Isolated third cranial nerve palsies may be caused by compressive intracranial aneurysms located at the junction of the internal carotid and posterior communicating arteries or, less commonly, at the apex of the basilar artery or its junction with the superior cerebellar or posterior cerebral arteries. Such aneurysms typically measure at least 4 mm in diameter. Technical improvements in noninvasive techniques, including CT and MRA, have yielded a detection rate of such aneurysms that approaches that of catheter cerebral angiography (CCA), which itself carries a small but serious risk. Multidetector technology, which allows a rapid scan time, has promoted CT to the first choice for investigating aneurysms in this setting except when dye or radiation exposure is unacceptable, as with pregnant women, children, and those with renal or severe cardiac disease. Major impediments to accurate detection are a lack of availability of trained technicians, who must perform manipulation of the raw imaging data ("post-processing"), and a paucity of certified neuroradiologists with the time, skill, and experience to devote to interpreting difficult cases. To avoid diagnostic mishaps, noninvasive studies should be reviewed by at least one neuroradiologist before aneurysm is rejected as the cause or before the patient undergoes CCA.

Objective To test the equivalence for clinical effectiveness between microdecompression and laminectomy in patients with central lumbar spinal stenosis. Design Multicentre observational study. Setting Prospective data from the Norwegian Registry for Spine Surgery. Participants 885 patients with central stenosis of the lumbar spine who underwent surgery at 34 Norwegian orthopaedic or neurosurgical departments. Patients were treated from October 2006 to December 2011. Interventions Laminectomy and microdecompression. Main outcome measures The primary outcome was change in Oswestry disability index score one year after surgery. Secondary endpoints were quality of life (EuroQol EQ-5D), perioperative complications, and duration of surgical procedures and hospital stays. A blinded biostatistician performed predefined statistical analyses in unmatched and propensity matched cohorts. Results The study was powered to detect a difference between the groups of eight points on the Oswestry disability index at one year. 721 patients (81%) completed the one year follow-up. Equivalence between microdecompression and laminectomy was shown for the Oswestry disability index (difference 1.3 points, 95% confidence interval −1.36 to 3.92, P<0.001 for equivalence). Equivalence was confirmed in the propensity matched cohort and full information regression analyses. No difference was found between groups in quality of life (EQ-5D) one year after surgery. The number of patients with complications was higher in the laminectomy group (15.0% v 9.8%, P=0.018), but after propensity matching for complications the groups did not differ (P=0.23). The duration of surgery for single level decompression was shorter in the microdecompression group (difference 11.2 minutes, 95% confidence interval 4.9 to 17.5, P<0.001), but after propensity matching the groups did not differ (P=0.15). Patients in the microdecompression group had shorter hospital stays, both for single level decompression (difference 1.5 days, 95% confidence interval 1.7 to 2.6, P<0.001) and two level decompression (0.8 days, 1.0 to 2.2, P=0.003). Conclusion At one year the effectiveness of microdecompression is equivalent to laminectomy in the surgical treatment of central stenosis of the lumbar spine. Favourable outcomes were observed at one year in both treatment groups. Trial registration ClinicalTrials.gov NCT02006901.

BACKGROUND: Appropriate thrombus-device interaction is critical for recanalization. Histology can serve as a proxy for mechanical properties, and thus inform technique selection.OBJECTIVE: To investigate the value of histologic characterization, we conducted a systematic review and meta-analysis on the relationship between thrombus histology and recanalization, technique, etiology, procedural efficiency, and imaging findings.METHODS: In this meta-analysis, we identified studies published between March 2010 and March 2020 reporting findings related to the histologic composition of thrombi in large vessel occlusion stroke. Studies with at least 10 patients who underwent mechanical thrombectomy using stent retriever or aspiration were considered. Only studies in which retrieved thrombi were histologically processed were included. Patient-level data were requested when data could not be directly extracted. The primary outcome assessed was the relationship between thrombus histology and angiographic outcome.RESULTS: A total of 22 studies encompassing 1623 patients met inclusion criteria. Clots associated with good angiographic outcome had higher red blood cell (RBC) content (mean difference [MD] 9.60%, 95% CI 3.85-15.34,P = .008). Thrombi retrieved by aspiration had less fibrin (MD −11.39, 95% CI −22.50 to −0.27,P = .046) than stent-retrieved thrombi. Fibrin/platelet-rich clots were associated with longer procedure times (MD 13.20, 95% CI 1.30-25.10,P = .037). Hyperdense artery sign was associated with higher RBC content (MD 14.17%, 95% CI 3.07-25.27,P = .027). No relationship was found between composition and etiology.CONCLUSION: RBC-rich thrombi were associated with better recanalization outcomes and shorter procedure times, suggesting that preinterventional compositional characterization may yield important prognostic and therapeutic guidance.

Background Endovascular therapy (EVT) dramatically improves clinical outcomes for patients with anterior circulation emergent large vessel occlusion (ELVO) strokes. With recent publication of two randomized controlled trials in favor of EVT for basilar artery occlusions, the Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee provides this focused update for the existing SNIS guideline, ‘Current endovascular strategies for posterior circulation large vessel occlusion stroke.’ Methods A structured literature review and analysis of studies related to posterior circulation large vessel occlusion (basilar or vertebral artery) strokes treated by EVT was performed. Based on the strength and quality of the evidence, recommendations were made by consensus of the writing committee, with additional input from the full SNIS Standards and Guidelines Committee and the SNIS Board of Directors. Results Based on the results of the most recent randomized, controlled trials on EVT for basilar or vertebral artery occlusion, the expert panel agreed on the following recommendations. For patients presenting with an acute ischemic stroke due to an acute basilar or vertebral artery occlusion confirmed on CT angiography, National Institutes of Health Stroke Scale (NIHSS) score of ≥6, posterior circulation Alberta Stroke Program Early CT Score (PC-ASPECTS) ≥6, and age 18–89 years: (1) thrombectomy is indicated within 12 hours since last known well (class I, level B-R); (2) thrombectomy is reasonable within 12–24 hours from the last known well (class IIa, level B-R); (3) thrombectomy may be considered on a case by case basis for patients presenting beyond 24 hours since last known well (class IIb, level C-EO). In addition, thrombectomy may be considered on a case by case basis for patients aged 89 years on a case by case basis (class IIb, level C-EO). Conclusions The indications for EVT of ELVO strokes continue to expand and now include patients with basilar artery occlusion. Further prospective, randomized controlled trials are warranted to elucidate the efficacy and safety of EVT in populations not included in this set of recommendations, and to confirm long term outcomes.

Aims: Over the past two decades, animal intracerebral hemorrhage (ICH) model studies have indicated that iron, released after hemoglobin degradation, is neurotoxic. Iron phantom and animal experiments have shown that magnetic resonance imaging (MRI) relaxivity maps correlate with iron concentration. This study expands this into patients.Methods: Eighteen human subjects with ICH underwent MRI at 3, 14, and 30 days. R2* relaxivity maps were used to calculate perihematomal iron concentrations and T2 imaging to determine hematoma and edema volumes.Results: Perihematomal iron concentrations were increased at all three time points and decreased with distance from the hematoma. While perihematomal iron concentrations did not vary with hematoma size, the total iron overload (increased iron concentration x volume of affected tissue) did. Total iron overload correlated with edema volume.Conclusions: These results demonstrate the feasibility of measuring perihematomal iron in ICH patients which may be important for monitoring treatment strategies and assessing efficacy noninvasively.