Regional Mechanical Thrombectomy Imaging Protocol in Patients Presenting with Acute Ischemic Stroke during the COVID-19 Pandemic

BACKGROUND AND PURPOSE

Chest CT is a rapid, useful additional screening tool for coronavirus disease 2019 (COVID-19) in emergent procedures. We describe the feasibility and interim outcome of implementing a modified imaging algorithm for COVID-19 risk stratification across a regional network of primary stroke centers in the work-up of acute ischemic stroke referrals for time-critical mechanical thrombectomy.

MATERIALS AND METHODS

We undertook a retrospective review of 49 patients referred to the regional neuroscience unit for consideration of mechanical thrombectomy between April 14, 2020, and May 21, 2020. During this time, all referring units followed a standard imaging protocol that included a chest CT in addition to a head CT and CT angiogram to identify Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infective pulmonary changes.

RESULTS

Overall, 2 patients had typical COVID-19 radiologic features and tested positive, while 7 patients had indeterminate imaging findings and tested negative. The others had normal or atypical changes and were not diagnosed with or suspected of having COVID-19. There was an overall sensitivity of 100%, specificity of 74.1%, negative predictive value of 100%, and positive predictive value of 22.2% when using chest CT to diagnose COVID-19 in comparison with the real-time reverse transcriptase-polymerase chain reaction test. The mean additional time and radiation dose incurred for the chest CT were 184 ± 65.5 seconds and 2.47 ± 1.03 mSv. Multiple cardiovascular and pulmonary incidental findings of clinical relevance were identified in our patient population.

CONCLUSIONS

Chest CT provides a pragmatic, rapid additional tool for COVID-19 risk stratification among patients referred for mechanical thrombectomy. Its inclusion in a standardized regional stroke imaging protocol has enabled efficient use of hospital resources with minimal compromise or delay to the overall patient treatment schedule.

Outcome of embolised vascular metastatic renal cell tumours causing spinal cord compression

PURPOSE

To present the results of the surgical management of metastatic renal cell tumours of the spine with cord compression who underwent pre-operative embolisation.

METHODS

We conducted a retrospective cohort study of all embolised vascular metastatic renal cell tumours of the spine that underwent urgent surgical intervention over a 7-year period (2005-2011). All medical notes, images and angiography/embolisation details were studied. We recorded the timing (immediate vs. delayed) and grade of embolisation and compared this to the estimated blood loss (EBL); extent of metastatic spinal cord compression (using the Tomita score and Bilsky scores) was also compared to EBL. Finally, neurological (Frankel grade), surgical outcome and complications were reviewed in all patients.

RESULTS

During the study period, we operated on 25 emergency patients with metastatic renal cell carcinoma causing spinal cord compression who had received pre-operative embolisation (mean age 59.6 (24-78) years; 8 females, 17 males). All but one of our patients had hypervascularisation/arterio-venous fistulae on angiography. We were able to achieve greater than 90 % embolisation in the majority (17/25, 68 %) The estimated blood loss was 1,696 (400-5,000) ml; mean operating time was 276 (90-690) min and an average of 2.3 (0-7) units of whole blood was transfused. Nine patients had a posterior only decompression/stabilisation, nine patients had a posterior decompression ± cement augmentation, six had combined anterior/posterior procedures and one had anterior corpectomy/reconstruction alone. There was no statistical difference in the EBL between immediate versus delayed surgery after embolisation or the grade of embolisation. Immediate surgery after embolisation and interestingly less complete embolisation showed a trend towards less EBL. The extent of the tumour as graded by the Bilsky score correlated with increased EBL (p = 0.042). No complications occurred during the embolisation procedure. The surgical complication rate was 32 % (8/25) including two major complications (septicaemia (1) and metal work failure (2)) and five minor complications. Postoperatively, 52 % (13/25) had no change in neurological status, 36 % (9/25) improved by at least one Frankel grade and 12 % (3/25) had neurological deterioration by one Frankel grade. The average survival following surgery was 14.1 (0.5-72) months.

CONCLUSION

Blood loss (mean 1,696 ml) and complications (32 %) remain a concern in the operative treatment of vascular metastatic spinal cord compression. Most patients remained the same neurologically or improved by at least 1 grade (22/25, 88 %). Paradoxically, greater embolisation showed a trend to more blood loss which could be due to more extensive surgery in this group, a rebound 'reperfusion' phenomena or even the presence of arterio-venous fistulae. Interestingly, we also found that the extent of the tumour, as graded by the Bilsky score, correlated with increased blood loss suggesting that more extensive cord compression by metastases could lead to more blood loss intra-operatively.

Primary care direct access MRI for the investigation of chronic headache

AIM

To assess the efficacy of a primary-care imaging pathway for neurology outpatients, from inception to deployment, compared with traditional outpatient referral.

MATERIALS AND METHODS

After local agreement, guidelines were generated providing pathways for diagnosis and treatment of common causes of headache, highlighting "red-flag" features requiring urgent neurology referral, and selecting patients for direct magnetic resonance imaging (MRI) referral. In addition, reports were clarified and standardized. To evaluate the efficacy of the access pathway, a retrospective sequential review of 100 MRI investigations was performed comparing general practitioner (GP) referral, with traditional neurology referral plus imaging, acquired before the pathway started.

RESULTS

No statistically significant difference in rates of major abnormalities, incidental findings or ischaemic lesions were identified between the two cohorts. Reported patient satisfaction was high, with a cost reduction for groups using the pathway.

CONCLUSION

The findings of the present study suggest that a defined access pathway for imaging to investigate chronic headache can be deployed appropriately in a primary-care setting.

Imaging of acute neurological conditions in pregnancy and the puerperium

Eclampsia is one of the most common acute neurological events occurring during pregnancy. However, there are many other conditions that can present during pregnancy and the puerperium and that may either mimic eclampsia or produce other acute neurological manifestations. Frequently the symptoms and signs are non-specific, and it can be difficult to differentiate between these conditions on clinical grounds alone. Neuroradiological studies can provide valuable diagnostic information, and interventional radiological procedures may play a part in the subsequent management of these conditions. This review focuses on the imaging of acute neurological conditions which may be associated with, or present during, pregnancy and the puerperium.

Internal carotid artery dissection presenting with ipsilateral tenth and twelfth nerve palsies and apparent mass lesion on MRI

We report the case of a 47-year-old man who presented with a few months' history of right-sided headache and dysphagia, with ipsilateral tenth and twelfth cranial nerve palsies on examination. The initial MRI showed an enhancing mass lesion in relation to the right carotid sheath and jugular foramen, and was reported as a possible paraganglioma. Subsequent angiography performed to assess tumour vascularity demonstrated a dissection involving a tonsillar loop of the right internal carotid artery (ICA). Imaging findings at MRI and angiography and the presentations and mechanisms of ICA dissection are briefly discussed.

Complete thrombosis of a giant distal middle cerebral artery aneurysm

SUMMARY

Complete thrombosis of a giant cerebral aneurysm is rarely reported and peripheral giant middle cerebral artery (MCA) aneurysms are similarly rare. We present a case of complete spontaneous thrombosis of a giant sylvian artery aneurysm that had previously been wrapped at surgery.

Major orbital complications of endoscopic sinus surgery

BACKGROUND

The paranasal sinuses are intimately related to the orbit and consequently sinus disease or surgery may cause severe orbital complications. Complications are rare but can result in serious morbidity, the most devastating of which is severe visual loss.

METHODS

A retrospective review was undertaken of four cases of severe orbital trauma during endoscopic sinus surgery.

RESULTS

All the cases suffered medial rectus damage, one had additional injury to the inferior rectus and oblique, and two patients were blinded as a result of direct damage to the optic nerve or its blood supply.

CONCLUSION

Some ophthalmic complications of endoscopic sinus surgery are highlighted, the mechanisms responsible are discussed, and recommendations for prevention, early recognition, and management are proposed.

Pituitary apoplexy with optic tract oedema and haemorrhage in a patient with idiopathic thrombocytopenic purpura

Bilateral optic tract oedema, left optic tract haemorrhage and subarachnoid haemorrhage occurred in a 70-year-old man with pituitary apoplexy associated with idiopathic thrombocytopenic purpura. Left optic tract haemorrhage was confirmed on MRI.

Segmental portal hypertension due to splenic vein obstruction: imaging findings and diagnostic pitfalls in four cases

Segmental portal hypertension due to isolated splenic vein obstruction is a rare but important entity as it is the only curable cause of portal hypertension by splenectomy. Four cases are presented illustrating the radiological features of splenic vein obstruction, and the diagnostic pitfalls that arose in patients with complicated clinical presentations.

Growing skull fracture extending posteriorly to the superior sagittal sinus with intradiploic extension

An intradiploic extension of a post-traumatic encephalocoele is described in an infant.

Identification of glioma-associated antigen MUC 2-63 as CD44

Monoclonal antibody MUC 2-63 recognises neurogenic tumours and has been used successfully for radioimaging human malignant gliomas. We now show that the MUC 2-63 antigen has the same tissue distribution and molecular weight range as the CD44 antigen and confirm the identity of these two molecules in blocking studies using MUC 2-63 and the CD44 anti-framework antibody F10-44-2. Thus not only MUC 2-63 but also other anti-CD44 monoclonal antibodies should prove useful in imaging and, perhaps, therapy of brain tumours.

Arterial constrictor response in a diving mammal

Angiograms were obtained in the harbor seal, Phoca vitulina, in air and during diving. During diving there is arterial constriction of the vascular beds of muscle, skin, kidney, liver, spleen, and presumably of all vascular beds except those perfusing the brain and heart. There is sudden constriction and narrowing of muscular arteries close to their origin from the aorta. Constriction of small arterial branches is so intense that blood flow is essentially lost in all involved organs.