G Lazzarotti

Silent Cerebral Ischemia Detected With Diffusion-Weighted Imaging in Patients Treated With Protected and Unprotected Carotid Artery Stenting

Background and Purpose— Percutaneous transluminal angioplasty with stent (CAS) is an alternative method to endarterectomy in the revascularization of carotid artery stenosis. Protected CAS is currently used to prevent distal embolization. Diffusion-weighted MRI (DWI) is the most sensitive tool to evaluate silent cerebral ischemia. The purpose of this research was to assess the incidence of cerebral embolic lesions during CAS and to evaluate whether cerebral protection devices can reduce the number of silent cerebral ischemia with respect to unprotected CAS. Methods— Fifty-two patients with high-grade internal stenosis underwent CAS; 30 patients (group a) were treated with a cerebral protection device, and 22 (group b) were treated without it. All of the patients were evaluated preoperatively and postoperatively with fluid-attenuated inversion recovery and DWI sequences to depict the number of new embolic silent cerebral lesions. Results— Embolic silent cerebral lesions occurred in 30% of CAS. Cerebral protection devices reduce the number of new lesions significantly reducing the consistent lesions ipsilateral to the treated vessel. Inconsistent lesions do not differ in both groups of patients. Clinical, radiological, and procedural variables do not correlate with the appearance of new cerebral lesions. Conclusions— Embolic cerebral lesions detected with DWI are more frequent with unprotected CAS, although they are present also with the use of cerebral protection devices. Probably a part of silent cerebral lesions arise from the procedural maneuver in the aortic arch.

Assessment of midbrain atrophy in patients with progressive supranuclear palsy with routine magnetic resonance imaging

Objectives –  To assess midbrain atrophy through morphometric (linear, surface and volumetric) measurements in patients with clinically diagnosed progressive supranuclear palsy (PSP) and to establish the most accurate measure to be implemented in routine magnetic resonance (MR) protocol in distinguishing PSP from healthy subjects and MSA‐p (multiple system atrophy, parkinsonian form) patients.

Dependence of brain DTI maps of fractional anisotropy and mean diffusivity on the number of diffusion weighting directions.

The rotational variance dependence of diffusion tensor imaging (DTI) derived parameters on the number of diffusion weighting directions (N) has been investigated by several Monte Carlo simulation studies. However, the dependence of fractional anisotropy (FA) and mean diffusivity (MD) maps on N, in terms of accuracy and contrast between different anatomical structures, has not been assessed in detail. This experimental study further investigated in vivo the effect of the number of diffusion weighting directions on DTI maps of FA and MD. Human brain FA and MD maps of six healthy subjects were acquired at 1.5T with varying N (6, 11, 19, 27, 55). Then, FA and MD mean values in high (FAH,MDH) and low (FAL,MDL) anisotropy segmented brain regions were measured. Moreover, the contrast‐to‐signal variance ratio (CVRFA,CVRMD) between the main white matter and the surrounding regions was calculated. Analysis of variance showed that FAL,FAH and CVRFA significantly (p<0.05) depend on N. In particular, FAL decreased (6%–11%) with N, whereas FAH (1.6%–2.5%) and CVRFA (4%–6.5%) increased with N.MDL,MDH and CVRMD did not significantly (p>0.05) depend on N. Unlike MD values, FA values significantly vary with N. It is noteworthy that the observed variation is opposite in low and high anisotropic regions. In clinical studies, the effect of N may represent a confounding variable for anisotropy measurements and the employment of DTI acquisition schemes with high N(>20) allows an increased CVR and a better visualization of white matter structures in FA maps. PACS number: 87.61.Tg, 82.56.Lz

In Stent Restenosis Predictors after Carotid Artery Stenting

Purpose. The long-term efficacy of carotid artery stenting is debated. Predictors of stent restenosis are not fully investigated. Our aim was to assess the incidence of long term restenosis after CAS and to identify some predictors of restenosis. Methods. We retrospectively selected 189 treated patients and we obtained the survival Kaplan-Meier curves for overall survival, for freedom from stroke or death and from restenosis. To correlate clinical, radiological, and procedural variables to stent restenosis, an univariate analysis was performed while to determine independent predictors of restenosis, a multivariate analysis was applied. Results. At 1, 3, and 5 years, the cumulative overall survival rate was 98%, 94%, and 92% with a cumulative primary patency rate of 87%, 82.5%, and 82.5%. The percentage residual stenosis after CAS and multiple stents deployment were independent predictors of restenosis, while diabetes and tumors are suggestive but not significant predictors of restenosis. Conclusions. In our CAS experience, encouraging long-term results seem to derive from both neurological event free rate and restenosis incidence. Adequate recanalization of the treated vessel is important to limit the development of stent restenosis. Multiple stents deployment, and with less evidence, diabetes, or neoplasms has to be considered to facilitate restenosis.

Cyclosporine-related posterior reversible encephalopathy syndrome (PRES) in non-transplant patient : a case report and literature review

A 53-year-old Caucasian female was referred because of acute speech difficulties and mental confusion. Six months prior to the referral she was treated by acetylsalicylic acid (325 mg/day) and methylprednisolone (4 mg/day), associated with cyclosporine A (CsA) (175 mg/ day) for psoriatic arthritis. A pure motor aphasia with recovery in 24 h was present, without other neurological signs. Blood investigation and blood pressure were normal. A cranial computed tomography (CT) depicted extensive areas of low attenuation involving the white matter (WM) of the temporo-parietal-occipital lobes. Cerebrospinal fluid examination and Doppler of the epiaortic vessels were normal. Magnetic resonance imaging showed a diffuse area, of high signal intensity (SI) on FLAIR and T2-weighted images and of low SI on T1-weighted ones, in the temporo-parieto-occipital WM including the subcortical U fibers. The alteration had major extension on the left hemisphere, mainly the fronto-parietal WM and temporo-occipital cortical layer, causing a partial sulcal effacement (Fig. 1a,b). No pathological contrastenhancement was appreciable. Diffusion weighted (DW) sequences showed isointensity of the lesions indicative of vasogenic edema (Fig. 1c). Clinical and MR findings suggested a toxic leukoencephalopathy. The patient gradually replaced cyclosporine with salazopyrine (2 g/day). Three months later, an MR examination showed a clear-cut reduction of the alteration (Fig. 1d–e), confirming the

Redistribution of cerebropetal blood flow in patients with carotid artery stenosis measured non-invasively with fast cine phase contrast MR angiography

The purpose was to evaluate the blood flow redistribution in the neck vessels of patients with internal carotid artery (ICA) stenosis. Eighty-six patients with ICA stenosis underwent contrast-enhanced magnetic resonance angiography (CEMRA) and fast 2D phase contrast (2D-PC) sequence to measure the mean blood flow (MBF) of ICA, basilar artery (BA) and middle cerebral artery (MCA). CEMRA revealed 53 severe stenoses, 45 moderate stenoses and 3 occluded vessels. Patients with a unilateral severe ICA stenosis had a significantly reduced MBF of the ICA compared to the control group; the MBF reduction of the severely stenosed ICA was less conspicuous if associated with a controlateral severe stenosis. The MBF of the BA increased significantly in the presence of the bilateral severe ICA stenosis and in the ICA occlusion. The MBF of the MCA was unchanged in the presence of various degrees of ICA stenosis. Measurement of MBF with fast PC MRA permits cerebropethal blood flow assessment and gives additional information in grading ICA stenosis. The reduced MBF of a severe ICA stenosis has to be considered with caution since it depends also on the status of the controlateral ICA and may be considered a confident parameter only in case of unilateral carotid stenosis.

Wrapping of intracranial aneurysms: Single-center series and systematic review of the literature

Background. Circumferential wrapping of the aneurysm wall with a variety of materials is a well-known therapeutic approach for the repair of unclippable intracranial aneurysms (IAs). Wrapping materials can stimulate foreign-body inflammatory reactions and parent artery narrowing with resultant ischemic stroke. In this study, a single-center retrospective review of the outcome with wrapping of IAs is presented beside an analysis of existing literature. Methods. For the institutional analysis, all patients who underwent wrapping of IAs in the last five years were analyzed. For the analysis of the literature, a MEDLINE search between 1990 and the present was performed for clinical series reporting wrapping of IAs. Specifically, the risk of rebleeding, cerebrovascular complications, and the incidence of granuloma formation were evaluated. Results. Two hundred and ninety patients with IA were surgically treated in our department. Fifteen patients (5.2%) underwent wrapping of IA. Early parent artery narrowing occurred in one patient (6.7%) and was associated with ischemic stroke. Delayed cerebrovascular complications, including parent artery narrowing (one case), granuloma formation (one case), and fatal bleeding from an unruptured aneurysm, occurred in three patients (20%). For the review of the literature, 197 cases of wrapped aneurysms were collected. Bleeding after wrapping occurred in 16 (12%) of the patients with ruptured aneurysms. Acute ischemic complications were reported in 7 cases (3.5%) and granuloma formation was observed in 3 patients (1.5%). Conclusions. These data suggest that the microsurgical wrapping of IAs present a risk of ischemic complications and granuloma formation. Additionally, the rebleeding rate of ruptured aneurysms remains high, although still lower than the natural history of untreated ruptured aneurysms

Stenting and coil embolization of a ruptured dissecting basilar artery aneurysm associated with coil embolization of a pericallosal artery aneurysm a case report

We describe the case of a 54-year-old woman who underwent endovascular treatment in the setting of a massive subarachnoid haemorrhage due to rupture of a dissecting basilar trunk aneurysm treated with stent implantation and coiling. A further saccular aneurysm in the left pericallosal artery disclosed by four-vessel angiography was treated with coiling during the same procedure. Follow-up DSA performed after six months confirmed complete occlusion of both aneurysms and patency of the stent.

Redistribuzione del flusso ematico misurato con Angio-RM 2D Fast-PC nella stenosi della carotide interna

La causa più frequente di ischemia cerebrale è rappresentata dalla tromboembolia dovuta a placche aterosclerotiche dei vasi cerbroafferenti. La patogenesi emodinamica nell’ischemia cerebrale gioca solo un ruolo marginale. Al fine di programmare una tromboendoarterectomia (TEA), un corretto inquadramento diagnostico con tecniche non invasive, come l’ecocolor Doppler e la risonanza magnetica tridimensionale con bolo di contrasto (CEMRA) sembra incrementare il beneficio del trattamento chirurgico. La possibilità di misurare quantitativamente il flusso e la velocità all’interno di un vaso utilizzando tecniche bidimensionali contrasto di fase triggerate permette di ottenere utili informazioni sull’impatto emodinamico di una stenosi carotidea. Nelle stenosi aterosclerotiche dei vasi del collo, le tecniche contrasto di fase, fornendo un dato emodinamico, consentono una valutazione quantitativa del grado di compromissione del flusso ematico all’interno del vaso in studio e possono essere utili nella valutazione della progressione o della stabilità di malattia. Diverse tecniche di imaging permettono la valutazione del flusso ematico totale, tra queste però solo l’eco-colo Doppler e la risonanza magnetica contrasto di fase forniscono informazioni quantitative sul flusso ematico in ogni singolo vaso. Lo scopo di questo studio è quello di valutare il volume ematico totale afferente all’encefalo con tecnica fast PC e la sua ridistribuzione nei pazienti con stenosi dell’arteria carotide interna (ICA). Materiale e metodi