Showered Calcific Emboli to the Brain, the ‘Salted Pretzel’ Sign, Originating From the Ipsilateral Internal Carotid Artery Causing Acute Cerebral Infarction

Persistent intracranial steno-occlusion from calcified embolism: a treatment challenge

INTRODUCTION

Calcified arterial cerebral embolism is a rare occurrence among large and medium vessel occlusions causing ischemic stroke and its diagnosis and treatment is a challenge. The sources of calcified embolism might be a calcific atheroma from the aortic arch and carotid artery, but also heart valve disease has been reported in the literature. Calcified embolism is frequently simultaneous on multiple vascular territories. The prognosis of patients is usually poor, including patients treated by using endovascular thrombectomy (EVT) and this diagnosis could be easily missed in the acute phase. In addition, the optimal secondary prevention has not been yet fully stated.

METHODS

We are presenting two cases of acute stroke due to calcified embolism in the middle cerebral artery (MCA) coming from a complicated carotid atheroma, non-stenosing in the first case (a 49 years old man) and stenosing in the second case (a 71 years old man) without clinical indications to intravenous thrombolysis and/or EVT, extensively investigated in the acute phase and followed-up for over 12 months with a favorable clinical course and the persisting steno-occlusion in the involved MCA. In both cases, antiplatelet treatment and targeting of vascular risk factors were done without recurrences in the follow-up period.

DISCUSSION

Cerebral calcified embolism has been reported in 5.9% of cases of acute ischemic stroke in a single center series and only in 1.2% of a large retrospective cohort of EVT-treated patients. In both series the prognosis was poor and only one third of EVT-treated patients had functional independence at 3-months follow-up. The natural history of these subtype of ischemic stroke is relatively poorly understood and both etiological diagnosis and treatment have not yet defined. It is possible that some cases might be underdiagnosed and underreported.

CONCLUSIONS

Calcified cerebral embolism is a rare cause of stroke, but it is largely underreported and both acute phase and secondary preventive treatment have to be defined.

Spontaneous calcified cerebral emboli: a comprehensive review and proposed diagnostic criteria

Spontaneous calcified cerebral emboli (SCCE) secondary to aortic valve calcification are a rare and underreported cause of acute ischaemic stroke. Only five cases of SCCE secondary to bicuspid aortic valve calcification have been reported in the literature. This review includes a unique case example of acute ischaemic stroke secondary to SCCE, as the first manifestation of a calcified bicuspid aortic valve. This is the first clinical case of calcified cerebral emboli (CCE) associated with borderzone infarction ('cortical ribbon sign'). Whilst previously assumed that most CCE are secondary to iatrogenic causes, recent literature suggests the majority of CCE are spontaneous and clinically silent. Despite CT imaging widely considered the 'gold standard' for diagnosis, CCE are frequently misdiagnosed and missed entirely. Misdiagnosis of CCE may have catastrophic consequences due to the high risk of recurrence and missed opportunity to prevent neurological disability and death. This review presents a revised CCE diagnostic criteria, using evidence that has emerged over the last decade to create both Compulsory (Major) and Supporting (Minor) criteria. Current CCE management is not evidence based and remains largely speculative. SCCE may be the first manifestation of cardiac or vascular disease and diagnosis should trigger aggressive treatment of emboligenic sources. Future epidemiological studies, analysing symptomatic and asymptomatic SCCE patients, would be beneficial in providing accurate quantification of disease burden. Other future research directions include exploring intracranial stenting for CCE revascularisation and cerebral intravascular lithotripsy.

Successful Recanalization by Intravenous Thrombolysis in a Patient With Calcified Cerebral Emboli With Major Vessel Occlusion: A Case Report

A 69-year-old man, with a history of left superficial temporal artery-middle cerebral artery bypass due to cerebral infarction by left internal carotid artery occlusion, was hospitalized with acute right hemispatial neglect and left hemiparesis. Diffusion-weighted imaging showed a high-intensity lesion in the right insular cortex. Although there seemed to be no arterial occlusion in magnetic resonance angiography (MRA), non-contrast computed tomography (CT) on admission showed calcification in the right Sylvian fissure. As hyperacute ischemic stroke within 4.5 hours after onset, we used an intravenous recombinant tissue plasminogen activator, and his symptoms improved. Follow-up MRA revealed recanalization of the right M2 branches with distal migration of calcification. Although calcification was identified on non-contrast CT in the initial assessment, the diagnosis of middle cerebral artery occlusion was missed. Therefore, arterial occlusion should be considered when calcification is observed in the brain sulcus. This case also illustrated that intravenous thrombolysis may be effective even in calcified cerebral emboli with major vessel occlusion.

Preprocedural Imaging : A Review of Different Radiological Factors Affecting the Outcome of Thrombectomy

BACKGROUND

Endovascular treatment (EVT) has strong evidence for its effectiveness in treatment of acute ischemic stroke (AIS); however, up to half of the patients who undergo EVT still do not have good functional outcomes. Various prethrombectomy radiological factors have been shown to be associated with good clinical outcomes and may be the key to better functional outcomes, reduced complications, and reduced mortality. In this paper, we reviewed the current literature on these imaging parameters so they can be employed to better estimate the probability of procedural success, therefore allowing for more effective preprocedural planning of EVT strategies. We reviewed articles in the literature related to imaging factors which have been shown to be associated with EVT success. The factors which are reviewed in this paper included: anatomical factors such as 1) the type of aortic arch and its characteristics, 2) the characteristics of the thrombus such as length, clot burden, permeability, location, 3) the middle cerebral artery features including the tortuosity and underlying intracranial stenosis, 4) perfusion scans estimating the volume of infarct and the penumbra and 5) the effect of collaterals on the procedure. The prognostic effect of each factor on the successful outcome of EVT is described. The identification of preprocedural thrombectomy imaging factors can help to improve the chances of recanalization, functional outcomes, and mortality. It allows the interventionist to make time-sensitive decisions in the treatment of acute ischemic stroke.

Development of an in vitro model of calcified cerebral emboli in acute ischemic stroke for mechanical thrombectomy evaluation

: ​ BACKGROUND: Calcified cerebral emboli (CCEs) are a rare cause of acute ischemic stroke (AIS) and are frequently associated with poor outcomes. The presence of dense calcified material enables reliable identification of CCEs using non-contrast CT. However, recanalization rates with the available mechanical thrombectomy (MT) devices remain low. OBJECTIVE: To recreate a large vessel occlusion involving a CCE using an in vitro silicone model of the intracranial vessels and to demonstrate the feasability of this model to test different endovascular strategies to recanalize an occlusion of the M1 segment of the middle cerebral artery (MCA). : ​ METHODS: An in vitro model was developed to evaluate different endovascular treatment approaches using contemporary devices in the M1 segment of the MCA. The in vitro model consisted of a CCE analog placed in a silicone neurovascular model. Development of an appropriate CCE analog was based on characterization of human calcified tissues that represent likely sources of CCEs. Feasibility of the model was demonstrated in a small number of MT devices using four common procedural techniques. : ​ RESULTS: CCE analogs were developed with similar mechanical behavior to that of ex vivo calcified material. The in vitro model was evaluated with various MT techniques and devices to show feasibility of the model. In this limited evaluation, the most successful retrieval approach was performed with a stent retriever combined with local aspiration through a distal access catheter, and importantly, with flow arrest and dual aspiration using a balloon guide catheter. : ​ CONCLUSION: Characterization of calcified tissues, which are likely sources of CCEs, has shown that CCEs are considerably stiffer than thrombus. This highlights the need for a different in vitro AIS model for CCEs than those used for thromboemboli. Consequentially, an in vitro AIS model representative of a CCE occlusion in the M1 segment of the MCA has been developed.

Calcified cerebral emboli: Incidence and implications

INTRODUCTION

Calcified cerebral emboli are an increasingly recognized cause of ischaemic stroke, although recognition amongst general radiologists and clinicians can be limited. Recent literature suggests that calcified cerebral emboli are likely more common than originally thought. This study aims to define the prevalence of calcified cerebral emboli as the most likely aetiology within a cohort of confirmed cases of acute stroke, as well as compare and contrast these cases with cases of 'incidental' intracranial calcification.

METHODS

Cases of confirmed stroke between May 2014 and May 2017 were reviewed by two readers to assess for the most likely aetiology. Cases of presumed calcified cerebral embolus were categorized in to 'possible' or 'definite'. The morphology, distribution and density were analysed by two independent readers, then subsequently discussed to reach a consensus. Cases were further studied in terms of likely proximal embolic source, therapeutic interventions and clinical outcomes. A further random selection of 220 non-contrast CT head examinations were reviewed over the same time period to assess for the presence of calcification which was favoured to be 'intravascular' using the same criteria.

RESULTS

A total of 220 cases of confirmed stroke were reviewed. Thirteen of these cases were thought to be most likely secondary to calcified cerebral emboli (5.9%). Of the 13 cases, eight were considered 'definite' as previous premorbid imaging without calcification was available. Twelve patients had emboli within the anterior circulation and only one patient had an embolus in the posterior circulation. Moderate calcified atherosclerotic disease was noted within the aorta and carotid arteries of all patients. Of the 220 patients within the control group, three cases were thought to have intracranial calcification most likely to be intravascular without clinical sequelae or other supportive imaging findings of infarct.

CONCLUSION

Previously thought to be a rare complication of intra-arterial instrumentation, calcified cerebral emboli have been shown to more commonly be associated with spontaneous cerebral infarction. Whilst literature in this area remains scant, recognition and differentiation of this entity has important clinical applications regarding immediate diagnosis of stroke on non-contrast imaging, modified treatment in the acute setting as well as in regards to recurrent event prognosis and secondary prevention.

Acute treatment of stroke due to spontaneous calcified cerebral emboli causing large vessel occlusion

INTRODUCTION

Calcified cerebral emboli (CCE) are rarely responsible for large vessel occlusion (LVO) in acute anterior stroke, and therefore therapeutic experience is scarce. We sought to expand current knowledge upon therapeutic options with three new cases and a review of current literature.

METHODS

Systematic search of patients with acute anterior stroke due to LVO in one comprehensive stroke center throughout a 4 year period. Literature search for reported cases of CCE.

RESULTS

In total, 21 cases (19 found in literature and 3 from our institution) are reported with a median age of 72 years (interquartile range [IQR] 63-80). Eleven patients were treated acutely, 4 of them with endovascular thrombectomy (EVT). Middle cerebral artery (MCA) M1 was the most affected segment and large artery atherosclerosis (LAA) and cardioembolism (CE) was causative in 41% of cases. EVT was significantly superior to intravenous recombinant tissue plasminogen activator (rtPA) at p = .048 (Fisher's exact test, chi square 6.7).

CONCLUSIONS

Given the small sample reported in literature and no reported randomised studies, definitive recommendations could not be reached. However, considering thrombus composition, thrombolysis is most probably not sufficient and priority should be given to EVT.

Utility of Carotid Ultrasonography in Management of an Atypical High Vascular-Risk Patient with Recurrent Calcified Cerebral Embolic Stroke

OBJECTIVE

To describe a case of recurrent calcified cerebral emboli (CCE)-related acute ischemic stroke (AIS) and the diagnostic utility of plaque morphology characterization on carotid ultrasound.

BACKGROUND

CCE are a rare cause of AIS. CCE-related AIS has been previously reported only in high vascular-risk patients such as those with severe carotid stenosis, widespread atheromatous disease, or cardiac valvular disease. CCE-related AIS from a carotid origin has not been reported in patients without carotid stenosis.

CASE

A 69-year-old man with no known medical history presented with hemiparesis and aphasia was found to have a curvilinear calcification in the left sylvian fissure on brain imaging, consistent with CCE. Two months later, he developed a second episode of CCE-related AIS. Standard workup, as well as advanced imaging with digital subtraction angiography, revealed no carotid stenosis or valvular disease. Carotid ultrasound demonstrated normal flow velocities but a left carotid heterogeneous plaque with multiple ulcerative craters and lucencies, suggestive of an active thromboembolic source.

CONCLUSION

To our knowledge, this is the first case reporting CCE-AIS from carotid origin in a patient with no carotid stenosis. Carotid ultrasound serves a diagnostic role in these patients.

Unusual Cerebral Emboli

The heart and the carotid arteries are the most common sites of origin of embolic disease to the brain. Clots arising from these locations are the most common types of brain emboli. Less common cerebral emboli include air, fat, calcium, infected vegetations, and tumor cells as well as emboli originating in the venous system. Although infarcts can be the final result of any type of embolism, described herein are the ancillary and sometimes unique imaging features of less common types of cerebral emboli that may allow for a specific diagnosis to be made or at least suspected in many patients.

Calcified cerebral emboli, a "do not miss" imaging diagnosis: 22 new cases and review of the literature

BACKGROUND AND PURPOSE

Calcified cerebral emboli are a rarely reported but devastating cause of stroke and may be the first manifestation of vascular or cardiac disease. Our aim was to evaluate the diagnosis, prevalence, imaging appearance, presumed embolic source, treatment, and outcome of patients with calcified cerebral emboli.

MATERIALS AND METHODS

Our radiology information system was searched for all CT scans by using keywords "calcified," "emboli," and their permutations. The radiology information system was also searched to identify all "stroke" CT reports to calculate the prevalence of calcified cerebral emboli. We also performed a MEDLINE search to identify all published case reports.

RESULTS

Twenty-two cases were identified from our database, and 48 were cases reported from the literature. The middle cerebral artery was the site of 83% of calcified emboli. Presumed sources were calcific aortic stenosis (36%), carotid atherosclerotic plaque (30%), and mitral annular calcification (11%). Spontaneous embolism occurred in 86%. Surgical treatment was performed in 34% of patients. Sixty-four percent of the patients with calcified aortic stenosis underwent aortic valve replacement. Among those with identifiable arterial disease, 53% underwent endarterectomy. Forty-one percent of patients experienced at least 1 recurrent stroke. The prevalence of calcified cerebral emboli identified on stroke CT scans at our institution was 2.7%. Seventy-three percent of cases were correctly identified. Twenty-seven percent were misdiagnosed on initial interpretation, while 9% were overlooked on preliminary interpretation.

CONCLUSIONS

Calcified cerebral emboli are more common than previously assumed, are frequently overlooked or misinterpreted, affect clinical course when diagnosed, and carry substantial risk for recurrent stroke.

[Effective thrombolytic therapy for calcified cerebral embolism originating from a calcified plaque in the internal carotid artery]

A 72-year-old man was transported to our emergency department after rear-ending another vehicle. He presented with acute left hemispatial neglect, left hemianopsia, and mild left hemiparesis. Computed tomography (CT) on admission showed a calcified embolus in the right middle cerebral artery. After intravenous thrombolytic therapy, the patient showed drastic improvement of neurological deficits. Follow-up CT showed disappearance of embolus, but distal migration of emboli to the downstream of the right middle cerebral artery was seen, sparing the massive territory of the right middle cerebral artery. Carotid duplex sonography and 3-dimensional CT angiography showed a calcified plaque with ulceration at the origin of the right internal carotid artery, representing the presumptive origin of the emboli. We report a rare case of effective intravenous thrombolysis for calcified cerebral embolism from the carotid artery. Further consideration of the mechanism, efficacy, and indication of intravenous thrombolysis for calcified cerebral emboli is needed.

Role of noncontrast head CT in the assessment of vascular abnormalities in the emergency room

Noncontrast CT of the head is a widely used noninvasive investigation for a variety of acute and chronic neurological conditions. Since CT head without contrast is usually the first and often the only investigation in the emergency room for many neurological symptoms, it is imperative to detect subtle vascular changes, which in many patients can be life-saving. The vascular abnormalities may present with increased density and/or size of the vessels, filling defects, and be associated with parenchymal and bony changes. In this article, we present examples of several vascular pathologies which can be identified on the noncontrast CT of the head, and learn imaging and interpretation techniques to help recognize what often are nebulous changes. While some of the findings are diagnostic by themselves and others subtle, any suspicious abnormality should be followed with dedicated vascular imaging such as CT/MR angiogram, venogram, or catheter angiogram for confirmation and better characterization.

Cardioscopic detection of left ventricular thrombi. -With special reference to a comparison with left ventriculography and echocardiography-

BACKGROUND

Thrombosis occurs in the left ventricle and causes ischemic cerebral attacks. However, differences in the incidence of left ventricular thrombi (LVT) among various categories of heart diseases are not known.

METHODS AND RESULTS

From April 2000 to 31 March 2008, 258 patients (104 females and 154 males; age 63 ± 6 years) with a heart disease underwent cardioscopy of the left ventricle. LVT were detected by cardioscopy in 78 of 258 patients; 12.5% of 57 patients with stable angina, 0% of 9 with unstable angina, 45.2% of 42 with acute myocardial infarction, 23.2% of 43 with old myocardial infarction, 61.9% of 21 with idiopathic acute myocarditis, 44.3% of 68 with idiopathic chronic myocarditis, 33.3% of 6 with rheumatic valvular disease, 25.7% of 31 with idiopathic dilated cardiomyopathy and in 8.0% of 12 with idiopathic hypertrophic cardiomyopathy. Nine of 78 thrombi were globular and 69 were mural. The detection rate of LVT by cardioscopy, left venticulography, non-contrast and contrast echocardiography was 30.2%, 2.7%, 1.9% and 7.0%, respectively.

CONCLUSIONS

LVT were frequently detected by cardioscopy in patients with heart diseases. Although invasive, cardioscopy was more sensitive in detecting LVT than left ventriculography, and non-contrast and contrast echocardiography.