MRI of hyperacute stroke in the AChA territory

Microvascular anatomy of the medial temporal region

OBJECTIVE

The authors investigated the microvascular anatomy of the hippocampus and its implications for medial temporal tumor surgery. They aimed to reveal the anatomical variability of the arterial supply and venous drainage of the hippocampus, emphasizing its clinical implications for the removal of associated tumors.

METHODS

Forty-seven silicon-injected cerebral hemispheres were examined using microscopy. The origin, course, irrigation territory, spatial relationships, and anastomosis of the hippocampal arteries and veins were investigated. Illustrative cases of hippocampectomy for medial temporal tumor surgery are also provided.

RESULTS

The hippocampal arteries can be divided into 3 segments, the anterior (AHA), middle (MHA), and posterior (PHA) hippocampal artery complexes, which correspond to irrigation of the hippocampal head, body, and tail, respectively. The uncal hippocampal and anterior hippocampal-parahippocampal arteries contribute to the AHA complex, the posterior hippocampal-parahippocampal arteries serve as the MHA complex, and the PHA and splenial artery compose the PHA complex. Rich anastomoses between hippocampal arteries were observed, and in 11 (23%) hemispheres, anastomoses between each segment formed a complete vascular arcade at the hippocampal sulcus. Three veins were involved in hippocampal drainage-the anterior hippocampal, anterior longitudinal hippocampal, and posterior longitudinal hippocampal veins-which drain the hippocampal head, body, and tail, respectively, into the basal and internal cerebral veins.

CONCLUSIONS

An understanding of the vascular variability and network of the hippocampus is essential for medial temporal tumor surgery via anterior temporal lobectomy with amygdalohippocampectomy and transsylvian selective amygdalohippocampectomy. Stereotactic procedures in this region should also consider the anatomy of the vascular arcade at the hippocampal sulcus.

Prognosis prediction of motor outcome in hemiparetic patients with anterior choroidal artery infarction: Radiologic and transcranial magnetic stimulation prognostic validation studies (STROBE)

ABSTRACT

To investigate prognosis prediction of motor outcome in anterior choroidal artery (AChA) infarction patients using radiologic and transcranial magnetic stimulation (TMS) studies.Twenty six patients with complete weakness of the affected hand were recruited. The Motricity Index (MI), Medical Research Council (MRC) scores for the affected finger extensors, Modified Brunnstrom classification (MBC) and Functional Ambulation Category (FAC) were evaluated twice: at onset and the chronic stage (3-4 months after onset). Patients were assigned according to the presence of infarction at the corona radiata (CR); the CR-positive group (infarct presence at the CR and posterior limb of internal capsule [PLIC], 11 patients) and CR-negative group (infarct presence at the PLIC, 15 patients), and the presence of motor evoked potentials at the affected hand muscle: the TMS-positive group (11 patients) and the TMS-negative group (15 patients).At the second evaluation, the MI scores were significantly different between the CR-positive (45.10 ± 7.06) and CR-negative groups (57.90 ± 11.56), and between the TMS-positive (60.37 ± 11.53) and TMS-negative groups (46.70 ± 7.99) (P < .05). The MRC scores for the finger extensors were also significantly different between the CR-positive (0.95 ± 1.01) and CR-negative (2.57 ± 1.33) groups and between the TMS-positive (3.05 ± 0.88) and TMS-negative (1.03 ± 1.14) groups (P < .05). Fourteen (53.85%) of the 26 patients recovered to have a functional hand score (MBC ≥5) and 19 (73.07%) of the 26 patients recovered to have an independent gait score (FAC ≥3) on their second evaluation.The results show that CR involvement in addition to the presence of a PLIC lesion and a TMS-negative response were related to poor motor outcomes in patients with an AChA infarction. Consequently, radiologic and TMS studies can be considered for motor outcome prognosis prediction in patients with an AChA infarction.

Existence and Significance of Internal Border Zone Infarcts with Accessory Lesions Located in the Anteromedial Temporal Lobe

OBJECTIVES

To examine the existence and significance of internal border zone (IBZ) infarcts with accessory lesions in the anteromedial temporal lobe (ATL).

MATERIALS AND METHODS

IBZ infarcts located at the corona radiata were selected based on diffusion-weighted imaging of 2535 consecutive patients with ischemic stroke and the presence of lesions in the ATL was identified. The Mann-Whitney U test, Student t-test, Pearson χ² test, or Fisher exact test was used to analyze differences between the IBZ infarct groups with and without accessory lesions in the ATL.

RESULTS

Thirty-six of 2535 patients (1.4%) had IBZ infarcts. The IBZ group with accessory lesions in the ATL (17 cases, 47.2%) showed a higher portion of occluded middle cerebral arteries than the IBZ group without accessory lesions in the ATL (p = 0.02). The initial National Institutes of Health Stroke Scale score (odds ratio, 2.03; 95% confidence interval, 1.04-3.99;   = 0.039) and progression after admission (odds ratio, 25.43; 95% confidence interval, 2.47-261.99; p = 0.007) were independently associated with poor prognosis in patients with IBZ infarcts. There were no differences in the progression rate and clinical outcomes, regardless of the presence of lesions in the ATL.

CONCLUSIONS

Our study suggests the existence of a distinct type of IBZ infarct characterized by accessory lesions in the ATL, which is associated with different arterial features but has a similar clinical course to IBZ infarcts without accessory lesions in the ATL.

[Cerebral deep vascular architectures and subcortical infarcts]

The lenticulostriate arteries (LSA) supply the lateral half of the head of the caudate nucleus, entire putamen, anterior limb, genu and the superior part of the internal capsule (IC) and a part of the corona radiata. The LSA consists with medial, intermediate and lateral branches. The medial branches perfuse the lateral segment of the globus pallidus, the head of the caudate nucleus and the anterior limb of the IC. The intermediate branches supply the anterior half of the LSA territory, while the lateral branches supply the posterior half. The anterior cerebral artery (ACA) perforators, predominantly Heubner's artery, perfuse the inferomedial part of the caudate head, the anteromedial part of putamen, the anterior part of the lateral segment of the globus pallidus and anterior limb of the internal capsule. Such territories can be represented by the anterior and ventral basal ganglions. The anterior choroidal artery (AChA) gives off three main groups of branches including the lateral branches that supply the medial temporal lobe, the medial branches that supply the cerebral peduncle and the superior branches that supply the internal capsule and the basal ganglia. The superior branches are further discriminated into proximal branches that supply the anterior one third of the posterior limb of internal capsule (PLIC) and the medial segment of the globus pallidus and distal branches that supply the posterior two-third of PLIC, retro-lenticular part of the internal capsule and the lateral thalamic nuclei. The superficial penetrating arteries, i.e. medullary arteries, arise from the cortical branches of the middle cerebral artery (MCA) and supply the deep white matter. Infarcts caused by the medullary artery occlusion are located in the centrum-semiovale and half of them were caused by embolic mechanism. The centrum-semiovale corresponds to cortical border-zone (BZ) while the corona radiate corresponds to internal BZ.

Hippocampal vascular reserve associated with cognitive performance and hippocampal volume

Medial temporal lobe dependent cognitive functions are highly vulnerable to hypoxia in the hippocampal region, yet little is known about the relationship between the richness of hippocampal vascular supply and cognition. Hippocampal vascularization patterns have been categorized into a mixed supply from both the posterior cerebral artery and the anterior choroidal artery or a single supply by the posterior cerebral artery only. Hippocampal arteries are small and affected by pathological changes when cerebral small vessel disease is present. We hypothesized, that hippocampal vascularization patterns may be important trait markers for vascular reserve and modulate (i) cognitive performance; (ii) structural hippocampal integrity; and (iii) the effect of cerebral small vessel disease on cognition. Using high-resolution 7 T time-of-flight angiography we manually classified hippocampal vascularization patterns in older adults with and without cerebral small vessel disease in vivo. The presence of a mixed supplied hippocampus was an advantage in several cognitive domains, including verbal list learning and global cognition. A mixed supplied hippocampus also was an advantage for verbal memory performance in cerebral small vessel disease. Voxel-based morphometry showed higher anterior hippocampal grey matter volume in mixed, compared to single supply. We discuss that a mixed hippocampal supply, as opposed to a single one, may increase the reliability of hippocampal blood supply and thereby provide a hippocampal vascular reserve that protects against cognitive impairment.

The anterior one third of the posterior limb of the internal capsule is also supplied by the anterior choroidal artery

PURPOSE

It is universally recognized that the anterior choroidal artery (AChA) supplies the posterior two-third of the posterior limb of internal capsule (PLIC). On the other hand, the blood supply to the anterior one third of the PLIC has remained undetermined. We posit the anterior one third of the PLIC is also supplied by the AChA referring the previous microsurgical descriptions.

METHODS

Ninety consecutive patients with isolated acute infarction in the PLIC were studied. We classified patients into 4 groups. 1. The anterior type that involved the anterior one-third part of the PLIC. 2. The posterior type that involved the caudal two-third part of the PLIC, 3. The combined type that located in the full length of the PLIC, 4. The dot type that restricted within PLIC up to10mm in diameter.

RESULTS

Patient numbers in groups 1 through 4 were 7 (7.7%), 46 (51.1%), 9 (10.6%) and 28 (31.1%). The anterior type involved the medial part of pallidum (MPP) in 5 patients (71.4%) and none in the lateral thalamus (LT), while the posterior type involved MPP only in 6 patients (13.0%) and LT in 33 patients (71.7%).

CONCLUSION

Corresponding to previous microsurgical descriptions, an occlusion of the proximal branches may cause anterior type infarct and that of the distal branches may cause posterior type infarcts. The anterior one third of the PLIC is also supplied by the branches of the AChA, albeit the low prevalence.

Acute middle cerebral artery stroke in a patient with a patent middle cerebral artery

Purpose of review

Knowledge of cerebrovascular anatomical variants is vital for clinicians working with patients presenting with signs and symptoms of cerebral infarction, particularly in the era of endovascular clot retrieval.

Recent findings

We provide an overview of a cerebrovascular anatomical variation and detail a patient presenting with cerebral infarction secondary to occlusion of their anomalous vessel who underwent successful endovascular clot retrieval with excellent functional outcome. We also include technical descriptions.

Summary

Given the clinical importance of the areas supplied by the accessory middle cerebral artery, knowledge of this vessel is not only important for diagnosis but also for neurosurgical or endovascular management of patients with this variant.

Imaging of Brain Infarctions: Beyond the Usual Territories

In this review, our intension is to present imaging features of several categories of uncommon cases of brain infarctions including infarctions associated with neurovascular variants, infarctions along small arterial territories, and brainstem stroke syndromes. Infarctions associated with neurovascular variants include azygos anterior cerebral artery territory infarction and artery of Percheron infarction. In the second group, we discuss anterior choroidal artery infarction and artery of Heubner infarction. The third group highlights brainstem stroke syndromes, including Claude and Benedikt syndromes due to midbrain infarction; Foville, Marie Foix, and locked-in syndromes due to pontine infarction; and Dejerine (medial medullary), bilateral medial medullary, and Wallenberg (lateral medullary) syndromes.

Treatment of Unruptured, Saccular, Anterior Choroidal Artery Aneurysms with Flow Diversion : A Single Centre Experience

Background

The region of the brain supplied by the anterior choroidal artery (AChoA) is exquisitely eloquent. Aneurysms arising at or close to the origin of the vessel are not uncommon and damage or occlusion to the vessel can result in devastating consequences. The optimal treatment strategy is yet to be determined.

Objective

We sought to determine the efficacy of flow diversion for the treatment of unruptured AChoA aneurysms.

Method

A retrospective review of our prospectively maintained database was performed to identify all patients with unruptured aneurysms of the AChoA between March 2009 and May 2017. The fundus size, number and type of flow-diverting stent (FD), complications and follow-up data were recorded.

Results

We identified 30 patients (60% female), average age 52.8 ± 10.8 years (range 27–73), with 30 aneurysms. The aneurysms were generally small with a mean fundus diameter of 3.4 mm (range 1–7 mm). Early angiographic follow-up data were available for all patients at which point 15 aneurysms were completely occluded (50%). Delayed angiographic follow-up was available in 24 patients and occlusion was seen in 21 patients (87.5%). Of the patients one developed transient ischemic symptoms after interruption of the antiplatelet medication and another patient had a small embolic infarct with transient symptoms in the periprocedural period.

Conclusion

Flow diversion can be used to successfully treat aneurysms of the AChoA. The treatment carries a high rate of technical and radiological success with a good safety profile.

Risks of Endoscopic Temporal Ventriculocisternostomy for Isolated Lateral Ventricle: Anatomic Surgical Nuances

BACKGROUND

Entrapment of the temporal horn, known as isolated lateral ventricle (ILV), is a rare type of noncommunicating focal hydrocephalus, and standard treatment has not been established. We report 2 cases of endoscopic surgery for ILV and highlight the anatomic surgical nuances to avoid associated surgical risks.

CASE DESCRIPTION

The first patient presented with recurrent ILV following initial shunt placement for ILV, owing to shunt malfunction. In the second patient, ILV recurred secondary to choroid plexus inflammation caused by cryptococcal infection. Endoscopic temporal ventriculocisternostomy was effective in both cases. However, in the second case, the choroidal fissure was fenestrated, which led to cerebral infarction in the territory of the choroidal artery zone, attributed to damage of the branches of the choroidal segment of the anterior choroidal artery.

CONCLUSIONS

Although endoscopic temporal ventriculocisternostomy is considered a safe and less invasive procedure for treatment of symptomatic ILV, the technique is still associated with risks. To avoid complications, it is necessary to be familiar with the anatomy of the choroidal arteries and the pertinent endoscopic intraventricular orientation. Additionally, sufficient experience is required before it can be recommended as the treatment of choice.

Perfusion Deficits and Association with Clinical Outcome in Patients with Anterior Choroidal Artery Stroke

BACKGROUND AND PURPOSE

Anterior choroidal artery (AChA) strokes have a varied pattern of tissue injury, prognosis, and clinical outcome. It is unclear whether perfusion deficit in AChA stroke is associated with the clinical outcome. This study aims to determine the frequency of perfusion abnormalities in AChA stroke and association with clinical outcome.

METHODS

The study cohort was derived from ischemic stroke patients admitted to 2 stroke centers between July 2001 and July 2014. All patients received an acute magnetic resonance imaging (MRI) scan. Patients with ischemic stroke restricted to the AChA territory were included in the study. Lesion size was measured as the largest diameter on diffusion-weighted imaging (DWI) or apparent diffusion coefficient and divided into 2 groups (<20 mm or ≥20 mm). Group comparisons were performed among patients with and without perfusion abnormalities and based on diffusion diameter. Favorable clinical outcome was defined as discharge to home.

RESULTS

A total of 120 patients were included in the study. Perfusion deficits were identified in 67% of patients. The admission National Institutes of Health Stroke Scale (NIHSS) was higher in patients with perfusion abnormalities (P = .027). Diameter lesion size on DWI was larger among patients with a perfusion deficit median [interquartile range], 1.63 [1.3-2.0], as compared with those without, 1.18 [1.0-1.7], P < .0001. Patients with a perfusion deficit were less likely to be discharged to home than those without (36% versus 60%, P = .013).

CONCLUSIONS

Two thirds of patients with an AChA stroke have a perfusion deficit on MRI, higher admission NIHSS, and larger DWI lesion size at presentation.

The cerebral circulation and cerebrovascular disease I: Anatomy

In this paper, which is the first in a three-part series that reviews cerebrovascular anatomy, pathogenesis, and stroke, we lay the anatomical foundation for the rest of the series. Beginning with its origin in the branches of the aorta, we start by describing the arterial system. This system is partitioned into two major divisions (anterior and posterior circulations) that differ significantly in features and pathogenic potential. The systems, and the major branches that comprise them, are described. Description of the arterial system proceeds to the point of the fulfillment of its function. This function, the exchange of gases and nutrients with the cerebral parenchyma, is the subject of a subsequent section on the microcirculation and blood-brain barrier. Finally, the cerebral venous system, which is composed of cerebral veins and dural venous sinuses, is described. Thus, an anatomical context is supplied for the discussion of cerebrovascular disease pathogenesis provided by our second paper.

Patency of the anterior choroidal artery covered with a flow-diverter stent

OBJECT

The concept of the flow-diverter stent (FDS) is to induce aneurysmal thrombosis while preserving the patency of the parent vessel and any covered branches. In some circumstances, it is impossible to avoid dangerously covering small branches, such as the anterior choroidal artery (AChA), with the stent. In this paper, the authors describe the clinical and angiographic effects of covering the AChA with an FDS.

METHODS

Between April 2011 and July 2013, 92 patients with intracranial aneurysms were treated with the use of FDSs in the authors’ institution. For 20 consecutive patients (21.7%) retrospectively included in this study, this involved the unavoidable covering of the AChA with a single FDS during endovascular therapy. AChAs feeding the choroid plexus were classified as the long-course group (14 cases), and those not feeding the choroid plexus were classified as the short-course group (6 cases). Clinical symptoms and the angiographic aspect of the AChA were evaluated immediately after stent delivery and during follow-up. Neurological examinations were performed to rule out hemiparesis, hemihypesthesia, hemianopsia, and other cortical signs.

RESULTS

FDS placement had no immediate effect on AChA blood flow. Data were obtained from 1-month clinical follow-up in all patients and from midterm angiographic follow-up in 17 patients (85.0%), with a mean length of 9.8 ± 5.4 months. No patient in either group complained of transient or permanent symptoms related to an AChA occlusion. In all cases, the AChA remained patent without any flow changes.

CONCLUSIONS

The results of this study suggest that when impossible to avoid, the AChA may be safely covered with a single FDS during intracranial aneurysm treatment, irrespective of anatomy and anastomoses.

Infarction in the anterior choroidal artery territory: clinical progression and prognosis factors

This study was undertaken to describe the still poorly known evolving profile of anterior choroidal artery (AChA) infarctions, identify their prognosis factors, and evaluate responses to intravenous (IV) thrombolysis. During 42 months, we prospectively enrolled patients with an isolated AChA stroke. Clinical and radiologic parameters were compared between patients with or without progression, defined as any clinical worsening. Factors associated with poor outcome (dependence or death) were tested, and IV thrombolysis responses were assessed. For the 100 of 1234 (8.1%) analyzed patients with AChA stroke (predominantly lacunar syndrome [88%]), mean admission and maximum National Institutes of Health Stroke Scale (NIHSS) scores were 4.4 and 5.2, respectively. Arterial hypertension (78%) and diabetes (30%) were the main vascular risk factors. Despite low 3-month mortality (3%), 26% of the patients were dependent; 46 patients with progressive stroke (over 56 ± 56 hours, 1.6 mean successive plateaus) had higher risks of dependence (P < .0001). An acute-phase NIHSS score of 6 or more significantly increased the risk of poor outcome (P < .0001). Maximum NIHSS score and progression were independently associated with poor outcome. Among 21 patients given IV thrombolysis, 12 AChA strokes continued to progress, leaving 8 disabled at 3 months. Almost half of AChA strokes progress during the first 2 to 3 days. Maximum acute-phase NIHSS scores and progression were independently associated with poor outcome, also strongly predicted by an NIHSS score of 6 or more at any time. Our unconvincing experience with IV thrombolysis means new therapeutic options and trials are needed, especially for patients with clinical progression and/or NIHSS score of 6 or more.

Microsurgical anatomy of the cisternal anterior choroidal artery with special emphasis on the preoptic and postoptic subdivisions

Object

The object of this study was to delineate the microsurgical anatomy of the cisternal segment of the anterior choroidal artery (AChA). The authors also propose a new classification of this segment on the basis of its complicated course within the carotid and crural cisterns in relation to important neurovascular structures, and the site of origin, course, and areas of supply of perforating arteries.

Methods

Thirty cadaveric cerebral hemispheres injected with colored latex were dissected under surgical magnification to view the cisternal segment of the AChA and its perforators. Fiber dissections using the Klingler technique were performed in two additional latex injected hemispheres to follow the penetration points, courses, and terminal areas of supply of perforating branches that arise from the cisternal segment of the AChA.

Results

The cisternal segment of the AChA was divided into pre- and postoptic parts that meet at the artery's genu, the most medial extension point of the cisternal segment where the artery makes an abrupt turn after passing under the optic tract. The preoptic part of the AChA extended from its origin at the inferomedial side of the internal carotid artery to the artery's genu, which is commonly located just inferomedial to the initial part of the optic tract. The postoptic part coursed within the crural cistern and extended from the genu to the inferior choroidal point. The genu of the AChA was 8 mm medial to the artery's origin and was located medial to the optic tract in 13% of the hemispheres. The postoptic part was longer than the preoptic part in all hemispheres and had more perforating arteries supplying critical deep structures (preoptic 3.4 per hemisphere vs postoptic 4.6 per hemisphere), and these results were statistically significant (p = 0.01). At the preoptic part, perforating arteries arose from the superolateral portion of the artery and coursed laterally; at the postoptic part, perforators arose from the inferomedial portion of the artery and coursed medially. Perforating arteries from both segments passed most commonly to the optic tract, followed by the anterior segment and apex of uncus in the preoptic part and the cerebral peduncle in the postoptic part.

Conclusions

Both parts of the cisternal segment of the AChA come into surgical view during surgeries for different pathologies in and around the perimesencephalic cisterns. However, attending to the artery's genu and defining pre- and postoptic parts during surgery may help the surgeon locate the origin and eventual course of these perforators, and even estimate the terminal areas of supply of most of the perforating arteries. The proposed classification system can prove helpful in planning any operative procedure along the crural cistern and may reduce the probability of inadvertent injury to perforating branches of the cisternal segment.

Acute ischemic stroke in anterior choroidal artery territory

OBJECTIVE

The aim of the study was to describe a series of patients with acute ischemic infarct in the anterior choroidal artery (AChA) territory. Moreover, we analyzed the prevalence of these strokes and compared them with hemispheric and deep infarcts. Finally, we hypothesized that the size of the infarct could be related to aetiology and prognosis.

METHODS

We studied a prospective series of 1350 patients with acute ischemic stroke. We analyzed the following factors: age, gender, diabetes mellitus, hypertension, hyperlipidaemia, current smoking, ischemic heart disease, previous stroke, peripheral arterial disease, prior antithrombotic treatment, major cardioembolic source, severe arterial stenosis, initial severity, progression, mortality, disability, and recurrence rate at three months. AChA strokes were classified as small (<20 mm) or large (>or=20 mm), as measured by diffusion-weighted MRI, and compared by size in the analysis.

RESULTS

112 patients (8.3%) had an ischemic lesion restricted to the AChA territory (large: 42 patients, small: 70 patients). Patients with AChA infarcts were younger, more likely to be diabetic, and predominantly male. We found significant differences in the rate of major embolic sources, recurrence, progression and prognosis. Large AChA strokes were associated with embolic pathologies and had worse prognosis than small AChA strokes.

INTERPRETATION

Infarcts in the AChA territory have different aetiological mechanisms and outcome than other territories. Large AChA infarcts have a higher association with an embolic source and worse prognosis than small lesions.

Contribution of right hemisphere to visual imagery: a visual working memory impairment?

Visual Imagery is the ability to generate mental images in the absence of perception, that is, We describe a patient, IM, who suffered from an acute ischemic stroke in the right anterior choroidal artery who appeared to demonstrate relatively isolated impairment in visual imagery. Her cognitive function, including her performance on tests of semantic function, was at ceiling, apart from a deficit in visual memory. IM failed in tasks involving degraded stimuli, object decision involving reality judgments on normal animals, and drawings from memory. By contrast, she was able to match objects seen from an unfamiliar viewpoint and to perform tasks of semantic and visual association. We hypothesize that IM has a visual working memory deficit that impairs her ability to generate full visual representations of objects given their names, individual feature, or partial representations. The deficit appears to be the result of damage to connections between the right thalamus and the right temporal lobe. Our findings may help to clarify the role of the thalamus in the cortical selective engagement processes that underlie working memory.

Anterior choroidal artery infarction: a clinical, etiologic and prognostic study

OBJECTIVES

To analyze the clinical, etiologic and prognostic profile of anterior choroidal artery (AChA) infarcts.

METHODS

42 consecutive patients with AChA infarction were included. Symptoms, etiology and scores on neurological and functional scales were analyzed on admission, discharge and at 3-month follow-up. A comparative study was performed between deep (n = 23) and deep + superficial (n = 19) infarcts.

RESULTS

Lacunar syndrome was present in 83.3% of patients. Etiology was large-vessel disease in 38.1% and cryptogenic in 38.1%. Ten patients had a National Institute of Health Stroke Scale score >7 on admission. At discharge, 45.3% had an modified Rankin Scale >2 (35.7% after 3 months). Infarcts involving superficial territory were more severe at admission (P = 0.034) and were associated with a worse functional status at discharge (P = 0.0008).

CONCLUSION

AChA infarcts usually present with lacunar syndrome, although they are often not lacunar infarcts. At discharge, almost half of the patients are dependent in their activities of daily living, and most remain so at 3-month follow-up. Infarcts involving superficial territory are associated with worse prognosis.