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Antoni Dávalos

Publications and source records attributed to Antoni Dávalos.

At least 19 recordsLinked to original sources
PubMed2006

Other neuroprotective therapies on trial in acute stroke.

New neuroprotective agents on trial may potentially offer benefit to stroke patients without the associated hemorrhagic risk of thrombolytic therapy. Clinical investigation of these drugs has been designed to obtain the highest probability of success, or concentrates on the salvageable ischemic brain and use infarct growth on MRI as a surrogate end-point. Nine substances in 10 trials are currently being tested in three therapeutical strategies in patients with acute ischemic stroke. These strategies focus on: (1) the optimal management of serum glucose with the infusion of glucose, insulin and potassium to induce and maintain euglycemia; (2) the modulation of the inflammatory response with recombinant human interferon-beta(1a), and (3) interfering with the ischemic cascade using magnesium, albumin, the metal iron chelator DP-b99, the AMPA receptor antagonist zonampanel, the serotonin agonists repinotan and piclozotan, the free radical scavenger cerovive, and the membrane modulator citicoline. Future directions should develop neuroprotective compounds that are safe and well tolerated, are effective in a broad range of patients and can be used with or without rt-PA.

Anti-Inflammatory Agents↗
PubMed2006

A polymorphism in the EAAT2 promoter is associated with higher glutamate concentrations and higher frequency of progressing stroke.

It remains unclear why some individuals are susceptible to excitotoxicity after stroke. A possible explanation is impaired glutamate uptake. We have found a highly prevalent polymorphism in the promoter of the glutamate transporter EAAT2 gene that abolishes a putative regulatory site for activator protein-2 (AP-2) and creates a new consensus binding site for the repressor transcription factor GC-binding factor 2 (GCF2). The mutant genotype is associated with increased plasma glutamate concentrations and with a higher frequency of early neurological worsening in human stroke. After transfection into astrocytes, the mutant promoter was not activated by AP-2 and was effectively repressed by GCF2, and its activity in the presence of GCF2 was reduced when compared with the AP-2-cotransfected wild-type promoter. We also show that GCF2 is expressed in ischemic rat brain, suggesting that decreased glutamate uptake occurs in individuals carrying the mutation after stroke. These findings may explain individual susceptibility to excitotoxic damage after stroke as well as the failure of glutamate antagonists in those patients without this polymorphism.

Aged↗
PubMed2006

Citicoline in intracerebral haemorrhage: a double-blind, randomized, placebo-controlled, multi-centre pilot study.

BACKGROUND: In experimental models citicoline has shown beneficial effects in intracerebral haemorrhage. Citicoline is a neuroprotectant drug with some beneficial effects in human ischaemic stroke and with an excellent safety profile. We decided to carry out a pilot study to test its safety and efficacy in human intracerebral haemorrhaging. METHODS: In this double-blind, placebo-controlled pilot study, patients had to be previously independent, aged between 40 and 85 years, and had to be admitted within 6 h after onset of symptoms of an acute primary supratentorial hemispheric cerebral haemorrhage diagnosed by neuroimaging (CT or MRI). Baseline severity was defined as patients with a score larger than 8 points on the Glasgow Coma Scale and larger than 7 on the National Institutes of Health Stroke Scale. Patients received either a placebo or 1 g/12 h citicoline for 2 weeks (orally or intravenously). The primary aim was to evaluate safety with respect to the number of adverse events that occurred. The efficacy endpoint was the percentage of patients with a modified Rankin Score (mRS) at 3 months. RESULTS: 19 patients in each group were included in the study. The incidence of serious adverse events was not different among groups (4 patients in each group). One patient in the placebo group was categorised as independent (mRS<or=2) in comparison with 5 patients in the citicoline group (OR, 5.38; 95% CI, 0.55-52). CONCLUSIONS: Citicoline seems to be a safe drug in human intracerebral haemorrhage with a positive trend regarding efficacy. These data should be confirmed in a larger trial.

Activities of Daily Living↗
PubMed2006

Rosiglitazone and 15-deoxy-Delta12,14-prostaglandin J2 cause potent neuroprotection after experimental stroke through noncompletely overlapping mechanisms.

Stroke triggers an inflammatory cascade which contributes to a delayed cerebral damage, thus implying that antiinflammatory strategies might be useful in the treatment of acute ischaemic stroke. Since two unrelated peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, the thiazolidinedione rosiglitazone (RSG) and the cyclopentenone prostaglandin 15-deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2), have been shown to possess antiinflammatory properties, we have tested their neuroprotective effects in experimental stroke. Rosiglitazone or 15d-PGJ2 were administered to rats 10 mins or 2 h after permanent middle cerebral artery occlusion (MCAO). Stroke outcome was evaluated by determination of infarct volume and assessment of neurological scores. Brains were collected for protein expression, gene array analyses and gene shift assays. Our results show that both compounds decrease MCAO-induced infarct size and improve neurological scores. At late times, the two compounds converge in the inhibition of MCAO-induced brain expression of inducible NO synthase and the matrix metalloproteinase 9. Interestingly, at early times, complementary DNA microarrays and gene shift assays show that different mechanisms are recruited. Analysis of early nuclear p65 and late cytosolic IkappaBalpha protein levels shows that both compounds inhibit nuclear factor-kappaB signalling, although at different levels. All these results suggest both PPARgamma-dependent and independent pathways, and might be useful to design both therapeutic strategies and prognostic markers for stroke.

Animals↗
PubMed2005

Thrombolysis in acute ischemic stroke: successes, failures, and new hopes.

Evidence from randomized clinical trials indicates that systemic administration of recombinant tissue plasminogen activator (rtPA) is a highly effective treatment for acute ischemic stroke, provided that treatment is administered within the first 3 h after stroke onset. An absolute increase in favorable outcome of up to 13% has been reported, and a pooled analysis of six randomized trials has shown that, although the sooner rtPA is given the greater the benefit, efficacy is present up to 4.5 h after stroke onset. Despite of the spreading use of tPA in different countries and continents, there are still a number of burdens and failures in the optimal accomplishment of thrombolytic treatment. rtPA is used in less than 4% of patients, reperfusion and complete recovery is achieved in less than 50% of patients, and treatment is denied to many patients. However, important advances in clinical investigation suggest that new aims and hopes will be achieved in the near future. Ultrasound-enhanced systemic thrombolysis, the use of MRI for selecting acute stroke patients for IV or IA thrombolysis after 3 h, mechanical embolus disruption or removal in proximal artery occlusions, and the potential usefulness of new biomarkers of blood brain barrier disruption and hemorrhagic risk are promising strategies that may improve the risk/benefit ratio and increase the number of patients who will benefit from thrombolytic therapy.

Acute Disease↗
PubMed2005

Neuroprotection afforded by prior citicoline administration in experimental brain ischemia: effects on glutamate transport.

BACKGROUND AND PURPOSE: Cytidine-5'-diphosphocholine (citicoline or CDP-choline), an intermediate in the biosynthesis of phosphatidylcholine, has shown beneficial effects in a number of CNS injury models including cerebral ischemia. Citicoline is the only neuroprotectant that has proved efficacy in patients with moderate to severe stroke. However, the precise mechanism by which citicoline is neuroprotective is not fully known. The present study was designed to search for mechanisms of citicoline neuroprotective properties using in vivo and in vitro models of brain ischemia. METHODS: Focal brain ischemia was produced in male adult Fischer rats by occluding both the common carotid and middle cerebral arteries. Brain glutamate levels were determined at fixed intervals after occlusion. Animals were then sacrificed, and infarct volume and brain ATP levels were measured. As in vitro model of ischemia, rat cultured cortical neurones or astrocytes, isolated or in co-culture, were exposed to oxygen-glucose deprivation (OGD) either in the absence or in the presence of citicoline (1-100 microM). Viability was studied by measuring LDH release. Glutamate release and uptake, and ATP levels were also determined. RESULTS: Citicoline (0.5, 1 and 2 g/kg i.p. administered 1 h before the occlusion) produced a reduction of the infarct size measured at striatum (18, 27 and 42% inhibition, respectively, n = 8, P < 0.05 vs. ischemia), effect that correlated with the inhibition caused by citicoline on ischemia-induced increase in glutamate concentrations after the onset of the ischemia. Citicoline also inhibited ischemia-induced decrease in cortical and striatal ATP levels. Incubation of cultured rat cortical neurones with citicoline (10 and 100 microM) prevented OGD-induced LDH and glutamate release and caused a recovery in ATP levels after OGD, confirming our previous results. In addition, citicoline (100 microM) caused an increase in glutamate uptake and in EAAT2 glutamate transporter membrane expression in cultured rat astrocytes. CONCLUSIONS: Our present findings show novel mechanisms for the neuroprotective effects of citicoline, which cooperate to decrease brain glutamate release after ischemia.

Adenosine Triphosphate↗
PubMed2005

TNFR1 upregulation mediates tolerance after brain ischemic preconditioning.

A short ischemic event (ischemic preconditioning (IPC)) can result in subsequent resistance to severe ischemic injury (ischemic tolerance (IT)). The expression and neuroprotective role of tumor necrosis factor (TNF-alpha) have been described in models of IPC and we have showed the participation of its processing enzyme, the TNF-alpha convertase enzyme (TACE) in this process. We have now decided to explore the expression and localization of TNF receptors (TNFR) as well as other signalling mechanisms involved in IT. A period of 10 mins of temporary middle cerebral artery occlusion (tMCAO) was used for focal IPC. To evaluate the ability of IPC to produce IT, permanent MCAO was performed 48 hours after IPC. Ischemic preconditioning produced a reduction in infarct volume, as we showed previously. Ischemic preconditioning caused upregulation of neuronal TNFR1 that was reduced by the selective TACE inhibitor BB1101. Intracerebral administration of TNFR1 antisense oligodeoxynucleotide, which caused a reduction in TNFR1 expression, inhibited the IPC-induced protective effect, showing that TNFR1 upregulation is implicated in IT. Moreover, treatment with BB1101, TNFR1 antisense and lactacystin-a specific proteasome inhibitor-blocked IPC-induced NF-kappaB. Immunohistochemical studies showed the expression of TACE and TNFR1 in neurons. In summary, these data show that IPC produces neuronal upregulation of TACE and TNFR1, and that the pathway TACE/TNF-alpha/TNFR1/NF-kappaB is involved in IT.

ADAM Proteins↗
PubMed2004

Molecular signatures of vascular injury are associated with early growth of intracerebral hemorrhage.

BACKGROUND AND PURPOSE: To investigate whether molecular markers of inflammation and endothelial injury are associated with early growth of intracerebral hemorrhage (ICH). METHODS: In a multicenter prospective study, we determined concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), matrix metalloproteinase-9 (MMP-9), and cellular fibronectin (c-Fn) in blood samples obtained on admission from 183 patients with primary hemispheric ICH of <12 hours' duration. Patients had a neurological evaluation and a computed tomography (CT) scan performed at baseline and at 48+/-6 hours. Early growth of the ICH was defined as a volume increase >33% between the 2 CT examinations for ICH with a baseline volume <20 mL and >10% for ICH > or =20 mL. Clinical, radiological, and biochemical predictive factors of ICH enlargement were analyzed by logistic regression analysis. RESULTS: Fifty-four (29.5%) patients showed a relevant early growth of ICH. High leukocyte count and fibrinogen levels, low platelet count, and intraventricular bleeding were associated with early ICH growth in bivariate analyses. Plasma concentrations of IL-6 (median [quartiles]: 19.6 [13.6; 29.9] versus 15.9 [11.5; 19.8] pg/mL), TNF-alpha (13.5 [8.4; 30.5] versus 8.7 [4.7; 13.5] pg/mL), MMP-9 (153.3 [117.7; 204.7] versus 70.6 [47.8; 103.8] ng/mL), and c-Fn (8.8 [6.2; 12.5] versus 2.8 [1.6; 4.2] microg/mL) were significantly higher in patients with early growth of ICH (all P<0.001). C-Fn levels >6 microg/mL (OR, 92; 95%CI, 22 to 381; P<0.0001) and IL-6>24 pg/mL (OR, 16; 95%CI, 2.3 to 119; P=0.005) were independently associated with ICH enlargement in the logistic regression analysis. CONCLUSIONS: Molecular signatures of vascular injury and inflammatory markers in the early acute phase of ICH are associated with subsequent enlargement of the hematoma.

Aged↗
PubMed2004

Semi-intensive monitoring in acute stroke and long-term outcome.

BACKGROUND AND PURPOSE: Factors that determine the benefit of stroke units (SU) are unknown. The aim of our study was to analyze whether semi-intensive monitoring during the acute phase of stroke reduces mortality and dependency at long term. METHODS: We studied patients with an ischemic stroke or intracerebral hemorrhage, consecutively admitted to our SU within 24 h of symptoms onset. Based on bed availability, patients were allocated to either a conventional care stroke unit (C-SU, n = 209) or a semi-intensive stroke unit (SI-SU, n = 321) with continuous monitoring of cardiac, respiratory, metabolic and neurological functions during the first 72 h. Both groups were treated following the same medical and nursing protocols. Criteria for exclusion were patients with stupor/coma, previously dependent (Barthel score <85) and with TIA. Using logistic regression models, we analyzed the influence of semi-intensive care on mortality and dependency at one year. RESULTS: Baseline characteristics were similar between patients admitted to the SI-SU and the C-SU, except for a higher frequency of more severe stroke and intracerebral hemorrhage in the SI-SU. Twenty-six percent of patients in the SI-SU and 4% in the C-SU were randomized in acute clinical trials (p < 0.01), and 61% and 39% were seen by a neurologist in less than 6 h from the onset of symptoms (p < 0.01). At 1 year, mortality and combined mortality and dependency were not significantly different between the two groups. However, due to the presence of a significant interaction between the type of unit and stroke severity, the OR of mortality for SI-SU allocation was 0.19 (95% CI, 0.07-0.54) in patients with severe stroke (CSS < or =4), whereas it was 0.64 (95% CI, 0.37-1.11) in those with mild-to-moderate stroke. CONCLUSIONS: This study suggests that semi-intensive monitoring in a stroke unit reduces mortality at 1 year in patients with severe stroke, with no influence over dependency.

Acute Disease↗
PubMed2004

Comparison of preperfusion and postperfusion magnetic resonance angiography in acute stroke.

BACKGROUND AND PURPOSE: The multimodal magnetic resonance imaging study in acute stroke includes perfusion-weighted imaging (PWI) after administration of contrast and magnetic resonance angiography (MRA). However, MRA may overestimate the degree of vessel obstruction caused by limitations to detect low flow states. Our aim was to determine the usefulness of a new fast imaging protocol combining classical MRA, PWI, and postperfusion MRA to improve the diagnostic management in acute ischemic stroke. METHODS: We studied 31 patients with a middle cerebral artery (MCA) infarction within the first 12 hours from the onset of symptoms. All patients had an MCA stenosis or occlusion. The study protocol included a preperfusion MRA and a postperfusion MRA. Modified thrombolysis in myocardial infarction (TIMI) classification was used to assess the patency of vessels. RESULTS: In 17 patients (group A, 55%), preperfusion MRA and postperfusion MRA accorded in the estimation of vascular status, whereas in 14 patients (group B, 45%) postperfusion MRA showed a better vascular flow than preperfusion MRA. The improvement in the depiction of flow was from a complete occlusion (TIMI I) to a partial occlusion (TIMI II) in 9 patients and from TIMI II to normal patency (TIMI III) in 5 patients. Thirty-six percent of the patients with suspected internal carotid artery occlusion in the preperfusion MRA showed flow in the intracranial internal carotid artery in the postperfusion MRA. CONCLUSIONS: Postperfusion contrast-enhanced MRA can demonstrate arterial segments with low flow and avoid overestimation of vascular obstruction.

Acute Disease↗
PubMed2004

Plasma cellular-fibronectin concentration predicts hemorrhagic transformation after thrombolytic therapy in acute ischemic stroke.

BACKGROUND AND PURPOSE: Elevated plasma levels of cellular fibronectin (c-Fn) reflect vascular damage, so c-Fn might be a marker of secondary bleeding risk in cerebral ischemia. We investigated whether high plasma levels of c-Fn were associated with hemorrhagic transformation (HT) after treatment with tissue plasminogen activator (tPA) in patients with acute stroke. METHODS: Eighty-seven patients (mean age: 67+/-12) received tPA after the ECASS II criteria (mean time to infusion: 160+/-46 minutes; median NIHSS: 12). HT and hypodensity volume were studied on computed tomography (CT) performed 24 to 36 hours after treatment. HT was classified according to the ECASS II definitions. c-Fn and matrix metalloproteinase 9 (MMP-9) levels were determined by ELISA in blood samples obtained before treatment and in 30 healthy subjects. RESULTS: HT was found in 26 patients (30%); 15 patients had hemorrhagic infarction type 1 (HI-1), 7 had HI-2, and 4 had parenchymal hemorrhage (PH). Median c-Fn concentrations were 1.3, 1.7, 4.2, 5.4, and 7.3 microg/mL in controls, non-HT, HI-1, HI-2, and PH groups, respectively (P<0.001); median MMP-9 values were 54, 87, 154, 176, and 225 ng/mL (P<0.001). Logistic regression analysis showed that only c-Fn plasma levels remained independently associated with HT after adjusting for potential confounders (OR, 2.1; 95% CI, 1.3 to 3.4; P=0.002). Similar results were obtained in the 71 patients treated within 3 hours. CONCLUSIONS: High plasma c-Fn levels are significantly associated with subsequent HT in stroke patients treated with tPA, so plasma c-Fn determinations might be useful in clinical practice to improve the risk/benefit ratio of thrombolytic treatment.

Aged↗
PubMed2004

Blood pressure decrease during the acute phase of ischemic stroke is associated with brain injury and poor stroke outcome.

BACKGROUND AND PURPOSE: Studies on the relation between blood pressure (BP) and stroke outcome have shown contradictory results. We explored the association of systolic (SBP) and diastolic (DBP) BP during acute stroke with early neurological deterioration, infarct volume, neurological outcome, and mortality at 3 months. METHODS: We included 304 patients with acute ischemic stroke. SBP and DBP on admission and on the first day were the average values of all readings obtained in the emergency department and during a 24-hour period after patient allocation in the stroke unit. RESULTS: A U-shaped effect was observed: for every 10 mm Hg 180 mm Hg, the risk of early neurological deterioration increased by 40% and the risk of poor outcome increased by 23%, with no effect on mortality. Mean infarct volume increased 7.3 and 5.5 cm(3) for every 10 mm Hg 180 mm Hg. A similar pattern was found in patients with DBP 100 mm Hg. These effects disappeared after adjustment for the use of antihypertensive drugs and BP drop >20 mm Hg within the first day, with the latter being the more important prognostic factor of poor outcome. CONCLUSIONS: High and low SBP and DBP, as well as a relevant drop in BP, are associated with poor prognosis in patients with ischemic stroke.

Acute Disease↗
PubMed2003

Neuroprotective effects of aspirin in patients with acute cerebral infarction.

Aspirin may reduce ischemic brain injury. The aim of this study was to explore the effect of aspirin on glutamate release after acute stroke. We studied 238 patients with a first episode of hemispheric ischemic stroke of less than 24 h duration. Early neurological deterioration was diagnosed when the Canadian Stroke Scale dropped 1 or more points between admission and 48 h. Glutamate was determined on cerebrospinal fluid (CSF) samples obtained at admission. Sixty-three patients were undergoing treatment with 75-500 mg/day of aspirin at the time of stroke onset. CSF glutamate concentrations were higher in the group of patients not taking aspirin (8.9+/-5.2 vs. 4.9+/-3.1 microM/l, P< 0.0001). Aspirin treatment at stroke onset had a 97% risk reduction of early neurological deterioration, and this effect remained unchanged after a further adjustment for glutamate concentrations. These findings suggest that low doses of aspirin may be useful in the management of patients with cerebral ischemia, not only for its antithrombotic properties, but also by direct neuroprotective effects.

Acute Disease↗
PubMed2003

[Intravenous tissue-type plasminogen activator for the treatment of acute cerebral ischemia].

BACKGROUND AND OBJECTIVE: Whether the risk of symptomatic hemorrhagic transformation (SHT) of cerebral infarction associated with the use of tissue plasminogen activator (t-PA) is higher in clinical practice than in clinical trials is unknown. The aim of this study was to analyze the safety profile and clinical outcome of patients with acute cerebral ischemia who received open treatment with t-PA in Spanish hospitals. PATIENTS AND METHOD: This prospective and observational study included 155 consecutive patients with an ischemic stroke treated within 3 hours from the onset of symptoms, or within 6 hours in the absence of early signs of large cerebral infarction on CT. Intravenous t-PA was administered at 0.9 mg/kg (10% as bolus) during a 60 minutes infusion. Neurological worsening within 24-36 hours was evaluated by the NIH stroke scale (NIHSS). Primary safety and outcome variables were SHT on CT performed at 24-36 hours, mortality and independence at 90 days. Patients were treated by neurologists with expertise in acute stroke, and stroke monitoring was performed in acute stroke units. RESULTS: Baseline median NIHSS was 16, and mean time from stroke onset to treatment was 163 minutes. SHT was found in 12 patients (7.7%; 95% CI, 4.0-13.1), and it was fatal in 7 (4.5%, 95% CI, 1.8-9.1). Overall mortality at 90 days was 16.8% (95% CI, 11.2-23.6). At 24 hours, 48% (95% CI, 39.7-55.9) of patients had improved >= 4 points in the NIHSS, and 29% (95 % CI, 22.0-36.8) showed a >= 10 points improvement or total recovery. At 3 months, 56% (95% CI, 47.9-64.1) of patients were independent. CONCLUSIONS: In Spanish hospitals with stroke units or stroke teams, the use in the clinical practice of intravenous t-PA by experienced neurologists is safe, and it is associated with a favourable outcome similar to that observed in clinical trials.

Acute Disease↗
PubMed2003

L-arginine levels in blood as a marker of nitric oxide-mediated brain damage in acute stroke: a clinical and experimental study.

There are no useful markers in blood of nitric oxide (NO)-mediated brain damage. Because l-arginine (l-arg) is the only known substrate for NO generation, the authors investigated the plasma profile of l-arg after cerebral ischemia, and the relationship of L-arg concentrations in blood with stroke outcome and infarct volume in a clinical and experimental study. l-Arg levels were determined with high-performance liquid chromatography in blood and CSF samples obtained on admission, and in blood 48 hours after inclusion, in 268 patients admitted with a hemispheric ischemic stroke lasting 8.2 +/- 5.9 hours. Infarct volume was measured by days 4 to 7 using computed tomography. Plasma l-arg profiles were analyzed in a separate group of 29 patients seen within 8 hours of onset (median, 4.5 hours) and in 24 male Fischer rats treated with subcutaneous vehicle or 20-mg/kg 1400W (a specific inducible NO synthase inhibitor) every 8 hours for 3 days after performing sham or permanent middle cerebral artery occlusion. Plasma l-arg concentrations decreased after the ischemic event, both in patients and rats, and peaked between 6 and 24 hours. In patients, there was a highly correlation between l-arg levels in CSF and plasma at 48 hours (r = 0.85, P<0.001). CSF and plasma l-arg concentrations negatively correlated with infarct volume (r = -0.40 and r = -0.35, respectively, P<0.001), and were significantly lower in patients with early neurologic deterioration and in those with poor outcome (Barthel index <85) at 90 days (P<0.001). In rats, the administration of 1400W resulted in a 55% significant reduction of infarct volume measured 72 hours after permanent middle cerebral artery occlusion, an effect that correlated with the inhibition caused by 1400W on the ischemia-induced decrease of plasma l-arg concentrations at 6 to 24 hours after the onset of the ischemia. Taken together, these data indicate that determination of l-arg levels in blood might be useful to evaluate the neurotoxic effects of NO generation. These findings might be helpful to guide future neuroprotective strategies in patients with ischemic stroke.

Acute Disease↗
PubMed2003

Stroke on awakening: looking for a more rational management.

BACKGROUND AND PURPOSE: Stroke on awakening (SOA) is denied the benefits of thrombolytic therapy and is typically excluded from acute clinical trials on the grounds that the time of onset is unknown. In this study we compared the clinical characteristics of SOA and of stroke while awake (SWA), particularly in the subgroup of patients seen within a time frame of 6 h after stroke awareness. MATERIAL AND METHODS: Patients were included consecutively in the Stroke Data Bank of the Spanish Neurological Society (BADISEN) that records 365 different items, including vascular risk factors, neurological findings, stroke severity, aetiopathogenic diagnosis and neuroimaging data. RESULTS: A total of 1,248 patients with acute cerebral infarction were included in the study, 301 (24.1%) with SOA and 947 (75.9%) with SWA. The peak time for stroke occurrence was between 6:01 a.m. and 12 noon, both in the whole stroke group and in each aetiopathogenic stroke subtype. Age, sex, stroke risk factors, stroke severity at admission, vital signs and stroke subtypes were not significantly different between SOA and SWA, neither in the group as a whole nor in the group of patients seen within 6 h of stroke recognition. Six hundred and fifty-four patients were seen within the potential 6-hour therapeutic window. In this group, the CT scan on admission was normal in 39.4% of SOA but the ultimate CT/MRI scan showed that 46.2% of these had a territorial infarction (in SWA these same figures were 60.8 and 67.7%, respectively). CONCLUSION: There are no relevant differences in the clinical, neuroimaging and aetiopathogenic characteristics of SOA and SWA. We should rely on new techniques such as DWI/PWI to indicate the most appropriate treatment in a more rational manner as nearly half of the patients with SOA seen early may benefit from them.

Aged↗
PubMed2003

Plasma metalloproteinase-9 concentration predicts hemorrhagic transformation in acute ischemic stroke.

BACKGROUND AND PURPOSE: Matrix metalloproteinase-9 (MMP-9) activity has been associated with hemorrhagic transformation (HT) in experimental models of cerebral ischemia. Our aim was to investigate the relationship between MMP-9 concentrations in blood within 24 hours of stroke onset and subsequent HT of cerebral infarction. METHODS: We studied 250 patients with a hemispheric ischemic stroke of 7.8+/-4.5 hours' duration. Early CT signs of cerebral infarction were evaluated on admission. The HT and infarct volume were analyzed from the CT performed on days 4 through 7. MMP-9 levels were determined by enzyme-linked immunosorbent assay in blood samples obtained on admission. RESULTS: HT was observed in 38 patients (15.2%): 24 (63.2%) had a hemorrhagic infarction, and 14 (36.8%) had a parenchymal hematoma. A total of 108 patients (43%) received anticoagulants before the second CT scan. Systolic and diastolic blood pressures, body temperature, frequency of early CT signs of ischemia (92% versus 22%), and treatment with anticoagulants (79% versus 37%) were significantly higher in the group with HT (P<0.001). Mean infarct volume was 126+/-60 cm(3) in the HT group and 90+/-68 cm3 in the group without HT (P=0.003). Median (quartiles) plasma MMP-9 concentrations were higher in the HT group (193 [163, 213] versus 62 [40, 93] ng/mL, P<0.001), even in the 24 patients seen within 3 hours of symptom onset (P=0.014). MMP-9 levels > or =140 ng/mL had a positive and negative predictive value of HT of 61% and 97%, respectively. MMP-9 > or =140 ng/mL was associated with HT (odds ratio, 12; 95% confidence interval, 3 to 51; P<0.001) after adjustment for potential confounders and final infarct volume. CONCLUSIONS: High plasma MMP-9 concentration in the acute phase of a cerebral infarct is an independent biochemical predictor of HT in all stroke subtypes.

Biomarkers↗