Noel Fanning

Wall enhancement, edema, and hydrocephalus after endovascular coil occlusion of intradural cerebral aneurysms

OBJECT Symptomatic local inflammation, aseptic meningitis, and hydrocephalus are reported in a group of patients treated with second generation/modified platinum coils. The purpose of this study was to define the frequency and determinants of magnetic resonance (MR) imaging findings of aneurysm wall enhancement, perianeurysmal edema, and hydrocephalus in a cohort of coil-embolized intradural cerebral aneurysms treated with bare platinum or modified platinum coils (Matrix or HydroCoils). METHODS The authors retrospectively reviewed 359 Gd-enhanced MR follow-up studies of 181 treated aneurysms (125 ruptured) for mural enhancement. Univariate and multivariate logistic regression analyses were used to define mural enhancement associations with demographic, clinical, angiographic, treatment, and follow-up data. Embolization-related edema and hydrocephalus were defined in 95 MR imaging studies of 56 unruptured aneurysms. RESULTS Asymptomatic wall enhancement was observed in lesions treated with all coil types, occurring in 21 (18.6%) of 113 bare platinum coil-treated aneurysms. Independent associations were HydroCoil treatment (odds ratio [OR] 9.75, 95% confidence interval [CI] 3.45-30.75) and increasing aneurysm size (OR 3.58, 95% CI 1.99-6.95). Five (8.9%) unruptured aneurysms had asymptomatic de novo edema, and 3 (5.3%) demonstrated hydrocephalus; all had been treated with HydroCoils. Hydrocephalus presentation was delayed (8-31 months) and symptomatic in 2 patients. CONCLUSIONS Asymptomatic aneurysm wall enhancement occurred in 18.6% of embolizations performed with bare platinum coils, and probably represents a normal healing response. Perimural edema and hydrocephalus were observed only in patients treated with HydroCoils, but have been reported in patients treated with other modified platinum coils. These symptoms appear to represent an exaggerated inflammatory response during aneurysm healing. Increased vigilance for delayed hydrocephalus is required. Judicious clinical use of modified platinum coils is warranted until results of randomized trials are published.

Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple iPad

Tablet devices have recently been used in radiological image interpretation because they have a display resolution comparable to desktop LCD monitors. We identified a need to examine tablet display performance prior to their use in preliminary interpretation of radiological images. We compared the spatial and contrast resolution of a commercially available tablet display with a diagnostic grade 2 megapixel monochrome LCD using a contrast detail phantom. We also recorded reporting discrepancies, using the ACR RADPEER system, between preliminary interpretation of 100 emergency CT brain examinations on the tablet display and formal review on a diagnostic LCD. The iPad display performed inferiorly to the diagnostic monochrome display without the ability to zoom. When the software zoom function was enabled on the tablet device, comparable contrast detail phantom scores of 163 vs 165 points were achieved. No reporting discrepancies were encountered during the interpretation of 43 normal examinations and five cases of acute intracranial hemorrhage. There were seven RADPEER2 (understandable) misses when using the iPad display and 12 with the diagnostic LCD. Use of software zoom in the tablet device improved its contrast detail phantom score. The tablet allowed satisfactory identification of acute CT brain findings, but additional research will be required to examine the cause of “understandable” reporting discrepancies that occur when using tablet devices.

PRES (posterior reversible encephalopathy syndrome), a rare complication of tacrolimus therapy

With increasing numbers of solid organ and hematopoietic stem cell transplantations being performed, there have been significant increases in the use of immunosuppressive agents such as cyclosporine and tacrolimus. Posterior reversible encephalopathy syndrome (PRES) is a serious complication of immunosuppressive therapy use following solid organ or stem cell transplants. Clinical findings including headache, mental status changes, focal neurological deficits, and/or visual disturbances. Associated with these are characteristic imaging features of subcortical white matter lesions on computed tomography (CT) or magnetic resonance imaging (MRI). The changes in the subcortical white matter are secondary to potentially reversible vasogenic edema, although conversion to irreversible cytotoxic edema has been described. These imaging findings predominate in the territory of the posterior cerebral artery. Many studies have shown that the neurotoxicity associated with tacrolimus may occur at therapeutic levels. In most cases of PRES, the symptom complex is reversible by reducing the dosage or withholding the drug for a few days. While PRES is an uncommon complication, it is associated with significant morbidity and mortality if it is not expeditiously recognized. MRI represents the most sensitive imaging technique for recognizing PRES. This report highlights the value of MRI in prompt recognition of this entity, which offers the best chance of avoiding long-term sequelae.

Does chronic occupational exposure to volatile anesthetic agents influence the rate of neutrophil apoptosis

Purpose: The purpose of this preliminary investigation was to determine whether the rate of neutrophil apoptosis in health care workers is influenced by exposure to volatile anesthetic agents.Methods: Percentage neutrophil apoptosis (Annexin-V FITC assay) was measured in health care workers (n=20) and unexposed volunteers (n=10). For the health care workers, time weighted personal exposure monitoring to N2O, sevoflurane and isoflurane was carried out.Results: The sevoflurane and isoflurane concentrations to which health care workers were exposed were less than recommended levels in all 20 cases. Percent apoptosis was less at 24 (but not at one and 12) hr culture in health care workers {50.5 (9.7)%;P=0.008} than in unexposed volunteers {57.3 (5.1)%}.Conclusion: Inhibition of neutrophil apoptosis at 24 hr culture was demonstrated in health care workers chronically exposed to volatile anesthetic agents. Exposure was well below recommended levels in the both scavenged and unscavenged work areas in which the study was carried out. Further study is required to assess the effect of greater degrees of chronic exposure to volatile anesthetic agents on neutrophil apoptosis.RésuméObjectif: Vérifier, lors d’une étude préliminaire, si le taux d’apoptose des polynucléaires neutrophiles chez les travailleurs de la santé est influencée par l’exposition aux agents anesthésiques volatils.Méthode: Le pourcentage d’apoptose neutrophile (dosage Annexin-V FITC) a été mesuré chez des travailleurs de la santé (n=20), et chez des volontaires non exposés aux anesthésiques (n=10). On a procédé au monitorage pondéré du temps d’exposition individuel au N2O, au sévoflurane et à l’isoflurane.Résultats: Les concentrations de sévoflurane et d’isoflurane auxquelles les travailelurs ont été exposés étaient plus faibles, dans tous les cas (20), que les niveaux recommandés. Le pourcentage d’apoptose a été moindre à 24 h de culture, mais non pas à une et 12 h, chez les travailleurs de la santé {50,5 (9,7) %;P=0,008} comparés aux volontaires non exposés {57,3 (5,1) %}.Conclusion: L’inhibition de l’apoptose neutrophile à 24 h de culture a été démontré chez les travailleurs de la santé exposés régulièrement aux anesthésiques volatils. L’exposition était bien en deçà des niveaux recommandés dans les environnements de travail stériles ou non où l’étude a été menée. Une étude complémentaire devra évaluer l’effet d’une exposition régulière à de plus fortes concentrations d’anesthésiques volatils sur l’apoptose neutrophile.

The pretzel sign: Angiographic pattern of tortuous intra-aneurysmal blood flow in a giant serpentine aneurysm

Giant serpentine aneurysms (GSAs) form a specific subgroup of giant cerebral aneurysms that have pathognomonic angiographic features. We report the angiographic findings of a GSA demonstrating a striking convoluted dynamic flow pattern, which we have called the ‘pretzel sign’. The aneurysm was successfully treated by permanent occlusion of the parent vessel using a detachable balloon. GSAs should be identified prior to treatment in view of their particular management requirements.

Benzodiazepines inhibit the rate of neutrophil apoptosis

AbstractBackground Benzodiazepines, which are commonly administered perioperatively, can depress immune function. Neutrophil apoptosis plays a central role in the regulation of inflammation. This is particularly important during and after surgery. Aim To examine the effects of benzodiazepines (midazolam and diazepam) on neutrophil apoptosis. Methods Venous blood samples were withdrawn from patients scheduled to undergo elective surgery, (a) immediately prior to, and 10 minutes after administration of midazolam 0.2mg/kg intravenously (n=11) and (b) immediately prior to, and 60 minutes after administration of diazepam 10mg po (n=10). Neutrophil apoptosis was measured by Annexin VFITC after 1 and 12 hours in culture. Results The percentage of apoptotic cells was significantly less after midazolam at 12% (11.9) hours in culture compared to pre-midazolam 29.7% (13.3) (p<0.05). After diazepam, the rates of neutrophil apoptosis were also significantly less after 12 hours in culture (p<0.05). Conclusion Administration of benzodiazepines in clinically relevant doses inhibits neutrophil apoptosis. In the perioperative period, this may influence the inflammatory response to surgery.

Image quality associated with the use of an MR-compatible incubator in neonatal neuroimaging

OBJECTIVES MRI in the neonate poses significant challenges associated with patient transport and monitoring, and the potential for diminished image quality owing to patient motion. The objective of this study was to evaluate the usefulness of a dedicated MR-compatible incubator with integrated radiofrequency coils in improving image quality of MRI studies of the brain acquired in term and preterm neonates using standard MRI equipment. METHODS Subjective and objective analyses of image quality of neonatal brain MR examinations were performed before and after the introduction of an MR-compatible incubator. For all studies, the signal-to-noise ratio (SNR) was calculated, image quality was graded (1-3) and each was assessed for image artefact (e.g. motion). Students t-test and the Mann-Whitney U-test were used to compare mean SNR values. RESULTS 39 patients were included [mean gestational age 39 weeks (range 30-42 weeks); mean postnatal age 13 days (range 1-56 days); mean weight 3.5 kg (range 1.4-4.5 kg)]. Following the introduction of the MR-compatible incubator, diagnostic quality scans increased from 50 to 89% and motion artefact decreased from 73 to 44% of studies. SNR did not increase initially, but, when using MR sequences and parameters specifically tailored for neonatal brain imaging, SNR increased from 70 to 213 (p=0.001). CONCLUSION Use of an MR-compatible incubator in neonatal neuroimaging provides a safe environment for MRI of the neonate and also facilitates patient monitoring and transport. When specifically tailored MR protocols are used, this results in improved image quality.

Osteogenesis imperfecta presenting as aneurysmal subarachnoid haemorrhage in a 53-year-old man

The authors describe a case of aneurysmal subarachnoid haemorrhage in a 53-year-old man with background of osteogenesis imperfecta (OI). CT brain revealed diffuse subarachnoid haemorrhage (SAH) and cerebral angiogram subsequently confirmed vertebral artery aneurysm rupture leading to SAH. To the authors knowledge this is the first case of vertebral artery aneurysmal SAH described in OI. A previously undiagnosed OI was confirmed by genetic analysis (COL1A1 gene mutation). This aneurysm was successfully treated by endovascular route. Post interventional treatment patient developed stroke secondary to vasospasm. Communicating hydrocephalus, which developed in the process of management, was successfully treated with ventriculo-peritoneal shunt. The aetio-pathogenesis and management of this condition is described. The authors have reviewed the literature and genetic basis of this disease.

Superior cerebellar aneurysm causing subarachnoid haemorrhage in a 17-year-old with alagille syndrome

Abstract Alagille syndrome is a rare autosomal dominant condition characterised by mutation in Jagged1 gene. Intracranial aneurysms may be seen in this condition and may present as subarachnoid hemorrhage. We describe the first case of superior cerebellar aneurysm rupture causing WFNS grade 1 subarachnoid haemorrhage in a 17-year-old girl. The clinical condition and management of this rare occurrence is discussed with a review of literature.

Solitaire FR stent as an adjunctive tool for pipeline stent deployment in the treatment of giant intracranial aneurysms.

BACKGROUND AND IMPORTANCE: The use of flow-diverting stents has gained acceptance during the past few years for the treatment of numerous intracranial aneurysms, especially large or giant ones. However, successful catheterization of the distal parent artery in giant intracranial aneurysms with a microcatheter can be extremely challenging. Forming a microcatheter loop in the aneurysm sac can aid distal catheterization. CLINICAL PRESENTATION: We report the use of a Solitaire FR stent as an adjunctive tool in the successful treatment of 2 giant intracranial unruptured aneurysms with a Pipeline Embolization Device. After having formed a loop inside the aneurysm sac, the microcatheter was anchored distally by a Solitaire FR stent. With the Solitaire FR device opened, the loop in the giant aneurysm sac was completely reduced without loss of the microcatheter position in the distal parent artery. A Pipeline Embolization Device could be delivered in both cases without any difficulty. There were no complications. CONCLUSION: The technique described results in ideal microcatheter alignment with a secure distal position before deployment of a flow-diverting stent. ABBREVIATIONS: PCA, posterior cerebral artery PED, Pipeline Embolization Device