Irene Volonghi

Cerebral amyloid angiopathy: a common cause of cerebral hemorrhage.

Amyloid is a term used to describe protein deposits with circumscript physical characteristics: beta-pleated sheet configuration, apple green birefringence under polarized light after Congo red staining, fibrillary structure and high insolubility. Cerebral amyloid angiopathy (CAA) defines a clinicopathological phenomenon characterized by amyloid deposition in the walls of leptomeningeal and cortical arteries, arterioles, and, less often capillaries and veins of the central nervous system. CAAs are currently classified according to the protein deposited including amyloid beta peptide (Abeta), cystatin C (ACys C), prion protein (PrP(Sc)), ABri/ADan, transthyretin (ATTR), and gelsolin (AGel). Most often amyloid deposition occurs in sporadic forms. In less common hereditary forms, a mutated variant protein or precursor protein is abnormally metabolized by proteolytic pathways in consequence of specific gene mutations, and accumulates as amyloid. The spectrum of clinical phenotypes associated with CAA-related vasculopathic changes includes both ischemic and hemorrhagic presentations, primary intracerebral hemorrhage (PICH) being probably the most well-recognized. However, in spite of accumulating data and recent progress in understanding the pathogenesis of CAA-related hemorrhage, the exact mechanisms leading to vessel rupture in these cases are yet to be established. This represents, at present, a major limitation to the identification of reliable biomarkers and the development of disease-specific treatment options. The present paper summarizes epidemiologic and clinical aspects of CAA, and highlights the presumed pathomechanisms of amyloid deposition in both sporadic and hereditary forms.

Ischemic Stroke during Pregnancy and Puerperium

Ischemic stroke during pregnancy and puerperium represents a rare occurrence but it could be a serious and stressful event for mothers, infants, and also families. Whenever it does occur, many concerns arise about the safety of the mother and the fetus in relation to common diagnostic tests and therapies leading to a more conservative approach. The physiological adaptations in the cardiovascular system and in the coagulability that accompany the pregnant state, which are more significant around delivery and in the postpartum period, likely contribute to increasing the risk of an ischemic stroke. Most of the causes of an ischemic stroke in the young may also occur in pregnant patients. Despite this, there are specific conditions related to pregnancy which may be considered when assessing this particular group of patients such as pre-eclampsia-eclampsia, choriocarcinoma, peripartum cardiomiopathy, amniotic fluid embolization, and postpartum cerebral angiopathy. This article will consider several questions related to pregnancy-associated ischemic stroke, dwelling on epidemiological and specific etiological aspects, diagnostic issue concerning the use of neuroimaging, and the related potential risks to the embryo and fetus. Therapeutic issues surrounding the use of anticoagulant and antiplatelets agents will be discussed along with the few available reports regarding the use of thrombolytic therapy during pregnancy.

Predictors of Migraine Subtypes in Young Adults With Ischemic Stroke: The Italian Project on Stroke in Young Adults

Background and Purpose— The mechanisms underlying the relationship between migraine and ischemic stroke remain uncertain. The aim of the present study was to investigate the predictive value of major cardiovascular risk factors, cardiac interatrial abnormalities, and additional biological markers on migraine subtypes in young adults with ischemic stroke. Methods— Ischemic stroke patients aged 45 years or younger were consecutively enrolled as part of the Italian Project on Stroke in Young Adults. A comprehensive evaluation was performed including assessment of self-reported migraine and cardiovascular risk factors, interatrial right-to-left shunt, and genotyping to detect factor V Leiden and the G20210A mutation in the prothrombin gene. Results— Nine hundred eighty-one patients (mean age, 36.0±7.6 years; 50.7% women) were included. The risk of migraine with aura increased with decreasing number of cardiovascular risk factors (OR, 0.50; 95% CI, 0.24–0.99 for 2 factors or more), increasing number of thrombophilic variants (OR, 2.21; 95% CI, 1.05–4.68 for carriers of at least 1 of the 2), and the presence of right-to-left shunt (OR, 2.41; 95% CI, 1.37–3.45), as compared to patients without migraine. None of these factors had influence on the risk of migraine without aura. Conclusions— In young adults with ischemic stroke, low cardiovascular risk profile, right-to-left shunt, and an underlying procoagulant state are predictors of migraine with aura. The biological effects of these factors should be considered in future studies aimed at investigating the mechanisms linking migraine to brain ischemia.

Predictors of Long-Term Recurrent Vascular Events After Ischemic Stroke at Young Age The Italian Project on Stroke in Young Adults

Background— Data on long-term risk and predictors of recurrent thrombotic events after ischemic stroke at a young age are limited. Methods and Results— We followed 1867 patients with first-ever ischemic stroke who were 18 to 45 years of age (mean age, 36.8±7.1 years; women, 49.0%), as part of the Italian Project on Stroke in Young Adults (IPSYS). Median follow-up was 40 months (25th to 75th percentile, 53). The primary end point was a composite of ischemic stroke, transient ischemic attack, myocardial infarction, or other arterial events. One hundred sixty-three patients had recurrent thrombotic events (average rate, 2.26 per 100 person-years at risk). At 10 years, cumulative risk was 14.7% (95% confidence interval, 12.2%–17.9%) for primary end point, 14.0% (95% confidence interval, 11.4%–17.1%) for brain ischemia, and 0.7% (95% confidence interval, 0.4%–1.3%) for myocardial infarction or other arterial events. Familial history of stroke, migraine with aura, circulating antiphospholipid antibodies, discontinuation of antiplatelet and antihypertensive medications, and any increase of 1 traditional vascular risk factor were independent predictors of the composite end point in multivariable Cox proportional hazards analysis. A point-scoring system for each variable was generated by their &bgr;-coefficients, and a predictive score (IPSYS score) was calculated as the sum of the weighted scores. The area under the receiver operating characteristic curve of the 0- to 5-year score was 0.66 (95% confidence interval, 0.61–0.71; mean, 10-fold internally cross-validated area under the receiver operating characteristic curve, 0.65). Conclusions— Among patients with ischemic stroke aged 18 to 45 years, the long-term risk of recurrent thrombotic events is associated with modifiable, age-specific risk factors. The IPSYS score may serve as a simple tool for risk estimation.

Do common prothrombotic mutations influence the risk of cerebral ischaemia in patients with patent foramen ovale? - Systematic review and meta-analysis

Conflicting results are available on the association of prothrombotic genetic abnormalities with patent foramen ovale (PFO)-related cerebral ischaemia. We comprehensively sought and identified studies of the association of both the factor V Leiden (FV(G1691A) mutation) and the prothrombin mutation (PT(G20210A) mutation) with PFO-related cerebral ischaemia and did meta-analyses to assess the evidence for such a relation. We analysed data from six eligible studies in 856 cases and 1,001 control subjects. Additional unpublished data from a new series including 463 subjects were also entered into the analysis. The PT(G20210A) variant was significantly associated with PFO-related stroke in comparison with both control subjects (odds ratio [OR] 3.85; 95% confidence interval [CI] 2.22 to 6.66) and non-PFO-associated stroke patients (OR 2.31; 95% CI 1.20 to 4.43), whereas a trend toward an association was observed for the FV(G1691A) mutation (OR 1.18; 95% CI 0.73 to 1.90, compared to control subjects; OR 1.14; 95% CI 0.62 to 2.09, compared to non-PFO-associated stroke patients). The status of carrier of either the FV(G1691A) mutation or the PT(G20210A) variant was associated with a risk for stroke of 1.98 (95% CI 1.38 to 2.83) and 1.62 (95% CI 1.03 to 2.57), as compared to control subjects and non-PFO-associated stroke patients, respectively. Addition of common prothrombotic genetic variants to standard initial screening may contribute to stratifying PFO-associated stroke patients at different risk of ischaemic events and targeting secondary prevention strategies.

The Migraine-Ischemic Stroke Connection: Potential Pathogenic Mechanisms

Strong epidemiological evidence indicates that migraine, especially migraine with aura, is associated with increased risk of ischemic stroke. However, the precise mechanisms of such a relation are currently not fully elucidated and are still a matter of speculation. Migraine may directly cause an ischemic event (i.e, migrainous infarct), by inducing cerebral microcirculatory vasoconstriction (cortical spreading depression-related oligemia), intracerebral large vessels spasm, and vascular endothelium-related hypercoagulability. On the other hand, migraine may predispose to cerebral ischemia outside of a migraine attack by affecting endothelial function, alone or in combination with traditional vascular risk factors, or by interacting with pre-existent stroke susceptibility conditions (i.e, patent foramen ovale). At least theoretically, the migraine-stroke link may be the consequence of the unfavourable effect of migraine-specific drugs (i.e, triptans or ergot alkaloids). Finally, migraine and ischemic vascular events may be linked via genetic pathways, certain genes playing a role on both diseases and influencing their relation. The coexistence of ischemic stroke and migraine in the context of specific syndromes (i.e, CADASIL) characterized by peculiar phenotype, proven inherited background and chronic alterations of the wall of cerebral small vessel arteries suggests that migraine and ischemic stroke may be the end phenotype of common pathogenic mechanisms. How to identify those migraineurs at highest risk of ischemic stroke and whether stroke can be prevented by specific therapeutic strategies are the goals of future research.

Complications of Acute Stroke and the Occurrence of Early Seizures

Background: Seizures are common neurological consequences of stroke. Although a number of factors including stroke severity on admission, cortical involvement, and stroke subtype have been consistently associated with post-stroke seizures, the effect that medical and neurological complications of stroke, occurring in the very acute phase, might have on such a risk has never been adequately explored. In the present study we aimed at determining the extent to which complications within the first week of stroke influence the risk of early seizures (ES). Methods: Data of consecutive patients with first-ever acute stroke included in the Brescia Stroke Registry were analyzed. ES (≤7 days) were recorded and correlated with demographic data, disease characteristics, risk factors, and prespecified medical and neurological stroke complications in a multivariate path analysis model. Results: 516 patients with first-ever acute stroke were eligible for inclusion in the present study. Of them, 436 patients had ischemic stroke (IS) [64 (14.6%) with hemorrhagic transformation (HT)] and 80 had intracerebral hemorrhage (ICH). Twenty patients (3.9%) developed ES. Patients with ES had a higher burden of complications compared with those without (30 vs. 4.2%, for patients with >6 complications). Lesion type, stroke complications, and lesion site were directly related to the risk of seizure occurrence (OR, 0.24; 95% CI, 0.07-0.80 for IS vs. ICH; OR, 1.57; 95% CI, 1.21-2.01 for any increase of 1 in the number of complications; OR, 0.15; 95% CI, 0.04-0.56 for subcortical lesions vs. cortical lesions). Complications appeared also to mediate the indirect effect of lesion type on the occurrence of ES (OR, 0.75; 95% CI, 0.60-0.94). No significant difference on the risk of ES was observed when HT and ICH were compared. The total effect of lesion type was 0.25 × 0.75 = 0.18, corresponding to (1-0.18) = 82% lower risk of ES for IS as compared to ICH. Conclusion: Although major determinants of ES are nonmodifiable, preventable and treatable medical and neurologic complications within the first week of stroke increase the risk of ES and mediate the effect of established predictors on the propensity to post-stroke epilepsy. Future epidemiologic studies aimed at investigating post-stroke seizures should include precise information on these complications.

Migraine and ischemic stroke : a debated question

Numerous epidemiologic observations reporting high prevalence of migraine among young individuals with stroke as well as dysfunction of cerebral arteries during migraine attacks prompt speculation on the existence of a comorbidity between the two disorders. The recent finding of silent infarct-like brain lesions in migraineurs reinforced this hypothesis and raised questions on whether migraine may be a progressive disorder rather than simply an episodic disorder. Stroke can occur during the course of migraine attacks with aura, supporting the assumption of a causal relation between the two diseases. Migraine may accentuate other existing risk factors for stroke, and both jointly increase the risk of cerebral ischemia outside of migraine attacks. In this regard, the role of migraine might be that of predisposing condition for cerebral ischemia. Migraine and ischemic stroke may be the end phenotype of common pathogenic mechanisms. Evidence of a migraine-stroke relation in cases of specific disorders, such as CADASIL (cerebral autosomal—dominant arteriopathy with subcortical infarcts and leukoencephalopathy) and MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), strongly supports this concept. Finally, acute focal cerebral ischemia can trigger migraine attacks, and, thus, migraine may be the consequence of stroke. In this paper, we will review contemporary epidemiologic studies, discuss potential mechanisms of migraine-induced stroke and comorbid ischemic stroke, and pose new research questions.

Mutations in TGFBR2 gene cause spontaneous cervical artery dissection

Mutations in the genes encoding transforming growth factor β receptors 1 and 2 (TGFBR1 and TGFBR2) have recently been associated with hereditary connective tissue disorders with widespread vascular involvement, including arterial dissection. To determine whether mutations in these genes cause spontaneous cervical artery dissection (sCAD), all coding exons of TGFBR1 and TGFBR2 were sequenced in 56 consecutive patients with sCAD. Novel TGFBR2 disease causing mutations were found in two patients. The two mutations were the pK327R substitution affecting the kinase domain of TGFBR2 and the pC138R substitution falling in the extracellular domain of the protein, involved in TGFβ binding and signalling. No TGFBR1 mutation was found. The findings indicate that TGFBR2 gene mutations are responsible for sCAD in 3.6% (95% CI 0.0 to 8.4) of cases, have implications in understanding the role of TGFβ signalling in the pathogenesis of sCAD and emphasise the importance of considering molecular characterisation of the TGFBR2 gene in these patients, regardless of the presence of clinical features suggestive of hereditary connective tissue disorders.

Antithrombotic medications and the etiology of intracerebral hemorrhage MUCH-Italy

Objective: To test the hypothesis that the effect of antithrombotic medications on the risk of intracerebral hemorrhage (ICH) varies according to the location of the hematoma. Methods: Consecutive patients with ICH were enrolled as part of the Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy). Multivariable logistic regression models served to examine whether risk factors for ICH and location of the hematoma (deep vs lobar) predict treatment-specific ICH subgroups (antiplatelets-related ICH and oral anticoagulants [OACs]–related ICH). Results: A total of 870 (313 lobar ICH, 557 deep ICH) subjects were included. Of these, 223 (25.6%) were taking antiplatelets and 77 (8.8%) OACs at the time of stroke. The odds of antiplatelet-related ICH increased with aging (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.03–1.07) and hypertension (OR 1.86; 95% CI 1.22–2.85) but had no relation with the anatomical location of ICH. Conversely, lobar location of the hematoma was associated with the subgroup of OAC-related ICH (OR 1.70; 95% CI 1.03–2.81) when compared to the subgroup of patients taking no antithrombotic medications. Within the subgroup of patients taking OACs, international normalized ratio (INR) values were higher in those with lobar ICH as compared to those with deep ICH (2.8 ± 1.1 vs 2.2 ± 0.8; p = 0.011). The proportion of patients with lobar hematoma increased with increasing intensity of anticoagulation, with a ∼2-fold increased odds of lobar compared to deep ICH (odds 2.17; p = 0.03) in those exposed to overanticoagulation (INR values >3.0). Conclusions: OACs, as opposed to antiplatelets, predispose to lobar location of brain hematomas according to a dose-response relationship.