1. Brinjikji W, Huston J, Rabinstein AA, Kim G, Lerman A, Lanzino G. Contemporary carotid imaging: from degree of stenosis to plaque vulnerability. J Neurosurg. 2016;124(1):27–42. doi:10.3171/2015.1.JNS142452.
Very nice and detailed review article on the various methods of evaluating carotid plaque. Topics covered include a review of histopathology and classification of plaque, MR imaging, CT (multidetector-row CT, dual-source CT and CTA), ultrasound (both B mode and contrast enhanced), TCD, and molecular imaging (FDG-PET). 10 figures and 3 tables.
2. Eisenmenger L, Porter M-C, Carswell CJ, et al. Evolution of Diffusion-Weighted Magnetic Resonance Imaging Signal Abnormality in Sporadic Creutzfeldt-Jakob Disease, With Histopathological Correlation. JAMA Neurol. 2015;73(1):1. doi:10.1001/jamaneurol.2015.3159.
This study is the largest to date to describe the evolution of MRI signal abnormality on DWI in patients diagnosed as having sporadic Creutzfeldt-Jakob disease (sCJD), with histopathological correlation. The authors found that disease progression is accompanied by an increase in the extent and intensity of signal abnormality with the basal ganglia. They evaluated gray matter involvement on DWI among 37 patients with sCJD in 26 cortical/ 5 subcortical subdivisions per hemisphere using a semi quantitative scoring system at baseline and follow-up. Age, disease duration, atrophy, codon 129 methionine valine polymorphism, Medical Research Council Rating Scale score, and histopathological findings were also documented. 59 of 62 regions showing increased signal intensity at follow-up, the greatest within the caudate and putamen. They conclude that DWI abnormalities in the basal ganglia in may provide a noninvasive biomarker of disease severity for future therapeutic trials. 6 graphs and 1 MR imaging set.
3. Fennell VS, Martirosyan NL, Palejwala SK, Lemole GM, Dumont TM. Morbidity and mortality of patients with endovascularly treated intracerebral aneurysms: does physician specialty matter? J Neurosurg. 2016;124(1):13–17. doi:10.3171/2014.11.JNS141030.
The authors conducted a retrospective analysis of a large database, the University HealthSystem Consortium, in the years 2009–2013. Outcome measures of morbidity and mortality were evaluated according to the specialty of the treating physician in patients with endovascularly obliterated unruptured aneurysms and with subarachnoid hemorrhage. For patients treated with an unruptured aneurysm (12,400), patients with at least 1 complication were reported in 799 cases (6.4%). Deaths were reported in 193 cases (1.6%). The highest incidence of complications (11.1%) and deaths (3.0%) were reported by neurologists. The fewest complications were reported by neurosurgeons (5.4%). For subarachnoid hemorrhage patients (8197), at least 1 complication was reported in 2385 cases (29%) and deaths in 983 cases (12%). The highest incidence of complications (34%) and deaths (13.5%) in subarachnoid hemorrhage was in cases performed by neurologists. The fewest complications were in cases by neurosurgeons (27%). Interventional radiologists fell in the middle for both patient groups. They conclude that there was a statistically significant finding that neurosurgically trained physicians demonstrate improved outcomes with respect to endovascular treatment of unruptured aneurysms in this cohort. They state that the lower complication and mortality rates for neurosurgeons is compelling and warrants further investigation.
4. Montanera W. Editorial: Does physician specialty matter? J Neurosurg. 2016;124(1):7–8. doi:10.3171/2015.1.JNS142794.
In this measured editorial regarding the Fennell paper, Dr. Montanera outlines several difficulties drawing conclusions from this paper:
- The limitations of the database are many, and the analysis is retrospective.
- Institutions or individuals “self-report” to the database and a “complication” is not defined or detailed.
- There is no data allowing comparison of the patients (age, comorbidities, subarachnoid hemorrhage grading), or the aneurysms treated (such as size, location, neck width).
- No data concerning the procedure volumes for treating centers.
Dr. Montanera asks the big question: How do we optimize training for the neuroendovascular practitioner of the future?
Having reliable data would be a start.
5. Fu MC, Webb ML, Buerba RA, et al. Comparison of agreement of cervical spine degenerative pathology findings in magnetic resonance imaging studies. Spine J. 2015;16(1):42–48. doi:10.1016/j.spinee.2015.08.026.
This is a retrospective study of 48 patients who underwent routine cervical spine MRI at the author’s institution between January 2011 and June 2012. A panel of 2 orthopedic spine surgeons and 4 musculoskeletal radiologists independently reviewed 48 sets of T2-weighted axial and sagittal MRI sequences for a series of preselected criteria, and their findings were compared with those of the other panelists to determine inter-rater agreement. Absolute inter-rater agreement ranged from 54.6% to 95.0%. Disc hydration (54.6%), central stenosis (72.7%), and foraminal stenosis (73.1%) demonstrated the lowest inter-rater agreement. Spondylolisthesis (95.0%) and cord signal change (92.9%) demonstrated the highest agreement. The conclude that physicians should be aware of inconsistencies in the interpretation of cervical MRI findings and should be aware that some findings demonstrate lower agreement than others. The Discussion has a nice review of the literature showing other investigators have also found wide variations in findings for central stenosis and foraminal stenosis.
6. Leslie-Mazwi TM, Hirsch JA, Falcone GJ, et al. Endovascular Stroke Treatment Outcomes After Patient Selection Based on Magnetic Resonance Imaging and Clinical Criteria. JAMA Neurol. 2015;02114(1):1. doi:10.1001/jamaneurol.2015.3000.
This is a single-center, prospective cohort study evaluating 72 patients with middle cerebral artery or terminal internal carotid artery occlusion (using CTA), followed by core infarct volume determination by DWI MRI, who underwent thrombectomy. Patients were prospectively classified as “likely to benefit” or “uncertain to benefit” using diffusion-weighted imaging lesion volume and clinical criteria (age, NIH Stroke Scale score, time from onset, baseline modified Rankin Scale [mRS] score, life expectancy). Forty patients were prospectively classified as likely to benefit and 32 as uncertain to benefit. Reperfusion (71 of 103 patients) and prospective categorization as likely to benefit (40 of 103 patients) were associated with favorable outcomes. They conclude that selection of patients using MRI compares favorably with selection using computed tomographic techniques with the distinction that a higher proportion of screened patients were treated.
So what defined the likely to benefit group? All of these criteria had to be met: (1) age younger than 80 years, (2) time from stroke onset or last seen well to groin puncture of less than 6 hours, (3) premorbid baseline mRS score of 1 or less and life expectancy greater than 12 months, and (4) DWI volume less than 70 mL.
The uncertain to benefit had age of 80 or greater, time from stroke onset of 6-8 hours, premorbid mRS 2-3, and DWI volume of 70-100 mL.
The theory is that patients with a clinical deficit and small core infarct despite a proximal vessel occlusion must have an excellent collateral circulation. A threshold DWI volume of <70 mL has been used to improve outcomes in patients with acute stroke treated endovascularly. This was also used in the DEFUSE 2 trial (Lansberg MG, Straka M, Kemp S, et al; DEFUSE 2 study investigators. MRI profile and response to endovascular reperfusion after stroke (DEFUSE 2): a prospective cohort study. Lancet Neurol. 2012;11(10):860-867).
7. Mok FPS, Samartzis D, Karppinen J, Fong DYT, Luk KDK, Cheung KMC. Modic changes of the lumbar spine: prevalence, risk factors and association with disc degeneration and low back pain in a large-scale population-based cohort. Spine J. 2015;16(1):32–41. doi:10.1016/j.spinee.2015.09.060.
Sagittal T2-weighted MRIs of the lumbar spine were assessed for the presence of Modic changes (MC) and other spinal phenotypes (disc degeneration, disc displacement, Schmorl nodes) in 2449 Southern Chinese volunteers. The subjects’ demographics, occupation, lifestyle, and clinical profiles were also assessed. Overall prevalence of MC was 5.8% (n=141) which increased with age. MC at L4/L5–L5/S1 were associated with age, the Schmorl nodes, disc degeneration or displacement, and a history of lumbar injury. The presence of MC at the lower lumbar levels were associated with a history of LBP and correlated with disc degeneration.
It is notable that because the study was originally designed to assess disc degeneration, only T2-weighted images were available, and the differentiation of types of MC was not done.
8. Srivastava SK, Aggarwal RA, Nemade PS, Bhosale SK. Single-stage anterior release and posterior instrumented fusion for irreducible atlantoaxial dislocation with basilar invagination. Spine J. 2016;16(1):1–9. doi:10.1016/j.spinee.2015.09.037
This is a retrospective case series of 19 patients surgically treated for irreducible atlantoaxial dislocation. The surgeries consisted of an anterior release done via transoral approach in 12 patients and a retropharyngeal approach in 7. Following the anterior release, all patients underwent posterior instrumented fusion. Causes of the dislocation included occipitalization of atlas in 16 patients, os odontoideum in 2 patients, and missing posterior elements of the axis in 1 patient. The anterior release is preformed by cutting the bilateral longus colli and longus capitis muscles along with anterior longitudinal ligament. If traction does not reduce the dislocation at this point, then subperiosteal stripping of the posterior pharyngeal wall is done to expose the C1–C2 joint capsule and the capsule is opened and adhesions released.
In this U.S., the most likely surgery for these patients would be transoral resection of the odontoid with posterior fixation.
