Electroencephalographic (EEG) features of encephalopathy in the setting of Covid-19: A case series.

OBJECTIVE: The Covid-19 pandemic is a global challenge presenting clinicians with an evolving diagnostic landscape. We sought to describe EEG findings observed from local experience in a typical case series of patients with severe Covid-19. METHODS: Ten cases of Covid-19 were identified in whom EEG recordings had been made during the course of admissions to Bristol hospitals which had required intensive care. Electro-clinical correlation between the EEG and available medical history, imaging and laboratory investigation results was explored. RESULTS: The predominant EEG features in severe Covid-19 are of generalised symmetrical slowing, consistent with encephalopathy. CONCLUSIONS: The presence of focal disturbances or irritative abnormalities may be a pointer away from a pure encephalopathy and warrant further investigation. SIGNIFICANCE: A growing range of neurological sequelae from Covid-19 are now recognised to be common amongst patients hospitalised by with this condition, being seen to affect approximately one third of such cases. Electroencephalography has a unique place in the diagnostic work-up of impaired consciousness, a frequent feature of severe Covid-19. However, there is currently a paucity of literature describing typical EEG findings in this setting.

Spinal dural arteriovenous fistula: delay to radiological diagnosis and sources of radiological error.

AIM: To highlight the magnetic resonance imaging (MRI) signs associated with spinal dural arteriovenous fistula (SDAVF) through categorisation of sources of radiological error and investigation of the delay to radiological diagnosis. MATERIAL AND METHODS: This was a retrospective, observational study of cases referred to a neuroscience centre over 11 years. All patients who underwent spinal digital subtraction angiography (DSA) with a subsequent diagnosis of SDAVF were identified. Prior imaging was reviewed and compared with the formal reports issued. RESULTS: Thirty-seven patients with SDAVF were initially imaged in seven institutions. Radiological abnormalities including intradural vessels (37/37, 100%), cord T2 signal change (34/37, 91.9%), and cord expansion (26/37, 70.2%) were present on prior MRI. These signs were not recognised in 22/37 (59.5%), 7/34 (20.5%), and 15/26 (57.7%) of cases, respectively. Increased T2 signal in the cord was the most commonly identified sign (27/34; 79.4%), but prompted either no diagnosis (7/34; 20.5%) or differential diagnoses including ischaemic, inflammatory, or neoplastic aetiologies or a syrinx in 11/34 (32.4%). An appropriate diagnosis was made on initial MRI in 15 patients (40.5%). The time from initial imaging to diagnosis was significantly delayed for those patients who did not have an arteriovenous vascular aetiology included in the initial differential diagnosis (281 (423.3) days versus 22 (15.7) days, p=0.03). CONCLUSION: SDAVF have imaging features that are frequently missed or misinterpreted. This results in a significant delay to definitive diagnosis and therefore treatment.

The emerging age of endovascular treatment of acute ischaemic stroke and the role of CT angiography in patient work-up: a guide for the radiologist.

Recent trial evidence suggests that for patients suffering large-vessel occlusive stroke, endovascular therapy based on the stent-retriever technique is associated with superior clinical outcomes when compared to intravenous thrombolysis alone. The challenge now is how this service is to be delivered. This may involve both centralisation of services around large cities and development of robust networks to receive patients from district general hospitals situated further afield. Both diagnostic and interventional neuroradiology will need to expand. Furthermore, we suggest that it would be advantageous for radiology departments in those hospitals receiving hyperacute stroke patients to perform computed tomography (CT) angiography in addition to non-contrast CT, which also has implications for service delivery in these units. This could swiftly aid identification of patients who might benefit from thrombectomy and improve decision-making through demonstration of occlusive thrombus and of collateral status.

Endovascular treatment of 300 consecutive middle cerebral artery aneurysms: clinical and radiologic outcomes.

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.

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.

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.

Retained and fractured microcatheter: a cause of transient ischaemic attacks: endovascular management using carotid stents.

A retained microcatheter is a rare complication of endovascular treatment of cerebral aneurysms. We describe such a case that was complicated by delayed microcatheter fracture within the internal carotid artery and subsequent thrombo-embolism resulting in transient ischaemic attacks. We also describe endovascular management of this complication through the use of several carotid stents.

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.

Use of expiratory CT pulmonary angiography to reduce inspiration and breath-hold associated artefact: contrast dynamics and implications for scan protocol.

AIM: To investigate the effects of scanning in expiration during computed tomography pulmonary angiography (CTPA). MATERIALS AND METHODS: One hundred and eighty-one consecutive expiratory CTPA examinations were compared with 145 inspiratory CTPA examinations performed using a standardized protocol through assessment of attenuation seen in the cardiac chambers, pulmonary artery (PA), and ascending aorta. RESULTS: Expiratory scans showed greater attenuation at the pulmonary trunk, right PA, left PA, lobar and segmental PAs (p<0.05). Expiratory scans showed a lower incidence of transient contrast medium interruption (p<0.001) and generalized unsatisfactory PA opacification (p<0.05). Scans with generalized low PA attenuation had lower attenuation in the right ventricle, left heart, and ascending aorta (p<0.001) suggesting that contrast medium delivery or dilution prior to contrast medium entry into the PA is responsible. Expiratory scans showed lower quality scores (p<0.001) for depiction of lung parenchyma. CONCLUSION: Expiratory scanning could be used as an optimal protocol for dedicated PA imaging. However, it suffers from inferior parenchymal imaging and should probably be reserved for failed inspiratory breath-hold CTPA.

Coarse pleural calcification in a mesothelioma patient raises the possibility of a rare tumour subtype: osteoblastic sarcomatoid mesothelioma.

It is often suggested that calcification seen in association with pleural thickening implies benign disease. However, we present a case of a patient presenting with coarse pleural calcification associated with a pleural effusion and thickening, which following biopsy was shown to represent osteoblastic sarcomatoid mesothelioma. We describe the imaging features associated with this and differentiate these findings from those seen with benign pleural calcification. Similarities are drawn to other rare cases described in the literature.

Multiphase multidetector CT in the diagnosis of haemobilia: a potentially catastrophic ruptured hepatic artery aneurysm complicating the treatment of a patient with locally advanced rectal cancer.

Acute haemobilia is an unusual and potentially catastrophic cause of gastrointestinal bleeding. We describe such a case presenting as a rare complication of a hepatic artery aneurysm following the development and successful treatment of subacute bacterial endocarditis during a radical downstaging chemoradiotherapy regime for locally advanced rectal cancer. We suggest that multiphase multidetector-row CT can have an important role in the diagnosis of acute haemobilia and discuss imaging findings associated with the condition. This case raises awareness of benign conditions mimicking malignancy in oncological patients and reinforces the importance of reviewing historical imaging.

Cross-sectional imaging for diagnosis and clinical outcome prediction of acute basilar artery thrombosis.

Basilar artery occlusion is a potentially fatal condition and imaging findings can be subtle. Prompt diagnosis is vital, as recognition may lead to therapeutic recanalization that may improve functional outcome and survival. Furthermore, cross-sectional imaging signs may help predict eventual outcome and, therefore, guide which patients should be subjected to aggressive treatment. Computed tomography (CT) signs include a hyperdense basilar artery that has a high specificity, accuracy, positive and negative predictive value. Evidence regarding the prognostic significance of the hyperdense basilar artery sign is conflicting. Early magnetic resonance imaging (MRI) features include loss of flow void, seen as increased signal intensity within the basilar artery on T2-weigted images and identification of acute thrombus, seen as intermediate signal on T1-weighted images. MRI sequences are more sensitive for early detection of acute ischaemia or infarction, ideally with diffusion-weighted imaging (DWI). Both CT and MR angiography are sensitive for detection of acute thrombus, seen as a filling defect or occlusion. These are the non-invasive imaging techniques of choice to confirm diagnosis, with perhaps the speed and accessibility of CT angiography resulting in this technique being valuable in the acute setting. Several new scoring systems based on arterial segmentation rather than global volume assessment using CT angiography source images and DWI have shown early promise in the prediction of eventual clinical outcome in order to isolate those patients who may benefit from therapeutic recanalization.

Analysis of gene expression in two large schizophrenia cohorts identifies multiple changes associated with nerve terminal function.

Schizophrenia is a severe psychiatric disorder with a world-wide prevalence of 1%. The pathophysiology of the illness is not understood, but is thought to have a strong genetic component with some environmental influences on aetiology. To gain further insight into disease mechanism, we used microarray technology to determine the expression of over 30 000 mRNA transcripts in post-mortem tissue from a brain region associated with the pathophysiology of the disease (Brodmann area 10: anterior prefrontal cortex) in 28 schizophrenic and 23 control patients. We then compared our study (Charing Cross Hospital prospective collection) with that of an independent prefrontal cortex dataset from the Harvard Brain Bank. We report the first direct comparison between two independent studies. A total of 51 gene expression changes have been identified that are common between the schizophrenia cohorts, and 49 show the same direction of disease-associated regulation. In particular, changes were observed in gene sets associated with synaptic vesicle recycling, transmitter release and cytoskeletal dynamics. This strongly suggests multiple, small but synergistic changes in gene expression that affect nerve terminal function.

Fear of venepuncture as a barrier to testing for blood-borne infection and use of an oral fluid test as an alternative to venepuncture in a genitourinary medicine clinic.

OBJECTIVE: A survey of 505 consecutive patients attending a UK genitourinary medicine clinic (GUM) included a psychometric tool to compute a fear of venepuncture (FOV) score, responses to the offer of venepuncture and to alternative testing. METHOD: An oral fluid test (OFT) was available to test for blood-borne infection (BBI). Completed fear scores were provided by 299 (59%) patients routinely offered venepuncture, of whom 72 (24%) who did not have venepuncture had higher fear scores compared with 227 (76%) who had venepuncture (p<0.001). RESULTS: Both FOV and female sex were independent predictors of not having venepuncture. CONCLUSIONS: FOV is an important barrier to uptake of venepuncture. FOV may not always be recognised by health carers. OFT is an acceptable alternative test for some patients with needle aversion who decline venepuncture.

Relationship between estrogen and schizophrenia.

There is a wealth of historical and circumstantial evidence to suggest that female patients with schizophrenia may suffer from a deficit in estrogenic function. The prolactin-inducing properties of most antipsychotic drugs, and subsequent negative feedback on estrogen levels, is in keeping with this. The functions of estrogen, its complex receptor organization and its numerous actions are the focus of ongoing research activity. Of particular interest are its neuroprotective properties, particularly with regard to cognitive impairment, and its involvement with neurotransmitter systems, which are the substrate for psychotropic drugs. Estrogen has now been used as an adjunct to standard antipsychotic medication in quite a few studies of female schizophrenia patients. However, most of these are not double-blind, randomized, controlled trials. Only two relatively small double-blind, randomized clinical trials returned positive results: one long-term study that selected for hypoestrogenism reported negative findings. Furthermore, recent evidence of the risks of long-term hormone replacement therapy is of concern. The advent of specific estrogen receptor modulators, which may avoid excess risks of cancer and cardiovascular events, will have little to add to schizophrenia treatment if estrogen is, essentially, devoid of any specific antipsychotic or adjuvant mechanism of action relevant to the pathophysiology of this disorder.

A longitudinal analysis of memory in patients with schizophrenia.

Memory deficits are widely reported in patients with schizophrenia, but uncertainties remain about the extent and the longitudinal course of these deficits. Twenty-eight patients with a DSM-IV diagnosis of schizophrenia were tested on multiple aspects of memory at baseline, 9- and 18-month follow-up. Measures included: digit span, the Rivermead Behavioural Memory test (RBMT) battery, the Graded Naming Test (GNT) and several computerized memory tests from the Cambridge Automated Neuropsychological Testing Battery (CANTAB). A group of healthy controls (N=17) was tested on the CANTAB battery at baseline and 9-month follow up. The patients performed significantly poorer than controls on all CANTAB measures; however, there was no difference in change between groups over a 9-month period. Within-group patient comparisons revealed that symptoms reduced significantly over the study period, but had no association with memory. Significant improvements were observed for patients on two verbal memory tasks: the GNT and digit span, but not on any other measure. Interestingly, these were the only two tests on which patients were within normal limits at baseline. This study shows that patients with schizophrenia have deficits in multiple aspects of memory which remain stable over long periods of time. In addition, patients showed a tendency to improve on memory tasks which contained a verbal component.