Posterior circulation infarcts simulating anterior circulation stroke. Perspective of the acute phase.

BACKGROUND AND PURPOSE: Ischemic stroke patients whose initial clinical presentation suggests an involvement of the anterior circulation (AC) are sometimes found to have a posterior circulation (PC) infarct, a fact that may generate erroneous decisions in clinical management. We investigated the prevalence of this misdiagnosis in the first few hours after stroke onset. METHODS: We performed a cohort study of 158 patients hospitalized within 5 hours of onset of a presumed AC ischemic stroke, as diagnosed on clinical grounds. RESULTS: Final CT or pathology diagnosis was AC infarct in 128 patients (81%), a repeatedly negative CT in 14 (9%), PC infarct (5 pons, 1 midbrain and cerebellum, 6 supratentorial territory of the posterior cerebral artery) in 12 (8%), and other or undiagnosed lesions in 4 (3%). AC and PC stroke patients did not differ in terms of age, vascular risk factors, and initial severity, but the latter were more frequently men (83% versus 53%; P = .04), were hospitalized later (mean +/- SD, 168 +/- 86 versus 109 +/- 55 minutes; P = .001), and presented a pure motor hemiparesis or a sensorimotor stroke (50% versus 33%) more often than their counterparts. At baseline CT, PC stroke patients never exhibited an early parenchymal hypodensity in the carotid territory or a hyperdense middle cerebral artery, which were instead found in 59% (P = .0003) and 31% (P = .02) of AC stroke patients, respectively. Early neurological deterioration, 1 month case-fatality rate, and disablement in survivors were comparable in the two groups. CONCLUSIONS: Shortly after onset the clinical discrimination between AC and nontypical PC infarcts is not reliable, which explains the frequent occurrence of this misdiagnosis. Emergency CT scan helps in the differential diagnosis only when it demonstrates an early focal hypodensity within the carotid territory.

Thrombolysis acute ischemic stroke.

Thrombolysis is an attractive but potentially dangerous they for cerebral ischemia: it is capable of dissolving an arterial thrombus, but can also transform a pale infarct into a hematoma and/or may cause severe oedema and herniation. The safety and efficacy of the treatment critically depend on the timing of intervention ad on patient selection. In recent studies on ischemic stroke, spontaneous hemorrhagic transformation of an infarct seems to be related to the size of the lesion, and can be reliably predicted as early as five hours from stroke onset by the presence of focal hypodensity in the CT scan. That is why in the European Co-operative Acute Stroke (ECASS), a randomised, double blind trial on intravenous rt-PA in hemispheric stroke, patients showing, on the admission CT scan, extended early hypodensity, involving more than one third of the territory of the middle cerebral artery, were excluded from the day. Other ongoing trials on thrombolytic agents are expected to provide further indications on how to identify those patients most likely to benefit and least likely to experience adverse effects from this treatment.

Cardiopulmonary bypass in pregnancy.

The cardiopathic patient can sustain acute heart failure during pregnancy. In such cases, if open heart operation is necessary to save the patient's life, the fetus could be seriously compromised after exposure to cardiopulmonary bypass. From 1958 to 1992, 69 reports of cardiac operations during pregnancy with the aid of cardiopulmonary bypass have been published. Maternal mortality was 2.9%. Embryofetal mortality was 20.2%. Examining only the last 40 patients, maternal and embryofetal mortality were 0.0% and 12.5%, respectively. Embryofetal mortality was 24.0% when hypothermia was used, compared with 0.0% while operating in normothermia. Maternal mortality did not change. The use of hypothermia during cardiopulmonary bypass provoked uterine contractions in several patients. Hypothermia decreases O2 exchange through the placenta. Pump flow and mean arterial pressure during cardiopulmonary bypass seem to be the most important parameters that influence fetal oxygenation. We speculate that cardiac operation is not a contraindication to pregnancy prolongation.

Prediction of long-term outcome in the early hours following acute ischemic stroke. Italian Acute Stroke Study Group.

OBJECTIVE: To develop a model for predicting outcome in the first few hours after the onset of an ischemic stroke on the basis of the clinical findings obtained during a rapid bedside examination. DESIGN: Clinical records were retrieved from the data bank of a randomized multicenter trial. The resulting case series was split into two subgroups that served as a "training set" and a "test set." Logistic regression was applied to the training set to select the prognostic predictors among baseline clinical findings. The performances of the model based on independent prognostic predictors were then validated in the test set. SETTING: Eleven primary care institutions (either hospitals or university clinics) participating in the Italian Acute Stroke Study on the efficacy of hemodilution and monosialoganglioside in acute ischemic stroke. PATIENTS: Consecutive noncomatose patients (N = 300) observed within the first 6 hours after the onset of a first supratentorial ischemic stroke. MAIN OUTCOME MEASURE: Death or disablement 4 months after the index stroke. Disablement was defined as a score of 3 or higher on the Rankin Scale. RESULTS: Age and CNS score defined six risk groups with a predicted 4-month poor outcome rate ranging from 10% (patients aged 70 years or younger and with an initial CNS score of 7 or higher) to 89% (patients older than 70 years and with a CNS score of 4.5 or lower). When a risk of poor outcome of 60% was taken as a cutoff, the accuracy of the prediction was 78% +/- 6% in the training set and 72% +/- 9% in the test set. CONCLUSION: Long-term outcome can be predicted in the first few hours following an acute ischemic stroke by means of a simple model based on age and CNS score.

Does hyperglycaemia play a role on the outcome of acute ischaemic stroke patients?

A consecutive series of 327 patients (188 males, 139 females; mean age 68.4, SEM 1.33) were hospitalized within 12 h of the onset of their first-ever hemispheric infarct. Three groups of patients were identified: diabetics (n = 70), non-diabetic hyperglycaemics (n = 93) and normoglycaemics (n = 164). Case-fatality ratios at 30 days after stroke were 38.6%, 22.6% and 9.2% (P less than 0.001) respectively, whereas the causes of death and functional outcome of survivors were not significantly different between the groups. Mean admission serum glucose levels (SGLs) of decreased, impaired/unchanged and improved patients within each one of the three groups, were also not significantly different as opposed to their mean Canadian Neurological Scale (CNS) scores at entry (P less than 0.01). Among patients with less severe initial neurological deficit (i.e., CNS score greater than or equal to 7.0), 82.6% of non-diabetic hyperglycaemic subjects fared well, in comparison with 56.5% of diabetic and 70.1% of normoglycaemic individuals. The size of the infarcted areas at the second CT correlated with mean CNS scores (P less than 0.01) but not with mean SGLs on admission. The site of the ischaemic areas did not correlate with mean SGLs at entry. Therefore the influence of initial SGLs on the clinical course of the present series of patients is questionable or, alternatively, varied probably according to the pattern of residual cerebral blood flow after arterial occlusion.

Controlled clinical trials in stroke.

Reasons for the unsatisfactory number and reliability of most trials on the pharmacological treatment of acute cerebral ischemia are reviewed, focusing mainly on the clinical aspects of the issue. The opportunity of early intervention, supported by current pathophysiological hypotheses, is recognized. Past and recent Italian trials on ischemic stroke patients evaluated and treated within the first 6 h from onset are reported, also mentioning the results of a study including early cerebral angiography and SPECT (Single Photon Emission Computed Tomography). Early fibrinolytics associated to brain protecting agents are regarded as the future choice in clinical trials of acute cerebral ischemia.

Myocardial ischemia during stroke: scintigraphic demonstration.

In a 74-year old female, admitted to the Acute Stroke Unit for a cerebral reversible ischemic attack, we investigated the occurrence of ischemic alterations on ECG, recorded during an acute relapse, using 99mTc (MIBI) myocardial scintigraphy. Scintigrams showed a transient anteroseptal and inferior hypoperfusion. This is the first direct demonstration of myocardial ischemia occurring during stroke.