Neuroimaging evaluation of unilateral asymptomatic carotid plaque ulceration: preliminary results of the Carotid Artery Multimodality imaging Prognostic study

Background

Carotid plaque ulceration has been associated with imaging characteristics of high risk of future events (plaque vulnerability) in patients with a significant degree of stenosis, while little is known about its role in patients with a lesser degree of stenosis and its association with markers of vascular inflammation.

Purpose

We evaluated the association between imaging characteristics of plaque vulnerability and vascular inflammation detected by different imaging tests.

Methods

One hundred and seven patients with unilateral asymptomatic carotid artery stenosis (40–60% detected by Doppler ultrasound (DUS)), enrolled in the ongoing Carotid Artery Multimodality Prognostic (CAMP) study were prospectively evaluated with computed tomography angiography (CTA), contrast-enhanced magnetic resonance imaging (CEMRA) and, in a subgroup of patients, with 18-F-fluorodeoxyglucose positron emission tomography (PET). Plaque ulceration was detected by CTA. Variables are expressed as median (1st–3rd quartiles) and number (percentages).The Student's t-test or Mann-Whitney and Chi square or Fisher's exact test were used to study associations among variables.

Results

An ulcerated plaque was present in 35% patients (n=33) of those undergoing CTA (n=94), while intraplaque hemorrhage and lipid-rich necrotic core were present in 9% and 15% of those undergoing CEMRA. Compared with patients with non-ulcerated plaques, those with an ulcerated plaque had a significant higher degree of stenosis at DUS, a higher target to background ratio (TBR) at 18F-FDG-PET and a higher high-sensitivity cardiac troponin (cTn) T.

Conclusions

Plaque ulceration is common and associated with higher degree of stenosis, higher indices of wall inflammation and higher serum markers of myocardial injury.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Regione Toscana

Silent cerebral embolisation during TAVI: evolution, predictors and neurocognitive effects

Background

Most patients undergoing transcatheter aortic valve implantation (TAVI) develop silent cerebral ischemic lesions (SCIL) detectable at magnetic resonance imaging (MRI). The natural history and clinical relevance of SCIL are not well established. We aimed to assess the characteristics, predictors, evolution, and neurocognitive effects of SCIL.

Methods

Cerebral MRI was performed within 7 days before TAVI to assess baseline status and age-related white matter changes (ARWMC) score. MRI was repeated postoperatively to assess the occurrence, location, number and dimensions of SCIL. Patients developing SCIL underwent a third MRI at 3–5 months follow-up. A neurocognitive evaluation was performed before TAVI, at discharge and at 3-month follow-up.

Results

Of the 117 patients enrolled, 96 underwent a postprocedural MRI; SCIL were observed in 76% of patients, distributed in all vascular territories, with a median number of 2 lesions, median diameter 4.5 mm, and median total volume 140 mm3. Independent predictors of SCIL occurrence were a higher baseline ARWMC score and the use of self-expanding or mechanically-expanded bioprostheses. Among 47 patients who underwent follow-up MRI, only 26.7% of postprocedural SCIL evolved into a gliotic scar. SCIL occurrence was associated with a more pronounced transient neurocognitive decline early after TAVI and with a lower recovery at follow-up.

Conclusions

SCIL occur in the vast majority of patients undergoing TAVR and are predicted by a more diffuse white matter damage at baseline and by the use of non-balloon-expandable prostheses. Although most SCIL disappear within months, their occurrence has a limited but significant impact on neurocognitive function.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): unrestricted grants from Edwards Lifesciences SA, Nyon, Switzerland, and from Medtronic Italia SpA, Milan, Italy

Epidemiology and cerebrovascular events related to cervical and intracranial arteries dissection: the experience of the city of Pisa

Spontaneous dissection of cervical arteries (sCAD) is a major cause of ischemic stroke in young patients, with an incidence varying from 1.7 to 3/100,000/year for extracranial internal carotid artery (ICAD) and 1 to 1.9/100,000/year for extracranial vertebral artery (VAD). Reliable epidemiological data on stroke incidence related to sCAD are scarce in Italy. This study aims to evaluate the incidence, clinical features, and outcome of cerebrovascular events related to sCAD and spontaneous intracranial arteries dissections (sIAD) in the city of Pisa (Italy). We retrospectively analyzed consecutive patients admitted between December 1997 and June 2015 with a diagnosis of stroke, TIA, or Bernard-Horner syndrome due to acute cervical or intracranial artery dissection. Considering that our hospital collects presumptively all patients hospitalized with sCAD coming from the referral geographical area, data may provide a good approximation to real incidence of sCAD in our population. Clinical and radiological features, acute treatment and outcome were collected. Seventy-seven cases were included (mean age 48.1±10.4 years, range 23-77,72.7% males), 66 residents in the district of Pisa. Crude incidence rate of cerebrovascular events due to intra or extracranial dissection was 1.88/100,000/year. The incidence of ICAD was 0.80/100,000/year and 0.43/100,000/year for VAD. Stroke occurred in 76.6% of patients. VAD was more prone to cause ischemic stroke and present with cervical pain or focal signs (p < 0.01) than ICAD group, which had older age at onset. sIAD were more frequent in the posterior circle (p = 0.01) and more associated with ischemic lesions. A good outcome (mRS 0-2) was observed in 79% of patients. This is the first epidemiological attempt to investigate impact of sCAD and sIAD in Italy.

A machine learning tool for re-planning and adaptive RT: A multicenter cohort investigation

PURPOSE

To predict patients who would benefit from adaptive radiotherapy (ART) and re-planning intervention based on machine learning from anatomical and dosimetric variations in a retrospective dataset.

MATERIALS AND METHODS

90 patients (pts) treated for head-neck cancer (H&N) formed a multicenter data-set. 41 H&N pts (45.6%) were considered for learning; 49 pts (54.4%) were used to test the tool. A homemade machine-learning classifier was developed to analyze volume and dose variations of parotid glands (PG). Using deformable image registration (DIR) and GPU, patients' conditions were analyzed automatically. Support Vector Machines (SVM) was used for time-series evaluation. "Inadequate" class identified patients that might benefit from replanning. Double-blind evaluation by two radiation oncologists (ROs) was carried out to validate day/week selected for re-planning by the classifier.

RESULTS

The cohort was affected by PG mean reduction of 23.7±8.8%. During the first 3weeks, 86.7% cases show PG deformation aligned with predefined tolerance, thus not requiring re-planning. From 4th week, an increased number of pts would potentially benefit from re-planning: a mean of 58% of cases, with an inter-center variability of 8.3%, showed "inadequate" conditions. 11% of cases showed "bias" due to DIR and script failure; 6% showed "warning" output due to potential positioning issues. Comparing re-planning suggested by tool with recommended by ROs, the 4th week seems the most favorable time in 70% cases.

CONCLUSIONS

SVM and decision-making tool was applied to overcome ART challenges. Pts would benefit from ART and ideal time for re-planning intervention was identified in this retrospective analysis.

Spontaneous Arteriovenous Fistula of the Vertebral Artery

Three cases of spontaneous arteriovenous fistulas of the vertebral artery (VAF) are reported. In one case the only symptom was a cervical bruit; in the other two cases, symptoms of multiple cervical radiculopathy were also observed. Definitive diagnostic findings were obtained by Doppler ultrasonography, computed tomography, magnetic resonance imaging, and angiography. Clinical signs of radiculopathy disappeared after endovascular balloon occlusion of the fistula, in about 1 month. In one case the vertebral artery was occluded without clinical consequences.

Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micropillars

Microfluidic separation of magnetic particles is based on their capture by magnetized microcollectors while the suspending fluid flows past the microcollectors inside a microchannel. Separation of nanoparticles is often challenging because of strong Brownian motion. Low capture efficiency of nanoparticles limits their applications in bioanalysis. However, at some conditions, magnetic nanoparticles may undergo field-induced aggregation that amplifies the magnetic attractive force proportionally to the aggregate volume and considerably increases nanoparticle capture efficiency. In this paper, we have demonstrated the role of such aggregation on an efficient capture of magnetic nanoparticles (about 80 nm in diameter) in a microfluidic channel equipped with a nickel micropillar array. This array was magnetized by an external uniform magnetic field, of intensity as low as 6-10 kA/m, and experiments were carried out at flow rates ranging between 0.3 and 30 μL/min. Nanoparticle capture is shown to be mostly governed by the Mason number Ma, while the dipolar coupling parameter α does not exhibit a clear effect in the studied range, 1.4 < α < 4.5. The capture efficiency Λ shows a strongly decreasing Mason number behavior, Λ∝Ma^{-1.78} within the range 32 ≤ Ma ≤ 3250. We have proposed a simple theoretical model which considers destructible nanoparticle chains and gives the scaling behavior, Λ∝Ma^{-1.7}, close to the experimental findings.

ELECTROPHYSIOLOGICAL EVALUATION OF GENITO-SPHINCTERIC DYSFUNCTION IN MULTIPLE SYSTEM ATROPHY

Thirteen patients with multiple system atrophy underwent multimodality neurophysiological evaluation, including sphincteric needle electromyography (EMG), sacral reflexes, pudendal nerve terminal latency, pudendal (PSEPs) and tibialis posterior nerve somatosensory evoked potentials (TPSEPs), and perineal motor evoked potentials (PMEPs). EMG revealed denervation or neurogenic changes, with reduction in spontaneous tonic activity at rest and abnormal pudendal nerve terminal latency in 10 patients (76.9%); anal reflex was delayed in 7 patients (53.8%). TPSEPs scalp responses were clearly abnormal in 4 patients (30.7%), whereas PSEPs exhibited changes in 9 (69.2%): in 6 patients responses were delayed at lumbar level (46.2%), and in 5 over the scalp (38.4%). PMEPs showed an increase in latency with a mild prolongation of central motor conduction time (CMCT) in 2 cases (15.3%); 1 patient had prolonged latencies following both cortical and sacral stimulation, but a normal CMCT. Even if diagnostic yield is not improved using these investigations they provide evidence of multiple lesion sites other than Onuf's nucleus.

MOTOR UNIT NUMBER ESTIMATION (MUNE) AS A QUANTITATIVE MEASURE OF DISEASE PROGRESSION AND MOTOR UNIT REORGANIZATION IN AMYOTROPHIC LATERAL SCLEROSIS

Motor Unit Number Estimation (MUNE), a technique allowing to estimate the number of functioning Motor Units (MU) in single muscles, was used to score the disease's severity and progression rate in a group of 58 patients with Amyotrophic Lateral Sclerosis (ALS). All patients underwent MUNE in the abductor digiti minimi (ADM) muscle during the diagnostic work-up (T0), after three (T1) and six (T2) months. A significant loss [p < .001] of MU and a decrease [p < .001] of the maximal M wave area at T0 was found, whereas mean step area was increased [p < .001]. During the follow-up (T1 and T2), MU loss continued, maximal M wave decreased, and mean step area increased significantly. The results confirm that MUNE is a suitable tool to quantify the pathological changes in MU in patients with ALS.

'INDOTEST' in atypical hemicrania continua

Hemicrania continua (HC) is an indomethacin-responsive headache characterized by a chronic, strictly unilateral, side-locked without side-shifting, persistent headache. We report three cases of HC with atypical features in which an acute administration of indomethacin 50 mg IM (INDOTEST) was performed. In all three cases INDOTEST predicted chronic responsiveness to indomethacin. Thus, in cases of HC with atypical features, INDOTEST could help for a correct diagnosis and therapy.

Chromatic pattern-reversal electroretinograms (ChPERGs) are spared in multiple system atrophy compared with Parkinson's disease

Idiopathic Parkinson's disease (IPD) patients have abnormal visual evoked potentials (VEPs) and pattern electroretinograms (PERGs), attributed to dopaminergic transmission deficiency in visual pathway, probably the retina. VEP abnormalities are not reported in multiple system atrophy (MSA). The aim of this study was to investigate and compare chromatic (Ch) red-green (R-G) and blue-yellow (B-Y), and luminance yellow-black (Y-Bk) PERGs in patients with MSA and IPD. We investigated 6 MSA patients (mean age: 62+/-7.4 years) not undergoing any pharmacological treatment, as well as 12 early IPD patients (mean age: 60.1+/-8.3 years) and 12 age-matched normal observers. ChPERGs were recorded monocularly in response to full-field equiluminant R-G, B-Y and Y-Bk horizontal gratings. In MSA only responses to R-G stimuli showed minimal insignificant changes (slight but not significant amplitude reduction without any significant latency delay); no significant abnormality was detected for B-Y and luminance Y-Bk stimuli. By contrast, in IPD all responses were reduced in amplitude and delayed in latency, above all for B-Y stimuli. Present data indicate that both chromatic and achromatic PERGs are virtually unaffected in MSA, whereas in early IPD they are clearly impaired, suggesting different pathogenic retinal mechanisms and a useful simple tool for distinguishing MSA from IPD.

Analysis of aneusomy level and HER-2 gene copy number and their effect on amplification rate in breast cancer specimens read as 2+ in immunohistochemical analysis

Our aim was to determine the aneusomy level and the HER-2 gene copy numbers, by fluorescence in situ hybridization (FISH) and to analyze their impact on the amplification rate in breast carcinomas considered HER-2 weakly positive cases by immunohistochemistry. We evaluated 343 breast carcinomas using double colour FISH (LSI Her-2/neu gene and CEP 17). Monosomy and polysomy were demonstrated in 24.2% and 46.1% respectively and 101/343 (29.6%) of the specimens were amplified by FISH. A statistically significant difference was observed, when we compared the amplification percentage in polysomic and monosomic specimens (P<0.0001) and, among polysomic specimens, when tumours were compared with HER-2 gene signals number per cell between 3 and 10 and >10 respectively (P<0.0001). Logistic regression analysis showed that HER-2 signals >10 and polysomy absence were independently associated with amplification. Our results confirm that the majority of 2+ IHC cases express the HER-2 protein without gene amplification and highlight the effect of chromosome 17 aneusomy and the HER-2 gene copy number on amplification.

The extent of right-to-left shunt fails to correlate with severity of clinical picture in migraine with aura

Several investigations have documented an increased incidence of right-to-left shunt (RLS) in migraine with aura (MA) and have emphasised its role in the physiopathology of aura; so far, however, no data are available concerning a possible correlation between the extent of the RLS and the clinical picture of MA patients. To investigate the possible relationship between the extent of the RLS, revealed by the number of microbubbles (MB) detected during transcranial Doppler with IV injection of ultrasound contrast (TCDc), and the clinical characteristics of MA (age at first onset of migraine, mean annual frequency of attacks and mean duration of the aura phase), 30 consecutive patients with typical aura and migraine headache positive on TCDc evaluation for RLS were enrolled. Permanent RLS was found in 12 patients and latent RLS was found in 18 patients; of these, 6 had a high-grade RLS, 5 medium-grade RLS and 7 low-grade RLS. No correlation has been documented between the number of MBs and the clinical parameters of both patients with latent shunts and those with permanent ones, nor between the clinical parameters of the two groups of patients. These data show that RLS does not seem to affect the clinical manifestation of MA and that the extent of RLS fails to correlate with the severity of the clinical picture of the disorder.

C-erb-2 gene amplification and chromosomal anomalies in bladder cancer: preliminary results

Studies recently suggested that different genetic factors are involved in the development and progression of bladder cancer. In this study, 30 consecutive patients affected by bladder neoplasm were evaluated in order to analyze the frequency of c-erb-2 gene amplification and chromosome 7, 9, 17 aneusomy using fluorescence in situ hybridization (FISH) technique. C-erb-2 gene amplification, chromosome 17 gain and aneusomy were respectively observed in 3.7% (1/27), in 47% (12/27) and in 74% (20/27) of examined tumors. Moreover, chromosome 7 and 9 aneusomy were detected in 74% (20/27) and in 72% (16/27) of specimens. A statistically significant correlation was observed between chromosome 17 aneusomy and tumor stage and grade (r: 0.642, p = 0.0001; r: 0.385, p = 0.04, respectively). In conclusion, we observed a low incidence of C-erb-2 gene amplification, while chromosome 17 aneusomy was confirmed as a marker of advanced and aggressive bladder cancer.

Electrophysiological evidence by single fibre electromyography of neuromuscular transmission impairment in a case of Miller Fisher syndrome

Miller Fisher syndrome is an autoimmune neuropathy characterised by ataxia, areflexia and ophthalmoplegia, with minimal if any limb weakness, and in the majority of cases by high titres of IgG anti-GQ1b ganglioside antibodies. In vitro electrophysiological experiments have demonstrated that these antibodies induce a transmission blockade at neuromuscular junction either pre- or post-synaptically. We report the case of a 63-year-old man with MFS that shows blood serum negative for anti-GQ1b but presents an impairment of neuromuscular transmission detected by single fibre electromyography. To the best of our knowledge, this represents the first case in the literature using jitter technique and suggests that other antibodies may be involved in the function of motor end plates by bindings to the synaptic membranes.

Rizatriptan does not change cerebral blood flow velocity during migraine attacks

Rizatriptan represents a major advance in the treatment of migraine attack: inhibition of peripheral trigeminal nerve and constriction of intracranial extracerebral blood vessels have been proposed as its main antimigraine mechanisms of action. Although many studies may suggest that rizatriptan causes highly selective vasoconstriction within intracranial extracerebral vessels (i.e., meningeal arteries), no literature data are available to date on possible cerebral hemodynamic changes in humans after treatment with rizatriptan. The aim of this study was to evaluate the effect of rizatriptan on cerebral blood flow velocity performing transcranial Doppler during spontaneous attacks of migraine without aura. Fourteen patients suffering from migraine without aura were monitored to evaluate mean flow velocity changes on both middle cerebral arteries during migraine attack 30 min before and 120 min after oral administration of rizatriptan 10mg. Monitoring was repeated for 30 min during the pain-free period. All patients turned out to be drug responders and no significant mean flow velocity changes were observed between the pain-free period and pre-treatment phase; besides no significant difference in mean flow velocity value have been detected between the periods after the drug administration during the attack versus both pre-treatment period and pain-free phase. These findings indicate that the antimigraine action of rizatriptan is not associated with clear intracranial cerebral hemodynamic changes and may support its cerebrovascular safety.

Intra-arterial thrombolysis in basilar artery occlusion and recent haemorrhagic stroke due to arteriovenous malformation

We report the case of a young patient suffering from a severe ischaemic stroke due to basilar artery occlusion occurring during selective digital subtraction angiography. This examination was performed in order to assess an arteriovenous malformation in posterior cerebral artery territory responsible for haemorrhagic stroke occurring 17 days before. Intra-arterial thrombolysis with urokinase was performed and basilar artery recanalization was obtained 8 h after stroke onset. Despite the severe neurological impairment, the prolonged symptoms of ischaemia and the high bleeding risk due to the recent cerebral haemorrhage in the same vascular territory involved in thrombolysis, the treatment determined a very favourable clinical outcome.

Saturation and electron-beam lifetime in a storage ring free-electron laser

We present a phenomenological treatment of free-electron laser storage ring saturation dynamics. The model includes longitudinal instabilities, Touschek intrabeam scattering, and nonzero off-energy-function contributions. The model predictions are compared with Super ACO experimental results and the agreement is shown to be satisfactory.

Flavor decomposition of the sea-quark helicity distributions in the nucleon from semiinclusive deep inelastic scattering

Double-spin asymmetries of semiinclusive cross sections for the production of identified pions and kaons have been measured in deep inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with reanalyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.

Evidence for quark-hadron duality in the proton spin asymmetry A1

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q2 between 1.2 and 12 GeV2 and values of W2 between 1 and 4 GeV2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2 above 1.6 GeV2.

Q2 dependence of nuclear transparency for exclusive rho0 production

Exclusive coherent and incoherent electroproduction of the rho(0) meson from 1H and 14N targets has been studied at the HERMES experiment as a function of coherence length (l(c)), corresponding to the lifetime of hadronic fluctuations of the virtual photon, and squared four-momentum of the virtual photon (-Q2). The ratio of 14N to 1H cross sections per nucleon, called nuclear transparency, was found to increase (decrease) with increasing l(c) for coherent (incoherent) rho(0) electroproduction. For fixed l(c), a rise of nuclear transparency with Q2 is observed for both coherent and incoherent rho(0) production, which is in agreement with theoretical calculations of color transparency.

Incidence of intracranial hypertension related to jugular bulb oxygen saturation disturbances in severe traumatic brain injury patients

OBJECTIVE

To analyze the Intracranial Hypertension (IH) development related to jugular bulb oxygen saturation (SjO2) disturbances in severe traumatic brain injury patients (sTBI).

MATERIALS AND METHODS

One hundred and thirty-five sTBI patients were reviewed. Those without IH at admission (n = 116) were included. All patients underwent ICP and SjO2 continuous monitoring. Two groups were distinguished according to the SjO2 values during the first 24 hours. Group A: those with abnormal SjO2 (SjO2 more than 75% or less than 55%) and Group B: those with normal SjO2 (55-75%). Differences in IH development and outcome between groups were analyzed. Causes of abnormally low SjO2 were identified.

RESULTS

IH developed in 56.9% of patients, between 12 and 48 hours from admission. Group A had a significantly higher incidence of IH than Group B (p < 0.001) and it also had a worse outcome than Group B (GOS 1-2) (p < 0.005). Patients from Group A had a risk of IH 4.5 fold higher than Group B. Considering only patients who developed IH, an abnormal SjO2 value increased 2.3 fold the risk of death compared to those without SjO2 disturbances. Main causes of SjO2 desaturation were hyperventilation (40.7%), hypovolemia (28.4%) and anemia (21%).

CONCLUSIONS

Early detection of disturbances in oxygen supply-demand relationship and prevention or resolution of the secondary insults which produce these disturbances, might lead to a reduction in the incidence of intracranial hypertension.