Clinical course of acute middle cerebral artery occlusion

Excellent rates of recanalization and good functional outcome after stent-based thrombectomy for acute middle cerebral artery occlusion. Is it time for a paradigm shift?

The natural history of untreated acute middle cerebral artery (MCA) occlusion is poor, with high rates of mortality (5-33%) and severe long-term disability (40-80% of survivors), despite therapy with intravenous tissue plasminogen activator. We analyzed outcomes in 31 consecutive patients with major ischemic stroke due to acute proximal MCA occlusion who were treated at the Hadassah-Hebrew University Medical Center from February 2010 to October 2012 by endovascular means, using the Solitaire stent (Covidien, Irvine, CA, USA) as a thrombectomy device. Patients had a mean age of 63.3±16.2 years (range, 26-92). The admission National Institutes of Health Stroke Scale score was 19.5±4.3 (median 20). Mean time from symptom onset to femoral artery puncture was 3.8±1.1 hours (median 4 hours). Mean time to recanalization was 46.9±11.1 minutes. Successful recanalization by means of stent-based thrombectomy alone was achieved in 90% of cases and reached 100% after combining definitive stent implantation in three patients. There was no arterial rupture or subarachnoid hemorrhage. Hemorrhagic transformation developed in seven patients (23%), but was symptomatic in only one. Post-procedure CT scan or MRI demonstrated >90% sparing of cortex at risk in all patients. Functional outcome at 90 day follow-up was modified Rankin Score 0-2 in 77% of all patients and 88% of patients younger than 80 years. Three patients (10%) died during hospitalization due to mesenteric event, sepsis, or pulmonary embolism. Our experience suggests that stent-based thrombectomy in selected patients for acute MCA occlusions is safe, very effective in terms of arterial recanalization, and associated with improved neurological outcome. If validated by other groups, endovascular treatment may be proposed as the therapy of choice for MCA occlusion.

Acute middle cerebral artery occlusion: reappraisal of the role of endovascular revascularization

Intravenous tissue plasminogen activator was the first successful stroke therapy in acute ischaemic stroke, after innumerable failed attempts at neuroprotection and neurorestoration. However, intravenous tissue type plasminogen activator has been shown to be effective in recanalizing middle cerebral artery occlusions in only about one-third of cases. The natural history of untreated acute middle cerebral artery occlusion is poor, leading to long-term disability in >70% and mortality in 20%. Recanalization alone is not the name of the game. Only timely, very rapid recanalization, achieved within minutes or at most a few hours after stroke has occurred, before irreversible brain damage develops, is effective. Is intravenous tissue type plasminogen activator the best available option we have for these patients? With recently introduced stent-based thrombectomy devices, neurointerventionalists have achieved complete recanalization rates of more than 90% in middle cerebral artery and 'T' occlusions, with a mean procedural recanalization time of less than one-hour and negligible complication rates. More than 80% of patients less than 80 years of age who were treated within eight-hours after stroke onset in our centre achieved a modified Rankin score of 0-2 at three-month follow-up. The site of arterial occlusion is a factor driving the choice between a standard intravenous tissue type plasminogen activator protocol and an alternative intervention such as intravenous and/or mechanical thrombolysis to achieve early recanalization. The role of intravenous tissue type plasminogen activator must be redefined in major occlusions, and the indications for endovascular therapy must also be reappraised.

Severe stroke: patient profile and predictors of favorable outcome

BACKGROUND

Severe stroke carries high rates of mortality and morbidity. The aims of this study were to determine the characteristics of patients who initially presented with severe ischemic stroke, and to identify acute and subacute predictors of favorable clinical outcome in these patients.

METHODS

An observational cohort study, Acute Stroke Registry and Analysis of Lausanne (ASTRAL), was analyzed, and all patients presenting with severe stroke - defined as a National Institute of Health Stroke Scale score of ≥ 20 on admission - were compared with all other patients. In a multivariate analysis, associations with demographic, clinical, pathophysiologic, metabolic and neuroimaging factors were determined. Furthermore, we analyzed predictors of favorable outcome (modified Rankin scale score of ≤ 3 at 3 months) in the subgroup of severe stroke patients.

RESULTS

  Of 1915 consecutive patients, 243 (12.7%) presented with severe stroke. This was significantly associated with cardio-embolic stroke mechanism (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.19-2.54), unknown stroke onset (OR 2.35, 95% CI 1.14-4.83), more neuroimaging signs of early ischemia (mostly computed tomography; OR 2.65, 95% CI 1.79-3.92), arterial occlusions on acute imaging (OR 27.01, 95% CI 11.5-62.9), fewer chronic radiologic infarcts (OR 0.43, 95% CI 0.26-0.72), lower hemoglobin concentration (OR 0.97, 95% CI 0.96-0.99), and higher white cell count (OR 1.05, 95% CI 1.00-1.11). In the 68 (28%) patients with favorable outcomes despite presenting with severe stroke, this was predicted by lower age (OR 0.94, 95% CI 0.92-0.97), preceding cerebrovascular events (OR 3.00, 95% CI 1.01-8.97), hypolipemic pretreatment (OR 3.82, 95% CI 1.34-10.90), lower acute temperature (OR 0.43, 95% CI 0.23-0.78), lower subacute glucose concentration (OR 0.74, 95% CI 0.56-0.97), and spontaneous or treatment-induced recanalization (OR 4.51, 95% CI 1.96-10.41).

CONCLUSIONS

Severe stroke presentation is predicted by multiple clinical, radiologic and metabolic variables, several of which are modifiable. Predictors in the 28% of patients with favorable outcome despite presenting with severe stroke include hypolipemic pretreatment, lower acute temperature, lower glucose levels at 24 h, and arterial recanalization.

Emergent middle cerebral artery embolectomy: a useful technique for cranial base surgery

Given the poor natural history of untreated symptomatic acute middle cerebral artery occlusion, we have attempted emergent reperfusion in all three cases of acute embolic middle cerebral artery occlusion seen on our cranial base service over the last 10 years. One patient developed a massive stroke requiring a life-saving "strokectomy" within 48 hours, which left him permanently hemiplegic, hemianopic, and hemihypesthetic after a failed attempt at reperfusion by superselective endovascular injection of urokinase. The other two patients, who were aphasic and densely hemiparetic, underwent successful emergent embolectomy with reperfusion established within 5 and 12 hours, respectively. One of the two is now neurologically normal, and the second is left with a subtle monoparesis but is independent in activities of daily living. Since middle cerebral artery embolism in cranial base patients usually occurs in a closely monitored hospital setting, we are presented with a unique opportunity for early successful operative intervention. Principles for optimizing outcome include: early recognition and diagnosis, maximization of medical therapy during the diagnostic workup prior to embolectomy (induced hypertension, intravascular volume expansion, and pharmacologic cerebral metabolic demand reduction), confirmation that the involved region does not have absent blood flow by xenon/computed tomography, early operative intervention, and careful surgical technique.

Factors predictive of fatality in massive middle cerebral artery territory infarction and clinical experience of decompressive hemicraniectomy

To determine the factors predictive of fatality in massive middle cerebral artery (MCA) territory infarction and outcome of decompressive hemicraniectomy, 62 patients who were retrospectively verified with first event massive MCA infarctions were enrolled in this study. Amongst them, 21 received decompressive hemicraniectomy during hospitalization. Clinical data between early and late hemicraniectomy groups were also compared. Significant deterioration occurred in 40 cases, 21 of whom received decompressive hemicraniectomy. The other 19 received conservative treatment. The mortality rate of these 40 cases between decompressive hemicraniectomy and conservative treatment was 29% (six of 21) and 42% (eight of 19), respectively. Factors that predicted fatalities in our massive MCA infarction patients with or without decompressive hemicraniectomy were total scores of baseline GCS at the time of admission, associated with coronary artery diseases, and significant deterioration during hospitalization. This study confirms the lifesaving procedure of hemicraniectomy that prevents death in patients deteriorating because of cerebral edema after infarction, although it may produce severe disability with an unacceptably poor quality of life in survival. Despite high mortality and morbidity, decompressive hemicraniectomy to prevent cerebral herniation when significant deterioration is demonstrated are essential for maximizing the potential for survival.

Decompressive craniectomy as a therapeutic option in the treatment of hemispheric stroke

Even though severe hemispheric stroke represents a small subtype of ischemic stroke, the extreme morbidity and mortality necessitate aggressive management strategies to improve outcome. Decompressive craniectomy is an important therapeutic tool with demonstrated effects in significantly reducing intracranial hypertension and mortality from herniation related to cerebral edema and elevated intracranial pressure. Its effect on functional outcome and quality of life varies, but there is evidence to suggest beneficial effects in younger patients and in patients treated earlier. Although more prospective data are required to further identify specific indications for the procedure, it represents an important tool in treatment of nondominant hemispheric stroke.

Clinical Course and Surgical Management of Massive Cerebral Infarction

OBJECTIVE:

Acute occlusion of the proximal middle cerebral artery (MCA) can lead to rapid development of fatal brain swelling and ischemic strokes. Decompressive surgery, if performed early in this subpopulation of patients, can reduce mortality and result in a favorable outcome. In this article, we describe our surgical approach for treating malignant MCA syndrome and compare it with other management strategies.

METHODS:

This is a retrospective review of patients who developed acute occlusion of the proximal MCA and underwent aggressive surgical decompression (large craniectomy, anterior temporal lobectomy, resection of infarcted tissue, and duraplasty). The outcome of this management strategy is compared with the previously published outcomes of hemicraniectomy and dural augmentation.

RESULTS:

Twelve patients were included in the study. The group consisted of six men and six women (mean age, 46.8 yr). Nine patients had right MCA stroke, and three had left MCA infarction. The causes of the strokes were cardioembolic, iatrogenic, small-vessel occlusive disease, and others. The interval between infarction and clinical evidence of herniation varied from 24 hours to 10 days. Two patients died, five were independent or had moderate disabilities, and five had severe disability.

CONCLUSION:

Surgical decompression consisting of a large craniectomy, anterior temporal lobectomy, resection of infarcted tissue, and duraplasty is beneficial to a significant number of patients with massive MCA stroke and clinical signs of herniation.

Motor recovery after stroke: a systematic review of the literature

OBJECTIVE

To collect and integrate existing data concerning the occurrence, extent, time course, and prognostic determinants of motor recovery after stroke using a systematic methodologic approach.

DATA SOURCES

A computer-aided search in bibliographic databases was done of longitudinal cohort studies, original prognostic studies, and randomized controlled trials published in the period 1966 to November 2001, which was expanded by references from retrieved articles and narrative reviews.

STUDY SELECTION

After a preliminary screening, internal, external, and statistical validity was assessed by a priori methodologic criteria, with special emphasis on the internal validity.

DATA EXTRACTION

The studies finally selected were discussed, based on the quantitative analysis of the outcome measures and prognostic determinants. Meta-analysis was pursued, but was not possible because of substantial heterogeneity.

DATA SYNTHESIS

The search resulted in 174 potentially relevant studies, of which 80 passed the preliminary screening and were subjected to further methodologic assessment; 14 studies were finally selected. Approximately 65% of the hospitalized stroke survivors with initial motor deficits of the lower extremity showed some degree of motor recovery. In the case of paralysis, complete motor recovery occurred in less than 15% of the patients, both for the upper and lower extremities. Hospitalized patients with small lacunar strokes showed relatively good motor recovery. The recovery period in patients with severe stroke was twice as long as in patients with mild stroke. The initial grade of paresis was the most important predictor for motor recovery (odds ratios [OR], >4). Objective analysis of the motor pathways by motor-evoked potentials (MEPs) showed even higher ORs (ORs, >20).

CONCLUSIONS

Our knowledge of motor recovery after stroke in more accurate, quantitative, and qualitive terms is still limited. Nevertheless, our data synthesis and quantitative analysis comprises data from many methodologically robust studies, which may support the clinician in the management of stroke patients. With respect to early prognosis of motor recovery, our review confirms clinical experience that the initial grade of paresis (as measured on admission in the hospital) is the most important predictor, although the accuracy of prediction rapidly improves during the first few days after stroke. Initial paralysis implies the worst prognosis for subsequent motor recovery. Remarkably, the prognostic accuracy of MEPs appears much higher than that of clinical examination for different subgroups of patients.

Effects of fluid management on edema volume and midline shift in a rat model of ischemic stroke

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the effects of fluid management on brain water content (BW) and midline shift (MLS) after a focal cerebral ischemic insult.

METHODS

A suture model was used to induce focal cerebral ischemia for 90 minutes (n=44). The rats were randomly assigned to 3 groups 2. 5 hours after reperfusion: dehydration (n=24), control (n=8), or hydration (n=12). BW was obtained with the wet-dry weight method 24 hours after middle cerebral artery (MCA) occlusion. In addition, MRI were obtained (n=31) 24 hours after the onset of ischemia so that the ratio of hemispheric volumes ipsilateral (IH) and contralateral (CH) to the infarct and the extent of MLS could be obtained.

RESULTS

Across the range from moderate dehydration to intravascular volume expansion with isotonic saline, BW of the IH increased linearly as a function of change in body weight (r(2)=0.89), whereas few changes in relation to body weight were observed in CH, indicating a preferential effect of fluid management on the infarcted hemisphere. Furthermore, the hemispheric volume ratio (IH/CH) and MLS also increased in relation to changes in body weight. However, paradoxical increases in BW, IH/CH, and extent of MLS were observed in comparison with controls when severe dehydration was produced with high-dose mannitol.

CONCLUSIONS

Changes in ischemic BW by fluid management correlated closely with changes in body weight except when high-dose mannitol was used. Mannitol, as a dehydrating agent, may be associated with bimodal effects, with a high dose aggravating ischemic BW.

Thrombolysis with intravenous rtPA in a series of 100 cases of acute carotid territory stroke: determination of etiological, topographic, and radiological outcome factors

BACKGROUND AND PURPOSE

Although new, large, double-blind, randomized studies are needed to establish the efficiency of intravenous thrombolysis, open trials of sufficient size may also provide novel data concerning specific outcomes after thrombolysis.

METHODS

An open study of intravenous rtPA in 100 patients with internal carotid artery (ICA) territory strokes between 20 and 81 years of age, with a baseline Scandinavian Stroke Scale (SSS) score of <48 at entry was conducted. Inclusion time was within 7 hours after stroke onset. rtPA (0.8 mg/kg) was infused for 90 minutes, with an initial 10% bolus. Heparin was given according to 3 consecutive protocols. The SSS evaluation was done on days 0, 1, 7, 30, and 90. CT scan was performed before treatment, on days 1 and 7. Etiological investigations included echocardiography and carotid Doppler sonography and/or angiography. Outcome at 1 year was documented by SSS score, the modified Rankin Scale (mRS) score, and a 10-point invalidity scale. Multivariate logistic regression was used to identify predictors of poor versus good outcome.

RESULTS

At day 90, 45 patients (45%) had a good result, defined as complete regression or slight neurological sequelae (mRS score of 0-1), 18 patients had a moderate outcome (mRS 2-3), and 31 patients had serious neurological sequelae (mRS 4-5). Six patients died, 2 with intracerebral hematoma after immediate heparin. Five of 11 patients (45.5%) treated between 6 and 7 hours had a good result. The overall intracerebral hematoma rate was 7%. Higher values of fibrin degradation products at 2 hours were observed in the subgroup with intracerebral hematomas. Significant predictors of poor outcome on multivariate logistic regression analysis were baseline SSS score of <15 (odds ratio [OR], 3.38; 95% confidence interval [CI], 1.07 to 10. 74; P=0.04), indistinction between white and gray matter on CT scan (OR, 6.59; 95% CI, 2.19 to 19.79; P=0.0008), and proximal internal carotid thrombosis (OR, 3.29; 95% CI, 0.99 to 10.95; P=0.05).

CONCLUSIONS

Our study confirms the safety of intravenous rtPA at a dose of 0.8 mg/kg and suggests efficacy for this drug even within 7 hours. Outcome and hematoma rates were at least as favorable as for trials of therapy with a 3-hour time window. Subgroups with a poor prognosis include low baseline neurological score, baseline CT changes, and proximal ICA thrombosis. However, approximately 30% of patients with each of these characteristics show a good outcome, so their inclusion in future routine rtPA protocols is still justified.

Middle cerebral artery revascularization. Anatomical studies and considerations on the anastomosis site

In the surgical management of skull base lesions and vascular diseases such as giant aneurysms, involvement of the internal carotid artery may require the resection or the occlusion of the vessel. The anastomosis of the external carotid artery and the middle cerebral artery with venous graft may be indicated to re-establish the blood flow. To determine the best suture site in the middle cerebral artery, an anatomical study was carried out. Fourteen cerebral hemispheres were analysed after the injection of red latex into the internal carotid artery. The superior and inferior trunk of the main division of the middle cerebral artery have more than 2 mm of diameter. They are superficial allowing an anastomosis using a venous graft. The superior trunk has a disadvantage, it gives rise to branches for the precentral and post-central giri. The anastomosis with the inferior trunk presents lower risk of neurological deficit even though the angular artery originates from it.

Decompressive craniectomy in a rat model of "malignant" cerebral hemispheric stroke: experimental support for an aggressive therapeutic approach

Acute ischemia in the complete territory of the carotid artery may lead to massive cerebral edema with raised intracranial pressure and progression to coma and death due to uncal, cingulate, or tonsillar herniation. Although clinical data suggest that patients benefit from undergoing decompressive surgery for acute ischemia, little data about the effect of this procedure on experimental ischemia are available. In this article the authors present results of an experimental study on the effects of decompressive craniectomy performed at various time points after endovascular middle cerebral artery (MCA) occlusion in rats. Focal cerebral ischemia was induced in 68 rats using an endovascular occlusion technique focused on the MCA. Decompressive craniectomy was performed in 48 animals (in groups of 12 rats each) 4, 12, 24, or 36 hours after vessel occlusion. Twenty animals (control group) were not treated by decompressive craniectomy. The authors used the infarct volume and neurological performance at Day 7 as study endpoints. Although the mortality rate in the untreated group was 35%, none of the animals treated by decompressive craniectomy died (mortality 0%). Neurological behavior was significantly better in all animals treated by decompressive craniectomy, regardless of whether they were treated early or late. Neurological behavior and infarction size were significantly better in animals treated very early by decompressive craniectomy (4 hours) after endovascular MCA occlusion (p < 0.01); surgery performed at later time points did not significantly reduce infarction size. The results suggest that use of decompressive craniectomy in treating cerebral ischemia reduces mortality and significantly improves outcome. If performed early after vessel occlusion, it also significantly reduces infarction size. By performing decompressive craniectomy neurosurgeons will play a major role in the management of stroke patients.

Open trial of intravenous tissue plasminogen activator in acute carotid territory stroke. Correlations of outcome with clinical and radiological data

BACKGROUND AND PURPOSE

Pilot studies using early thrombolytic therapy in stroke have suggested that recombinant tissue plasminogen activator (rTPA) might be effective. While large, double-blind, randomized studies are needed, open trials could generate hypotheses concerning (1) the clinical correlations of outcome, (2) the significance of CT scan data during the first week, and (3) the use of adjunctive therapies.

METHODS

We performed an open trial of intravenous rTPA on patients referred to our emergency service with all types of ischemic stroke in the carotid territory. All patients between 20 and 81 years hospitalized during 1994 with completed stroke in the internal carotid artery territory and a baseline Scandinavian Stroke Scale score lower than 48, even with severe disturbances of consciousness, were included. The inclusion time was within 7 hours after stroke onset. A 0.8-mg/kg dose of rTPA was infused for 90 minutes. Intravenous heparin was given either immediately at efficient dosage or after 24 hours. Mannitol was used in patients with severe presentation. The Scandinavian Stroke Scale evaluation was done at baseline, 3 hours, and 1, 7, 30, and 90 days. The CT scan was performed before the treatment and at days 1 (24 +/- 6 hours) and 7.

RESULTS

Forty-three consecutive patients met the criteria of the protocol. The mean age at inclusion was 65 +/- 10.4 years, and the mean interval to treatment was 232 +/- 79 minutes. At day 90, 25 patients (58.1%) exhibited a complete regression of symptoms, and 3 had moderate neurological sequelae. Thirteen patients had severe neurological sequelae, 11 with infarcts and 2 with secondary parenchymal hematomas. Two patients died (4.6%), 1 with hematoma. The overall hematoma rate was 6.9%. Excellent outcome at day 90 was significantly correlated with major neurological improvement at day 1. Intravenous immediate heparin versus delayed heparin after 24 hours improved the ischemic outcome but not the overall outcome. Reinfarction syndromes after major neurological improvement, likely to be rethrombosis syndromes, were observed in 3 patients (6.9%). For the day 1 CT scan, poor outcome was associated with the presence of structured and homogeneous hypodensities likely to represent classic infarcts, as confirmed by day 7 CT scan. Conversely, total recovery was significantly associated with the absence of any image or with unstructured hypodensities, a particular type of image characterized by its heterogeneous darkness and often polylobar shape. This type of image disappeared at day 7 in 17.6% of the cases and is likely to represent reperfusion images and/or incomplete ischemic damage.

CONCLUSIONS

The results obtained in this open, small study suggest safety and effectiveness of rTPA thrombolysis at the dose of 0.8 mg/kg within 7 hours in acute strokes of the carotid territory, including highly serious baseline neurological presentations, until age 81 years and under special therapeutic conditions. Complete recovery is significantly associated with major neurological improvement during the first 24 hours and the presence of a particular type of image at day 1 CT scan characterized by an unstructured hypodensity, often polylobar and heterogeneous, which is likely to correspond to reperfusion images.

Middle cerebral artery endarterectomy: experience with two cases

BACKGROUND

Atherosclerotic stenosis of the middle cerebral artery (MCA) is uncommon and long-term prognosis is not well defined. Methods of treating stenosis of the MCA range from the administration of anticoagulants to endarterectomy.

METHODS

We present two cases of patients with focal symptomatic stenosis of the MCA with evidence of focally decreased cerebral blood flow and compromise of cerebral blood flow reserves on xenon-enhanced computed tomography (Xe CT) scanning. Endarterectomies were performed after unsuccessful anticoagulation therapy.

RESULTS

Both patients underwent successful endarterectomies of the MCA. Improvement in cerebral blood flow postoperatively was documented for both patients. At last follow-up neither patient had demonstrated any additional ischemic episodes.

CONCLUSIONS

Atherosclerotic stenosis of the MCA may be responsible for distal emboli and compromised hemodynamics, and endarterectomy of this vessel may provide definitive therapy.

Decompressive craniectomy for cerebral infarction. An experimental study in rats

BACKGROUND AND PURPOSE

Acute ischemia in the territory of the carotid artery can lead to massive cerebral edema with raised intracranial pressure and progression to coma and death due to uncal, cingulate, or tonsillar herniation. Thus far, only anecdotal experience with supratentorial ischemia treated by decompressive craniectomy has been reported; and there are no published experimental data dealing with this kind of therapy in acute supratentorial stroke. In this study, we present our results on the effect of decompressive craniectomy in an endovascular model of cerebral infarction in rats.

METHODS

Focal cerebral ischemia was induced in 50 rats using an endovascular occlusion technique of the middle cerebral artery. Decompressive craniectomy was performed in 30 animals: in 15 animals after 1 hour and in the remaining 15 animals 24 hours after vessel occlusion. Twenty animals were not treated by decompressive craniectomy (control group).

RESULTS

Mortality in the nontreated group was 35%, whereas none of the animals treated by decompressive craniectomy died. Neurological behavior, weight loss, and infarction size were all significantly better in the animals treated by decompressive craniectomy, regardless of whether they had been treated after 1 or 24 hours (P < .01).

CONCLUSIONS

Our results suggest that decompressive craniectomy for cerebral ischemia not only reduces mortality but also significantly improves outcome and reduces infarction size, probably because of increased perfusion pressure through leptomeningeal collaterals. This experimental study suggests that a controlled study of decompressive craniectomy in patients with acute internal carotid or middle cerebral artery occlusion would be worthwhile. By performing decompressive craniectomy in a small, selected group of patients, neurosurgeons may play an important role in the management of these patients.

Vein graft replacement of the middle cerebral artery after unsuccessful embolectomy: case report

A forty-one-year-old man with a cavernous hemangioma of the right cavernous sinus underwent a preoperative cerebral angiogram and a balloon occlusion test of the internal carotid artery. During the operation to remove the cavernous sinus lesion, the ipsilateral electroencephalogram was found to be abnormal. An embolic occlusion of the M2 and M3 segments of the middle cerebral artery (MCA) was discovered. A platelet and thromboembolus was removed via multiple incisions, and flow was restored. The cavernous sinus lesion was removed uneventfully. At the end of the operation, the MCA was found to be reclotted. Flow was eventually restored by replacing the M2 segment of the MCA with a 2-cm saphenous vein graft. The patient recovered without any deficits of brain function and with transient deficits of Cranial Nerves III and VI. Computed tomography revealed infarcts in the temporal and parietal areas. When MCA embolectomy is unsuccessful, vein graft replacement should be considered to restore flow and to avoid major neurological deficits.

The efficacy and safety of tissue plasminogen activator in acute ischemic strokes

Over the past decade there has been an increasing use of thrombolytic agents in the treatment of coronary artery disease, pulmonary embolism, and thromboembolic strokes. The use of thrombolytic agents has been most successful in treating acute myocardial infarction. When treatment with intravenous streptokinase or tissue plasminogen activator (tPA) is initiated within the first 3 to 4 hours from the onset of symptoms, the rate of reperfusion ranges from 60% to 90%, as compared to a rate of 13% to 21% for placebo control. Both streptokinase and tPA have been extensively studied as therapies for acute myocardial infarction, and in general, a higher initial rate of reperfusion is achieved in tPA-treated patients than in streptokinase-treated patients, although the final arterial patency rate may not be different in the two groups due to a higher rate of reocclusion in the tPA-treated population. Furthermore, time dependency for efficacy from the onset of symptoms to the initiation of treatment is less for tPA than for streptokinase. However, the role of thrombolytic agents in the treatment of thromboembolic strokes is more experimental than clinical at the present time. Of all agents, tPA is the most promising and the most extensively studied. This paper will review the experimental data on the use of tPA in acute thromboembolic strokes as well as the existing clinical data on stroke reperfusion.

Three-dimensional transcranial Doppler in acute ischemic stroke in the territory of the middle cerebral artery: clinical and CT correlation

We studied 34 patients with acute ischemic stroke in the territory of the middle cerebral artery (MCA) by three-dimensional transcranial Doppler (TCD-3D). The parameters analyzed were: mean blood flow velocity, systolic and diastolic velocities; indices of pulsatility, hemisphere asymmetry and pulsatility transmission. Of the 34 patients 11 presented marked slowing of flow velocity in the MCA on the infarct side with an asymmetry index (AI) of over 40%, 8 patients with slightly reduced flow velocity in the MCA and an AI of 25-40%, 2 patients in whom there was indirect evidence of collateral circulations in the anterior cerebral artery distribution together with slowing of MCA flow; 5 patients had stenosis of the MCA, 9 patients showed no alterations of the Doppler parameters. The correlation between neurological symptom pattern and AI was significant (r = 0.76). Noninvasive, easy to perform, performable at once and reliable, TCD-3D is a great improvement on traditional transcranial Doppler and is especially useful in assessing the hemodynamics of the cerebral circulation in ischemic stroke.

Mortality in acute cerebral infarction in young adults--a ten-year experience

We reviewed the one-month mortality among 213 patients aged fifteen to forty-five years (mean thirty-five) with acute cerebral infarction (CI) evaluated during the period July 1, 1977, to February 1, 1988. Atherosclerotic cerebral infarction (ACI) was diagnosed in 59 (27.7%) patients, 53 (24.9%) had non-atherosclerotic vasculopathies (NAV); 46 (21.6%) had cardioembolic infarcts (CEI). Hematologically related disorders were diagnosed in 30 (14.1%) patients; the cause of CI could not be established in 25 (11.7%) patients. Fourteen patients (9 men, 5 women, mean age 34.8 years), (6.6%) died within thirty days of their CI: 7 had CEI (7/46,15.2%); 4 had ACI (4/59, 6.7%); and 3 had NAV (3/53, 5.6%). Our data suggest that young patients with acute CI have a thirty-day mortality rate lower than older patients. Deaths were most common in patients with CEI. Brain edema and herniation accounted for 6 (43%) of the deaths.

Anterior cerebral artery velocity changes in disease of the middle cerebral artery stem

Transcranial Doppler ultrasonography can map the changes in blood velocity that result from stenosis or occlusion of the middle cerebral artery. To evaluate patterns of collateral blood flow in disease of the middle cerebral artery stem, we used both cerebral angiography and transcranial Doppler ultrasonography to study the systolic blood velocities in both anterior cerebral arteries in 10 consecutive patients with middle cerebral artery stenosis or occlusion. Five patients had no evidence of hemodynamically significant carotid disease and good-quality measurements of systolic velocity in each anterior cerebral artery. Two of the five patients had middle cerebral artery stem stenosis and the other three had occlusion. The ratios of mean blood velocity in the normal compared with the abnormal side for the five patients (mean 1.34 +/- 0.23, range 1.15-1.74) were significantly higher than ratios for 10 controls (mean 1.04 +/- 0.12, range 0.76 +/- 1.19) using an unpaired t test (t = 3.492, 0.0005 less than p less than 0.005). Our results suggest that transcranial Doppler ultrasound measurements of anterior cerebral artery blood velocity may be a useful index of collateral blood flow from the anterior cerebral artery territory into the middle cerebral artery territory. Changes in mean velocity ratio may document the evolution and adequacy of collateral blood flow over the cerebral convexity in middle cerebral artery stem disease. In addition, the changes in anterior cerebral artery blood velocity appear to be an important corroborative finding for middle cerebral artery stem occlusion.

Intracarotid urokinase with thromboembolic occlusion of the middle cerebral artery

Intracarotid urokinase infusion therapy was performed on 22 patients with evolving cerebral infarction due to acute thromboembolic occlusion of the middle cerebral artery. Mean time from onset of symptoms to start of infusion and mean dosage of urokinase were 4.5 hours and 927,000 units, respectively. Immediate recanalization was achieved in 10 patients (45%) after urokinase therapy. In patients with successful recanalization, rapid amelioration of symptoms followed the restoration of blood flow. Thrombolytic recanalization was associated with reduction of neurologic deficits and of computed tomography-demonstrable infarction volume. The reduction of infarction volume and functional outcome correlated highly with the degree of reflow. Hemorrhagic transformation of infarction occurred in four patients and controllable extracranial bleeding in three patients. These results support the safety and efficacy of urokinase therapy for acute thromboembolic occlusion of the middle cerebral artery.