroke treatments in posterior circulation stroke, even in case of mild but disabling neurological deficits.

Comparison of aspiration versus combined technique as first-line approach in terminal internal carotid artery occlusion: a multicenter experience

BACKGROUND

There is no consensus on the most effective endovascular technique to use in patients with acute ischemic stroke due to terminal internal carotid artery (ICA) occlusion. The aim of this study was to compare safety and efficacy of the aspiration technique (AT) and combined technique (CT) as first-line approach in terminal ICA occlusions.

METHODS

We performed a retrospective analysis of prospectively collected databases from seven Italian stroke centers. Patients were divided into two subgroups according to the first-line approach: AT group or CT group. We followed the STROBE guidelines for cohort studies. We used Chi-square test, one-way and multivariate ANOVA analysis, together with contrast analysis and post hoc tests, logistic regression and Pearson's bivariate correlation for the statistical analyses.

RESULTS

Between January 2018 and August 2020, 353 patients were treated for a terminal ICA occlusion, with either AT or CT. CT was associated with a higher Thrombolysis in Cerebral Infarction (TICI) 2B-3 after the first pass (51.0% vs 26.9%) and at the end of the procedure (84% vs 73.3%) and with an improved clinical outcome at discharge (modified Rankin Scale (mRs) 0-2 of 47.8% vs 34.0%) and at 3 months' follow-up (mRs 0-2 of 56.5% vs 38.9%) compared with AT.

CONCLUSION

Thrombectomy of terminal ICA occlusions obtained using CT as first-line approach demonstrated better technical and functional outcomes in comparison with AT.

Functional and radiological outcomes after bridging therapy versus direct thrombectomy in stroke patients with unknown onset: Bridging therapy versus direct thrombectomy in unknown onset stroke patients with 10-point ASPECTS

BACKGROUND AND PURPOSE

The aim was to assess functional and radiological outcomes after bridging therapy (intravenous thrombolysis plus mechanical thrombectomy) versus direct mechanical thrombectomy (MT) in unknown onset stroke patients.

METHODS

A cohort study was conducted on prospectively collected data from unknown onset stroke patients who received endovascular procedures at ≤6 h from symptom recognition or awakening time.

RESULTS

Of the 349 patients with a 10-point Alberta Stroke Program Early Computed Tomography Score (ASPECTS), 248 received bridging and 101 received direct MT. Of the 134 patients with 6-9-point ASPECTS, 123 received bridging and 111 received direct MT. Each patient treated with bridging was propensity score matched with a patient treated with direct MT for age, sex, study period, pre-stroke disability, stroke severity, type of stroke onset, symptom recognition to groin time (or awakening to groin time), ASPECTS and procedure time. In the two matched groups with 10-point ASPECTS (n = 73 vs. n = 73), bridging was associated with higher rates of excellent outcome (46.6% vs. 28.8%; odds ratio 2.302, 95% confidence interval 1.010-5.244) and successful recanalization (83.6% vs. 63%; odds ratio 3.028, 95% confidence interval 1.369-6.693) compared with direct MT; no significant association was found between bridging and direct MT with regard to rate of symptomatic intracerebral hemorrhage (0% vs. 1.4%). In the two matched groups with 6-9-point ASPECTS (n = 45 vs. n = 45), no significant associations were found between bridging and direct MT with regard to rates of excellent functional outcome (44.4% vs. 31.1%), successful recanalization (73.3% vs. 76.5%) and symptomatic intracerebral hemorrhage (0% vs. 0%).

CONCLUSIONS

Bridging at ≤ 6 h of symptom recognition or awakening time was associated with better functional and radiological outcomes in unknown onset stroke patients with 10-point ASPECTS.

Endovascular treatment of cerebral dural arteriovenous fistulas with SQUID 12

BACKGROUND

Endovascular therapy with liquid embolic agents (LEAs) is the gold standard for the treatment of cerebral dural arteriovenous fistulas (cDAVFs). The aim of the study is to retrospectively evaluate effectiveness, safety, and midterm follow-up results of endovascular treatment of cDAVFs using SQUID 12.

METHODS

Between June 2017 and January 2020 the authors retrospectively reviewed clinical, demographic and embolization data of 19 consecutive patients with cDAVF who underwent embolization using SQUID 12. The number of arteries catheterized for each procedure, the total amount of embolic agent, the occlusion rate, the injection time, any technical and/or clinical complications were recorded. Mid-term follow-up with DSA was reviewed.

RESULTS

20 procedures were performed in 19 patients. A transarterial approach was accomplished in 19 procedure; a combined transvenous-transarterial approach was realized in 1 treatment. The average time of injection was 33 minutes (2-82 minutes), and the average amount of SQUID 12 was 2.8 mL (0.5-6 mL). Complete angiographic cure at the end of the procedure was achieved in 17 patients. No major periprocedural adverse events were recorded. Mid-term follow-up was achieved in 15 out of 19 patients and confirmed complete occlusion of the cDAVFs in 13/15 patients (87%); in 2 of the initially cured patients a small relapse was detected.

CONCLUSIONS

The treatment of the cDAVFs using SQUID 12 was effective and safe. The lower viscosity seems to allow an easier penetration of the agent with a high rate of complete occlusion of the cDAVFs.

Direct thrombectomy for stroke in the presence of absolute exclusion criteria for thrombolysis

BACKGROUND

Intravenous thrombolysis (IVT)-ineligible patients undergoing direct thrombectomy tended to have poorer functional outcome as compared with IVT-eligible patients undergoing bridging therapy. We aimed to assess radiological and functional outcomes in large vessel occlusion-related stroke patients receiving direct thrombectomy in the presence of absolute exclusion criteria for IVT vs relative exclusion criteria for IVT and vs non-exclusion criteria for IVT.

METHODS

A cohort study on prospectively collected data from 2282 patients enrolled in the Italian Registry of Endovascular Treatment in Acute Stroke cohort for treatment with direct thrombectomy (n = 486, absolute exclusion criteria for IVT alone; n = 384, absolute in combination with relative exclusion criteria for IVT; n = 777, relative exclusion criteria for IVT alone; n = 635, non-exclusion criteria for IVT).

RESULTS

After adjustment for unbalanced variables (model 1), ORs for 3-month death was higher in the presence of absolute exclusion criteria for IVT alone (vs relative exclusion criteria for IVT alone) (1.595, 95% CI 1.042-2.440) and in the presence of absolute exclusion criteria for IVT alone (vs non-exclusion criteria for IVT) (1.235, 95% CI 1.014-1.504). After adjustment for predefined variables (model 2: age, sex, pre-stroke mRS ≤ 1, NIHSS, occlusion in the anterior circulation, onset-to-groin time, and procedure time), ORs for 3-month death was higher in the presence of absolute exclusion criteria for IVT alone (vs relative exclusion criteria for IVT alone) (1.235, 95% CI 1.014-1.504) and in the presence of absolute exclusion criteria for IVT alone (vs non-exclusion criteria for IVT) (1.246, 95% CI 1.039-1.495). No significant difference was found between the groups as regards any type of intracerebral hemorrhage and parenchymal hematoma within 24 h, successful and complete recanalization after procedure, and modified Rankin Scale score 0-2 at 3 months. After adjustment for predefined variables of model 2, ORs for death were higher in the presence of recent administration of IV heparin (OR: 2.077), platelet count < 100,000/mm³ (OR: 4.798), bacterial endocarditis (OR: 15.069), neoplasm with increased hemorrhagic risk (OR: 6.046), and severe liver disease (OR: 6.124).

CONCLUSIONS

Radiological outcomes were similar after direct thrombectomy in patients with absolute, relative, and non- exclusion criteria for IVT, while an increase of fatal outcome was observed in the presence of some absolute exclusion criterion for IVT.

IER-SICH Nomogram to Predict Symptomatic Intracerebral Hemorrhage After Thrombectomy for Stroke

Background and Purpose—

As a reliable scoring system to detect the risk of symptomatic intracerebral hemorrhage after thrombectomy for ischemic stroke is not yet available, we developed a nomogram for predicting symptomatic intracerebral hemorrhage in patients with large vessel occlusion in the anterior circulation who received bridging of thrombectomy with intravenous thrombolysis (training set), and to validate the model by using a cohort of patients treated with direct thrombectomy (test set).

Methods—

We conducted a cohort study on prospectively collected data from 3714 patients enrolled in the IER (Italian Registry of Endovascular Stroke Treatment in Acute Stroke). Symptomatic intracerebral hemorrhage was defined as any type of intracerebral hemorrhage with increase of ≥4 National Institutes of Health Stroke Scale score points from baseline ≤24 hours or death. Based on multivariate logistic models, the nomogram was generated. We assessed the discriminative performance by using the area under the receiver operating characteristic curve.

Results—

National Institutes of Health Stroke Scale score, onset-to-end procedure time, age, unsuccessful recanalization, and Careggi collateral score composed the IER-SICH nomogram. After removing Careggi collateral score from the first model, a second model including Alberta Stroke Program Early CT Score was developed. The area under the receiver operating characteristic curve of the IER-SICH nomogram was 0.778 in the training set (n=492) and 0.709 in the test set (n=399). The area under the receiver operating characteristic curve of the second model was 0.733 in the training set (n=988) and 0.685 in the test set (n=779).

Conclusions—

The IER-SICH nomogram is the first model developed and validated for predicting symptomatic intracerebral hemorrhage after thrombectomy. It may provide indications on early identification of patients for more or less postprocedural intensive management.

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.

Thromboaspiration technique as first approach for endovascular treatment of acute ischemic stroke: initial experience at nine Italian stroke centers

BACKGROUND AND PURPOSE

Aspiration thrombectomy of large vessel occlusions has made a comeback among recanalization techniques thanks to recent advances in catheter technology resulting in faster recanalization and promising clinical results when used either alone or as an adjunct to stent retriever. This multicenter retrospective study reports angiographic data, complications, and clinical outcome in patients treated with aspiration thrombectomy as the first-line option.

MATERIALS AND METHODS

We analysed the clinical and procedural data of patients treated from January 2014 to March 2015. Recanalization was assessed according to the Thrombolysis in Cerebral Infarction score. Clinical outcome was evaluated at discharge and after 3 months.

RESULTS

Overall, 152 patients (mean age 68 years) were treated. Sites of occlusion were 90.8% anterior circulation (including 16.4% tandem extracranial/intracranial occlusions) and 9.2% basilar artery. In 79 patients administration of intravenous tissue plasminogen activator was attempted. Recanalization of the target vessel was obtained in 115/152 cases (75.6%) whereas direct aspiration alone was successful in 83/152 cases (54.6%) with an average puncture to revascularization time of 44.67 min. Symptomatic intracranial hemorrhage occurred in 7.8% and embolization to new territories in 1.9%. 77 patients (50.6%) had a good outcome at 90-day follow-up: 55/96 in the direct aspiration alone group and 22/56 in the aspiration-stent retriever group.

CONCLUSIONS

Direct aspiration thrombectomy appears a feasible technique with good revascularization results achieved in more than half the patients. In light of the self-reported data, inhomogeneous patient selection, absence of a core imaging laboratory, and a non-standardized approach, the results should be validated in a larger trial.

Hemodynamic and Anatomic Variations Require an Adaptable Approach during Intra-Arterial Chemotherapy for Intraocular Retinoblastoma: Alternative Routes, Strategies, and Follow-Up

BACKGROUND AND PURPOSE

Intra-arterial chemotherapy for retinoblastoma is not always a straightforward procedure, and it may require an adaptable approach. This study illustrates strategies used when the ophthalmic artery is difficult to catheterize or not visible, and it ascertains the effectiveness and safety of these strategies.

MATERIALS AND METHODS

A retrospective study was performed on a series of 108 eyes affected by intraocular retinoblastoma and selected for intra-arterial chemotherapy (follow-up range, 6-82 months). We recognized 3 different patterns of drug delivery: a fixed pattern through the ophthalmic artery, a fixed pattern through branches of the external carotid artery, and a variable pattern through either the ophthalmic or the external carotid artery.

RESULTS

We performed 448 sessions of intra-arterial chemotherapy, 83.70% of them through the ophthalmic artery and 16.29% via the external carotid artery. In 24.52% of eyes, the procedure was performed at least once through branches of the external carotid artery. In 73 eyes, the pattern of drug delivery was fixed through the ophthalmic artery; for 9 eyes, it was fixed through branches of the external carotid artery; and for 17 eyes, the pattern was variable. Statistical analysis did not show any significant difference in the clinical outcome of the eyes (remission versus enucleation) treated with different patterns of drug delivery. Adverse events could not be correlated with any particular pattern.

CONCLUSIONS

Alternative routes of intra-arterial chemotherapy for intraocular retinoblastoma appear in the short term as effective and safe as the traditional drug infusion through the ophthalmic artery.

Transorbital anastomotic pathways between the external and internal carotid systems in children affected by intraocular retinoblastoma

PURPOSE

It is well known that many anastomoses can join the external carotid system and the ophthalmic artery. However, their frequency has never been reported. Since they can be relevant for interventional radiologists operating in the orbit, we decided to illustrate and determine the frequency of the anastomoses that can be found in children.

METHODS

A retrospective study of 443 angiographic procedures (via ophthalmic artery and/or external carotid artery) carried out on 97 children affected by intraocular retinoblastoma was made to investigate the arterial anatomy of 106 orbits.

RESULTS

Anastomoses were observed in 44.33 % of orbits. However, their true frequency is likely much higher as the rate of visualization increased up to 91.11 % of orbits when the angiographic study was extended to the external carotid artery. In order of frequency we detected the following anastomoses: lacrimal artery-middle meningeal artery, lacrimal artery-anterior deep temporal artery, ophthalmic artery-middle meningeal artery, ophthalmic artery-facial artery, supraorbital artery-superficial temporal artery, supratrochlear artery-superficial temporal artery, supraorbital artery-middle meningeal artery, dorsal nasal artery-infraorbital artery, supraorbital artery-zygomaticoorbital artery, lacrimal artery-zygomaticoorbital artery.

CONCLUSION

When properly searched, anastomoses between the ophthalmic artery and the external carotid artery are almost constant in children. Depending on the clinical scenario, they can represent dangers or valuable alternative routes for collateral circulations and intraarterial chemotherapy.

Identification of Intraorbital Arteries in Pediatric Age by High Resolution Superselective Angiography

PURPOSE

Angiography is a powerful tool to identify intraorbital arteries. However, the incidence by which these vessels can be identified is unknown. Our purpose was to determine such incidence and which angiographic approach is best for the identification of each artery.

METHODS

A retrospective study of 353 angiographic procedures (via ophthalmic artery and/or external carotid artery) carried out on 79 children affected by intraocular retinoblastoma was made to investigate the arterial anatomy in 87 orbits. For each intraorbital artery two parameters were calculated: the angiographic incidence, as the percentage of times a given artery was identified, and the visibility index, as the ratio between the angiographic incidence and the true anatomic incidence.

RESULTS

All collaterals of the ophthalmic artery could be spotted. Most of them were identified with a high angiographic incidence; some of them were less easily identified because too thin or because frequently shielded. The visibility index paralleled the angiographic incidence of most arteries. However, the lacrimal and meningolacrimal arteries had a higher visibility index suggesting that their identification was more frequent than the angiographic incidence alone could suggest. Statistical analysis demonstrated that the lacrimal artery and some muscular branches had higher chances to be identified if the angiography of the ophthalmic artery was accompanied by the study of the external carotid system.

CONCLUSION

This work provides an objective measure of how powerful angiography is to identify intraorbital arteries as well as useful references for professionals who need to operate in the orbit.

Cerebral circulation time is prolonged and not correlated with EDSS in multiple sclerosis patients: a study using digital subtracted angiography

Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27s) and control group (mean = 2.8s; sd = 0.51s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.

Superselective ophthalmic artery infusion of melphalan for intraocular retinoblastoma: preliminary results from 140 treatments

PURPOSE

To report our experience in superselective ophthalmic artery infusion of melphalan (SOAIM) for intraocular retinoblastoma.

METHODS

  From June 2008 to October 2010, 38 patients (18 women, 20 men; age range at first treatment, 7 months to 22 years) with 41 eyes with retinoblastoma were scheduled for SOAIM, for 17 newly diagnosed retinoblastomas Tumour, Node and Metastasis (TNM) 7th Edition 1a (n = 1), 1b (n = 1), 2a (n = 7), 2b (n = 4) and 3a (n = 4) and 24 retinoblastomas with partial remission/relapse TNM 7th Edition 1b (n = 13), 2a (n = 1) and 2b (n = 10). Eight patients (ten eyes) have been treated by SOAIM alone. Follow-up was 6-27 months in 28 patients (30 eyes).

RESULTS

Ophthalmic artery cannulation failed in two patients. Thirty-six patients underwent 140 treatments by internal (n = 112) or external (n = 28) carotid arteries. No major procedural complications occurred. Two patients have been lost to follow-up. Remaining 34 patients (37 eyes) had no metastatic disease. Four patients suffered permanent ocular complications: chorioretinal dystrophy (n = 2), ptosis (n = 1) and strabismus/exotropia (n = 1). Eight (22%) eyes in eight (24%) patients underwent enucleation: 7/16 (43%) newly diagnosed retinoblastomas and 1/22 (4.5%) retinoblastomas undergoing partial remission/relapse. For all treated eyes, Kaplan-Meier eye enucleation-free rates (K-M) were 85.4% (95% CI, 73.3-97.5%), 74.4% (95% CI, 57-91.8%) and still stable at 6, 12 months and 2 years, respectively. For eyes with partial remission/relapse, and eyes at presentation, K-M at 2 years were 95.5% (95% CI, 86.9-100%) and 45.6% (95% CI, 16.6-74.6%), respectively.

CONCLUSION

Superselective ophthalmic artery infusion of melphalan was safe and powerful, especially following other therapies. Superselective ophthalmic artery infusion of melphalan should be added to focal therapies spectrum. In selected cases, melphalan should be combined with other chemotherapeutic agents.

[Neuroimaging and definition of transient ischemic attack]

AIM

Transient ischemic attack (TIA) has to be considered an "alarm bell" of a more or less severe organic or systemic vasculopathy. Positive findings at neuroimaging means tissue damage. The purpose of this retrospective study was to assess the role of neuroimaging in the management of patients presenting with TIA, and to consider the relative implications.

METHODS

In a consecutive series of 82 patients (53 males, 29 females, mean age: 65.9±13.1 years) admitted for TIA, it was possible to review the history and the clinical data of 66 patients, including ABCD2 score, laboratory including plasmatic D-dimer, and neuroimaging data including computed tomography (CT) and magnetic resonance imaging including diffusion-weighted with apparent diffusion coefficient measure (DWI-ADC) obtained at diagnosis and by a week later (16 by CT, and 50 by DWI-ADC). Thirty-three patients underwent DWI-ADC within 24 hours from symptoms onset. Statistical analysis has been performed by non-parametric tests (χ2 and Mann-Whitney), and logistic regression by a commercially available software.

RESULTS

CT and/or DWI-ADC showed signs of acute ischemic lesions in 23/66 (35%) patients. 12 out of the 35 patients with a 24-hour DWI-ADC follow-up were positive. Statistical analysis showed that positive neuroimaging was significantly associated only with familial history of cardiovascular diseases (P<0.012) and previous TIA/stroke (P<0.046).

CONCLUSION

In this patients series, at least 35% of patients with TIA had a positive neuroimaging, especially DWI-ADC. Positive neuroimaging seems an independent factor. Patients with TIA need an early assessment by neuroimaging including DWI-ADC, in order to obtain a correct classification and prognosis.

Effect of a vertical magnetic field on turbulent rayleigh-Benard convection

The effect of a vertical uniform magnetic field on Rayleigh-Benard convection is investigated experimentally. We confirm that the threshold of convection is in agreement with linear stability theory up to a Chandrasekhar number Q approximately 4x10(6), higher than in previous experiments. We characterize two convective regimes influenced by MHD effects. In the first one, the Nusselt number Nu proportional to the Rayleigh number Ra, which can be interpreted as a condition of marginal stability for the thermal boundary layer. For higher Ra, a second regime Nu approximately Ra0.43 is obtained.