IMPORTANCE Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice. OBJECTIVE To develop a probability score based on the most relevant brain MRI findings to assess the likelihood of an underlying spinal cerebrospinal fluid (CSF) leak in patients with SIH. DESIGN, SETTING, AND PARTICIPANTS This case-control study in consecutive patients investigated for SIH was conducted at a single hospital department from February 2013 to October 2017. Patients with missing brain MRI data were excluded. Three blinded readers retrospectively reviewed the brain MRI scans of patients with SIH and a spinal CSF leak, patients with orthostatic headache without a CSF leak, and healthy control participants, evaluating 9 quantitative and 7 qualitative signs. A predictive diagnostic score based on multivariable backward logistic regression analysis was then derived. Its performance was validated internally in a prospective cohort of patients who had clinical suspicion for SIH. MAIN OUTCOMES AND MEASURES Likelihood of a spinal CSF leak based on the proposed diagnostic score. RESULTS A total of 152 participants (101 female [66.4%]; mean [SD] age, 46.1 [14.3] years) were studied. These included 56 with SIH and a spinal CSF leak, 16 with orthostatic headache without a CSF leak, 60 control participants, and 20 patients in the validation cohort. Six imaging findings were included in the final scoring system. Three were weighted as major (2 points each): pachymeningeal enhancement, engorgement of venous sinus, and effacement of the suprasellar cistern of 4.0 mm or less. Three were considered minor (1 point each): subdural fluid collection, effacement of the prepontine cistern of 5.0 mm or less, and mamillopontine distance of 6.5 mm or less. Patients were classified into groups at low, intermediate, or high probability of having a spinal CSF leak, with total scores of 2 points or fewer, 3 to 4 points, and 5 points or more, respectively, on a scale of 9 points. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. CONCLUSIONS AND RELEVANCE This 3-tier predictive scoring system is based on the 6 most relevant brain MRI findings and allows assessment of the likelihood (low, intermediate, or high) of a positive spinal imaging result in patients with SIH. It may be useful in identifying patients with SIH who are leak positive and in whom further invasive myelographic examinations are warranted before considering targeted therapy.

Background and Purpose-Sustained successful reperfusion is an important prognostic factor for good clinical outcome in acute ischemic stroke. We aimed to identify the prevalence, clinical impact, and predictors of early reocclusion after initially successful thrombectomies within a prospective cohort. Methods-A total of 711 stroke patients with successful reperfusion (modified Thrombolysis in Cerebral Infarction, 2b/3) followed with magnetic resonance or computed tomographic angiography at 24 to 48 hours were included. Multivariable logistic regression analysis was used to evaluate associated factors and clinical impact. Results are displayed as adjusted odds ratio (aOR) and 95% CI. Improvement in accuracy of additional imaging findings on angiography control runs after the intervention was evaluated by area under the curve. Results-Early reocclusion was observed in 16 of 711 successfully reperfused patients (2.3%; 95% CI: 1.1-3.3; median delay: 20 hours). Suggestive predictors were higher platelets on admission (aOR, 1.01; 95% CI: 1.01-1.02), prestroke functional dependence (aOR, 7.12; 95% CI: 1.49-34.03), and stroke of undetermined or other specified pathogenesis in the TOAST classification (aOR, 7.19; 95% CI: 1.10-47.05 and aOR, 36.50; 95% CI: 4.47-298.11, respectively). When implementing residual embolic fragments or stenosis at the thrombectomy site into the logistic regression model, discrimination between patients with and without reocclusion improved significantly (area under the curve, 0.955 versus 0.854; P=0.023). Early reocclusion was an independent predictor of unfavorable outcome at 90 days (aOR for modified Rankin Scale ≤2, 0.13; 95% CI: 0.03-0.57). Conclusions-Early reocclusion within 48 hours after successful mechanical thrombectomy is rare but associated with poor outcome. Patients with high platelets on admission and residual embolic fragments or stenosis at the thrombectomy site are at high risk for reocclusion, which may be prevented or corrected after carefully re-evaluating the past angiographic run. (Stroke. 2018;49:00-00.

Reasons for reperfusion failure in stent-retriever thrombectomy are heterogeneous. The failure to establish intracranial or cervical access is almost as common as stent-retriever failure after establishing intracranial access. Systematic reporting standards of reasons may help to further estimate relative frequencies and thereby guide priorities for technical development and scientific effort.

Stent retriever thrombectomy of calcified thromboemboli seems less effective than with other types of clots. Different mechanical properties of calcified clots may render them stiffer and less accessible for stent retrievers. When faced with a calcified intracranial thromboembolus in clinical practice, a more contained approach may be warranted in view of low recanalization rates, and the potential for periprocedural adverse events.