Silent brain infarct in migraine: Systematic review and meta-analysis

BACKGROUND

While migraine, particularly migraine with aura, is a recognized risk factor for ischemic stroke, the association of migraine with silent brain infarction is a matter of debate, as studies on this topic have yielded conflicting results.

METHODS

A systematic review of the literature was conducted of studies reporting migraine and silent brain infarction, assessed by magnetic resonance imaging, between January 1980 and April 2022, by consulting Medline and Embase databases. Studies with a control group were included in a meta-analysis of population-based studies. An exploratory meta-analysis of both population-based and clinical-based studies was further performed to test the association between migraine with aura and silent brain infarction.

RESULTS

A total of 2,408 articles were identified, among which 24 were included in the systematic review and 10 in the meta-analysis. The meta-analysis of population-based studies showed no association of migraine with silent brain infarction (odds ratio (OR)=1.32 [95% CI 0.92;1.90], P=0.13) and migraine with aura with silent brain infarction (OR=1.56 [0.74;3.30], P=0.24). However, in the exploratory meta-analysis of population-based and clinical-based studies, migraine with aura was significantly associated with silent brain infarction (OR=1.91 [1.02;3.59], P=0.04) and to silent cerebellar infarcts (OR=2.57 [1.01;6.56], P=0.05).

CONCLUSION

In this updated systematic review and meta-analysis of population-based studies, migraine and migraine with aura were not associated with silent brain infarction.

Large artery intracranial stenosis in young adults with ischaemic stroke

Large artery intracranial stenosis (ICS) is a common finding in stroke patients, but is much less prevalent in Western countries than in Asia and in young adults than in the elderly. We investigated the prevalence and causes of ICS among French young adults with ischaemic stroke. Clinical and radiological data of patients aged 18-54 years treated consecutively for acute ischaemic stroke in the anterior circulation at a tertiary stroke centre were analysed retrospectively. Patients with>50% ICS were identified. ICS was evaluated using TOF-MRA, vessel wall-MRI, digital subtraction angiography and CT-angiography. A total of 316 patients were included. ICS was diagnosed in 29 patients, resulting in a prevalence of 9.2% (95% CI, 6.2 to 13.3). The leading cause of ICS was atherosclerosis (n=13), ahead of moyamoya disease (n=4), dissection (n=2), vasculitis (n=2), and reversible cerebral vasoconstriction syndrome (n=1). The cause of ICAS could not be determined in 7 patients. ICS was found in nearly one in 10 ischaemic strokes among French young adults. Atherosclerosis was the leading cause of ICS. The cause of ICS could not be determined in almost a quarter of the patients.

Standard Diffusion-Weighted Imaging in the Brain Can Detect Cervical Internal Carotid Artery Dissections

BACKGROUND AND PURPOSE

The ICA is the most common site of cervical artery dissection. Prompt and reliable identification of the mural hematoma is warranted when a dissection is clinically suspected. The purpose of this study was to assess to capacity of a standard DWI sequence acquired routinely on the brain to detect dissecting hematoma related to cervical ICA dissections.

MATERIALS AND METHODS

This was a retrospective study of a cohort of 110 patients younger than 55 years of age (40 women; mean age, 46.79 years) admitted at the acute phase of a neurologic deficit, headache, or neck pain and investigated by at least a standard 3T diffusion-weighted sequence of the brain. Among them were 50 patients (14 women; mean age, 46.72 years) with subsequently confirmed ICA dissection. In the whole anonymized cohort, both a senior and junior radiologist separately assessed, on the DWI sequences only, the presence of a crescent-shaped or circular hypersignal projecting on the subpetrosal segment of the ICA arteries, assuming that it would correspond to a mural hematoma related to an ICA dissection.

RESULTS

The senior radiologist found 46 subpetrosal hyperintensities in 43/50 patients with ICA dissection and none in patients without dissection (sensitivity, 86%; specificity, 100%). The junior radiologist found 48 subpetrosal hyperintensities in 45/50 patients with dissection and none in patients without dissection (sensitivity, 90%; specificity, 100%).

CONCLUSIONS

In our cohort, a standard DWI sequence performed on the brain at the acute phase of a stroke or for a clinical suspicion of dissection detected nearly 90% of cervical ICA dissections.

Intracranial artery stenosis or occlusion predicts ischemic recurrence after transient ischemic attack

BACKGROUND AND PURPOSE

Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA.

MATERIALS AND METHODS

We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis).

RESULTS

Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04).

CONCLUSIONS

Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.

Executive dysfunction in adults with moyamoya disease is associated with increased diffusion in frontal white matter

BACKGROUND AND PURPOSE

Alteration of the cerebrovascular reserve (CVR) in the frontal lobes has been associated with cognitive dysfunction in adults with moyamoya disease (MMD). Elevation of the apparent diffusion coefficient (ADC) in normal-appearing white matter on conventional MRI may occur as a consequence of chronic haemodynamic failure. In the present study, the authors examined the relation of ADC with CVR and cognitive dysfunction in adults with MMD.

METHODS

The authors measured ADC and CVR in the normal-appearing frontal white matter. CVR was calculated using dynamic susceptibility contrast-enhanced MRI and the acetazolamide challenge. A standardised and validated neuropsychological assessment test battery focusing on executive function was used.

RESULTS

14 patients, 9 women and 5 men (mean age 36.6±12.9 years), were included. The authors found executive dysfunction in 7 of 13 tested patients. ADC and CVR were negatively correlated (Spearman coefficient: -0.46; p=0.015). Elevation of ADC predicted executive dysfunction (area under receiver operating characteristic curve (95% CI): 0.85 (0.59 to 1.16); p=0.032).

CONCLUSION

Elevation of ADC in the normal-appearing frontal white matter of adults with MMD was associated with reduced CVR and executive dysfunction. This preliminary study suggests that measurement of ADC might be used to detect patients at risk for cerebral ischaemia and cognitive impairment.

Patent foramen ovale and ischemic stroke

Patent foramen ovale (PFO) is a common finding in healthy subjects and has not been associated with increased risk of ischemic stroke in population-based cohort studies. Nevertheless, case-control studies have consistently shown an increased prevalence of PFO in cryptogenic stroke, suggesting that PFO might be a cause of stroke. The risk of stroke recurrence in patients with cryptogenic stroke and PFO is low under aspirin therapy but may be substantially higher in patients with an associated atrial septal aneurysm (ASA). The mechanisms of stroke associated with PFO or ASA are uncertain. Paradoxical embolism through the PFO is rarely documented. The optimal treatment for secondary prevention in patients with cryptogenic stroke and PFO is still uncertain and debated. A randomized controlled trial failed to demonstrate the superiority of transcatheter PFO closure over medical therapy. Whether anticoagulation is superior to aspirin should be tested in a randomized controlled trial.

Etiologic investigation of ischemic stroke in young adults

OBJECTIVES

We attempted to classify causes of ischemic stroke in young adults using a progressive diagnostic algorithm and the ASCO (atherosclerosis, small-vessel disease, cardiac source, other cause) classification system.

METHODS

Patients aged 16-54 years consecutively treated for acute ischemic stroke in a tertiary stroke unit were included in this retrospective analysis. Causes of stroke were classified using the ASCO system, which assigns a graded level of likelihood to each potential cause in individual patients. The initial etiologic workup included brain imaging, magnetic resonance or CT angiography of cerebral and cervical vessels, EKG, and routine blood studies. Patients without a definite cause of ischemic stroke after initial evaluation underwent transesophageal echocardiography.

RESULTS

We included 318 patients (195 men and 123 women); 131 patients were aged 16-44 years, and 187 were aged 45-54 years. A definite cause of stroke (ASCO grade 1) could be identified in 145 patients (45.5%). An uncertain cause of stroke (ASCO grade 2) was found in 59 (18.5%) further patients. Most (130 of 145) definite causes were identified by initial evaluation. The 2 major definite or uncertain causes of stroke were patent foramen ovale associated with atrial septal aneurysm (PFO-ASA) (20 of 131 [15.3%]) and dissection of the cervical or cerebral artery (19 of 131 [14.5%]) in patients aged 16-44 years and large-vessel atherosclerosis (37 of 187 [19.8%]) and PFO-ASA (23 of 187 [12.3%]) in patients aged 45-54 years.

CONCLUSIONS

Our findings suggest that PFO-ASA may be a major cause of ischemic stroke in young adults.

Autonomic neuropathy is associated with impairment of dynamic cerebral autoregulation in type 1 diabetes

HYPOTHESIS

The mechanisms underlying impairment of dynamic cerebral autoregulation in diabetes are not well known. Cardiovascular autonomic neuropathy (CAN) could contribute to dynamic cerebral autoregulation impairment. In this study, we assessed the association between CAN and impairment of dynamic cerebral autoregulation in patients with type 1 diabetes.

METHODS

We evaluated dynamic cerebral autoregulation (DCA) in patients with type 1 diabetes and no history of cerebrovascular disease. DCA was assessed with transcranial Doppler using the correlation coefficient index Mx method. Mx was calculated from slow changes in mean cerebral blood flow velocity and mean arterial blood pressure. Increase in Mx indicates weaker DCA, with a threshold for impaired DCA above 0.3. Moderate CAN was defined as reduced heart rate variability (HRV) on the following tests: deep controlled breathing, Valsalva maneuver or initiation of active standing. Severe CAN was defined as reduced HRV associated with orthostatic hypotension.

RESULTS

60 patients were included (M/F: 33/27; mean age ± SD: 46 years ± 11.5). 23 patients had moderate CAN and 15 patients severe CAN. DCA was impaired in 37 patients. CAN was associated with impaired DCA (p = 0.005). Impairment of DCA was more pronounced in patients with severe CAN (p = 0.019). Glycosylated haemoglobin (HbA1c) was associated with impaired DCA in univariate analysis (p = 0.05). In multivariate analysis, only CAN was associated with impaired DCA (p = 0.007) whereas HbA1c was not (p = 0.161).

CONCLUSIONS

CAN was associated with impaired DCA in type 1 diabetes. The magnitude of DCA impairment increased with the severity of CAN.

Isolated acute nontraumatic cortical subarachnoid hemorrhage

Our aim was to review the etiologic background of isolated acute nontraumatic cSAH. While SAH located in the basal cisterns originates from a ruptured aneurysm in approximately 85% of cases, a broad spectrum of vascular and even nonvascular pathologies can cause acute nontraumatic SAH along the convexity. Arteriovenous malformations or fistulas, cortical venous and/or dural sinus thrombosis, and distal and proximal arteriopathies (RCVS, vasculitides, mycotic aneurysms, Moyamoya, or severe atherosclerotic carotid disease) should be sought by noninvasive imaging methods or/and conventional angiography. Additionally, PRES may also be a source of acute cSAH. In elderly patients, cSAH might be attributed to CAA if numerous hemorrhages are demonstrated by GRE T2 images. Finally, cSAH is rarely observed in nonvascular disorders, such as abscess and primitive or secondary brain tumors.

Prevalence of atrial septal abnormalities in older patients with cryptogenic ischemic stroke or transient ischemic attack

OBJECTIVE

To evaluate the association of atrial septal abnormalities--patent foramen ovale (PFO), atrial septal aneurysm (ASA), or the combination of both (PFO+ASA)--with cryptogenic stroke or transient ischemic attack (TIA) in older patients.

METHODS

We examined the prevalences of PFO, ASA, and PFO+ASA in 132 consecutive patients aged 55 years or more who underwent transesophageal echocardiography (TEE) for evaluation of ischemic stroke or TIA. We compared patients with cryptogenic stroke/TIA and those with stroke/TIA of known cause.

RESULTS

PFO+ASA was more common in patients with cryptogenic stroke/TIA than in patients with stroke/TIA of known cause (12/62 or 19% vs. 2/70 or 3%; adjusted odds ratio, 7.4; 95% CI, 1.4-38.2). Differences between groups for isolated PFO, and isolated ASA were not significant. The association of PFO+ASA with cryptogenic stroke/TIA was confirmed in the subgroup of patients aged 75 years or more (odds ratio, 15.0; 95% CI, 1.5-146.7).

CONCLUSION

This study indicates a significant association of PFO+ASA with cryptogenic stroke or TIA in older patients.

Paralysie périodique hypokaliémique et grossesse: prise en charge périnatale à propos d'un cas

Familial hypokalemic periodic paralysis (FHPP) is a rare inherited disease characterized by a dysfunction of the membrane ion channels. Clinical manifestations are attacks of hypokaliemia with flaccid muscle paralysis. Paralysis is sometimes severe but always reversible with symptomatic treatment. Pregnancy and delivery have been reported to exacerbate FHPP. Authors report a case of FHPP during pregnancy with a favourable outcome. Vaginal delivery is usually possible with monitoring and epidural analgesia, avoiding active maternal expulsive efforts (passive descent of the fetus and elective outlet forceps) and other stimulating factors (carbohydrate loads, maternal stress, betamimetics, epinephrine...). Administration of IV potassium supplementation is often necessary.

Carotidynia: a new case for an old controversy

Whereas International Headache society (IHS) criteria of carotidynia were defined in 1988, its validity as a distinct nosological entity has recently been questioned, leading this entity to be removed from the second IHS classification in 2004. We report the case of a 30-year-old woman who developed a pain located at the left carotid bulb, associated with typical findings on ultrasonography and MRI. We discuss new criteria and denomination of this clinical entity.

Lipoprotein (a) and risk of ischemic stroke in young adults

Lipoprotein (a) [Lp(a)] is a LDL-particle linked to apoprotein (a) [apo(a)]. High Lp(a) plasma level is a risk factor for coronary heart disease and, in older men, for ischemic stroke. The role of Lp(a) as a risk factor for ischemic stroke in young adults is uncertain.

METHODS

Lp(a) concentration was prospectively measured in 100 consecutive patients with acute ischemic stroke (58 men and 42 women) aged 18-55 years, and in 100 controls matched for age and gender.

RESULTS

The distribution of Lp(a) concentration was skewed toward the highest and median tertiles in male patients. In multivariate logistic regression analyses adjusting on classical risk factors for ischemic stroke and lipid variables, Lp(a) concentration in the highest and medium tertiles compared with the lowest tertile was significantly associated with ischemic stroke in men (OR 3.55, 95% CI 1.33-9.48, p = 0.012), but was not in women (OR 0.42, 95% CI 0.14-1.26, p = 0.12). Although large vessel atherosclerosis was more common in men than in women, there were no differences in Lp(a) concentration according to the cause of ischemic stroke.

CONCLUSION

Among subjects aged 18-55 years, a slightly elevated Lp(a) concentration was strongly and independently associated with ischemic stroke in men, but not in women. Further studies are required to elucidate the mechanisms underlying this gender-specific association.

La sonothrombolyse dans l’accident ischémique cérébral

Numerous experimental studies,in vitro and in animal models, have demonstrated that ultrasound can accelerate clot lysis. This effect is probably related to the cavitation of microbubbles contained in the medium exposed to ultrasound. Clinical studies show that transcranial application of low-intensity, low-frequency ultrasound identical to that routinely used for diagnostic purposes can improve recanalization rates in patients with acute ischemic stroke. These promising findings should be confirmed in larger studies and using MR or CT angiography to assess recanalization independently. The optimal method of ultrasound-assisted thrombolysis has not been determined yet. Experimental data suggest that it may be enhanced by coadministration of microbubbles used as contrast agents.

Enhancement of enzymatic fibrinolysis with 2-MHz ultrasound and microbubbles

BACKGROUND

Microbubbles used for echo-contrast agents accelerate enzymatic fibrinolysis of clots exposed to low-frequency ultrasound (US). It is not known whether microbubbles are also effective in enhancing high-frequency US-driven enzymatic fibrinolysis.

METHODS AND RESULTS

Calibrated whole blood clots were exposed to US, or US and galactose-based microbubbles (Levovist), with or without recombinant tissue plasminogen activator (rt-PA) in an in-vitro flow system. We used low-intensity, 2-MHz, pulsed wave US. Relative weight reduction of clot +/- SD was 30.7 +/- 9.5% after exposure to microbubbles, rt-PA and US, 13.1 +/- 2.6% after exposure to rt-PA and US, 10.9 +/- 3.6% after exposure to microbubbles and US, and 6.1 +/- 1.9% after exposure to US alone. anova demonstrated a significant effect of rt-PA (P =0.001), microbubbles (P = 0.012), and interaction of both (P = 0.022).

CONCLUSIONS

The application of galactose-based microbubbles (Levovist) strongly accelerates lysis of clots exposed to 2 MHz, low-intensity US in vitro both with and without rt-PA. The findings suggest a synergy between microbubbles and rt-PA. These methods routinely used for transcranial diagnostic applications have the potential to improve the efficacy of intravenous rt-PA in acute ischemic stroke.

Asymptomatic cerebral embolic signals in patients with acute cerebral ischaemia and severe aortic arch atherosclerosis

Severe aortic arch atheroma (AAA) is a strong risk factor for ischaemic stroke, but it is unclear whether AAA is a source of cerebral emboli or simply a marker of cerebral atherosclerosis. The purpose of this study was to find out the prevalence of asymptomatic cerebral embolic signals (ES) in patients with acute cerebral ischaemia, AAA and no other potential source of cerebral embolism. Forty patients with anterior circulation ischaemic stroke or transient ischaemic attack (TIA) were prospectively studied using transesophageal echocardiography (TEE) and transcranial Doppler (TCD) scanning within seven days of symptom onset. Patients with a cardiac source of embolism or carotid stenosis > 50% were excluded. ES were detected in 14.3% (2/14) of patients with AAA > or = 4 mm and in no patients with AAA < 4 mm or no AAA (p=0.14). The findings suggest that ES may be associated with severe AAA but their prevalence is low in this setting.

Risk factors for severe hemorrhagic transformation in ischemic stroke patients treated with recombinant tissue plasminogen activator: a secondary analysis of the European-Australasian Acute Stroke Study (ECASS II)

BACKGROUND AND PURPOSE

Intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA) improves the outcome for ischemic stroke patients who can be treated within 3 hours of symptom onset. The efficacy of thrombolysis has been demonstrated despite an increased risk of severe hemorrhagic transformation (HT) in patients treated with rtPA. We performed an analysis of risk factors for severe HT in the second European-Australasian Acute Stroke Study (ECASS II).

METHODS

HTs were classified by using clinical and radiological criteria as follows: hemorrhagic infarction (HI), parenchymal hemorrhage (PH), and symptomatic intracranial hemorrhage (SICH). Potential risk factors for HT were tested by stepwise logistic regression analysis, including rtPA-by-variable interactions. In addition, the distribution of bad outcome (modified Rankin score 5 to 6) at day 90 was stratified according to each category of HT.

RESULTS

PH and SICH but not HI were associated with rtPA. Also, PH and SICH but not HI were more severe in rtPA-treated patients than in those receiving placebo. Risk factors for PH were rtPA, extent of parenchymal hypoattenuation on baseline CT, congestive heart failure, increasing age, and baseline systolic blood pressure. The risk of PH on rtPA was increased in older patients and in those who were treated with aspirin before thrombolysis. Risk factors for SICH were rtPA, congestive heart failure, extent of parenchymal hypoattenuation, and increasing age. The risk of SICH on rtPA was increased in patients who were treated with aspirin before thrombolysis.

CONCLUSIONS

This secondary analysis of ECASS II has confirmed the importance of the extent of hypoattenuation as a risk factor for severe HT. The findings also suggest that older patients and those who have used aspirin before stroke are at higher risk of a severe HT on rtPA.

Hemorrhagic transformation within 36 hours of a cerebral infarct: relationships with early clinical deterioration and 3-month outcome in the European Cooperative Acute Stroke Study I (ECASS I) cohort

BACKGROUND AND PURPOSE

The clinical correlates of the varying degrees of early hemorrhagic transformation of a cerebral infarct are unclear. We investigated the cohort of a randomized trial of thrombolysis to assess the early and late clinical course associated with different subtypes of hemorrhagic infarction (HI) and parenchymal hematoma (PH) detected within the first 36 hours of an ischemic stroke.

METHODS

We exploited the database of the European Cooperative Acute Stroke Study I (ECASS I), a randomized, placebo-controlled, phase III trial of intravenous recombinant tissue plasminogen activator in acute ischemic stroke. Findings on 24- to 36- hour CT were classified into 5 categories: no hemorrhagic transformation, HI types 1 and 2, and PH types 1 and 2. We assessed the risk of concomitant neurological deterioration and of 3-month death and disability associated with subtypes of hemorrhagic transformation, as opposed to no bleeding. Risks were adjusted for age and extent of ischemic damage on baseline CT.

RESULTS

Compared with absence of hemorrhagic transformation, HI1, HI2, and PH1 did not modify the risk of early neurological deterioration, death, and disability, whereas, in both the placebo and the recombinant tissue plasminogen activator groups, PH2 had a devastating impact on early neurological course (odds ratio for deterioration, 32.3; 95% CI, 13. 4 to 77.7), and on 3-month death (odds ratio, 18.0; 95% CI, 8.05 to 40.1). Risk of disability was also higher, but not significantly, after PH2.

CONCLUSIONS

Risk of early neurological deterioration and of 3-month death was severely increased after PH2, indicating that large hematoma is the only type of hemorrhagic transformation that may alter the clinical course of ischemic stroke.

Association of hyperdense middle cerebral artery sign with clinical outcome in patients treated with tissue plasminogen activator

BACKGROUND AND PURPOSE

The hyperdense middle cerebral artery sign (HMCAS) is a marker of thrombus in the middle cerebral artery. The aim of our study was to find out the frequency of the HMCAS, its association with initial neurological severity and early parenchymal ischemic changes on CT, its relevance to clinical outcome, and the efficacy of intravenous recombinant tissue plasminogen activator (rtPA) in patients with the HMCAS.

METHODS

Secondary analysis of the data from 620 patients who received either rtPA or placebo in the European Cooperative Acute Stroke Study I (ECASS I), a double-blind, randomized, multicenter trial. The baseline CT scans were obtained within 6 hours from the onset of symptoms. Functional and neurological outcomes were assessed using the modified Rankin Scale and the Scandinavian Stroke Scale at day 90.

RESULTS

We found an HMCAS in 107 patients(17.7%). The initial neurological deficit was more severe in patients with the HMCAS than in those lacking this sign (P<0.0001). Early cerebral edema and mass effect were also more common in patients with the HMCAS (P<0.0001). The HMCAS was related to the risk of poor functional outcome (grade of 3 to 6 on the modified Rankin Scale) on univariate analysis: 90 patients (84%) with the HMCAS and 310 patients (62%) lacking this sign were dependent or dead at day 90 (P<0.0001). However, this association was no longer significant in a logistic model accounting for the effect of age, sex, treatment with rtPA, initial severity of neurological deficit and early parenchymal ischemic changes on CT. Patients with the HMCAS who were given rtPA had better neurological recovery than those who received placebo (P=0.0297).

CONCLUSIONS

The HMCAS is associated with severe brain ischemia and poor functional outcome. However, it has no significant independent prognostic value when accounting for the effect of initial severity of neurological deficit and of early parenchymal ischemic changes on CT. Patients with the HMCAS may benefit from intravenous rtPA.

Randomised double-blind placebo-controlled trial of thrombolytic therapy with intravenous alteplase in acute ischaemic stroke (ECASS II). Second European-Australasian Acute Stroke Study Investigators

BACKGROUND

Thrombolysis for acute ischaemic stroke has been investigated in several clinical trials, with variable results. We have assessed the safety and efficacy of intravenous thrombolysis with alteplase (0.9 mg/kg bodyweight) within 6 h of stroke onset.

METHODS

This non-angiographic, randomised, double-blind, trial enrolled 800 patients in Europe, Australia, and New Zealand. Computed tomography was used to exclude patients with signs of major infarction. Alteplase (n=409) and placebo (n=391) were randomly assigned with stratification for time since symptom onset (0-3 h or 3-6 h). The primary endpoint was the modified Rankin scale (mRS) at 90 days, dichotomised for favourable (score 0-1) and unfavourable (score 2-6) outcome. Analyses were by intention to treat.

FINDINGS

165 (40.3%) alteplase-group patients and 143 (36.6%) placebo-group patients had favourable mRS outcomes (absolute difference 3.7%, p=0.277). In a posthoc analysis of mRS scores dichotomised for death or dependency, 222 (54.3%) alteplase-group and 180 (46.0%) placebo-group patients had favourable outcomes (score 0-2; absolute difference 8.3%, p=0.024). Treatment differences were similar whether patients were treated within 3 h or 3-6 h. 85 (10.6%) patients died, with no difference between treatment groups at day 90+/-14 days (43 alteplase, 42 placebo). Symptomatic intracranial haemorrhage occurred in 36 (8.8%) alteplase-group patients and 13 (3.4%) placebo-group patients.

INTERPRETATION

The results do not confirm a statistical benefit for alteplase. However, we believe the trend towards efficacy should be interpreted in the light of evidence from previous trials. Despite the increased risk of intracranial haemorrhage, thrombolysis with alteplase at a dose of 0.9 mg/kg in selected patients may lead to a clinically relevant improvement in outcome.

Microembolic signals and risk of early recurrence in patients with stroke or transient ischemic attack

BACKGROUND AND PURPOSE

Asymptomatic microembolic signals (MES) can be demonstrated in patients with cerebral ischemia using transcranial Doppler (TCD) ultrasonographic monitoring of the middle cerebral artery. However, the clinical relevance of MES remains uncertain. The purpose of this study was to estimate the independent contribution of microembolism to the risk of early ischemic recurrence (EIR) in patients with stroke or transient ischemic attack (TIA) of presumed arterial origin.

METHODS

We studied the incidence of EIR in 73 consecutive patients with carotid stroke or TIA in whom TCD scanning of the symptomatic middle cerebral artery was performed within 7 days from the onset of symptoms. Patients with a potential cardiac source of embolism were excluded from the study.

RESULTS

Eight patients had EIR during a mean+/-SD follow-up of 10+/-8 days. The incidence of EIR was 4.3 per 100 patient-days in patients with MES and only 0.5 per 100 patient-days in patients without MES. The presence of MES was a significant predictor of EIR after adjustment for the presence of carotid stenosis or aortic arch atheroma, antiplatelet therapy during follow-up, and other potential confounding variables (relative risk, 8.7; 95% confidence interval, 2 to 38.2; P=0.0015).

CONCLUSIONS

Microembolism is a significant independent predictor of EIR in patients with stroke or TIA of presumed arterial origin.

[Etiological investigations in cerebral ischemic accidents]

First-line investigations for all patients include full blood count, erythrocyte sedimentation rate, plasma glucose, plasma cholesterol, plasma electrolytes, creatinine. ECG, chest X-ray and colour Doppler sonography of the neck. Carotid selective arteriography is performed when colour Doppler of the symptomatic carotid artery shows a stenosis of about 70% or more, provided the patient is fit for carotid endarterectomy. The search for paroxysmal atrial fibrillation is worthwhile in patients with palpitations. Transesophageal echocardiography is indicated if a cardiac source of embolism is suspected on the basis of clinical examination, ECG or chest X-ray and in patients without any apparent cause of stroke, if an embolic mechanism is likely. Finally, in the young patient atherosclerosis is so rare that special etiological investigations are justified.

Cerebral microembolism in patients with stroke or transient ischaemic attack as a risk factor for early recurrence

The incidence of early recurrence in 32 patients who had had a transient ischaemic attack or stroke in the anterior circulation was studied. Patients with a potential cardiac source of embolism were excluded from the study. All patients had transcranial Doppler (TCD) monitoring of the symptomatic middle cerebral artery for microembolic signal detection within seven days from the onset of symptoms. Four patients had early recurrence during a mean follow up of 15 (SD11) days. All early recurrences occurred in the same arterial territory as the initial ischaemic event. Three of the four patients with early recurrence had prior microembolic signals. The incidence of early recurrence was 50% (3/6) in patients with microembolic signals and 3.8% (1/26) in patients without microembolic signals (P=0.02). The findings suggest that TCD monitoring of patients with recent cerebral ischaemia of presumed arterial origin allows recognition of a subset of patients at high risk for early recurrence.

Hemorrhagic transformation in acute ischemic stroke. Potential contributing factors in the European Cooperative Acute Stroke Study

BACKGROUND AND PURPOSE

Recent studies suggest that thrombolytic therapy may be of benefit to patients with acute ischemic stroke. However, the treatment also carries a significant risk of hemorrhagic transformation (HT). The purpose of this study was to select potential contributors to HT.

METHODS

We provide an explanatory analysis of the European Cooperative Acute Stroke Study (ECASS) data. ECASS was a multicenter, placebo-controlled, randomized trial of recombinant tissue plasminogen activator in ischemic stroke, within 6 hours of symptom onset, which enrolled 620 patients. HTs were classified into either hemorrhagic infarction or parenchymal hemorrhage according to their CT scan appearance. We used logistic regression analysis to select potential contributing factors to each type of HT.

RESULTS

The severity of initial clinical deficit (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.6 to 4.0) and the presence of early ischemic changes on CT scan (OR, 3.5; 95% CI, 2.3 to 5.3) were associated with increased risk of hemorrhagic infarction. Increasing age (in decades; OR, 1.3; 95% CI, 1.0 to 1.7) and treatment with recombinant tissue plasminogen activator (OR, 3.6; 95% CI, 2.1 to 6.1) were related to the risk of parenchymal hemorrhage.

CONCLUSIONS

Since all potential contributing factors are readily discernible upon hospital admission, they should be used to improve selection of patients into future studies.

[Malignant endovascular large-cell lymphoma: disclosing central nervous system involvement confirmed by cerebral biopsy]

Intravascular malignant lymphomatosis (IML) is characterised by proliferation of tumoral cells within small vessels. Angiotropic large cell lymphoma commonly affects the central nervous system and the skin, although any organ may be involved. Few cases are diagnosed ante mortem. We report a new case of IML in a 62-year-old woman who presented with the main clinical features of central nervous system involvement: cerebrovascular events, epileptic seizures, subacute dementia and spinal cord syndrome. Cranial magnetic resonance imaging demonstrated increased periventricular signal on T2-weighted images. Diagnosis was established by brain biopsy. Despite corticosteroid and radiation therapy no improvement occurred and the patient died 14 months after the onset of the first symptoms.

Asymptomatic cerebral embolic signals in patients with carotid stenosis. Correlation with appearance of plaque ulceration on angiography

BACKGROUND AND PURPOSE

Asymptomatic cerebral emboli may be detected in patients with carotid stenosis by transcranial Doppler ultrasonography of the middle cerebral artery (MCA). The aim of this study was to determine the angiographic correlates of such embolic signals.

METHODS

Doppler signals from 48 MCAs in 26 patients with carotid stenosis that was either symptomatic (n = 20) or asymptomatic (n = 6) were recorded for 40 minutes. The grade of carotid stenosis and the ulcerated or nonulcerated appearance of the plaque were assessed using the criteria of the North American Symptomatic Carotid Endarterectomy Trial.

RESULTS

Embolic signals were detected in 8 MCAs from 7 patients; 4 (50%) of these MCAs were clinically symptomatic compared with 16 (40%) without embolic signal. Although there was a trend toward more severe stenosis in the cases with embolic signals, this was not significant (mean +/- SD, 67 +/- 29% versus 55 +/- 36%). In contrast, an image of ulceration was found on ipsilateral carotid angiography in 5 cases (63%) with embolic signals and in only 9 cases (23%) without embolic signals (odds ratio, 5.74; 95% confidence interval, 1.15 to 28.79, by multivariate regression analysis).

CONCLUSIONS

This study demonstrates that the occurrence of embolic signals in patients with carotid stenosis is associated with the appearance of plaque ulceration on angiography.

The functional anatomy of attention in humans: cerebral blood flow changes induced by reading, naming, and the Stroop effect

We measured changes in regional cerebral blood flow (rCBF) induced by reading, naming, and the Stroop effect in 12 right-handed normal volunteers. rCBF was quantified with a single-photon emission computerized tomograph after intravenous injection of 133Xe. Data were analyzed using predetermined regions of interest and a linear model. A significant relative activation was revealed in the right superior mesial frontal region during the Stroop effect.

[Effects of captopril on the cerebral blood flow in the hypertensive aged subjects]

Cerebral blood flow (CBF) was measured in 13 subjects (4 men and 9 women, mean age +/- SD = 63 +/- 7) with moderate, uncomplicated and untreated hypertension and 11 normotensive subjects (6 men and 5 women, mean age +/- SD = 66 +/- 5). A second CBF measurement was performed in hypertensive subjects after a 60 days randomized double blind treatment with either captopril, 75 mg a day (n = 8) or placebo (n = 5). CBF was quantified using the 133Xe inhalation technic and 16 stationary detectors by hemisphere. Comparison of CBF values between hypertensive subjects before treatment and normotensive subjects demonstrated a decrease of CBF in the hypertensive group (49 +/- 9 vs 72 +/- 14 ml/100 g/min; p < 0.001). After the trial the results in the captopril group showed a significant fall in systolic (p < 0.001) and diastolic (p < 0.05) blood pressure and a significant increase in CBF (60 +/- 14 vs 49 +/- 11 ml/100 g/min; p < 0.05). In the placebo group there was no change in blood pressure and CBF (Table). [Table; see text] Our results demonstrate a decrease in CBF of uncomplicated and untreated elderly hypertensive subjects. This decrease is reversible under chronic treatment with captopril.

[Guillain-Barré syndrome associated with cytomegalovirus infection after kidney transplantation]

The Guillain-Barré syndrome associated with cytomegalovirus infection is a recognized entity of unknown pathogenesis. We observed two characteristic cases with acute polyradiculoneuropathy which occurred after renal transplantation. Both patients fulfilled the diagnostic criteria for Guillain-Barré syndrome: tetraparesis with diffuse areflexia and moderate sensorial signs, high protein level in cerebrospinal fluid without cellular reaction, slow or blocked nerve conduction and partial cure after several months delay. In two-thirds of such cases, the syndrome follows an episode of infection. Cytomegalovirus has been recognized as a possible association. The demyelinating polyradiculoneuropathy induced by cytomegalovirus has been reported essentially in immunodepressed patients infected with the human immunodeficiency virus in whom a pathogenic role for cytomegalovirus in peripheral nerves has been suggested. In our two cases, the cytomegalovirus infection occurred before onset of the acute polyradiculoneuropathy. In both cases, specific IgM antibodies and clear IgG positivization occurred before the first signs of neurological impairment even though neither the virus nor specific antibodies could be concomitantly detected in the cerebrospinal fluid. Despite the frequency of cytomegalovirus infections in transplant recipients, to our knowledge, only 9 cases of Guillain-Barré syndrome after transplantation have been reported and the exact mechanism remains to be ascertained. These two cases suggest that the onset of the Guillain-Barré syndrome after renal transplantation was closely related to cytomegalovirus infection. Adequate measures should be taken to quickly diagnose such cases in order to instore rapid treatment for the polyradiculoneuropathy. In addition, this particular situation of post-transplantation onset might help better understand the exact role of cytomegalovirus infection in the Guillain-Barré syndrome.