Marcus D Bradley

Endovascular therapy for acute basilar artery occlusion: a review of the literature

Basilar artery occlusion is an infrequent form of acute stroke; clinical outcomes are heterogeneous, but the condition can be fatal. There is a lack of randomized controlled trial data in this field. Case series suggest that patients who are recanalized have much better outcomes than those who are not, and it is generally accepted that intra-arterial techniques achieve high rates of recanalization. Controversially, several studies, including a meta-analysis and registry-based investigation, that have compared intravenous thrombolysis (IVT) and intra-arterial treatment suggest similar outcomes. However, there are many potential sources of bias in each of these studies, precluding a firm conclusion. Indeed, there are many confounding factors that can influence the outcome including severity of presentation, site of occlusion, clot load, degree of collateral flow, timing of therapy, agent used for recanalization and dose of thrombolytic agent. Additionally, pretreatment infarct core imaging using diffusion-weighted imaging and the posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) scoring systems have been shown to predict outcome and therefore may be useful in selecting patients for aggressive therapy. Protocols combining intravenous agents such as glycoprotein IIb/IIIa receptor antagonists or thombolytics agents with intra-arterial techniques (‘bridging’ therapy) have shown encouraging improvements in neurological outcome and survival. Furthermore, initial case series describing the use of mechanical clot extraction devices or aspiration catheters suggest high rates of recanalization. What would be useful is a randomized trial comparing IVT, endovascular approaches and a combined IVT/endovascular approach. However, the small numbers of patients and multiple confounding factors are barriers to the development of such a trial.

Endovascular Treatment of 300 Consecutive Middle Cerebral Artery Aneurysms: Clinical and Radiologic Outcomes

Controversy about the best treatment method for MCA aneurysms persists and these authors report the results of endovascular treatment of these lesions in a large series in which 295 such aneurysms were treated during a 17-year period and the results retrospectively analyzed. Complete occlusion was achieved in 94% and treatment failed in 4.3%. Procedure-related morbidity and mortality occurred in nearly 8%. Death occurred in 13.6% of patients and 4.3% needed to be re-treated. Thus, endovascular treatment of MCA aneurysms is acceptable as a primary treatment. BACKGROUND AND PURPOSE: There is controversy as to the best mode of treating MCA aneurysms. We report the results of a large endovascular series of patients treated at our center. MATERIALS AND METHODS: This study was a retrospective analysis of a prospectively acquired data base. All patients with saccular MCA aneurysms treated between November 1996 and June 2012 were included. World Federation of Neurosurgical Societies grade, aneurysm site, size, and aneurysm neck size were recorded, along with clinical outcome assessed with the Glasgow Outcome Scale and radiographic occlusion assessed with the Raymond classification at 6 months and 2.5 years. RESULTS: A total of 295 patients with 300 MCA aneurysms were treated including 244 ruptured aneurysms (80.7%). The technical failure rate was 4.3% (13 patients). Complete occlusion or neck remnant was achieved in 264 (91.4%). Complications included rupture in 15 patients (5%), thromboembolism in 17 patients (5.7%), and early rebleeding in 3 patients (1%). Overall permanent procedural-related morbidity and mortality were seen in 12 patients (7.8%). Of the ruptured aneurysms, 189 (79.4%) had a favorable clinical outcome (Glasgow Outcome Scale score, 4–5). A total of 33 patients (13.6%) died. On initial angiographic follow-up, aneurysm remnant was seen in 18 aneurysms (8.1%). A total of 13 patients (4.3%) were re-treated. CONCLUSIONS: Our experience demonstrates that endovascular treatment of MCA aneurysms has an acceptable safety profile with low rates of technical failure and re-treatment. Therefore, coiling is acceptable as the primary treatment of MCA aneurysms.

Thunderclap headache: Diagnostic considerations and neuroimaging features

Thunderclap headache (TCH) is an acute and severe headache that has maximum intensity at onset; TCH can be primary or secondary. Primary TCH is diagnosed when no underlying cause is discovered; however, imaging is crucial in distinguishing secondary causes, which are wide-ranging. The radiologist should be aware of the list of potential diagnoses. Subarachnoid haemorrhage (SAH) is the most common cause of secondary TCH. Aneurysmal SAH accounts for the majority of cases, although other causes should also be considered and these include perimesencephalic haemorrhage, arteriovenous malformations, and dural arteriovenous fistula as well as reversible cerebral vasoconstriction syndrome. Conditions that may present with TCH, with or without SAH include cervical artery dissection and cerebral venous sinus thrombosis. Ischaemic stroke, pituitary apoplexy, and posterior reversible leucoencephalopathy are other potential causes, whereas non-vascular causes include colloid cysts of the third ventricle and spontaneous intracranial hypotension. Imaging features are reviewed with reference to clues gleaned from initial imaging using computed tomography, as well as characteristics that should be sought using magnetic resonance imaging or angiographic imaging.

Endovascular Treatment of Children With Cerebral Venous Sinus Thrombosis: A Case Series

BACKGROUND Cerebral venous sinus thrombosis is a potentially serious condition affecting 0.56 to 0.67 per 100,000 children annually; adverse outcomes are common. The standard of care is anticoagulation with heparin. A proportion of patients, however, remain in a severe clinical condition and in these, endovascular therapy is an alternative treatment. There is little published literature on the use of endovascular treatments in children with cerebral venous sinus thrombosis. METHODS We retrospectively reviewed case notes and imaging in a consecutive series of nine children treated using endovascular therapy after diagnosis of cerebral venous sinus thrombosis. Clinical presentation, decision to escalate therapy, methods of recanalization, and clinical outcome were assessed. RESULTS Nine children were treated (age range 18 months to 16 years). Diagnosis was made by computed tomography, computed tomography venography, magnetic resonance imaging, or magnetic resonance venography. Seven children were in a coma; one had signs of raised intracranial pressure with progressive cranial nerve palsies; and one was drowsy with a fluctuating hemiparesis. Eight children had been treated with heparin without improvement. Several endovascular methods were used including local tissue plasminogen activator, microguidewire and catheter disruption, balloon angioplasty, and thromboaspiration using the Penumbra device. Eight children had good functional outcomes. One child died as a result of uncontrolled intracranial hypertension secondary to cerebral venous sinus thrombosis. CONCLUSION Endovascular therapy may have a role in the treatment of cerebral venous sinus thrombosis in children when medical therapy has failed and the patient is in a poor clinical condition.

Thrombus length estimation in acute ischemic stroke: a potential role for delayed contrast enhanced CT

Purpose Thrombus length has been shown to be an important determinant of recanalization using intravenous thrombolysis in hyperacute ischemic stroke. Various studies have attempted to quantify thrombus based on non-contrast CT (NCCT) or CT angiography (CTA). However, thrombus may not be seen on NCCT, and CTA may fail to delineate the distal extent of the thrombus. Contrast enhanced CT (CECT) following CTA can be used to estimate infarct core, but we investigated whether the angiographic data available on these images provided reliable information on thrombus length. Materials and methods 15 consecutive patients, mean age 81 years (range 63–93), with terminal internal carotid artery or M1-middle cerebral artery occlusions underwent NCCT, CTA (bolus tracked technique), and CECT (acquired 80 s post initial CTA injection). Three radiologists assessed thrombus length on thin slice NCCT, and CTA and CECT. Results CTA overestimated thrombus length relative to NCCT (p<0.001) and CECT (p<0.001). There was less difference between CTA and CECT estimation in patients with good collateral scores (p<0.05). There was good correlation between NCCT and CECT (Pearsons correlation coefficient=0.90, 95% CI 0.81 to 0.95, p<0.001). Inter-rater reliability assessed using intraclass correlation was 0.95 (95% CI 0.87 to 0.98) for NCCT and 0.98 (95% CI 0.94 to 0.99) for CECT. Conclusions CTA regularly overestimates thrombus length as the distal end of the thrombus is not delineated. This can be overcome through the use of a CECT acquisition which can reliably be used to estimate thrombus length.

Computed Tomography Angiography in Hyperacute Ischemic Stroke: Prognostic Implications and Role in Decision-Making

Computed tomography (CT) remains the initial imaging modality of choice in hyperacute stroke (HIS). CT scanners are more widely available than MRI scanners and are often located in emergency departments of district hospitals. Noncontrast CT (NCCT) excludes intracranial hemorrhage and tumor and detects early signs of infarction. Inclusion of arterial and parenchymal imaging with CT angiography (CTA) can rapidly provide useful information that may influence management and may indicate infarct size, location, and extent of vessel occlusion and collateral integrity, all of which can influence clinical outcome and recanalization in HIS.1 We will discuss the impact of these findings on prognosis and clinical decision-making, as well as practicalities of CTA in the HIS setting. CTA accurately localizes thrombus and quantifies clot burden. Both provide prognostic information in HIS and may guide management. In the late 1990s, several relatively small trials demonstrated that CTA had excellent correlation with digital subtraction angiography (DSA), magnetic resonance angiography, and transcranial Doppler ultrasound.2–4 Using DSA as a reference standard, Lev et al5 directly compared CTA and DSA findings in 224 vessel segments (divided into internal carotid artery [ICA], middle cerebral artery [M1 and M2-MCA], anterior cerebral artery [A1-ACA],posterior cerebral artery [P1 and P2-PCA], basilar artery [BA], and vertebral artery) in 44 patients with acute stroke. Sensitivity and specificity for the detection of large-vessel occlusion was 98.4% and 98.1%, respectively. More recently, Bash et al6 assessed 672 vessel segments in 28 patients who underwent CTA and magnetic resonance angiography, using DSA as a reference standard. CTA had sensitivity and positive predictive value for occlusion of 100%, significantly better than magnetic resonance angiography (87% and 59%, respectively).6 When maximum intensity projection images have been compared with CTA source images (CTA-SI) for identification of occlusion, the latter seems slightly more sensitive. …

Cranial neuroimaging in pregnancy and the post-partum period

Several diverse neurological conditions may be seen during pregnancy and the post partum period. These usually require neuroimaging for definitive diagnosis and range from a predisposition to neurovascular abnormalities, such as acute ischaemic stroke and cerebral venous sinus thrombosis, through to more specific pregnancy-related conditions, such as eclampsia/posterior reversible leukoencephalopathy and post-partum angiopathy. Additionally, the pregnant patient is predisposed to pituitary disease. It is necessary that the radiologist has an awareness of these conditions to allow swift specific diagnoses or suggest the most appropriate diagnosis when imaging findings are non-specific. We describe epidemiological and radiological features to allow the radiologist to guide the clinician in management, and review guidelines for safe cranial imaging of the pregnant patient.

Endovascular Therapy in Hyperacute Ischaemic Stroke: History and Current Status

This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset. Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement. Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved. Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65–95% and, rates of favourable outcome (mRS 0–2) in the order of 55% (42.5–77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5–15%. A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.

Retroclival subdural haematoma secondary to pituitary apoplexy

Abstract Retroclival haematomas are rare entity and they are mostly caused by trauma. There has been only one case published to have a retroclival haematoma following pituitary apoplexy. We present a patient diagnosed with pituitary apoplexy who was found to have acute subdural retroclival haematoma on the MRI.

Spinal arachnoiditis and cyst formation with subarachnoid haemorrhage

We present the case of a 58-year-old lady with p-ANCA vasculitis who suffered a WFNS grade 1 subarachnoid haemorrhage (Fisher grade 1) secondary to a ruptured left posterior inferior cerebellar artery aneurysm and then developed a rare complication of radiologically progressive spinal arachnoiditis despite maintained clinical response to definitive treatment measures.