1. Roa JA, Zanaty M, Osorno-Cruz C, et al. Objective quantification of contrast enhancement of unruptured intracranial aneurysms: a high-resolution vessel wall imaging validation study. J Neurosurg 2020;134(March):1–8
High-resolution vessel wall imaging (HR-VWI) has emerged as a valuable tool in assessing unruptured intracranial aneurysms (UIAs). There is no standardized method to quantify contrast enhancement of the aneurysm wall. Contrast enhancement can be objectively measured as signal intensity (SI) or subjectively adjudicated. In this study, the authors compared the different methods to quantify wall enhancement of UIAs and determined the sensitivity and specificity of each method as a surrogate of aneurysm instability. They also compared SI quantification between scanners from different manufacturers.
The mean and maximal SI values of the aneurysm wall, pituitary stalk, and genu of the corpus callosum were used to compare 3 different measurement methods:
1) aneurysm enhancement ratio AER = (SIwall post − SIwall pre)/SIwall pre;
2) aneurysm-to–pituitary stalk contrast ratio CRstalk = SIwall post/SIstalk post; and
3) aneurysm enhancement index AEI = ([SIwall post/SIbrain post] − [SIwall pre/SIbrain pre])/(SIwall pre/SIbrain pre).
9 UIAs underwent the same HR-VWI protocol using a 3T General Electric (GE) scanner and a 3T Siemens scanner. Three UIAs also underwent a third scanning procedure on a unit with a different magnet strength (7T GE).
CRstalk using maximal SI values was the most reliable objective method to quantify enhancement of UIAs on HR-VWI. The same ratios were obtained between different manufacturers and on scans obtained using magnets of different strengths.
3 figures with MR, 3 tables
2. Alhilali LM, Little AS, Yuen KCJ, et al. Early postoperative MRI and detection of residual adenoma after transsphenoidal pituitary surgery. J Neurosurg 2020;1–10
MRI is the standard of care for evaluation of sellar lesions; however, its use in the immediate postoperative period is controversial, with several studies suggesting that early postoperative (EPO) imaging cannot be reliably interpreted. As a result, the neurosurgical consensus guidelines for postoperative follow-up after transsphenoidal resection do not recommend early postoperative MRI.
At the author’s institution, patients undergoing microscopic resection of adenomas receive both early postoperative (< 48 hours after surgery) and LPO (3 months after surgery) MRI. This protocol is based on their own experience, in which early postoperative MRI has demonstrated its value by providing actionable clinical information regarding residual tumor and the need for immediate reresection. This protocol of performing both early postoperative and LPO MRI for patients with pituitary adenomas provides an opportunity to directly compare the value of EPO MRI with the current standard of surgical assessment followed by delayed imaging at 3 months after surgery. They sought to determine whether early postoperative MRI outperforms surgical assessment and LPO MRI for detecting residual tumor after transsphenoidal resection.
102 consecutive patients who underwent microscopic transsphenoidal resection of a pituitary adenoma were included. Eighteen patients (18%) had confirmed residual tumors (12 confirmed by tumor growth, 5 by surgery, and 1 by biochemical evidence of persistent disease). Interreader reliability for detecting residual tumor on early postoperative MRI was almost perfect (κ = 0.88) and significantly higher than that for LPO MRI (κ = 0.69). EPO MRI was highly specific for residual tumor (98%), a finding similar to that for intraoperative assessment (99%) and significantly higher than that for LPO MRI (81%).
EPO MRI is accurate and reliable for the detection of residual tumor after transsphenoidal resection, increasing sensitivity for detecting residual tumors in the immediate postoperative period.
5 MR figures, 3 tables
3. Kim DK, Carr CM, Benson JC, et al. Diagnostic yield of lateral decubitus digital subtraction myelogram stratified by brain MRI findings. Neurology 2021;96:e1312–18
This retrospective diagnostic study included consecutive adult patients investigated for SIH who underwent lateral decubitus digital subtraction myelography. Patients without preprocedure brain and spine MRI and patients with extradural fluid collection on spine MRI (type 1 leak) were excluded. Lateral decubitus digital subtraction myelography images and brain MRIs were assessed by 2 independent blinded readers; a third reader adjudicated any discrepancies.
Diagnostic yield of lateral decubitus digital subtraction myelography was assessed, both overall and stratified by Bern SIH scoring (Dobrocky T, Grunder L, Breiding PS, Branca M, Limacher A, Mosimann PJ, et al. Assessing Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension With a Scoring System Based on Brain Magnetic Resonance Imaging Findings. JAMA Neurol [Internet]. 2019;76(5):580–7. Available from: http://www.ncbi.nlm.nih.gov/pubmed/30776059).
62 patients included in this study, 33 (53.2%) had a CSF leak identified on lateral decubitus digital subtraction myelography. Right-sided leaks were more common (70.6%), and the most commonly identified levels of leaks were at T6, T7, and T10. No leak was found in any of the 9 patients with Bern SIH score of 2 or less. Of the 11 patients with Bern SIH score of 3–4, 5 (45.5%) had a CSF leak identified; of the 42 patients with Bern SIH score of 5 or higher, 28 (66.7%) had a CSF leak identified. While the diagnostic yield for lateral decubitus digital subtraction myelography is high, these findings suggest that even in patients with high probability Bern SIH score, a third will not have a leak site identified on LDDSM. Pachymeningeal enhancement subgroup analysis shows that patients with or without pachymeningeal enhancement have similar diagnostic yield in LDDSM as long as the overall Bern SIH score is equivalent.
The authors propose that patients with brain MRI or clinical findings suspicious for SIH and a negative spine MRI or conventional CT myelogram require further testing with lateral decubitus digital subtraction myelography.
3 figures, 2 tables
4. Mac Grory B, Schrag M, Biousse V, et al. Management of central retinal artery occlusion: a scientific statement from the American Heart Association. Stroke 2021;55:157–66. Available from: https://www.ahajournals.org/doi/10.1161/STR.0000000000000366
They performed a literature review of randomized controlled clinical trials, prospective and retrospective cohort studies, case-control studies, case reports, clinical guidelines, review articles, basic science articles, and editorials concerning the management of CRAO. They assembled a panel comprising experts in the fields of vascular neurology, neuro-ophthalmology, vitreo-retinal surgery, immunology, endovascular neurosurgery, and cardiology, and document sections were divided among the writing group members. Each member received an assignment to perform a literature review, synthesize the data, and offer considerations for practice. Multiple drafts were circulated among the group until consensus was achieved.
CRAO refers to compromise of blood flow via the central retinal artery to the inner layers of the retina. This may result in infarction of the retina, and when it does, this conforms to the diagnosis of acute ischemic stroke. Ophthalmic artery occlusion variably involves infarction of the inner and outer retina, optic nerve head, globe, and ocular tissues (with the extent of tissue involvement dependent on the degree of collateral flow via the external carotid artery circulation). The diagnosis of CRAO is made by identifying classic clinical findings of sudden, painless vision loss, a relative afferent pupillary defect, and funduscopic findings indicative of retinal hypoperfusion.
The age- and sex-adjusted incidence of CRAO is 1.9 per 100 000 person-years in the United States, with the incidence rising to 10.1/100 000 person-years in those >80 years of age. CRAO is most strongly associated with an ipsilateral internal carotid artery stenosis. A single-center study of 103 cases of CRAO found that 37% of patients had ipsilateral critical carotid disease. In the EAGLE study (European Assessment Group for Lysis in the Eye), 77 of 84 patients had a comprehensive workup for potential pathogeneses, in whom 31 (40%) had ≥70% carotid artery stenosis. The EAGLE study demonstrated a high prevalence of cardiovascular risk factors: obesity (82%), hypertension (73%), tobacco use (49%), hypercholesterolemia (49%), and diabetes (14%) in the 77 patients evaluated. The natural history with respect to visual recovery is poor. 177 patients with nonarteritic CRAO (of whom 121 had visual acuity recorded during follow-up) found that nearly 80% of patients had a visual acuity of “count fingers” or worse at follow-up. Treatments discussed primarily include IV tpa, IA tpa and hyperbaric oxygen. There is an unmet need for a pragmatic, multicenter, randomized, double-blind, placebo-controlled clinical trial comparing intravenous tPA with placebo at early time points in patients with CRAO.
2 tables, 3 figures, no imaging
5. Sehn LH, Salles G. Diffuse large B-cell lymphoma. N Engl J Med 2021;384:842–58. Available from: http://www.ncbi.nlm.nih.gov/pubmed/33657296
Large B-cell lymphomas, with an estimated 150,000 new cases annually worldwide, represent almost 30% of all cases of non-Hodgkin’s lymphoma. Patients typically present with progressive lymphadenopathy, extranodal disease, or both and require therapy. Despite the advanced stage at presentation in the majority of patients, more than 60% can be cured with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) immunochemotherapy. Patients with treatment failure after R-CHOP often have a poor outcome — in particular, those with disease that is refractory to frontline or subsequent therapies — although some patients can have a durable remission and be cured after secondary therapies. Over the past two decades, improved insights into large B-cell lymphomas, in terms of epidemiology, prognostic factors, and biologic heterogeneity, have led to a refinement of disease classification and the development of new therapeutic approaches.
4 tables, 2 figures, no imaging
6. Rahmanzadeh R, Lu P, Barakovic M, et al. Myelin and axon pathology in multiple sclerosis assessed by myelin water and multi-shell diffusion imaging. Brain 2021 Mar 9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/33693571
The authors applied myelin water and multi-shell diffusion imaging to quantify the relative damage to myelin and axons (i) among different lesion types; (ii) in normal-appearing tissue; and (iii) across multiple sclerosis clinical subtypes and healthy controls. They also assessed the relation of focal myelin/axon damage with disability and serum neurofilament light chain as a global biological measure of neuroaxonal damage.
Ninety-one multiple sclerosis patients (62 relapsing-remitting, 29 progressive) and 72 healthy controls were enrolled in the study. Differences in myelin water fraction and neurite density index were substantial when lesions were compared to healthy controls and normal-appearing MS tissue: both white matter and cortical lesions exhibited a decreased myelin water fraction and neurite density index compared with healthy (P < 0.0001) and peri-plaque white matter (P< 0.0001). Periventricular lesions showed decreased myelin water fraction and neurite density index compared with lesions in the juxtacortical region (P < 0.0001 and P < 0.05). Similarly, lesions with paramagnetic rims showed decreased myelin water fraction and neurite density index relative to lesions without a rim (P < 0.0001). Also, in 75% of white matter lesions, the reduction in neurite density index was higher than the reduction in the myelin water fraction.
More extensive reduction in myelin water fraction and neurite density index in normal-appearing cortex was observed in progressive versus relapsing-remitting participants. Neurite density index in white matter lesions correlated with disability in patients with clinical deficits (P<0.01, beta=-10.00); and neurite density index and myelin water fraction in white matter lesions were associated to serum neurofilament light chain in the entire patient’s cohort.
Conclusions: (i) myelin and axon pathology in multiple sclerosis is extensive in both lesions and normal-appearing tissue; (ii) particular types of lesions exhibit more damage to myelin and axons than others; (iii) progressive patients differ from relapsing-remitting because of more extensive axon/myelin damage in the cortex; and (iv) myelin and axon pathology in lesions is related to disability in patients with clinical deficit.
5 figures, 3 tables
7. Zanon Zotin MC, Sveikata L, Viswanathan A, et al. Cerebral small vessel disease and vascular cognitive impairment: from diagnosis to management. Curr Opin Neurol 2021;34:246–57. Available from: https://journals.lww.com/10.1097/WCO.0000000000000913
Among the multiple mechanisms involved in vascular cognitive impairment, cerebral small vessel disease (SVD) is arguably the most prevalent one, contributing to cognitive impairment irrespective of stroke. SVD is characterized by abnormalities that affect the structure and function of small vessels of the brain, with multiple neuroimaging and neurological manifestations, including cognitive decline. Rather than a homogeneous disorder, SVD encompasses different sporadic and inherited diseases, resulting from a complex mix of genetic and vascular risk factors. The prevalence of SVD increases with age, and the two most common sporadic types are arteriolosclerosis, also referred to as hypertensive arteriopathy or deep perforator arteriopathy, and cerebral amyloid angiopathy (CAA). Arteriolosclerosis has been traditionally linked to hypertension and type II diabetes. In pathology, arteriosclerosis is characterized by abnormal thickening of arteriolar walls, preferentially located in the deep grey nuclei and deep white matter, observed in >80% of individuals over 80 years of age, according to autopsy studies. CAA is defined by pathological deposition of amyloid-b in the walls of cortical and leptomeningeal arterioles and capillaries. Moreover, CAA is known to commonly co-occur with Alzheimer’s disease. In this narrative review, the authors focus on the latest advances in the management of sporadic SVD related VCI, with an update on diagnostic criteria, neuroimaging markers and cognitive profile.
Vascular risk factor control and healthy lifestyle interventions are associated with reduced risk of dementia and are key to slowing down SVD progression and cognitive decline. Lowering blood pressure control to the standard target (<140/80 mmHg) is the primary modifiable prevention strategy, but a more aggressive blood pressure target (SBP<120 mmHg) and reduction of blood pressure variability may be beneficial in selected middle-aged and elderly patients.
157 references, 2 figures
8. Pennington Z, Ehresman J, McCarthy EF, et al. Chordoma of the sacrum and mobile spine: a narrative review. Spine J 2021;21:500–17. Available from: https://doi.org/10.1016/j.spinee.2020.10.009
Primary vertebral column malignancies affect 3 out of every million patients annually. Except for Ewing’s sarcoma, these pathologies − chordoma, osteosarcoma, chondrosarcoma − disproportionately affect patients aged 50 to 60 years. Among these, chordoma is unique in that while sparse extra-axial cases have been reported, it is almost exclusively found in the axial skeleton. Historically there have been no effective chemotherapeutic options for the treatment of chordoma. Additionally, the extremely high doses required for treatment with conventional radiation modalities carried unacceptable side effects from off-target exposure. Consequently, treatment has revolved around surgical resection, the gold standard of which is en bloc resection with negative margins. En bloc resection continues to be the standard of care, but increasingly neoadjuvant or adjuvant radiotherapy with focused photon therapy or charged particle therapy is to be included in treatment paradigms to improve local control. Additionally, ongoing recent and ongoing clinical trials have begun investigating the use of chemotherapy adjuvants for metastatic and unresectable disease.
6 figures, 2 tables
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