TIA patients with higher ABCD3-I scores are prone to a higher incidence of intracranial stenosis, unstable carotid plaques and multiple-vessel involvement

The ABCD3-I criteria have proved to be effective for use in regular clinical practice to assist in transient ischemic attack (TIA) risk stratification and treatment. In this prospective study we aimed to explore the relationships between risk stratification and arterial stenosis location, carotid plaque morphology and vessel involvement in 90 TIA patients, stratifying risk by ABCD3-I scores. Clinical variables such as total cholesterol, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin, homocysteine and high-sensitive C-reactive protein levels were recorded. The endpoint was subsequent stroke at seven-day follow-up. Ninety patients were divided into three risk groups on the basis of their ABCD3-I scores. The results revealed that patients with higher ABCD3-I scores showed a higher occurrence of intracranial stenosis (P < 0.05), less organized carotid plaques (P < 0.05) and multiple-vessel involvement (P < 0.05).

Specific Factors to Predict Large-Vessel Occlusion in Acute Stroke Patients

BACKGROUND

The effectiveness of thrombectomy for acute ischemic stroke has been established, and earlier treatment produces better outcomes. If possible to identify large-vessel occlusion (LVO) at the prehospital phase, eligible patients can be shipped directly to a hospital that can perform thrombectomy. The purpose of this study was to determine factors that are specific to LVO and can be known before hospital arrival.

METHODS

The subjects were stroke patients during the period between July 2014 and June 2016, who had a National Institutes of Health Stroke Scale (NIHSS) score of 8 or higher and came to our hospital within 6 hours of onset. These patients were divided into an LVO group and a non-LVO group, and background factors, mode of onset, individual NIHSS item scores, and blood pressure at the time of the visit were retrospectively investigated. The selected factors were compared with LVO prediction scales reported in the past.

RESULTS

There were 196 stroke patients who had NIHSS scores of 8 or higher and arrived at the hospital within 6 hours. Of these 196 patients, 56 had LVO. This LVO group included a significantly higher number of patients with the 2 items of atrial fibrillation (odds ratio [OR], 11.5: 95% confidence interval [CI], 4.04-32.9; P < .0001) and systolic blood pressure of 170 mm Hg or lower (OR, 2.99: 95% CI, 1.33-6.71, P = .008). These 2 items predicted LVO equally to existing LVO prediction scales.

CONCLUSIONS

The 2 items of atrial fibrillation and systolic blood pressure of 170 mm Hg or lower were significantly correlated with LVO.

Non-Atherosclerotic Intracranial Arterial Diseases

Atherosclerosis is not the only cause of intracranial arterial disease. Arterial dissection, moyamoya disease, vascular inflammatory disease, vasospasm and immunologic disorders are important non-atherosclerotic intracranial arterial diseases. Identification of the correct etiology is important in establishing treatment strategies and assessing prognosis. Careful history taking and appropriate laboratory testing are essential. Although catheter angiography is the most important diagnostic tool to examine various intracranial arterial diseases, other diagnostic modalities such as CT angiography and MR angiography are nowadays widely used. High resolution vessel wall MRI also can assist in making the correct diagnosis as this can yield information regarding vessel wall pathology. Certain diseases such as infectious vasculopathies and moyamoya disease are more prevalent in certain parts of the world, and physicians practicing in these regions should be mindful of these disorders. In this chapter, these non-atherosclerotic intracranial arterial diseases are discussed. Moyamoya disease will be described in another chapter.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

Magnetic resonance angiography signal intensity as a marker of hemodynamic impairment in intracranial arterial stenosis

Background

Intracranial arterial stenosis (ICAS) is the predominant cause of ischemic stroke and transient ischemic attack in Asia. Change of signal intensities (SI) across an ICAS on magnetic resonance angiography (MRA) may reflect its hemodynamic severity.

Methods

In-patients with a symptomatic single ICAS detected on 3D time-of-flight MRA were recruited from 2 hospitals. Baseline and 1-year follow-up data were collected. Signal intensity ratio (SIR) [ =  (mean post-stenotic SI -mean background SI)/(mean pre-stenotic SI - mean background SI)] was evaluated on baseline MRA to represent change of SIs across an ICAS. Acute infarct volume was measured on baseline diffusion-weighted images (DWI). Relationships between SIR and baseline characteristics as well as 1y outcomes were evaluated.

Results

Thirty-six subjects (86.1% males, mean age 55.0) were recruited. Overall, mean SIR was 0.84±0.23. Mean SIRs were not significantly different between the 23 (63.9%) anatomically severe stenoses and the 13 (36.1%) anatomically moderate stenoses (0.80±0.23 versus 0.92±0.21, p = 0.126). SIR was significantly, linearly and negatively correlated to acute infarct volume on DWI (Spearman correlation coefficient −0.471, p = 0.011). Two patients (5.6%) had recurrent ischemic strokes at 1y, not related to SIR values.

Conclusions

Change of signal intensities across an ICAS on MRA may reflect its hemodynamic and functional severity. Future studies are warranted to further verify the relationships between this index and prognosis of patients with symptomatic ICAS.

Intracranial artery stenosis or occlusion predicts ischemic recurrence after transient ischemic attack

BACKGROUND AND PURPOSE

Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA.

MATERIALS AND METHODS

We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis).

RESULTS

Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04).

CONCLUSIONS

Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.

[Intracerebral haemorrhage, arterial ischaemic stroke, and cerebral sinovenous thrombosis in children]

We describe the risk factors and treatment recommendations of intracerebral haemorrhage, arterial ischaemic stroke, and cerebral sinovenous thrombosis in childhood. The aetiology in children differ a lot from the aetiology in adults, hence guidelines specifically for children have been written. These guidelines build mainly on expert opinions, since only few evidence-based studies exist. Paediatric stroke is one of the major causes of lifelong disability, and the high costs to the families and the society make further research very important.

Intracranial arterial dissections in ischemic stroke assessed by 3D rotational angiography

BACKGROUND

Dissections involving intracranial arteries are sometimes difficult to assess using conventional digital subtraction angiography (DSA). We evaluated the value of three-dimensional rotational angiography (3D-RA) for the assessment of intracranial arterial dissections (ICADs).

METHODS

The subjects were 39 patients (26 males, 13 females; average age 50+/-15years) who were diagnosed as having ICADs and who underwent both DSA and 3D-RA in our hospital between April 1999 and March 2005. We retrospectively compared 3D-RA images to conventional DSA images in a blinded manner with respect to double lumen sign, pearl and string sign, string sign, and aneurysmal dilatation. On the basis of the caliber size of the artery affected by dissections, we divided patients into two groups: smaller artery group (S group) and larger artery group (L group).

RESULTS

The detection rate of double lumen sign with 3D-RA (79%) was significantly higher than with conventional DSA (18%; P<0.001). Reliable findings of arterial dissections (double lumen sign and/or pearl and string sign) were observed more often with 3D-RA (90%) than with conventional DSA (36%; P<0.001). In S group, the double lumen sign was detected only with 3D-RA.

CONCLUSIONS

3D-RA allows increased conspicuity of ICADs findings with conventional DSA, especially in smaller-caliber intracranial arteries.

Abrupt-onset severe headaches

Thunderclap headache, a severe headache which is maximal in intensity at onset, is associated with numerous underlying disorders, including subarachnoid hemorrhage, unruptured intracranial aneurysm, cervical artery dissection, cerebral venous sinus thrombosis, stroke, intracranial hemorrhage, reversible cerebral vasoconstriction syndrome, and reversible posterior leukoencephalopathy. After exclusion of all possible causes, thunderclap headache may be considered a primary headache. This review summarizes the diagnostic considerations and clinical approach to thunderclap headache, with particular emphasis on the reversible cerebral vasoconstriction syndromes.

Traumatic pseudoaneurysm of the occipital artery: case report and review of the literature

Only 3 cases of traumatic pseudoaneurysm of the occipital artery have been reported since 1644. We report a fourth case, which occurred in an 85-year-old woman who experienced a blunt trauma during a fall. The pseudoaneurysm resolved without surgical intervention. We also review the literature on traumatic pseudoaneurysms, as well as true aneurysms, of the external carotid system, with emphasis on current diagnostic and therapeutic options.

Perivascular spaces: normal and giant

The purpose of this paper is to discuss both normal perivascular spaces (PVSs) and pathological giant perivascular spaces (GPVSs). The anatomy and physiology of normal PVSs, including important immunological and lymphatic roles, are described. Special attention is given to the Magnetic Resonance Imaging (MRI) findings of both normal and GPVSs. Furthermore, the clinical features and pathogenesis of GPVSs are explored, with special emphasis on the pathological implications of these lesions, and their relevance. It is important that symptomatic GPVSs not be mistaken for more devastating disease processes. When the lesions in question occur in a characteristic location along the path of a penetrating vessel, are isointense with cerebrospinal fluid on all MRI sequences, do not enhance with contrast material, are not calcified, and have normal adjacent brain parenchyma, their appearance is pathognomonic of GPVSs. The clinician should realize that an extensive differential diagnosis is superfluous and that biopsy is unnecessary in these patients. Instead, the clinical focus should be aimed at neurosurgical intervention, as dictated by the symptoms of mass effect.

CT angiography in the evaluation of intracranial occlusive disease with collateral circulation: comparison with MR angiography

The purpose of this study is to determine whether three-dimensional computed tomography angiography (CTA) is superior to magnetic resonance angiography (MRA) in the evaluation of collateral circulation in patients with intracranial arterial occlusive disease. Conventional angiography was used as the standard reference. Collateral vessels were well visualized by CTA, but not by MRA, while conventional angiography revealed leptomeningeal collateral vessels that were filled in a retrograde fashion. CTA is superior to MRA for evaluating collateral vessels.

Intracranial arterial aneurysm vasculopathies: targeting the outer vessel wall

The pathogenesis of intracranial arterial aneurysms (AA) remains unclear, despite their clinical importance. An improved understanding of this disease is important in choosing therapeutic options. In addition to the "classical" berry-type aneurysm, there are various other types of intracranial AA such as infectious, dissecting or giant, partially-thrombosed aneurysms. From the clinician's perspective, the hypothesis that some of these intracranial AA might be due to abluminal factors has been proposed for several years. Indeed, this hypothesis and the empirical use of anti-inflammatory drugs in giant intracranial aneurysms have been confirmed by recent studies reporting that an enzyme involved in the inflammatory cascade (5-lipoxygenase or 5-LO) promotes the pathogenesis of specific aneurysms in humans. 5-LO generates different forms of leukotrienes which are potent mediators of inflammation. Adventitial inflammation leads to a weakening of the media from the abluminal part of the vessel wall due to the release of proinflammatory factors that invade the media, thereby degrading the extracellular matrix, the elastic lamina of the vascular wall, and, finally, the integrity of the vessel lumen. This in turn results in a dilation of the vessel and aneurysm formation. Moreover, neoangiogenesis of vasa vasorum is found in close proximity to 5-LO activated macrophages. In addition to this biological cascade, we argue that repeated subadventitial haemorrhages from the new vasa vasorum play an important role in aneurysm pathogenesis, due to a progressive increase in size mediated by the apposition of new layers of intramural haematoma within the vessel wall. Intracranial giant AA can therefore be regarded as a proliferative disease of the vessel wall induced by extravascular activity. Considering certain aneurysmal vasculopathies as an abluminal disease might alter current therapeutic strategies. Therapy should not only be aimed at the intraluminal repair of the artery, but also cross the vessel wall to reach the vasa vasorum. Drug-eluting stents placed proximal to the lesion and targeted to the origin of the vasa vasorum could be considered as a potential future option. "Intelligent" MRI contrast agents (i.e., macrophage marking) could be used to detect vasa vasorum proliferation and weakening of the vessel wall in vivo.

Visualization of intracranial vessel anatomy using high resolution MRI and a simple image fusion technique

A new technique for fusion and 3D viewing of high resolution magnetic resonance (MR) angiography and morphological MR sequences is reported. Scanning and image fusion was possible within 20 min on a standard 1.5 T MR-scanner. The procedure was successfully performed in 10 consecutive cases with excellent visualization of wall and luminal aspects of the intracranial segments of the internal carotid artery, the vertebrobasilar system and the anterior, middle and posterior cerebral artery.

Quand, comment et pourquoi réaliser une imagerie des carotides extracrâniennes ?

The indications for treating carotid artery stenosis are related to the symptomatic nature of the lesion and the degree of stenosis. Duplex sonography is adequate for screening. While some groups believe that Duplex US alone or in combination with transcranial Doppler imaging may be sufficient for presurgical evaluation, it often is recommended to complete the evaluation with either MRA or CTA. Both techniques are advantageous since they allow evaluation of the cervical and intracranial arteries as well as cerebral parenchyma hence providing valuable information prior to definitive management. Catheter angiography remains indicated in patients with multi-vessel disease and ischemic cardiomyopathy, when results at non-invasive evaluation are discordant or in an emergency setting. Duplex US is used for routine follow-up of non-surgical lesions and after endarterectomy. Transcranial Doppler as well as advances in MRA and CTA techniques will be reviewed. Even though the treatment of atherosclerotic carotid artery stenoses remains primarily surgical, specific considerations related to angioplasty will be reviewed. Finally, diseases of the intracranial carotid artery and non-atherosclerotic diseases (dissection...) will also be discussed.

Intracranial arterial dolichoectasia and its relation with atherosclerosis and stroke subtype

OBJECTIVE

To investigate the relationship between intracranial arterial dolichoectasia (IADE) and vascular risk factors, atherosclerosis of the carotid arteries as measured by ultrasound scan, and stroke subtypes.

METHODS

The sample consists of 510 consecutively recruited patients with brain infarction confirmed by MRI. The diagnosis of IADE was made by consensus between two neurologists based on MRI results. An independent reading of the 510 scans was made, with measurement of the diameter of the seven main intracranial arteries with a 16-diopter lens to validate the consensus and to better characterize patients with IADE.

RESULTS

Sixty-three IADE(+) patients were identified by consensus (12%), of whom 59 (94%) had at least one intracranial artery in the fourth quartile of the distribution of diameters of intracranial arteries. Multivariate analyses found an association between IADE(+) and age (OR [95% CI] 1.04 [1.01-1.08]), male sex (3.31 [1.67-6.55]), hypertension (1.94 [1.01-3.72]), and previous myocardial infarction (2.68 [1.33-5.38]). There was no association between IADE and carotid atherosclerosis markers such as plaque or intima-media thickening. Lacunar infarct was more frequent in patients with IADE (36% versus 19%), with an adjusted OR of 2.89 (95% CI 1.29-6.46) compared with atherothrombotic infarct.

CONCLUSIONS

IADE was associated with vascular risk factors such as age, male sex, hypertension, previous history of myocardial infarction, and lacunar infarct, but not with carotid atherosclerosis.

Recurrent Thromboembolism in Infants and Children Suffering From Symptomatic Neonatal Arterial Stroke

Background and Purpose— The present study was performed to evaluate the rate of recurrent symptomatic thromboembolism with respect to prothrombotic risk factors and underlying clinical conditions.

Methods— In a series of 215 consecutively enrolled neonates with arterial ischemic stroke (AIS), the factor V G1691A mutation, factor II G20210A variant, methylenetetrahydrofolate reductase (MTHFR) T677T genotype, lipoprotein (Lp) (a), antithrombin, protein C, protein S, and anticardiolipin antibodies (ACA) were investigated. Patient median follow-up was 3.5 years (range, 1 to 8 years).

Results— During follow-up, 7 infants and children (3.3%) showed recurrent symptomatic thromboembolism (AIS, n=4; venous sinus thrombosis, n=2; deep vein thrombosis of the leg, n=1). The factor V mutation, factor II variant, elevated Lp(a) >30 mg/dL, protein C deficiency, and protein S or antithrombin deficiency were associated with first stroke onset. In 5 of 7 cases (71.4%), prothrombotic risk factors [MTHFR T677T, elevated Lp(a), hyperhomocysteinemia, protein C deficiency] were involved at the time of recurrence. Furthermore, a second thromboembolic event was triggered additionally by underlying diseases (71%), eg, cardiac malformation and immobilization, diarrhea, mastoiditis, and moyamoya syndrome.

Conclusions— Data shown here give evidence that symptomatic recurrent thromboembolism is not common in children with neonatal AIS. The risk of a second event, however, is increased when underlying diseases occur and prothrombotic risk factors are involved.

Variations of the superior cerebellar artery: MR angiographic demonstration

PURPOSE

The purpose of this study was to describe variations of the proximal segments of the superior cerebellar artery (SCA) detected by magnetic resonance (MR) angiography.

MATERIALS AND METHODS

We reviewed 145 consecutive MR angiograms. All patients were studied with a 1.5-Tesla imager using the three-dimensional time-of-flight technique.

RESULTS

There were 16 duplicated SCAs in 13 patients, seven SCAs originating from the posterior cerebral arteries in six patients, four early bifurcations of the SCAs in four patients, and one SCA arising from the internal carotid artery. Because the SCA is small in caliber, the bilateral SCAs in nine patients could not be identified on MR angiograms owing to patient movement. In two patients with duplicated SCA, one of the duplicated trunks compressed the trigeminal nerve at the root entry zone, resulting in trigeminal neuralgia.

CONCLUSION

Although most of these SCA variations have no clinical significance, preoperative identification of SCA variations is important for avoiding complications during surgery and/or for interventional procedures of the distal basilar artery.

Intracranial giant cell arteritis with fatal middle cerebral artery territory infarct

A 37 year-old man who developed a fatal middle cerebral territory infarct was found at autopsy, to have widespread granulomatous angiitis involving meningeal and intracranial--extracerebral vessels but not intracerebral vessels or other extra-cranial vessels. The findings are unique and overlap with those of granulomatous angiitis of the nervous system (GANS) and classic giant cell arteritis (GCA). A possible precipitant for this devastating illness was a recent Chlamydia infection. The salient clinical and pathologic differences between GANS and GCA of the nervous system are discussed.

Investigation of cerebrovascular disease with MR angiography: comparison of volume rendering and maximum intensity projection algorithms--initial assessment

We assessed the clinical utility of the volume-rendering (VR) algorithm as a postprocessing technique of intracranial magnetic resonance angiography (MRA) for the evaluation of cerebrovascular disease in comparison with the maximum intensity projection (MIP) algorithm. VR and MIP images were compared with digital subtraction angiography (DSA). Volume-rendered views improved the perceptibility of intracranial vasculature and consequently augmented diagnostic confidence, improved the characterization of underlying vascular pathologies, and facilitated image interpretation. Volume rendering has the potential to expand the role of cerebral MRA in the diagnostic investigation and treatment planning of cerebrovascular disease.

Sudden deafness and anterior inferior cerebellar artery infarction

BACKGROUND AND PURPOSE

Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery (AICA) is known to be associated with vertigo, nystagmus, facial weakness, and gait ataxia. Few reports have carefully examined the deafness associated with the AICA infarction. Furthermore, previous neurological reports have not emphasized the inner ear as a localization of sudden deafness. The aim of this study was to investigate the incidence of deafness associated with the AICA infarction and the sites predominantly involved in deafness.

METHODS

Over 2 years, we prospectively identified 12 consecutive patients with unilateral AICA infarction diagnosed by brain MRI. Pure-tone audiogram, speech discrimination testing, stapedial reflex testing, and auditory brainstem response were performed to localize the site of lesion in the auditory pathways. Electronystagmography was also performed to evaluate the function of the vestibular system.

RESULTS

The most common affected site on brain MRI was the middle cerebellar peduncle (n=11). Four patients had vertigo and/or acute auditory symptoms such as hearing loss or tinnitus as an isolated manifestation from 1 day to 2 months before infarction. Audiological testings confirmed sensorineural hearing loss in 11 patients (92%), predominantly cochlear in 6 patients, retrocochlear in 1 patient, and combined on the affected side cochlear and retrocochlear in 4 patients. Electronystagmography demonstrated no response to caloric stimulation in 10 patients (83%).

CONCLUSIONS

In our series, sudden deafness was an important sign for the diagnosis of AICA infarction. Audiological examinations suggest that sudden deafness in AICA infarction is usually due to dysfunction of the cochlea resulting from ischemia to the inner ear.

Advances in non-invasive imaging of intracranial vascular disease

Intra-arterial catheter angiography has, in the past, been the mainstay for the investigation of intracranial vascular disease. It is, however, invasive, usually requires in-patients admission, and is associated with a rate of neurological complications between 1% and 3%. In recent years, magnetic resonance angiography (MRA) and CT angiography (CTA) have emerged as non-invasive alternatives for imaging blood vessels and have made a significant impact on neuroradiological investigations. It is the purpose of this article to explain the basic technical principles of these two methods and to give an overview of their current clinical applications.

3D TOF turbo MR angiography for intracranial arteries: phantom and clinical studies

This work investigated whether turbo magnetic resonance angiography (MRA) can replace conventional MRA in screening examination of intracranial arteries. A phantom was used to evaluate the effect of the zero-filling interpolation (ZFI) technique on spatial resolution and partial volume effect. Thirty-one consecutive patients underwent both turbo MRA with a slice thickness of 0.7 mm (data were measured as 1.33 mm sections) and conventional MRA with 1.0 mm sections. In the phantom studies, ZFI did not improve the spatial resolution, but the partial volume effect was somewhat reduced. In the clinical evaluation, turbo MRA showed better signal-to-noise and contrast-to-noise ratios of the intracranial major vessels than conventional MRA. The lesions included cerebral aneurysms less than 3 mm in diameter, occlusive vascular disease, arteriovenous malformations, and arteriovenous fistulas. These were all depicted on both turbo MRA and conventional MRA. Turbo MRA is a useful screening procedure because of its capability of delineating lesions in approximately half the usual imaging time. J. Magn. Reson. Imaging 1999;10:939-944.