May Journal Round-Up

Welcome to the May journal round-up. Before we start, registration to the joint BSNR/ISNR annual meeting in Dublin has just opened and the deadline for abstract submission is 31/7/18, so get those abstracts in and I hope to see you there!

Trauma – We have previously looked at the difficult issue of blunt cerebrovascular injury (see the March journal round-up), and two articles this month explore this topic further. In JNS, Grandhi et al. retrospectively analysed their BCVI patients who had undergone screening according to the Denver criteria, and importantly followed up positive CTA with DSA, finding that there was a very high false-positive rate particularly for grade 1 injuries (47.9%). They suggest the use of DSA after a positive CTA to minimise unnecessary antithrombotic therapy.

The available criteria for BCVI are highly geared towards sensitivity, and therefore are likely to be inappropriate in paediatric populations. Herbert et al. in JNS Paediatrics devised a new set of criteria, the McGovern score, to select patients for angiographic imaging based on their cohort of blunt trauma patients, which adapts the Utah score by adding mechanism of injury. They compared available scoring systems including the Denver, Memphis, EAST and Utah scores and found significant misclassifications using these scores.

Vascular – Perimesencephalic haemorrhage is a form of subarachnoid haemorrhage with a more benign clinical course, and the workup for these patients can be rationalised based on this knowledge. Mensing et al. in Stroke conducted a systematic review of perimesencephalic haemorrhage, and among useful clinical factors the radiological finding was that a single CTA is the preferred diagnostic approach over multiple DSAs or subsequent MRI, as only 4% will be due to aneurysm. They also found evidence to support the hypothesis that perimesencephalic haemorrhage is likely venous in origin.

The absence of contrast opacification in the extracranial ICA in the setting of ischaemic stroke can present a diagnostic dilemma, as the possibilities include occlusion, dissection or pseudo-occlusion. Kappelhof et al. used the MR CLEAN trial data to determine whether these could be distinguished on CTA, finding that this was possible with good sensitivity and specificity, using the finding of gradual contrast decay in the ICA above the carotid bulb in the absence of atherosclerotic findings and the presence of carotid T or large M1 occlusion to suggest pseudo-occlusion.

Intervention – Despite the profusion of evidence for mechanical thrombectomy in ischaemic stroke, there is little data on the effectiveness of thrombectomy in elderly populations, and Hilditch et al. in AJNR aimed to summarise what data exists in a systematic review. They found that although outcomes were inferior to those in younger patients, a significant benefit could be obtained using thrombectomy and suggest that age should not exclude patients from this treatment.

The Society for Neurointerventional Surgery released a report this month in JNIS on endovascular strategies for cerebral venous thrombosis, reviewing the risk factors, clinical and imaging findings and outcomes for CVT. They present an algorithm for treatment which includes endovascular treatment if there is clinical deterioration despite anticoagulation, if anticoagulation can’t be administered, if there is coma, deep CVT or intracranial haemorrhage. However, evidence is lacking as to the appropriate timing of endovascular treatment following anticoagulation and the specific technique to be used.

Neoplastic – Barisano et al. provide a useful review of effects related to radiation surgery and radiotherapy for the treatment of brain and spinal tumours, covering pseudoprogression and radiation necrosis in detail and including the imaging features of multiple other complications such as leukoencephalopathy, myelopathy, atherosclerosis, and radiation induced cavernous malformations and tumours.

Inflammatory/Autoimmune – The intracranial findings of neuromyelitis optica spectrum disorders (NMOSD) have been increasingly recognised and Wang et al. have published a review in BJR summarising the characteristic intracranial findings within their own cohort, using the characteristic localisations to help to distinguish from other demyelinating disorders (with a table dedicated to differentiating from MS). This article works well in conjunction with the review in our January round-up.

Anti-NMDA receptor encephalitis can be difficult to diagnose as a result of its nonspecific brain MRI findings. Zhang et al. in AJNR examined a cohort of patients to assess the imaging findings and any association with 2 year clinical outcome, finding that while imaging is often normal, hippocampal abnormalities were the most common abnormal finding and were a predictor for poor prognosis at 2 years.

Degenerative – Ollivier et al. in Neurographics present an interesting review of imaging findings in atypical Parkinsonian syndromes, focusing on the clinical utility of advanced imaging techniques in this group of patients as well as summarising the structural MRI findings. They highlight the high rate of misdiagnosis due to overlapping clinical findings in these diseases, and knowledge of the relevant advanced imaging techniques is therefore likely to be crucial in investigation of these patients in future.

Spine – In Practical Neurology this month Mariano et al. have written a pragmatic approach to spine lesions, starting from clinical findings and presenting a number of useful algorithms to determine a specific cause. This review would be particularly useful for on-call and exam preparation, with concise clinical information and useful imaging and laboratory tests in an easy to read format.

The spectrum of developmental vertebral anomalies is wide and can be daunting, and it is helpfully demystified in a clear pictorial review by Chaturvedi et al. in Insights into Imaging, which starts with the relevant embryology and highlights malformations which may either mimic or be at increased risk for traumatic injury.

Paediatric – Reddy et al. describe the imaging findings in organic acidemias and aminoacidopathies in a comprehensive review in Radiographics, highlighting the role for imaging in narrowing down the differential and guiding appropriate diagnostic workup and the differentiation of these inborn errors of metabolism from acute intracranial pathologies.

Miscellaneous – Two reviews published this month may be more head and neck in flavour but cover topics very important to neuroradiologists. The first, in Radiographics, presents the craniofacial manifestations of systemic disease, acting as a useful reference for those tricky incidental findings on head CTs. The second is a helpful review by Capobres et al. in Neurographics of the anatomy and pathology of the facial nerve.

That’s all for this month. If you’re a UK trainee, please look out for the trainee survey which will be sent out this month, and in particular your feedback on the blog and what you’d like to see included in the future. We’re also hoping to move to the main BSNR website as part of its update and redesign – watch this space!