Pathogenetic profile of TIA before 55. A three-year investigation

Cervical Arterial Fibromuscular Dysplasia in a Biethnic Population: A Retrospective Study in the U.S.-Mexican Border

Background  There have been studies trying to characterize Fibromuscular Dysplasia (FMD); however, most of them are based in mainly non-Hispanic sample. The objective of this study is to better understand the epidemiology and clinical characteristics of craniocervical FMD in the Hispanic population. Methods  We retrospectively reviewed the cerebral angiograms performed in our center in a period of 3.5 years under any indication looking for angiographic patterns of FMD. Exclusion criteria consisted of cases in which the first angiogram was done when the patients were younger than 18 years. Patients were subdivided based on those with FMD and those without it for baseline characteristics and were looked for any associations. We further compared the same baseline characteristics among Hispanic FMD and non-Hispanic FMD population. A chart review was conducted looking for clinical features and vascular events. Results  We analyzed 448 angiograms among patients younger than 18 years. We identified 47 patients with evidence of FMD involving the cervical arteries and 401 patients without FMD. Of the 47 patients with FMD in our neuroendovascular registry, we found that 76.6% were women and 57.4% were Hispanics. There was no statistical significant difference when comparing the variables across ethnicities, except history of cigarette smoking and dyslipidemia. The most common associated supra-aortic arterial lesions seen in the FMD group were intracranial aneurysm and arterial dissections. We then used same variables to compare Hispanic FMD with non-Hispanic FMD. We have found that there has been a positive association of cigarette smoking and dyslipidemia with FMD ( p ≤ 0.05). Conclusion  Our study suggests that FMD affecting the carotid and vertebral arteries has similar demographic pattern across ethnicities in the United States. In Hispanics, the disease appears to have a predilection for women and history of cigarette smoking. Intracranial aneurysm and arterial dissection were the most commonly associated arterial lesions.

Fibromuscular dysplasia: what the radiologist should know: a pictorial review

Abstract

Fibromuscular dysplasia (FMD) is an idiopathic, segmentary, non-inflammatory and non-atherosclerotic disease that can affect all layers of both small- and medium-calibre arteries. The prevalence of FMD is estimated between 4 and 6 % in the renal arteries and between 0.3 and 3 % in the cervico-encephalic arteries. FMD most frequently affects the renal, carotid and vertebral arteries, but it can theoretically affect any artery. Radiologists play an important role in the diagnosis of FMD, and good knowledge of FMD’s signs will certainly help reduce the delay between the first symptoms and diagnosis. The common string-of-beads aspect is well known, but less common presentations also have to be considered. These less common imaging findings include vascular loops, fusiform vascular ectasia, arterial dissection, aneurysm and subarachnoid haemorrhage. These radiologic presentations should be known by radiologists in order to diagnose possible FMD, particularly when present in young females or when associated with personal or familial hypertension, to reduce the delay between the onset of the first symptom and the final diagnosis. The patients have to be referred to specialised FMD centres for dedicated management.

Teaching Points

• Fibromuscular dysplasia is not a rare disease.

• Radiologists should recognise less common presentations to orient specific management.

• Vascular loops, fusiform vascular ectasia and a “string-of-beads” aspect are typical presentations.

• Arterial dissection, aneurysm and subarachnoid haemorrhage are less typical radiologic presentations.

The United States Registry for Fibromuscular Dysplasia: results in the first 447 patients

BACKGROUND

Fibromuscular dysplasia (FMD), a noninflammatory disease of medium-size arteries, may lead to stenosis, occlusion, dissection, and/or aneurysm. There has been little progress in understanding the epidemiology, pathogenesis, and outcomes since its first description in 1938.

METHODS AND RESULTS

Clinical features, presenting symptoms, and vascular events are reviewed for the first 447 patients enrolled in a national FMD registry from 9 US sites. Vascular beds were imaged selectively based on clinical presentation and local practice. The majority of patients were female (91%) with a mean age at diagnosis of 51.9 (SD 13.4 years; range, 5-83 years). Hypertension, headache, and pulsatile tinnitus were the most common presenting symptoms of the disease. Self-reported family history of stroke (53.5%), aneurysm (23.5%), and sudden death (19.8%) were common, but FMD in first- or second-degree relatives was reported only in 7.3%. FMD was identified in the renal artery in 294 patients, extracranial carotid arteries in 251 patients, and vertebral arteries in 82 patients. A past or presenting history of vascular events were common: 19.2% of patients had a transient ischemic attack or stroke, 19.7% had experienced arterial dissection(s), and 17% of patients had an aneurysm(s). The most frequent indications for therapy were hypertension, aneurysm, and dissection.

CONCLUSIONS

In this registry, FMD occurred primarily in middle-aged women, although it presents across the lifespan. Cerebrovascular FMD occurred as frequently as renal FMD. Although a significant proportion of FMD patients may present with a serious vascular event, many present with nonspecific symptoms and a subsequent delay in diagnosis.

Releasable tissue plasminogen activators in ischemic stroke

To determine if patients who suffer atherothrombotic ischemic stroke have altered release of tissue plasminogen activator (t-PA), we measured levels in 22 patients within 24 h of onset of symptoms and 1-2 months later. t-PA levels were measured in blood samples by using a colorimetric method after subjecting the plasma to euglobulin fractionation and reacting it with plasminogen and plasmin substrate. Values from a group of normal volunteers previously studied were used as controls. Individual variability in t-PA levels was found acutely and in the recovery phase. During the latter, patients' levels were significantly higher than controls, which was not the case in the acute phase. There was no correlation among t-PA levels, size of cerebral infarct, and patients' clinical status. We propose that endothelial repair and a rebound in endogenous fibrinolytic activity in the absence of peripheral venous disease are responsible for the late (recovery phase) elevation in t-PA.

Transient cerebral ischemic attacks in the young and middle aged. A population study

During an investigation of coronary risk factors, a population 20 to 54 years old in Tromsø, Northern Norway was screened for transient ischemic cerebral attacks. Three simple screening questions were used. Sixteen thousand six hundred and twenty-one subjects participated in the study. Among the responders, a sample of 501 were evaluated neurologically and 10 men and 16 women identified as TIA cases. Mean age for men was 41.3 years, for women 33 years. Five women (mean age 24.4) had the events during pregnancy, pointing to pregnancy as a period of risk. Five-year incidence was found to be 2.5. per 1000. Clinical expressions and ratio carotid to vertebral-basilar TIA hardly differed from that found in materials of older patients. All 26 remained stroke-free during a mean observation period of 55 months. Known risk factors like hypertension, carotid stenosis and cardiac disease were found in only a few. Five women had low blood pressure. It is suggested that TIA in younger age groups may constitute a separate entity where, among other, haemodynamic factors and pregnancy play a role.

Stroke before 55 years of age at Karolinska Hospital 1973-77. A study of 399 well-defined cases. Risk indicators and etiological considerations

The etiological characteristics of cerebrovascular disease (CVD) before the age of 55 are reviewed in 399 patients admitted to the Department of Neurology, Karolinska Hospital, Stockholm, from 1973-77. The material was well-defined with regard to subtypes of stroke as well as to the diseased population. The control material consists of 829 males and females of corresponding age randomly selected from the Stockholm population. In the ischemic group, 61% had angiographic evidence of atherosclerosis and, compared to controls, in most patient groups a significant (P less than 0.05-0.001) association with hypertension, diabetes, heart disease and smoking was found as well as for female patients under age 40 the use of oral contraceptives (P less than 0.001). In the hemorrhagic group, angiography demonstrated aneurysms in 76% of the patients with subarachnoidal bleeding but also atherosclerotic lesions in about 12% of the whole group. This would imply that atherosclerosis is an important precursor also for hemorrhagic lesions, further supported by a significant (P less than 0.01-0.001) association of hypertension, diabetes and smoking with this group.

Epidemiology of acute cerebrovascular disease before the age of 55 in the Stockholm County 1973-77: I. Incidence and mortality rates

The incidence and mortality rates of cerebrovascular disease (CVD) before age 55 were estimated for the Stockholm county between 1973 and 1977 using community based diagnosis and death statistics registers. Annual validation procedures concluded that less than 5% of hospitalized patients may have escaped registration. During the study period a diagnosis of CVD (initial stroke or TIA) was reported in 2,103 individuals, giving annual average crude incidence rates for stroke and TIA of 34 and 4 respectively per 100,000 inhabitants under age 55. Hemorrhagic lesions were reported in 45.4% of the cases, ischemic lesions in 33.1% and unclassified lesions in 21.5%. For all diagnostic categories a strong correlation to age is found, and for most categories the male:female ratio is high. The mortality rates are high for hemorrhagic lesions and low for ischemic and unclassified lesions. Incidence rates are higher than in Uppsala and Gothenburg, Sweden, but lower than in North Karelia, Finland. Mortality rates are similar to those reported by most other investigators.

Reversible cerebral ischemias: a comparative analysis of risk factors in TIAs and in RINDs

A retrospective study in which 709 patients, 522 with RIND and 187 with TIA, were compared in respect of common risk factors (RFs) for acute cerebrovascular disease. The two forms of the disease differed significantly in respect of smoking, hematocrit, hypercholesteremia, hypertriglyceridemia and hyperuricacidemia. Although these RFs do not seem to be determinants of or discriminants between the two forms of acute cerebrovascular disease, it is nonetheless highly probable that, together with all the other RFs, they have a facilitatory role.

Occlusive cerebrovascular disease in young adults

This retrospective study documents the experience of two large Canadian teaching hospitals with occlusive cerebrovascular disease in young adults. Chart review disclosed 76 patients aged 15-40 years during a recent six year period. An apparent cause, or significant coincident risk factors were found in 51 patients (67%). The most prevalent recognized causes were atherosclerosis, emboli from cardiac sources or intracranial aneurysms, and complicated migraine. Pregnancies or use of oral contraceptives were apparent coincident risk factors.

Italian multicenter study on reversible cerebral ischemic attacks: III--Influence of age and risk factors on cerebrovascular atherosclerosis

The influence of age and other risk factors (history of hypertension and diabetes, cigarette smoking, dyslipidemia) on cerebral atherosclerosis was studied in 462 patients with RIA who had cerebral angiography. The degree of atherosclerosis was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesion in 11 extracranial and 21 intracranial arterial segments. Thirty-six percent of the patients under age 45 had a normal angiogram compared with 17% of the patients over 45. In the subgroup of patients with abnormal angiogram the mean ECS and ICS vascular scores were not significantly different in the two age groups. Cigarette smoking was the only risk factor to show a strong association with the extracranial score, and it was independent of the effect of age and other risk factors.

A rapid and highly sensitive solid-phase radioassay for plasminogen activators

A rapid and highly sensitive solid-phase radioassay for the measurement of plasminogen activators is presented. The method employs a convenient and stable 125I-fibrinogen-latex bead product and can reproducibly detect 0.25 milli Ploug units/ml of urokinase. This represents a 100-fold increase in sensitivity over previously published radioisotopic solid-phase technique and a 120-fold increase over the sensitivity of the fibrin plate method. Since the assay can readily detect plasminogen activator levels in euglobulin solutions prepared from pre- and post-venous occlusion plasma, it may be useful for rapidly detecting and monitoring the fibrinolytic potential of patients predisposed to thromboembolic disease.

A study of hemostasis in ischemic cerebrovascular disease. II. Abnormalities in platelet ADP release, platelet cyclooxygenase regeneration time and platelet factor 3 availability

Most earlier studies of platelet function in stroke patients have been performed in the acute phase and are hampered by diagnostic insecurity. A sample of totally 67 young adults below the age of 55, with ischemic cerebrovascular disease (TIA and minor stroke) were investigated at a late stage after acute disease and compared to 20 healthy controls. Patients with atherosclerotic signs at cerebral angiography had significantly (p less than 0.05) higher platelet factor 3 availability than angionegative patients. Unexpectedly, female patients compared to male patients had significantly (p less than 0.05) larger ADP-release after stimulation with collagen in vitro. Furthermore, when female patients were compared to female controls a significantly (p less than 0.05) increased platelet factor 3 availability was found. The results indicate that platelets in female patients may have an increased tendency to aggregate in vivo. Patients had significantly (p less than 0.01) shortened platelet cyclooxygenase regeneration half times (PRT). This was correlated to high levels of factor VIII related antigen (r=0.59) and high levels of factor VIII biological activity (r=0.67), indicating that platelets may be consumed by platelet adhesion and mural thrombi formation in abnormal vessel walls. PRT appears to be a reliable method to assess platelet function in vivo and to optimize aspirin dose and dose intervals in the individual.

A study of hemostasis in ischemic cerebrovascular disease. III. Abnormalities in vascular plasminogen activators, antiactivators and alpha 2-antiplasmin

A sample of in all 119 patients with ischemic cerebrovascular disease (TIA and minor stroke) below the age of 55 years, were submitted for testing of fibrinolysis in the late recovery phase after acute disease. Defective fibrinolysis, as tested after venous stasis, was found in patients (p less than 0.01) as compared to controls using a conventional fibrin plate method. A new chromogenic peptide substrate method showed a similar tendency. Antiactivator activity, measured as antiurokinase, using a peptide substrate, was significantly higher (p less than 0.01) in young female patients than in female controls. Alpha 2-antiplasmin (peptide substrate method) was significantly (p less than 0.001) higher in female than male patients. However, no correlation was found between inhibitors of fibrinolysis and defective fibrinolysis after venous occlusion. Furthermore, in a pilot study of vein biopsies, normal content of vascular plasminogen activators was found in the majority of cases. Thus, it is suggested that defective fibrinolysis in most cases reflects a disturbed release function.

A study of hemostasis in ischemic cerebrovascular disease. I. Abnormalities in factor VIII and antithrombin

A sample of in all 119 young adults below the age of 55, with ischemic cerebrovascular disease (TIA and minor stroke), was investigated later than three months after acute disease. Factor VIII biological activity and antithrombin antigen were significantly (p less than 0.001) increased as compared to 80 healthy controls. In combination, these two variables correctly classified 85 percent of patients and controls at a stepwise discriminant analysis. Factor VIII related antigen was increased (p less than 0.02) in patients with atherosclerotic signs at cerebral angiography and in postmenopausal female patients (p less than 0.001). It is suggested that high levels of factor VIII might predispose for thrombosis/atherosclerosis. Antithrombin biological activity was normal in spite of high antithrombin antigen levels, possibly indicating a relative insufficiency in the antithrombin defense line. It is concluded that young stroke patients provide good opportunities to look for early operating factors and predictors in human atherosclerosis and arterial thromboembolism.

The cause and prognosis of strokes in people under 50 years

A study of 192 personal cases of completed stroke, reversible ischaemic neurological deficit (RIND) or transient ischaemic attack (TIA) in patients aged 10-49 years seen between 1961 ad 1979 inclusive is reported. Three died acutely; 189 were followed for up to 15 years. The main cause of the initial event was atheromatous or hypertensive vascular disease. Of the 90 patients whose initial event was a completed stroke 19(21%) developed a second stroke, whereas only 4 of the 78 patients with TIA suffered a stroke later. In the entire series there were 6 cardiac deaths and one from mesenteric thrombosis during the follow-up period. The risk of stroke following TIA is less in persons under 50 years than in the older age group. The risk of a second stroke following an initial stroke depends on whether or not there is evidence of vascular disease. In the absence of such evidence the risk is small; in the presence of evidence it is high, being of the order of 20%.