Rabinstein, Alejandro A.

Background and Purpose— Superficial siderosis (SS) is characterized by hemosiderin deposition in the superficial layers of the central nervous system and can be seen during postmortem examination or with iron-sensitive magnetic resonance imaging techniques. The distribution of SS may predict the probable underlying cause. This study aimed to report the prevalence and natural history of SS in a population-based study. Methods— Brain magnetic resonance imaging scans from the MCSA (Mayo Clinic Study of Aging), a population-based study of residents 50 to 89 years of age in Olmsted County, Minnesota, were reviewed. Participants with imaging consistent with SS were identified from 2011 through 2016. An inverse probability weighting approach was used to convert our observed frequencies to population prevalence of SS. Additional data abstracted included amyloid positron emission tomography, Apolipoprotein E genotype, coexisting cerebral microbleeds, and extent of SS. Results— A total of 1412 participants had eligible magnetic resonance imaging scans. Two participants had infratentorial SS, restricted to the posterior fossa. Thirteen participants had cortical SS involving the cerebral convexities (7 focal and 6 disseminated). Only 3 of the participants with cortical SS (23%) also had cerebral microbleeds. The population prevalence of SS was 0.21% (95% confidence interval, 0–0.45) in those 50 to 69 years old and 1.43% (confidence interval, 0.53–2.34) in those over 69 years old. Apolipoprotein E ε2 allele was more common in those with SS (57.1% versus 15.0%; P <0.001). Compared with participants without SS, those with SS were also more likely to have a positive amyloid positron emission tomographic scan (76.9% versus 29.8%; P <0.001). Conclusions— SS may be encountered in the general elderly population. The association with increased amyloid burden and Apolipoprotein E ε2 genotype supports cerebral amyloid angiopathy as the most common mechanism. Longitudinal follow-up is needed to evaluate the risk of subsequent hemorrhage in cases of incidentally discovered SS.

OBJECTIVEIt has been suggested that increased body mass index (BMI) may confer a protective effect on patients who suffer from aneurysmal subarachnoid hemorrhage (aSAH). Whether the modality of aneurysm occlusion influences the effect of BMI on patient outcomes is not well understood. The authors aimed to compare the effect of BMI on outcomes for patients with aSAH treated with surgical clipping versus endovascular coiling.METHODSThe authors retrospectively reviewed the outcomes for patients admitted to their institution for the management of aSAH treated with either clipping or coiling. BMI at the time of admission was recorded and used to assign patients to a group according to low or high BMI. Cutoff values for BMI were determined by classification and regression tree analysis. Predictors of poor functional outcome (defined as modified Rankin Scale score > 2 measured ≥ 90 days after the ictus) and posttreatment cerebral hypodensities detected during admission were then determined separately for patients treated with clipping or coiling using stepwise multivariate logistic regression analysis.RESULTSOf the 469 patients admitted to the authors’ institution with aSAH who met the study’s inclusion criteria, 144 were treated with clipping and 325 were treated with coiling. In the clipping group, the frequency of poor functional outcome was higher in patients with BMI ≥ 32.3 kg/m2 (47.6% vs 19.0%; p = 0.007). In contrast, in the coiling group, patients with BMI ≥ 32.3 kg/m2 had a lower frequency of poor functional outcome at ≥ 90 days (5.8% vs 30.9%; p < 0.001). On multivariate analysis, high BMI was independently associated with an increased (OR 3.92, 95% CI 1.20–13.41; p = 0.024) and decreased (OR 0.13, 95% CI 0.03–0.40; p < 0.001) likelihood of poor functional outcome for patients treated with clipping and coiling, respectively. For patients in the surgical group, BMI ≥ 28.4 kg/m2 was independently associated with incidence of cerebral hypodensities during admission (OR 2.44, 95% CI 1.16–5.25; p = 0.018) on multivariate analysis. For patients treated with coiling, BMI ≥ 33.2 kg/m2 was independently associated with reduced odds of hypodensities (OR 0.45, 95% CI 0.21–0.89; p = 0.021).CONCLUSIONSThe results of this study suggest that BMI may differentially affect functional outcomes after aSAH, depending on treatment modality. These findings may aid in treatment selection for patients with aSAH.

Background and Purpose— There is currently controversy on the ideal anesthesia strategy during mechanical thrombectomy for acute ischemic stroke. We performed a systematic review and meta-analysis of studies comparing clinical and angiographic outcomes of patients undergoing general anesthesia (GA group) and those receiving either local anesthesia or conscious sedation (non-GA group). Methods— A literature search on anesthesia and endovascular treatment of acute ischemic stroke was performed. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome at 90 days (modified Rankin Score≤2), symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, and time to groin puncture. Results— Twenty-two studies (3 randomized controlled trials and 19 observational studies), including 4716 patients (1819 GA and 2897 non-GA) were included. In the nonadjusted analysis, patients in the GA group had higher odds of death (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.66–2.45) and respiratory complications (OR, 1.70; 95% CI, 1.22–2.37) and lower odds of good functional outcome (OR, 0.58; 95% CI, 0.48–0.64) compared with the non-GA group. There was no difference in procedure time between the 2 primary comparison groups. When adjusting for baseline National Institutes of Health Stroke Scale, GA was still associated with lower odds of good functional outcome (OR, 0.59; 95% CI, 0.29–0.94). When considering studies performed in the stent-retriever/aspiration era, there was no significant difference in good neurological outcome rates (OR, 0.84; 95% CI, 0.67–1.06). Conclusions— Acute ischemic stroke patients undergoing intra-arterial therapy may have worse outcomes when treated with GA as compared with conscious sedation/local anesthesia. However, major limitations of current evidence (ie, retrospective studies and selection bias) indicate a need for adequately powered, multicenter randomized controlled trials to answer this question.

We present a case of supraclinoid internal carotid artery dissection. Eleven months prior, the patient developed isolated periorbital pain and was diagnosed with giant-cell arteritis with iritis. The patient experienced recurrent spells concerning for transient ischaemic attacks and was transferred to our institution for endovascular intervention after head CT revealed an embolic infarct with a ‘dense middle cerebral artery sign.’ Digital subtraction angiography was negative for occlusion, instead demonstrating luminal stenosis and poststenotic dilatation. He subsequently experienced acute neurological decline secondary to massive subarachnoid haemorrhage. Non-invasive vascular imaging revealed an intimal flap and a pseudoaneurysm at the site of luminal stenosis, confirming our suspicion for intracranial carotid artery dissection. Given the moribund clinical state, the family opted to withdraw care, and he quickly expired.

Intracranial aneurysms are heterogeneous in histopathology and imaging appearance. The biological behavior of different types of aneurysms is now known to depend on the structure and physiology of the aneurysm wall itself in addition to intraluminal flow and other luminal features. Aneurysm wall structure and imaging markers of physiology such as aneurysm wall enhancement have been assessed in many prior investigations using conventional-resolution MRI. Recently, high-resolution vessel wall imaging (HR-VWI) techniques with MRI have been introduced. Reports of findings on high-resolution imaging have already emerged for many types of aneurysms demonstrating detailed characterization of wall enhancement, thickness, and components, but many questions remain unexplored. This review discusses the key HR-VWI literature to date. Aneurysm wall findings on conventional-resolution MRI are also discussed as these may help one understand the potential utility and findings on HR-VWI for various aneurysm types. The authors have illustrated these points with several examples demonstrating both features already described in the literature and novel cases demonstrating the potential for future clinical and research applications.