Migraine and Patent Foramen Ovale: A Residual Coincidence or a Pathophysiological Intrigue?

Migraine is one of the most common neurological disorders and one of the most frequent primary headaches. It imposes a significant burden on the affected individuals, society and health care system. As the etiology and pathophysiology of migraine are not well understood, treatment is largely symptomatic. Patent foramen ovale is a remnant of a fetal circulation and is highly prevalent in the general population. Its presence was linked to several disorders including migraine. The aim of this review was to search in the available data the answer to the question whether the link between migraine and patent foramen ovale is coincidental or whether they represent a pathophysiological entity.

Continuous assessment of electrical epileptic activity in acute stroke

OBJECTIVE

To determine the incidence and risk factors of electrical seizures and other electrical epileptic activity using continuous EEG (cEEG) in patients with acute stroke.

METHODS

One hundred consecutive patients with acute stroke admitted to our stroke unit underwent cEEG using 10 electrodes. In addition to electrical seizures, repetitive focal sharp waves (RSHWs), repetitive focal spikes (RSPs), and periodic lateralized epileptic discharges (PLEDs) were recorded.

RESULTS

In the 100 patients, cEEG was recorded for a mean duration of 17 hours 34 minutes (range 1 hour 12 minutes to 37 hours 10 minutes). Epileptic activity occurred in 17 patients and consisted of RSHWs in seven, RSPs in seven, and PLEDs in three. Electrical seizures occurred in two patients. On univariate Cox regression analysis, predictors for electrical epileptic activity were stroke severity (high score on the National Institutes of Health Stroke Scale) (hazard ratio [HR] 1.12; p = 0.002), cortical involvement (HR 5.71; p = 0.021), and thrombolysis (HR 3.27; p = 0.040). Age, sex, stroke type, use of EEG-modifying medication, and cardiovascular risk factors were not predictors of electrical epileptic activity. On multivariate analysis, stroke severity was the only independent predictor (HR 1.09; p = 0.016).

CONCLUSION

In patients with acute stroke, electrical epileptic activity occurs more frequently than previously suspected.

Changes in artistic style after minor posterior stroke

BACKGROUND

Two professional painters experienced significant changes in their art as the main consequence of minor stroke located in the left occipital lobe or thalamus.

METHODS

The features of this artistic conversion were analysed on the basis of extensive neurological, neuropsychological, and psychiatric evaluations.

RESULTS

Both painters, initially unaware of the artistic changes, exhibited mild signs of executive dysfunction, but no general cognitive decline. The first painter, who showed mild visual-perceptive difficulties (dyschromatopsia and scotoma in his right upper visual field after left occipital stroke), together with increased anxiety and difficulty in emotional control, switched to a more stylised and symbolic art. The second painter, who also presented features of emotionalism related to his left latero-thalamic stroke, switched from an impressionist style to a more joyous and geometric, but more simplistic, abstract art.

CONCLUSIONS

These findings show that mild cognitive and affective modifications due to focal posterior brain lesions can have significant repercussions on artistic expression.

Stroke patterns, etiology, and prognosis in patients with diabetes mellitus

BACKGROUND

Although diabetes mellitus (DM) is a risk factor for stroke, it is unclear whether stroke features are different in diabetic vs nondiabetic individuals.

OBJECTIVE

To assess the role of DM in stroke patients.

METHODS

Risk factors, etiology, lesion topography, clinical features, and outcome were assessed in 611 diabetic individuals (history of DM or fasting plasma glucose level of > or =7.0 mmol/L) among 4,064 consecutive patients of the Lausanne Stroke Registry.

RESULTS

Patients with DM were 5.3 years older than non-DM patients. After multivariate analysis, DM was associated with lower relative prevalence of intracerebral hemorrhage (ICH; odds ratio [95% CI]: 0.63 (0.45 to 0.9); p = 0.022), higher relative prevalence of subcortical infarction (SCI; 1.34 [1.11 to 1.62]; p = 0.009), and higher relative frequency of small-vessel (SVD; 1.78 [1.31 to 3.82]; p = 0.012) and large-artery (LAD; 2.02 [1.31 to 2.02]; p = 0.002) disease. In the cohort of diabetic stroke patients, there was no interaction of DM with either hypertension or age for the outcomes of ICH, SCI, SVD, and LAD. Moderate to severe deficit on admission (31.1 vs 31.6%; p = 0.4) and poor functional outcome at 1 month (14.1 vs 15.3%; p = 0.24) did not differ in patients with DM compared with non-DM patients. In multivariate analysis, neither DM (0.86 [0.63 to 1.11]; p = 0.15) nor hypertension (1.09 [0.91 to 1.39]; p = 0.32) was associated with poor functional outcome.

CONCLUSIONS

Diabetic stroke patients are associated with specific patterns of stroke type, etiology, and topography but not with poor functional outcome. There was no interaction between DM and hypertension or age.

Prodromal and early epileptic seizures in acute stroke: does higher serum cholesterol protect?

In a case-control study, patients (n = 43/3,628) presenting seizures <1 week before (n = 6), < or =3 hours after (n = 26), and 3 to 24 hours after (n = 11) a first-ever stroke were studied. On multivariate analysis, they were characterized by lower levels of serum cholesterol (5.86 +/- 0.51 vs 6.34 +/- 0.58; p < 0.0001). Mortality and functional outcome at discharge were not influenced. Early poststroke seizures occur mainly during the critical 3-hour window for thrombolysis. Hypercholesterolemia appears to protect against seizures and cerebral ischemia.

Stroke or transient ischemic attacks with basilar artery stenosis or occlusion: clinical patterns and outcome

BACKGROUND

Basilar artery occlusion (BAO) is associated with a high mortality rate, although cases with spontaneous favorable outcomes have recently been reported, and basilar artery stenosis (BAS) has received little consideration until now.

OBJECTIVE

To study the prognostic clinical factors by testing numerous combinations of admission status characteristics of patients with brain ischemia caused by BAO or BAS.

METHODS

We conducted a retrospective review from the Lausanne Stroke Registry (group 1) of patients with stroke or transient ischemic attack caused by BAS less than 50% or BAO as diagnosed by magnetic resonance angiography who were not treated by thrombolysis. Neurologic findings on admission were correlated with outcomes. We compared clinical patterns associated with poor outcomes in group 1 with those in patients with stroke who died from BAO or BAS (confirmed at autopsy) (group 2).

RESULTS

Eighty-eight patients were studied. The outcomes of patients with stroke in group 1 (35/43) was poor (severe disability or death) in 54% of cases. A statistical analysis revealed that 4 factors-dysarthria, pupillary disorders, lower cranial nerve involvement, and consciousness disorders on admission-were strongly (P<.001) associated with poor outcomes. The multivariate analysis showed that the outcome was poor in 100% of cases in which consciousness disorders or the combination of the remaining 3 factors were present, whereas in the absence of these factors, a poor outcome was reported in only 11%. In 87% of the 45 patients with stroke in group 2, the same clinical patterns were present on admission.

CONCLUSIONS

The prognosis of BAS greater than 50% or BAO is diverse and certain clinical characteristics seem to predict a lower risk of poor outcome. Their presence may help to decide the most suitable therapy.

Automatic classification of HITS into artifacts or solid or gaseous emboli by a wavelet representation combined with dual-gate TCD

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) can detect high-intensity transient signals (HITS) in the cerebral circulation. HITS may correspond to artifacts or solid or gaseous emboli. The aim of this study was to develop an offline automated Doppler system allowing the classification of HITS.

METHODS

We studied 600 HITS in vivo, including 200 artifacts from normal subjects, 200 solid emboli from patients with symptomatic internal carotid artery stenosis, and 200 gaseous emboli in stroke patients with patent foramen ovale. The study was 2-fold, each part involving 300 HITS (100 of each type). The first 300 HITS (learning set) were used to construct an automated classification algorithm. The remaining 300 HITS (validation set) were used to check the validity of this algorithm. To classify HITS, we combined dual-gate TCD with a wavelet representation and compared it with the current "gold standard," the human experts.

RESULTS

A combination of the peak frequency of HITS and the time delay makes it possible to separate artifacts from emboli. On the validation set, we achieved a sensitivity of 97%, a specificity of 98%, a positive predictive value (PPV) of 99%, and a negative predictive value (NPV) of 94%. To distinguish between solid and gaseous emboli, where positive refers now to the solid emboli, we used the peak frequency, the relative power, and the envelope symmetry of HITS. On the validation set, we achieved a sensitivity of 89%, a specificity of 86%, a conditional PPV of 89%, and a conditional NPV of 89%.

CONCLUSIONS

An automated wavelet representation combined with dual-gate TCD can reliably reject artifacts from emboli. From a clinical standpoint, however, this approach has only a fair accuracy in differentiating between solid and gaseous emboli.

Three-dimensional computed tomography angiography and magnetic resonance angiography of carotid bifurcation stenosis

PURPOSE

To evaluate the role of computed tomography angiography (CTA) and magnetic resonance angiography (MRA) in the quantification of atherosclerotic stenosis of carotid artery bifurcation in comparison with digital substraction angiography (DSA) and Doppler sonography (DS).

MATERIALS AND METHODS

Twenty-five patients with atherosclerotic disease of the carotid arteries with proven stenosis by DSA, had spiral CTA, MRA using two- and three-dimensional time-of-flight gradient echo techniques, and DS using Doppler flow signal recording (total 47 carotid artery bifurcations). The degree of stenosis was measured according to the North American Symptomatic Carotid Endarterectomy Trial criteria: total occlusion (100%), severe (70-99%), moderate (30-69%) and mild (0-29%). The degree of stenosis measured by CTA, MRA and DS was compared to DSA, used as the gold standard.

RESULTS

Ninety-seven percent of MRA measures were equivalent to DSA, and 3% were underestimated; 96% of CTA measures were equivalent to DSA, and 4% were underestimated; 77% of DS measures were equivalent to DSA, 21% were overestimated and 2% were underestimated.

CONCLUSIONS

CTA and MRA are equally accurate methods in quantifying the degree of carotid bifurcation stenosis.

Recent progress in drug treatment for acute ischemic stroke

The publication of the positive results of the National Institute of Neurological Disorders and Stroke (NINDS) trial of alteplase (a recombinant tissue plasminogen activator; rt-PA) for acute stroke patients in 1995 and its approval by the US Food and Drug Administration as well as the American Academy of Neurology and American Heart Association increased the interest and attention of the medical community in acute stroke treatment. However, the implication of this NINDS Stroke Study and other thrombolytic trials in clinical practice remains controversial and debated. Furthermore, the recent publication of the results from the European Cooperative Acute Stroke Study II (ECASS II) and Alteplase Thrombolysis of Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) studies will feed the controversy, since the results of these two studies are disappointing and do not confirm the positive results of the NINDS Stroke Study as expected by clinicians managing patients with acute stroke. The Standard Treatment with Alteplase to Reverse Stroke (STARS) and Cleveland studies, which involved a large number of community hospitals to assess the safety profile and the benefit of rt-PA thrombolysis for acute stroke patients in clinical practice, have shown controversial results. Consequently, the issue arises of which is the more reasonable position concerning thrombolysis by alteplase, which seems to work but has not been proven yet beyond reasonable doubt? The recent publication of the results from the Prolyse in Acute Cerebral Thromboembolism (PROACT II) study has shown that intra-arterial thrombolysis with prourokinase is a benefit treatment in stroke patients with a proven middle cerebral artery occlusion within 6 h of stroke onset. Numerous trials devoted to neuroprotection against acute ischemic stroke have been prematurely stopped because of safety concerns or poor risk-benefit ratios, but some new neuroprotective drugs seem promising and are being tested in ongoing studies. The third issue under study concerns the use of antithrombotic drugs in the acute phase of stroke, particularly the new potent platelet glycoprotein IIb/IIIa antagonists such as abciximab. In this paper, we have reviewed selected recent clinical trials focusing on recent advances in acute stroke therapy.

Stroke with internal carotid artery stenosis

BACKGROUND

Stroke patterns in patients with different degrees of carotid stenosis have not been systematically studied.

OBJECTIVE

To determine first-ever stroke subtypes in nonselected patients with extracranial internal carotid artery (ICA) stenosis, based on a primary care hospital stroke registry.

METHODS

One hundred seventy-three patients who experienced their first-ever stroke and who had 50% or greater (North American Symptomatic Carotid Endarterectomy Trial method) ipsilateral extracranial ICA stenosis, corresponding to 6.5% of 2649 patients with anterior circulation stroke included in the Lausanne Stroke Registry, were studied. All these patients underwent Doppler ultrasonography, carotid angiography (conventional or magnetic resonance angiography), neuroimaging (computed tomography or magnetic resonance imaging), and other investigations from the standard protocol of the Lausanne Stroke Registry.

RESULTS

We found the following types of infarct in the middle cerebral artery territory: anterior pial in 54 (31%) of the patients; subcortical, 34 (20%); posterior pial, 32 (19%); large hemispheral, 20 (12%); and border zone, 17 (10%). There were multiple pial in 14 (8%) and multiple deep infarcts in 2 (1%) of the patients. Moderate (50%-69%) ICA stenosis was significantly associated with large hemispheral infarcts and a normal contralateral ICA (P =.04 and P =.02, respectively). Seventy percent to 89% of ICA stenosis was associated with prior transient ischemic attacks (P =.02). After adjusting for cardioembolism, border zone infarcts showed a strong trend to appear mostly in patients with 90% to 99% ICA stenosis (P =.06).

CONCLUSIONS

The association of a large hemispheral infarct with moderate ICA stenosis suggests a large embolism and/or an inadequate collateral supply. While an embolism may also contribute, the association of border zone infarcts with 90% to 99% ICA stenosis emphasizes the significance of hemodynamic disturbance in the pathogenesis of these types of infarct.

Atrial fibrillation with small subcortical infarcts

OBJECTIVES

To evaluate the characteristics of cardioembolic small (maximum lesion diameter<1.5 cm) subcortical infarcts (SSI) in patients with atrial fibrillation (AF).

METHODS

Twenty seven patients with chronic AF and an isolated SSI established by CT/MRI in the anterior circulation (SSI-AF group) were evaluated and their characteristics compared with those of 45 age matched (+/-1 year) patients with SSI, but no arterial or cardiac embolic source (SSI-control group). Using the criterion of the presence or absence of established risk factors (hypertension or diabetes mellitus) for small artery disease (SAD), the SSI-AF group we also subdivided into two groups, SSI-AF-SAD+ (n=22) and SSI-AF-SAD- (n=5) and their characteristics compared.

RESULTS

Although the lack of any significant difference in the distribution of hypertension and diabetes mellitus between the SSI-AF and SSI-control groups emphasises SAD as a common cause of infarct in SSI-AF, the presence of AF-together with the higher frequency of neuropsychological disturbances in the SSI-AF group versus the SSI-control group (15% v 2%; p=0.066)-favours cardioembolism as a potential cause of infarct in several patients. The characteristic factors seen more often in the SSI-AF-SAD- group compared with the SSI-AF-SAD+ group were secondary haemorrhagic transformation, faciobrachial pure motor weakness, subinsular involvement, and better recovery of neurological deficits.

CONCLUSIONS

The study suggests that either SAD or cardioembolism can be the cause of SSI in patients with AF. Atrial fibrillation is not always coincidental in patients with SSI and a clinical lacunar stroke. Certain clinical and radiological findings may be useful in differentiating cardioembolism from SAD in patients with SSI.

Uncommon ultrasound findings in traumatic extracranial vertebral artery dissection

We report a case of internal carotid artery dissection (ICAD) associated with contralateral vertebral artery dissection (VAD). The interest of this case is to discuss an unusual Doppler pattern manifesting by a spectrum of an alternating vertebral artery flow suggesting a hemodynamic contribution from the contralateral vertebral artery (VA) and a clear depiction of both antegrade (red) and retrograde (blue) flow within the false and true lumen of the VAD by color Duplex flow imaging.

[Cholesterol and stroke risk: a role for statins?]

Atherosclerosis is the most common cause of vascular diseases, but the relevance of cholesterol has only been definitely associated with coronary artery disease and peripheral vascular disease. In comparison, the role of cholesterol in stroke is, while a tempting assumption, subject to controversy in the literature. The crucial question--is cholesterol a risk factor for stroke?--remains open. Recent trials with statin drugs, such as 4 S, CARE, LIPID and WOSCOP, have created a new wave of enthusiasm by showing decreased risk of stroke in the statin-treated patients. However, these trials are most often designed for patients with a known history of coronary artery disease. In contrast, studies investigating the impact of statins in the secondary prevention of stroke are still lacking. Moreover, the beneficial effects of statins on clinical events may involve non-cholesterol mechanisms. In regard to stroke prevention, there is no absolute evidence to recommend the use of statin drug therapy.

Coexisting causes of ischemic stroke

BACKGROUND

Coexistence of multiple potential causes of cerebral infarct (MPCI) has been poorly studied.

OBJECTIVE

To determine the risk factors, clinical findings, and topographical patterns of patients with at least 2 potential causes of cerebral infarct.

DESIGN

Data analysis from a prospective acute stroke registry (the Lausanne Stroke Registry, Lausanne, Switzerland) in a community-based primary care center.

RESULTS

Among 3525 patients with first-ever ischemic stroke consecutively admitted to a primary care stroke center, 250 patients (7%) had at least 2 MPCIs, with the following subgroups: large artery disease and a cardiac source of embolism (LAD + CSE) (43%), small artery disease and CSE (SAD + CSE) (34%), LAD + SAD (18%), and LAD + SAD + CSE (5%). Hypertension, cardiac ischemia, and a history of atrial fibrillation predominated in the LAD + SAD + CSE subgroup (P<.001), while cigarette smoking was more prevalent in the LAD + SAD subgroup (P<.05). A decreased level of consciousness and speech disorders were more common in the LAD + CSE subgroup (P<.001). Lacunar syndromes predominated in the LAD + SAD subgroup. Pure motor stroke was the most frequent lacunar syndrome in all subgroups, but sensory motor stroke predominated in the LAD + CSE subgroup (P<.05). The outcome at 1 month was worse in the LAD + CSE and SAD + CSE subgroups (P<.001). Other stroke characteristics and clinical features did not differ significantly between the 4 subgroups of patients with MPCI.

CONCLUSIONS

Our findings suggest that MPCIs are uncommon. The most frequent association is LAD + CSE. Topographical patterns of stroke and clinical characteristics in patients with MPCI only rarely allow emphasis of a preeminent cause. Arch Neurol. 2000;57:1139-1144

What is the significance of leukoaraiosis in patients with acute ischemic stroke?

BACKGROUND

Leukoaraiosis (LA) may have specific clinical correlates in patients with stroke, but this is not well investigated, so that the significance of LA in patients with stroke remains unclear.

METHODS

In a study of 2289 patients with a first-ever acute ischemic stroke, LA was noted in 149 by the use of baseline computed tomography of the brain. These patients were compared with the non-LA group. Statistical tests, including Fisher exact test or a chi(2) test, were used to compare variables, and a multivariate approach using stepwise logistic regression was performed.

RESULTS

Patients with LA were significantly older (73.7 vs 62.7 years; P<. 001), and had a higher incidence of hypertension (72.5% vs 47.1%; P<. 001) and subcortical or lacunar infarction (40.3% vs 25.4% and 21.5% vs 8.0%, respectively; P<.001) on neuroimaging studies, compared with the non-LA group. The most common cause of stroke in the LA group was presumed to be small-artery disease associated with hypertension (46% vs 13.5% in the non-LA group). Age and hypertension were very strongly associated with LA (respective odds ratios [95% confidence intervals], 1.06 [1.04-1.08] and 2.33 [1.60-3. 39]). In addition to these risk factors, a close relationship was found between LA and nonsevere stenosis (<50%) of the internal carotid artery (odds ratio, 2.23 [95% confidence interval, 1.32-3. 76]), although the significance of this association remains speculative. The outcome at 1 month after stroke was similar in both groups.

CONCLUSION

Our results provide further evidence that LA is related primarily to small-vessel disease.

The matching pursuit: a new method of characterizing microembolic signals?

Detection of clinically silent circulating microemboli within cerebral arteries by transcranial Doppler ultrasound (US) is now being widely investigated in the hope of identifying patients at increased risk for stroke. However, the widespread application of embolus detection is still limited in clinical practice because current transcranial Doppler systems have not the required sensitivity and specificity to analyze microembolic signals, particularly to distinguish between gaseous, or solid brain emboli and artefacts. In this work, we proposed to investigate the potential of a new approach for the analysis of microembolic signals via the so-called matching pursuit, which is closely related to wavelet transform and is not subject to the same limitations as the fast Fourier transform. Our preliminary results clearly indicate that matching pursuit is well suited to this task.

Better outcome after stroke with higher serum cholesterol levels

OBJECTIVE

To examine whether serum cholesterol levels have any prognostic value in the first month following acute ischemic stroke.

BACKGROUND

Although the association between serum cholesterol levels and cerebrovascular disorders has been extensively studied, the relationship between cholesterol levels and outcome following ischemic stroke has not been investigated.

METHODS

Using data from 3,273 consecutive patients with first-ever ischemic stroke, the authors compared poor functional outcome (severe disability or death) at 1 month in patients with high cholesterol (total serum cholesterol greater than 6.5 mmol/L or 250 mg/dL) and normal cholesterol (level equal to or less than 6.5 mmol/L or 250 mg/dL). Data were analyzed by univariate and multivariate analysis.

RESULTS

In comparison with patients with normal cholesterol levels, patients with high cholesterol levels had a 2.2-fold lower risk of death (p = 0.002) and a 2.1-fold lower risk of poor functional outcome at 1 month (p < 0.001). After adjustment for known confounding variables, multivariate analysis showed that higher cholesterol levels remained an independent predictor of better functional outcome (OR 0.48, CI 0. 34 to 0.69, p < 0.001).

CONCLUSIONS

The authors' findings suggest that higher levels of cholesterol are associated with a better outcome in the early phase after ischemic stroke.

Motor strokes sparing the leg: different lesions and causes

BACKGROUND

A considerable number of patients develop stroke without involvement of the lower limb. However, there are few reports about the motor syndrome when the leg is spared.

OBJECTIVE

To study clinical findings, causative factors, and lesion topography in stroke patients with a motor deficit sparing the leg.

PATIENTS AND METHODS

We studied 895 patients with paresis sparing the leg from the 3,901 patients enrolled in the Lausanne Stroke Registry. They were compared with 1,644 stroke patients with paresis involving the leg, by means of univariate and multivariate analysis.

RESULTS

Eight hundred forty-four infarcts (94.3%) and 51 hemorrhages (5.7%) led to weakness sparing the leg. Different sites of lesion were found, but the majority were caused by superficial infarcts. Almost half of the lesions were confined to superficial branches of the middle cerebral artery territory, with 276 (30.8%) in the anterior (superior) and 138 (15.4%) in the posterior (inferior) middle cerebral artery. More than half of the infarcts had a presumed embolic source from large-artery disease or from the heart. In comparison with patients with paresis involving the leg, patients without leg involvement had a lower prevalence of small-artery disease (P<.001), but a higher prevalence of migraine (P<.001), transient ischemic attack (P = .001), atherosclerosis without stenosis (P = .005), large-artery disease (P<.001), and left hemispheric strokes (P<.001). They also had a lower frequency of hemorrhagic stroke.

CONCLUSIONS

Patients without leg involvement had different stroke lesions and causes and were characterized by more superficial infarcts mainly caused by emboli from large-artery disease and atherosclerosis without stenosis.

Clinical trial update: neuroprotection against acute ischaemic stroke

One of the most recent advances and hopes in stroke therapy concerns neuroprotection, which has recently been investigated in several clinical trials. Furthermore, some new neuroprotective drugs, which are based on newly identified cellular and molecular mechanisms that underlie the development of focal ischaemic injury, will be tested in stroke patients in the future. It must be emphasized, however, that the concept and application of neuroprotection must remain within the frame of the global network and organization of acute stroke care, because neuroprotection at best may become only a link among many other management strategies for acute stroke.

Power Doppler imaging and color Doppler flow imaging for the evaluation of normal and pathological vertebral arteries

Recently, an ultrasound method for vascular applications using the amplitude of the reflected echosignal for the generation of intravascular color signals has been introduced. We compared the utility of this power Doppler imaging (PDI) with conventional color Doppler flow imaging (CDFI) for examination of vertebral arteries (VA). Forty-nine patients with signs and symptoms suggesting ischemia within the posterior circulation were evaluated. Quality of blood flow visualization by PDI and CDFI at the different VA segments was classified according to a four point scale. Furthermore, combined sonographic findings were correlated with the results of digital substraction and/or magnetic resonance angiography (DSA, MRA). Power Doppler imaging provided a significantly superior visualization of the intertransversal VA, whereas display of the intracranial V4 segment was superior significantly on CDFI. Both methods were complementary for the evaluation of the VA at the origin. With respect to the angiographic findings, combined CDFI and PDI achieved a sensitivity of 90.63% and a specificity of 97.22% for the differentiation of healthy and pathologic VAs. Power Doppler imaging is complementary to CDFI for the sonographic assessment of VA disease. Combined use of PDI and CDFI achieves a high sensitivity and specificity, thus increasing diagnostic confidence.

Status of patent foramen ovale, atrial septal aneurysm, atrial septal defect and aortic arch atheroma as risk factors for stroke

During the last few years, there has been emphasis on the role of the interatrial septum and the aortic arch atheroma in the genesis of stroke. The causal relationship of these disorders with stroke is still controversial because direct evidence may be lacking. The diagnosis is often presumed and based on indirect signs, i.e. by visualization of the interatrial septal or aortic arch abnormalities which are detectable by transesophageal echocardiography. The optimal therapeutic strategy including some more invasive treatments, such as surgery, is uncertain. In this article, we review the current knowledge concerning the interatrial septum and aortic arch disorders as risk factors for stroke and current therapeutic strategies.

Prevention of stroke recurrence with presumed paradoxical embolism

Paradoxical cerebral embolism (PCE) through a patent foramen ovale (PFO) should be considered as a cause of ischemic stroke, particularly in young patients without an alternative cause for stroke. PCE is even more important that it is potentially treatable. However, PCE remains often presumed because it rests upon the rarely demonstrated findings of a deep venous thrombosis and a thrombus lodged in the PFO. Recent studies have shown a rather low stroke recurrence rate in patients with PFO and stroke but suggest that some subgroups of patients with a higher stroke recurrence risk-exist according clinical, echocardiographical and radiological characteristics. For these subgroups, it seems that a more invasive treatment should be required. There are four therapeutic options; antiaggregants, anticoagulation, transcatheter closure of PFO, and surgical closure of PFO. However, these treatments have yet to be evaluated in clinical trials.

Complementarity of contrast transcranial Doppler and contrast transesophageal echocardiography for the detection of patent foramen ovale in stroke patients

All studies concerning the detection of patent foramen ovale (PFO) have compared transthoracic or transesophageal echocardiography (c-TEE) to transcranial Doppler ultrasound after contrast injection (c-TCD), but combining both techniques in the search of PFO has received no consideration. Our study aims to substantiate this claim in 37 patients with cryptogenic stroke. It includes two protocols for the detection of PFO to assess the complementarity of c-TCD and c-TEE performed simultaneously or separately. Firstly, we used a standardized protocol, performing c-TCD alone. Secondly, we used a standardized and a simultaneous protocol which associated c-TCD with c-TEE. When c-TCD and/or c-TEE found right-to-left shunts, they were classified as minimal, intermediate and massive. c-TCD revealed all PFO detected by c-TEE in 24 patients out of 37 (65%). Furthermore, c-TCD was positive for a PFO in 5 other patients whereas c-TEE was negative. The degree of right-to-left interatrial shunting varied according to the protocol: c-TCD performed alone found 15 massive, 4 intermediate and 5 minimal shunts whereas 10, 9 and 5, respectively, were detected by c-TCD when it was combined with c-TEE. In contrast, c-TEE revealed 8 massive, 8 intermediate and 8 minimal shunts. c-TCD can identify minimal shunts missed by c-TEE and could be more relevant to detect massive shunts, particularly when not performed simultaneously with c-TEE because no sedation is required for c-TCD alone as opposed to c-TEE: thus patients are more cooperative and produce a better Valsalva strain. c-TEE confirms pulmonary shunts suspected by c-TCD and determines the morphologic characteristics of the interatrial septum. While previous studies opposed c-TEE against c-TCD for the detection of a PFO, we think that both techniques are complementary and that it is interesting to associate them, particularly when they are deferred, to increase the ability of detecting PFO and to specify the degree of right-to-left shunting.

Prognosis after stroke followed by surgical closure of patent foramen ovale: a prospective follow-up study with brain MRI and simultaneous transesophageal and transcranial Doppler ultrasound

BACKGROUND

The risk of stroke and the long-term prognosis of recurrent strokes in young patients with patent foramen ovale (PFO) are not well known. For this reason, the treatment of these patients remains empirical. An alternative treatment to prolonged antithrombotic therapy may be surgical closure of the PFO.

METHODS

Thirty patients (20 men and 10 women) with stroke and PFO were prospectively selected among 138 patients with stroke and PFO for a study of surgical closure of PFO at our center. Eligible patients were < 60 years old, had negative results of a systematic search for another cause of stroke (first criterion), and met two of the four following criteria: (1) recurrent clinical cerebrovascular events or multiple ischemic lesions on brain MR, (2) PFO associated with an atrial septal aneurysm, (3) > 50 microbubbles counted in the left atrium on contrast transesophageal echocardiography (TEE), and (4) Valsalva maneuver or cough preceding the stroke. Patients selected in this manner for surgery were considered to be a subgroup with a higher risk of stroke recurrence.

RESULTS

All patients had a direct suture of PFO while under cardiopulmonary bypass without recorded early or delayed significant complication. All patients underwent a new brain MRI and TEE simultaneous with transcranial Doppler ultrasonography after contrast injection at 8 +/- 3 months after surgery. After a mean follow-up of 2 years without antithrombotic treatment, no recurrent cerebrovascular event (stroke or transient ischemic attack [TIA]) and no new lesion on MRI had developed. Postoperative contrast TEE and transcranial Doppler ultrasonography showed that two patients had residual interatrial right-to-left shunting, although much smaller than before surgery, associated with single versus double continuous suture.

CONCLUSIONS

Our study of 30 selected stroke patients with surgical suture of PFO showed a stroke recurrence rate of 0% and no significant complication. Residual right-to-left shunting may be avoided by double continuous suture of the PFO. In the absence of controlled studies to guide individual therapeutic decisions, our findings show that PFO closure can be done safely and may be considered to avoid recurrence in selected patients with long life expectancy and presumed paradoxic embolism.

Surgical prophylaxis of recurrent stroke in patients with patent foramen ovale: a pilot study

Prevention of recurrent stroke in adults with patent foramen ovale represents a therapeutic challenge. Antiplatelet or anticoagulant treatment is widely introduced, but its exact indication is not known. In this pilot study, eight men and three women with previous ischemic cerebral events underwent direct surgical closure of the patent foramen ovale. Mean age was 39.4 (from 30 to 58) years. No coexisting cause of stroke was found after extensive investigations, including blood and coagulation tests, echocardiography, 24-hour three-lead electrocardiographic monitoring, extracranial and transcranial Doppler ultrasonography, and cerebral angiography. Criteria for operation also included at least two of the following: atrial septal aneurysm, multiple cerebral infarcts, a history of multiple cerebral events, and Valsalva strain before stroke. Before operation, one patient had two shunts (1 patent foramen ovale, 1 intrapulmonary shunt). No intraoperative or postoperative complications occurred, but a few hours after operation transient arrhythmias developed in two patients without atrial fibrillation, hemodynamic instability, or embolism. During a median follow-up of 12.2 months, no patient had recurrent stroke. All patients prospectively underwent brain magnetic resonance imaging and contrast echocardiography with simultaneous transcranial Doppler ultrasonography. A residual right-to-left interatrial shunt, smaller than the preoperative one, was observed in only one patient, whereas no lesion was seen on magnetic resonance imaging. Our study suggests that surgical closure of patent foramen ovale in patients with presumed paradoxic embolism is safe, with no recurrent stroke in the first year of follow-up. Further studies are needed to evaluate the long-term prognosis of patients with versus without operation and to define the role of operation as an alternative to prolonged antithrombotic treatment.