Spontaneous intracerebral hemorrhage following carotid endarterectomy. Experience of 328 operations from 1983-1988.

In a consecutive series of 328 carotid endarterectomies there were two cases of postoperative intracerebral hemorrhage. The patients with transient ischemic attacks and subsequent major cerebral infarction had repair of their very tight carotid stenosis. Each developed intracerebral hemorrhage after a symptom free interval and hypertension was uncontrolled during the postoperative period. Hypertension is a significant complication of carotid endarterectomy and may be a prominent factor in the development of intracerebral hemorrhage after carotid endarterectomy. Also defective cerebrovascular autoregulation in chronic ischemic brain regions may predispose patients to intracerebral hemorrhage.     

Intracerebral haemorrhage after carotid endarterectomy

Among 662 consecutive carotid endarterectomies eight cases of postoperative ipsilateral intracerebral haemorrhage were identified, occurring into brain areas which, preoperatively were without infarction. As blood pressures across the stenosis were routinely measured during surgery, the internal carotid artery (ICA) perfusion pressure could be related to the occurrence of haemorrhage. In addition, cerebral blood flow (CBF) was studied with the intravenous xenon-133 technique in four patients and histopathologic examination of the brain was available in four patients who died subsequent to their haemorrhage. All eight patients had a high grade of ICA stenosis and a marked reduction of ICA perfusion pressure (average of 40%) which was significantly greater than that observed (average of 6%) in the other patients undergoing carotid surgery (P less than 0.0001). Relative hyperperfusion of the ipsilateral hemisphere was seen in the four patients studied postoperatively. In at least two cases the haematoma was preceded by an asymptomatic postoperative ischaemic infarct. Histologic examination did not confirm previous findings of changes resembling those seen in malignant hypertensive encephalopathy. These results substantiate the view, that patients at risk of haemorrhage after endarterectomy are those with a low preoperative cerebral perfusion pressure and postoperative hyperperfusion. Postoperative silent brain infarction is an additional risk factor.     

Intracerebral haemorrhage after internal carotid endarterectomy

This paper reports three fatal cases of intracerebral haemorrhage after internal carotid artery thrombendarterectomy, one in a patient operated on four weeks after a cerebral infarction and two in patients operated after a transient ischemic attack. Two other late intracerebral haemorrhagic events are reported in patients submitted to internal carotid artery surgery, one from a ruptured intracerebral aneurysm and another probably due to anticoagulation medication. It is emphasized to make a clear distinction between haemorrhagic and ischemic events when reporting stroke frequency in patient materials after internal carotid artery surgery.     

Acute carotid artery stenting in symptomatic high-grade cervical carotid artery stenosis

The safety and efficacy of emergency carotid artery stenting (CAS) for patients with acute ischemic stroke resulting from internal carotid artery stenosis are not established. In this retrospective study, we evaluated outcomes for CAS performed within 2 weeks of acute ischemic stroke for 16 patients treated between December 2009 and February 2014. Cases of internal carotid artery occlusion, internal carotid dissection, or intracranial major arterial trunk occlusion were excluded. Five patients were treated with CAS during the hyperacute phase (within 24 h of stroke onset), three in the advanced phase (within 24 h of stroke-in-evolution after admission), and eight in the acute phase (24 h to 2 weeks after onset). We evaluated modified Rankin scale (mRS) scores 90 days after CAS. For patients treated during the hyperacute phase without intravenous tissue-type plasminogen activator (IV-tPA), two had mRS scores of 2 and one had a score of 3. Two patients treated in the hyperacute phase with IV-tPA had scores of 5: one with symptomatic intracerebral hemorrhage and the other with acute brain swelling. For patients treated in the advanced phase, mRS scores were 1, 3, and 5; the patient with 5 had contralateral cerebral infarction. All patients treated in the acute phase had scores of 2 or lower. Patients treated with IV-tPA in advanced or acute phases had no severe post-CAS complications. CAS was effective and safe for treating ischemic stroke within 2 weeks of onset. However, IV-tPA treatment may be a risk factor for CAS treatment during the hyperacute phase.     

Potential roles for early revascularization in patients with acute cerebral ischemia

The risk of carotid endarterectomy in acute cerebral ischemic situations is well documented. By using the superficial temporal or occipital artery, it is possible to provide relatively low flow revascularization conduits, potentially avoiding the risk of postoperative hemorrhage. Eighteen patients at The University of Texas Health Science Center at Dallas, Texas, have been treated recently with extracranial to intracranial bypass in the setting of acute neurological deficit, stroke in evolution, or recent completed infarction. Angiographic causes of these deficits included cervical carotid occlusion in 5 patients, carotid siphon disease in 2 patients, middle cerebral stenosis or occlusion in 3 patients, and delayed cerebral ischemia following subarachnoid hemorrhage in 8 patients. Neurological improvement was demonstrated within 24 hours following revascularization in 15 cases (83%); 3 patients were unchanged following bypass, and no patient's condition was worsened. The only case of postoperative intracerebral hemorrhage occurred 1 week following a long saphenous vein graft from the subclavian to the middle cerebral artery. After an average follow-up of 19 months, 7 patients are neurologically normal, 8 patients have mild to moderate deficits, and 3 patients have died. Low flow revascularization procedures appear to be safe in the setting of acute cerebral ischemia and may in selected patients boost regional cerebral blood flow from levels of symptomatic ischemia into a range compatible with normal neuronal function.     

Intracerebral hemorrhage in a patient with moyamoya phenomenon caused by tuberculous arteritis: a case report]

A case of intracerebral hemorrhage which probably had been caused by a rupture of abnormal "moyamoya vessels" due to tuberculous arteritis was reported. A 42-year-old female had a history of tuberculous meningitis at the age of 2 years and suffered from a sudden onset of severe headache in January of 1998. CT scan disclosed a medium-sized intracerebral hematoma in the left frontal base and many calcifications in the basal cistern. Subsequent angiography demonstrated high-grade stenosis in the terminal portion of the right internal carotid artery and near-by "moyamoya vessels". No surgery was performed on the patient. A second angiography was carried out two months later and it newly disclosed ophthalmic artery-feeding "moyamoya vessels" in the place where the intracerebral hematoma had been located. This led us to conclude that a rupture of "moyamoya vessels" was the cause of the intracerebral hemorrhage and "moyamoya vessels" were not visible in the first angiograms because they had been compressed by the hematoma. Although cerebral infarction is common in tuberculous arteritis, cerebral hemorrhage is uncommon. The pathogenesis of cerebral hemorrhage due to tuberculous arteritis and its difference from that of hemorrhage caused by moyamoya disease is discussed.     

Symptomatic acute occlusion of the internal carotid artery: reappraisal of urgent vascular reconstruction based on current stroke imaging

OBJECTIVE: We hypothesized that a subgroup of patients with frank stroke due to sudden occlusion of the internal carotid artery could safely undergo surgery to restore carotid patency and to rescue brain tissue not yet irreversibly damaged if current stroke diagnostic methods were applied. METHODS: From November 1997 to March 2007, 1810 patients underwent carotid endarterectomy of the internal carotid artery for occlusive disease at our department. Within the same period, 5369 patients were examined at our stroke unit, and 502 from this cohort underwent internal carotid artery reconstruction. A subgroup of 35 patients (28 men, 7 women; mean age, 61 +/- 10 years) underwent urgent surgical revascularization due to an acute internal carotid artery occlusion < or =72 hours (mean 25 +/- 17 hours) after the onset of stroke symptoms and < or =36 hours (mean 16 +/- 10 hours) after admission to our stroke unit. Our diagnostic workup consisted of extracranial intracranial duplex sonography, cerebral computed tomography, digital subtraction angiography, magnetic resonance imaging, and angiography, including diffusion- and perfusion-weighted imaging, to discriminate between viable and irreversibly damaged brain tissue. The study excluded patients who presented an impaired level of consciousness, occlusion of the intracranial internal carotid artery, occlusion of the ipsilateral middle cerebral artery, or infarction more than one-third of the territory perfused by the middle cerebral artery. Imaging showed signs of recent ischemic infarction in all 35 cases. On admission, eight patients (23%) scored 0 to 2 points and 27 (77%) scored 3 to 5 points in Rankin scale. RESULTS: Confirmed by postoperative Doppler and duplex sonography at discharge, internal carotid artery patency could be achieved in 30 of 35 cases (86%). Intracranial hemorrhage occurred in two patients (6%) and reinfarction in another two (6%). Two patients died during their hospital stay (30-day mortality, 6%). Compared with the preoperative neurologic status, rates of clinical improvement (> or =1 point in Rankin scale), stability, and deterioration were 57%, 31%, and 6%, respectively. CONCLUSIONS: Restoration of blood flow in an acutely occluded internal carotid artery can only be achieved in the acute stage. Our pilot study demonstrated that a thorough diagnostic workup allows selection of patients who may benefit from urgent revascularization of acute internal carotid artery occlusion in the stage of an acute stroke. A prospective randomized multicenter trial comparing surgery with conservative medical treatment is needed.     

The value of acetazolamide single photon emission computed tomography scans in the preoperative evaluation of asymptomatic critical carotid stenosis.

PURPOSE: Acetazolamide (ACZ)-enhanced single photon emission computed tomography (SPECT) scans can assess both cerebral perfusion and vascular reactivity. Patients with asymptomatic critical carotid artery stenosis were evaluated for cerebral vascular reactivity to determine the effect of extracranial occlusive disease and the effect of carotid endarterectomy (CEA) on intracerebral reactivity. METHODS: In 44 patients with asymptomatic critical carotid artery stenosis, cerebral perfusion and vascular reactivity were assessed before CEA with resting and ACZ-enhanced SPECT scans. All patients had a 70% or greater ipsilateral internal carotid artery stenosis. Preoperative ACZ-enhanced SPECT scans were obtained, usually 5 days before CEA. Postoperative ACZ-enhanced SPECT scans were obtained in 30 patients. RESULTS: Preoperative SPECT scans were asymmetric, revealing focal (n = 19) or global (n = 15) decreased reactivity in 34 patients (77%). Ten patients had symmetric or normal reactivity. After CEA, 23 patients demonstrated an improvement in reactivity ipsilateral to the side of surgery. The remaining seven patients failed to improve after surgery. CONCLUSION: Although all patients had a high-grade internal carotid stenosis, nearly a quarter of the patients had excellent intracerebral collateral flow. Only 71% of patients demonstrated improved intracerebral vasoreactivity after CEA. The lack of improvement in the other patients may have resulted from intracerebral pathology or lack of improvement in the extracranial carotid hemodynamics.     

Intracerebral hemorrhage after carotid endarterectomy associated with asymptomatic perioperative cerebral ischemia detected by cerebral perfusion imaging: case report

BACKGROUND: Risk factors for intracerebral hemorrhage following carotid endarterectomy (CEA) include perioperative cerebral ischemia, postoperative cerebral hyperperfusion, and postoperative anticoagulation therapy, and at least 2 of these risk factors are typically present in the context of intracerebral hemorrhage (ICH). CASE DESCRIPTION: A 75-year-old man with severe bilateral cervical internal carotid artery stenosis and a minor stroke resulting in left motor weakness underwent a right CEA. The operation was uneventful, and the patient did not experience new neurologic deficits upon recovery from anesthesia. Brain single photon emission computed tomography (SPECT) obtained immediately after CEA showed a perfusion defect in the right parietal lobe and absence of cerebral hyperperfusion. A computed tomography (CT) scan showed no new abnormal findings. Aspirin therapy was instituted postoperatively. On the second postoperative day, the patient experienced abrupt worsening of left hemiparesis, and subsequent CT imaging demonstrated a hematoma in the right parietal lobe. Cerebral hyperperfusion was absent on repeat SPECT. CONCLUSION: Perioperative cerebral ischemia can result in intracerebral hemorrhage after CEA even in the absence of cerebral hyperperfusion and/or anticoagulation therapy. Further, cerebral perfusion imaging performed immediately after CEA is a useful modality for the identification of occult cerebral ischemia or hyperperfusion that may lead to intracerebral hemorrhage.     

Correlation of clinical findings, duplex carotid artery scanning and CT scanning of the brain in 54 consecutive patients with bruits over the carotid artery bifurcation.

Fifty-four patients presenting consecutively with bruits over the carotid artery bifurcation have been studied by Duplex ultrasonography of the carotid artery and CT of the brain. The patients were divided into symptomatic (transient ischaemic attacks (TIA), non-focal neurological symptoms, minor and major strokes) and asymptomatic groups. The duplex scans were subdivided into those showing a greater than 50% stenosis of the internal carotid artery and those with a less than 50% stenosis. The CT brain scans were subdivided into those showing evidence of cerebral infarction and those without. Symptomatic patients were found to be more likely to have an area of cerebral infarction than asymptomatic ones (P = 0.0086 Fisher's Exact Test). Patients with a significant stenosis (greater than 50%) of the internal carotid artery were more likely to have an ipsilateral cerebral infarction on CT than patients with a minor stenosis (less than 50% stenosis) (P = 0.028 Fisher's Exact Test). Three patients (two with TIA's and one with non-focal neurological symptoms) were found to have unsuspected cerebral infarcts on CT of the brain. These patients could theoretically be at risk following carotid endarterectomy and revascularization if the infarct were an early one. Patients with non-focal neurological symptoms and carotid bruit were more likely to have a significant stenosis than asymptomatic patients with carotid bruit (P = 0.0069 Fisher's Exact Test). Therapy should be directed at the carotid artery lesion in these cases. Duplex scanning of the carotid artery bifurcation may be combined usefully with CT brain scanning in the non-invasive investigation of patients with symptomatic extracranial carotid artery bruits.     

Hyperbaric oxygen as an adjunct to acute revascularization of the brain

Two recent cases suggest that hyperbaric oxygen may be an important adjunct to the surgical treatment of occlusion of major cerebral arteries within the first few hours after onset of neurological deficit. In both patients, one with an embolus to the right middle cerebral artery and one with a surgical occlusion of the left internal carotid artery, circulation to the ischemic area was restored more than eight hours after occlusion. In the patient with the middle cerebral artery embolus, hemiplegia cleared after a six-minute exposure to hyperbaric oxygen. The patient with occlusion of the internal carotid artery was revascularized by anastomosis of a superficial temporal artery less than 1 mm in diameter to a branch of the middle cerebral artery. Her hemiplegia and aphasia cleared rapidly and concomitantly with intermittent exposure to hyperbaric oxygen during the first nine postoperative days. Postoperative angiograms demonstrated patency in both cases. The implications of these observations are discussed.     

Propofol EEG burst suppression in carotid endarterectomy.

BACKGROUND: The results of randomized trials indicate that carotid endarterectomy, performed with a low morbidity-mortality perioperative risk, is the best therapeutic option both for patients with high-grade symptomatic and asymptomatic stenosis. Since the main operative risk is represented by embolic or hemodynamic cerebral ischemia, it appears necessary to maintain an adequate intraoperative cerebral blood flow and to carry out a meticulous endarterectomy. METHODS: On the basis of these considerations we prospectively studied a series of 100 consecutive patients operated on for high-grade carotid stenosis, by using a protocol based on: 1) an accurate selection of patients for surgery; 2) meticulous surgical technique without any shunt; 3) perioperative cerebral protection by barbiturate or propofol; 4) pre- and postoperative medical treatment of risk factors. All patients of our series performed preoperatively brain CT scan, transcranial Doppler, carotid duplex scanning, four vessel angiography, brain 99mTc-HMPAO SPECT. Eighty-two patients had symptomatic carotid stenosis ranged between 70 and 90%, 18 had carotid stenosis higher than 90%. RESULTS: In this series there have been one postoperative death due to myocardial infarction and one major stroke. CONCLUSIONS: We think that this protocol can significantly minimize risks of endarterectomy and probably maximize the benefits of surgery, also in patients with asymptomatic high-grade carotid stenosis.     

Early cerebral complications in carotid endarterectomy: risk factors

Three hundred and thirty one carotid endarterectomies were performed on 279 patients during a period of twenty years from 1965 to 1984. The indication for surgery was transient ischemic attack in 67.4%, stroke in 22.7% and asymptomatic carotid stenosis in 10.0% of the operations. The overall major cerebral complication rate attending the operation was 9.6%. During the last four years' period from 1981 to 1984 the procedure morbidity was 3.6% and there was no mortality. Postoperative complications comprised 31 ipsilateral strokes and one contralateral stroke; the complications occurred during the first 24 hours in 28 cases and on the fourth or fifth day in four cases. Of these patients 11 succumbed to internal carotid thrombosis, one to cerebral infarction without thrombosis and one to intracerebral hemorrhage. The associated factors for major complications were analyzed retrospectively in the light of 32 parameters. Patients of advanced age, patients with type II diabetes mellitus, elevated serum triglycerides, high-grade stenosis or occlusion of the contralateral carotid artery, negative smoking history and those undergoing a second operation proved to be at high risk of early postoperative cerebral complications. These complications can be reduced by intraoperative use of heparin, preoperative ASA treatment and a short clamping time. Also peroperative use of shunt is obviously of benefit.     

Dorsal internal carotid artery aneurysm treated by coil embolization--case report.

A 50-year-old male presented with an extremely rare dorsal wall aneurysm of the internal carotid artery manifesting as intracerebral hemorrhage. Computed tomography demonstrated intracerebral hemorrhage on the frontal base. Magnetic resonance imaging clearly showed the hemorrhage was related to an aneurysm of the internal carotid artery. Cerebral angiography disclosed an elongated aneurysm of the dorsal wall of the internal carotid artery. The aneurysm was packed as fully as possible with Guglielmi detachable coils to achieve complete obliteration. The patient was discharged without neurological deficits. Dorsal internal carotid artery aneurysms have a high risk of premature rupture due to their unusual shape and position, adhesion to the brain tissue, and fragile neck. Direct clipping requires careful brain retraction, necessary exposure of the aneurysm, and gentle neck manipulation. Endovascular treatment is an alternative method for obliteration of the aneurysmal sac.     

Supratentorial intracerebral hemorrhage after posterior fossa operation

Three cases of supratentorial intracerebral hemorrhage after posterior fossa operation are described, and nine other cases reported in the literature are reviewed. The possible causes are discussed, but in eight cases no definite cause could be found. All eight patients were operated on in the sitting position, and all had hematomas in the subcortical white matter. A possible cause might be changes in intracranial dynamics in the sitting position with disruption of subcortical veins. Other authors mention the possibility of occlusion of carotid or vertebral vessels in the neck by improper positioning of the head leading to intraoperative infarction and to hemorrhage within the infarcted brain after repositioning of the patient. With the patient in a lateral or semilateral position, this complication should be preventable.     

Association of carotid artery atheromatous plaque types with cerebral perfusion

Background: In an attempt to define the association of internal carotid artery atheromatous plaque morphology with potential cerebral ischaemia, we have investigated the relationship of different carotid plaque types with defects in cerebral perfusion. Methods: In 130 patients requiring surgical correction of internal carotid artery stenoses greater than 70%, defects in cerebral perfusion due to both haemodynamic insufficiency and intracerebral vessel occlusion were identified using single photon emission computed tomography scans (SPECT). Carotid artery plaques in these patients were classified as homogeneous or heterogeneous based on preoperative Doppler Duplex Scanning and on the macroscopic characteristics of the plaques recorded by the surgeon during carotid endarterectomy, with sub‐classification into potentially embolus‐generating and non‐ embolus‐generating plaques. In individual patients, plaque types were then correlated with the perfusion defects found in the SPECT scans. Results: Of 130 patients, 112 (86%) had cerebral perfusion defects. In 56 asymptomatic patients in the study, 48 (85.7%) had perfusion defects as did 64 (86.5%) of 74 symptomatic patients. Cerebral infarcts were seen in 41 (31.5%). Occlusive infarcts (66%) were twice as frequent as haemodynamic insufficiency infarcts (34%). Eighteen patients with small cerebral infarcts on SPECT scanning gave no medical history of cerebral symptoms. Statistical analysis of the results revealed that there was no statistically identifiable association between carotid plaque type and the generation of cerebral symptoms or infarction. Conclusion: This study found that internal carotid plaque morphology has no statistically significant association with perfusion defects, symptoms or cerebral infarction in patients with significant internal carotid artery stenosis. Also, it is suggested that haemodynamic cerebral infarction may be more common that previously believed (34% of infarcts identified in the study). Further, it is suggested that plaque morphology alone is not an indication for carotid endarterectomy.     

Results of extracranial-intracranial arterial bypass for bilateral carotid occlusion

The results of superficial temporal to middle cerebral artery bypass surgery for bilateral internal carotid artery occlusion were reviewed in 39 patients. Preoperative symptoms included recurrent transient ischemic attacks (TIA's) in 31 patients (80%) and mild or moderate stroke in 15 (29%). Deficits were unilateral in 23 cases and bilateral in 14. Dementia or personality changes were observed in 19 patients (49%). Operative morbidity occurred in six of 39 cases and was neurological in one; the surgical mortality rate was 8% (three of 39 patients), including two cases of cerebral hemorrhage. The outcome was good or excellent (relief of TIA's and reduction of neurological deficit) in 82% of patients over a follow-up period of 3 to 139 months. Five patients had a late postoperative stroke, which occurred in the unoperated hemisphere in each case; one patient had an ipsilateral TIA 6 years after the bypass procedure. These results suggest that an extracranial-intracranial arterial bypass procedure to augment collateral cerebral blood flow can be performed safely in patients with bilateral internal carotid artery occlusion and may be associated with relief of ischemic symptoms. Future studies may document a role for this procedure in the prevention of stroke.     

Surgical management of aneurysms in the cavernous sinus

Summary A series of 32 patients with aneuryms in the cavernous sinus region is presented. All of them have been operated upon through an intradural pterional approach and the aneurysms directly attacked. Only in 6 patients was the complete dissection of the internal carotid artery and of the aneurysm impossible because of the size of the aneurysms. In these cases the aneurysm has been traped by ligation of the internal carotid artery in the neck and its supraclinoid course and at the same time and extracranial intracranial anastomosis performed. One patient died from massive cerebral infarction after a trapping procedure and another died from a transoperative haemorrhage; another two developed a moderate hemiparesis which resolved within the first six postoperative weeks, and in two patients a preoperative severe visual impairment progressed postoperatively to complete visual loss. All others had a complete resolution of their preoperative symptoms and remained well.The advantages and disadvantages of the different approaches to intracavernous carotid artery aneurysms are discussed and the related literature reviewed.Presented at the European Congress of Neurosurgery, Barcelona, September 1987.     

Treatment of intracranial aneurysms by combined proximal ligation and extracranial-intracranial bypass with vein graft

Seven patients with internal carotid artery aneurysms, and one patient with a middle cerebral artery aneurysm, were managed by combining proximal ligation with an extracranial-intracranial bypass procedure. Five bypasses were done with an interposed vein graft between the external carotid artery and the distal middle cerebral artery (vein graft), and three were superficial temporal-middle cerebral artery bypasses (superficial temporal artery grafts). As demonstrated in postoperative angiograms, all eight patients had patent bypasses with nonfilling of the aneurysm. One patient developed transient dysphasia, but there were no permanent neurological deficits associated with carotid occlusion. Four patients had resolution of their neurological problems, and another three patients improved. The distribution of flow from vein grafts is more extensive than from superficial temporal artery grafts. This offers increased protection against ischemia, and increases the likelihood of internal carotid artery aneurysm thrombosis by reducing the turbulence in the distal internal carotid artery.     

Early carotid endarterectomy after ischemic stroke improves diffusion/perfusion mismatch on magnetic resonance imaging: report of two cases

OBJECTIVE AND IMPORTANCE: The functional magnetic resonance imaging techniques of diffusion-weighted imaging and perfusion-weighted imaging allow for ultra-early detection of brain infarction and concomitant identification of blood flow abnormalities in surrounding regions, which may represent brain "at risk." CLINICAL PRESENTATION: We report two patients with acute ischemic stroke associated with ipsilateral high-grade carotid stenosis. The first patient, a 64-year-old woman with a remote history of ischemic stroke and a vertebral artery aneurysm, presented with worsening of her preexisting right hemiparesis. The second patient, another 64-year-old woman with known multiple intracranial aneurysms and bilateral high-grade internal carotid artery stenosis, was admitted for the elective microsurgical clipping of an enlarging giant left carotid-ophthalmic artery aneurysm. Postoperatively, she developed right hemiparesis and mild aphasia. Both patients showed progressive worsening of their neurological deficits in the setting of small or undetected diffusion-weighted imaging abnormalities and large perfusion-weighted imaging defects. INTERVENTION: After prompt carotid endarterectomy, symptoms in both patients resolved or improved. Follow-up magnetic resonance imaging scans demonstrated resolution or significant improvement in the perfusion abnormalities in both patients. CONCLUSION: Carotid endarterectomy in the setting of diffusion-weighted/perfusion-weighted imaging mismatch can lead to improvement in cerebral perfusion as evidenced by resolution of the perfusion-weighted imaging lesion. Diffusion/perfusion magnetic resonance imaging may be useful in identifying patients with severe neurological deficits but without large territories of infarction who may safely undergo early surgical revascularization.