1. Frisoli FA, Srinivasan VM, Catapano JS, et al. Vertebrobasilar dissecting aneurysms: microsurgical management in 42 patients. J Neurosurg 2022;137(August):393–401
Dissecting intracranial aneurysms are formed by a longitudinally oriented tear in the arterial wall that creates a false lumen with intramural thrombus and luminal stenosis. Multiple consequences of these aneurysms include vessel thrombosis, thromboembolism, and subarachnoid hemorrhage (SAH). Unlike saccular aneurysms, dissecting aneurysms are not amenable to conventional clipping or coil obliteration. Experiences with endovascular management using VA sacrifice, stent coiling, and flow diversion have shown good results, but fewer modern microsurgical series have been published. Three surgical options exist to treat VBD aneurysms: clip wrapping, bypass trapping, and parent artery occlusion.
The medical records of patients with dissecting aneurysms affecting the intracranial VA (V4), basilar artery, and PICA that were treated microsurgically over a 19-year period were reviewed. Patient demographics, aneurysm characteristics, surgical procedures, and clinical outcomes were analyzed.
Forty-two patients with 42 VBD aneurysms were identified. Twenty-six aneurysms (62%) involved the PICA, 14 (33%) were distinct from the PICA origin on the V4 segment of the VA, and 2 (5%) were located at the vertebrobasilar junction. Thirty-four patients (81%) presented with SAH with a mean Hunt and Hess grade of 3.2 at presentation. Six (14%) of the 42 patients had been previously treated using endovascular techniques. Nineteen aneurysms (45%) underwent clip wrapping, 17 (40%) were treated with bypass trapping, and 6 (14%) underwent parent artery sacrifice. The complete aneurysm obliteration rate was 95% (n = 40), and the surgical complication rate was 7% (n = 3). Good outcomes (mRS score ≤ 2) were observed in 20 patients (48%). Eight patients (19%) died.
These data demonstrate that patients with VBD aneurysms often present after a rupture in poor neurological condition, but favorable results can be achieved with open microsurgical repair in almost half of such cases. Microsurgery remains a viable treatment option.
4 tables, 3 figures with intraop photos, CTA and catheter angiograms
2. Benjamin CG, Gurewitz J, Kavi A, et al. Survival and outcomes in patients with ≥ 25 cumulative brain metastases treated with stereotactic radiosurgery. J Neurosurg 2022;137(August):571–81
In the era in which more patients with greater numbers of brain metastases (BMs) are being treated with stereotactic radiosurgery (SRS) alone, it is critical to understand how patient, tumor, and treatment factors affect functional status and overall survival (OS). The authors examined the survival outcomes and dosimetry to critical structures in patients treated with Gamma Knife radiosurgery (GKRS) for ≥ 25 metastases in a single session or cumulatively over the course of their disease.
The institution’s prospective Gamma Knife (GK) SRS registry was queried to identify patients treated with GKRS for ≥ 25 cumulative BMs between June 2013 and April 2020. Ninety-five patients were identified, and their data were used for analysis.
Ninety-five patients were treated for ≥ 25 cumulative metastases, resulting in a total of 3596 tumors treated during 373 separate treatment sessions. The median number of SRS sessions per patient was 3 (range 1–12 SRS sessions), with nearly all patients (n = 93, 98%) having > 1 session. On univariate analysis, factors affecting OS in a statistically significant manner included histology, tumor volume, tumor number, diagnosis-specific graded prognostic assessment (DS-GPA), brain metastasis velocity (BMV) (the cumulative number of new brain metastases that developed over time since first SRS in years) and need for subsequent whole-brain radiation therapy (WBRT).
Seventy-nine patients (83%) had all treated tumors controlled at last follow-up, reflecting the high and durable control rate. Corticosteroids for tumor or treatment-related effects were prescribed in just over one-quarter of the patients. Of the patients with radiographically proven adverse radiation effects (AREs; 15%), 4 were symptomatic. Four patients required subsequent craniotomy for hemorrhage, progression, or AREs.
In selected patients with a large number of cumulative BMs, multiple courses of SRS are feasible and safe. Together with new systemic therapies, the study results demonstrate that the achieved survival rates compare favorably to those of larger contemporary cohorts, while avoiding WBRT in the majority of patients.
3 figures, 5 tables with no imaging
3. Yoo J, Yoon S-J, Kim KH, et al. Patterns of recurrence according to the extent of resection in patients with IDH–wild-type glioblastoma: a retrospective study. J Neurosurg 2022;137(August):533–43
This single-center study included 358 eligible patients with histologically confirmed isocitrate dehydrogenase (IDH)–wild-type GBM from November 1, 2005, to December 31, 2018. Patients were assigned to one of three separate groups according to EOR: supratotal resection (SupTR), gross-total resection (GTR), and subtotal resection (STR) groups. The patterns of recurrence were classified as local, marginal, and distant based on the range of radiation. The relationship between EOR and recurrence pattern was statistically analyzed.
To determine the patterns of recurrence, they merged simulation CT images containing isodose volumes from RT planning with the MR images used to diagnose the recurrence. Recurrence was categorized along with T1 CE images as follows: local (i.e., infield gross target volume [GTV] within the 60-Gy isodose line and infield clinical target volume [CTV] within the 46-Gy isodose line); marginal, within 2 cm of the 46-Gy isodose line; and distant, all outside the 46-Gy isodose line. Illustrations and clinical examples with isodose lines are shown in Fig. 3 in the manuscript.
Observed tumor recurrence rates for each group were as follows: SupTR group, 63.4%; GTR group, 75.3%; and STR group, 80.5% (p = 0.072). Statistically significant differences in patterns of recurrences among groups were observed with respect to local recurrence (SupTR, 57.7%; GTR, 76.0%; STR, 82.8%; p = 0.036) and distant recurrence (SupTR, 50.0%; GTR, 30.1%; STR, 23.2%; p = 0.028). Marginal recurrence showed no statistical difference between groups. Both overall survival and progression-free survival were significantly increased in the SupTR group compared with the STR and GTR groups.
Whereas novel treatments, including immunotherapy, have recently been attempted, surgical treatment remains one of the most important approaches in the treatment of GBM. In this study on the effects of EOR on GBM recurrence, the authors demonstrated a significant decrease in local recurrence and an increase in distant recurrence as the EOR increased. These findings may aid in making decisions regarding the EOR and adjuvant therapy, help identify patients at risk for recurrence, and inform planned postoperative surveillance imaging.
3 tables and 5 figures, with MRI
4. Charidimou A, Boulouis G, Frosch MP, et al. The Boston criteria version 2.0 for cerebral amyloid angiopathy: a multicentre, retrospective, MRI-neuropathology diagnostic accuracy study. Lancet Neurol 2022;21:714–25. Available from: http://www.ncbi.nlm.nih.gov/pubmed/35841910
The clinical and imaging Boston criteria, first introduced in the 1990s and later updated to the modified Boston criteria in 2010, are widely used for the diagnosis of cerebral amyloid angiopathy (CAA). Two independent reviewers did a systematic review of diagnostic accuracy studies that used different versions of the Boston criteria against the reference standard of neuropathologically proven CAA. Studies were restricted to those listed in PubMed published between Sept 15, 1994, and Feb 23, 2022, in the English language.
According to the 2010 version of the criteria a diagnosis of probable CAA entails demonstration of multiple (ie, two or more) hemorrhagic lesions restricted to lobar brain regions, including intracerebral hemorrhage, cerebral microbleeds, and the presence of cortical superficial siderosis. The 2010 criteria have not been validated across the spectrum of CAA clinical presentations and have not systematically incorporated more recently identified MRI features.
The authors derived the Boston criteria version 2.0 (v2.0) by selecting MRI features to optimize diagnostic specificity and sensitivity in a prespecified derivation cohort (Boston cases 1994–2012, n=159), then externally validated the criteria in a prespecified temporal validation cohort (Boston cases 2012–18, n=59) and a geographical validation cohort (non-Boston cases 2004–18; n=123), comparing accuracy of the new criteria to the currently used modified Boston criteria with histopathological assessment of CAA as the diagnostic standard. They also assessed performance of the v2.0 criteria in patients across all cohorts who had the diagnostic gold standard of brain autopsy.
Probable CAA;
For patients aged 50 years and older, clinical data and MRI demonstrating:
• Presentation with spontaneous intracerebral hemorrhage, transient focal neurological episodes, or cognitive impairment or dementia
• At least two of the following strictly lobar hemorrhagic lesions on T2*-weighted MRI, in any combination: intracerebral hemorrhage, cerebral microbleeds, or foci of cortical superficial siderosis or convexity subarachnoid hemorrhage
OR
• One lobar hemorrhagic lesion plus one white matter feature (severe perivascular spaces in the centrum semiovale or white matter hyperintensities in a multispot pattern)
A substantial update in the Boston criteria v2.0 is incorporation of the white matter markers of severe perivascular spaces in the centrum semiovale and white matter hyperintensities in a multispot pattern. Although these white matter lesions are neither perfectly specific nor perfectly sensitive for CAA, the authors data suggest their presence in conjunction with a single hemorrhagic lesion identifies a subset of true-positive patients with CAA who would otherwise be diagnosed as possible rather than probable CAA. Even in the absence of a hemorrhagic lesion, these white matter lesions identify some additional true-positive patients with CAA.
4 tables, 2 figures with MR
5. Boschert EN, Hagan DP, Christ AS, et al. Transpsoas lateral lumbar interbody fusion technique and indications. Semin Spine Surg 2022;34:100945. Available from: https://doi.org/10.1016/j.semss.2022.100945
This approach classically utilizes two separate incisions to access the retroperitoneal space through the abdominal wall musculature (external and internal obliques, transversus abdominis, and fascia) though it can be performed with only the lateral incision over the targeted disc space. Classically, the retroperitoneal space is first entered through an incision between the erector spinae muscle and the abdominal oblique muscle posterior to the mark (and eventual lateral incision) made over the disc space being targeted. Once through the abdominal layers, the access incision will allow finger palpation of the structures within the retroperitoneal space including the lateral aspect of the transverse process, inner table of the iliac crest, and the twelfth rib. Significant blunt dissection should be avoided in the retroperitoneal space to avoid nerve injury. This incision is utilized to guide the initial tissue dilator through the lateral incision over the disc space to the psoas muscle body.
Blunt dissection is performed through the retroperitoneal space to the psoas muscle and the dilator is passed from the lateral margin of the psoas to the disc space of interest on the medial aspect of the psoas. Coursing anterior to the psoas and vertebral body are the major vessels, which are largely avoided in this approach. Nerves at potential risk for injury include the iliohypogastric, ilioinguinal, and genitofemoral nerves as they course lateral to and through the psoas, respectively. In addition, the lumbar plexus is at particular risk during this approach given its position in the posterior 3rd of the psoas muscle with progressive anterior migration as it moves caudally through the lumbar spine.
14 figures with plenty of imaging
6. Vollmer BL, Solowey J, Chen X, et al. Individual and joint effects of influenza-like illness and vaccinations on stroke in the young: a case-control study. Stroke 2022;53:2585–93. Available from: https://www.ahajournals.org/doi/10.1161/STROKEAHA.121.038403
Influenza-like illness (ILI) is an acute trigger for stroke, although joint effects of vaccinations and ILI have not yet been explored. Data for this case-control study was obtained from MarketScan Commercial Claims and Encounters between 2008 and 2014. Patients 18 to 65 years old who experienced a stroke were matched on age and admission date to a control, defined as patients with head trauma or ankle sprain at an inpatient or emergency department visit. Exposures were ILI in the prior 30 days, and any type of vaccination during the year prior. Logistic regression models estimated adjusted odds ratios controlling for preventive care visits, diabetes, valvular heart disease, smoking, alcohol abuse, obesity, and hypertension.
The authors identified and matched 24,103 cases 18 to 44 years old and 141,811 45 to 65 years old. Those aged 18 to 44 years had increased stroke risk 30 days after ILI and reduced risk with any vaccination in the year prior.
In summary, this case-control study found ILI associated with increase in risk of stroke, while vaccines appeared to decrease the risk of stroke, particularly among the young. Further, this study uniquely examines joint effects of ILI and vaccinations on stroke with results indicating vaccinations can reduce the effect of ILI on stroke. These findings aid in informing at-risk groups who may most benefit from vaccination programs for stroke prevention and may provide additional motivation for younger populations to get their yearly influenza vaccine.
4 tables, and of course no imaging
7. Pirson FAV (Anne), Boodt N, Brouwer J, et al. Etiology of large vessel occlusion posterior circulation stroke: results of the MR CLEAN Registry. Stroke 2022;53:2468–77. Available from: https://www.ahajournals.org/doi/10.1161/STROKEAHA.121.038054
The authors used data of patients with posterior circulation stroke included in the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) registry, a prospective multicenter observational study, between 2014 and 2018. Stroke cause was categorized into large artery atherosclerosis (LAA), cardioembolism, arterial dissection, embolic stroke of undetermined source (ESUS), other determined cause, or undetermined cause. For primary analysis on the association between cause and outcome, they used multivariable ordinal logistic regression analysis to estimate the adjusted common odds ratio for a shift towards a better functional outcome on the modified Rankin Scale at 90 days with LAA as a reference group. Secondary outcomes included favorable functional outcome (modified Rankin Scale score 0–3), National Institutes of Health Stroke Scale score at 24 to 48 hours, reperfusion on digital subtraction angiography, and stroke progression.
Of 264 patients with posterior circulation stroke, 84 (32%) had large artery atherosclerosis, 48 (18%) cardioembolism, 31 (12%) dissection, and 14 (5%) embolic stroke of undetermined source. Patients with a dissection were younger (48 years) and had a lower National Institutes of Health Stroke Scale at baseline (12) than patients with other cause. Functional outcome was better for patients with cardioembolism and ESUS compared to LAA (modified Rankin Scale adjusted common odds ratio, 2.4, respectively adjusted common odds ratio, 3.1). Patients with a dissection had a lower chance of successful reperfusion compared with large artery atherosclerosis.
The authors conclude that unlike the anterior circulation, most frequent cause in the posterior large vessel occlusion stroke cohort is LAA followed by cardioembolism, dissection, and embolic stroke of undetermined source. Patients with cardioembolism and ESUS have a better prognosis for functional outcome after endovascular thrombectomy than patients with LAA.
2 figures, 2 tables, no imaging
8. Kopparapu S, Mao G, Judy BF, et al. Fifty years later: the “rule of Spence” is finally ready for retirement. J Neurosurg Spine 2022;37(August):1–8
Determination of the optimal approach to traumatic atlas fractures with or without transverse atlantal ligament (TAL) injury requires a nuanced understanding of the biomechanics of the atlantoaxial complex. The “rule of Spence” (ROS) was created in 1970 in a landmark effort to streamline management of burst-type atlas fractures. The ROS states that radiographic evidence of lateral mass displacement (LMD) (i.e., the distance that the C1 lateral masses extend beyond the C2 superior articular processes) greater than 6.9 mm may indicate both a torn TAL and need for surgical management. Since then, the ROS has become ubiquitous in the spine literature about atlas injuries. However, in the decades since the original paper by Spence et al., modern research efforts and imaging advancements have revealed that the ROS is inaccurate on both fronts: it neither accurately predicts a TAL injury nor does it inform surgical decision-making. The purpose of this review was to delineate the history of the ROS, demonstrate its limitations, present findings in the existing literature on ROS and LMD thresholds, and discuss the current landscape of management techniques for TAL injuries, including parameters such as the atlantodental interval and type of injury according to the Dickman classification system and AO Spine upper cervical injury classification system. The ROS was revolutionary for initially investigating and later propelling the biomechanical and clinical understanding of atlas fractures and TAL injuries; however, it is time to retire its legacy as a rule.
3 figures, 2 tables
9. Raji CA, Benzinger TLS. The value of neuroimaging in dementia diagnosis. Continuum (Minneap Minn) 2022;28:800–21
Nice extensive review of neuroimaging in dementias, including MRI brain quantitative volumetrics, routine MR imaging findings, PET and dopamine transporter scans (DAT).
12 figures and 2 tables
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