Mendis, Dinith

Introduction: AI-driven software has been recommended as a means of triaging suspected large vessel occlusions (LVOs) on CT angiography (CTA), and different solutions are now commercially available. This study compared the performance of two software packages, Brainomix 360 Triage LVO and Rapid LVO, in prospective, real-world use. Methods: Consecutive patients scanned for suspected stroke at 3 comprehensive stroke centres from May to July 2024 (3 months) were included in the study. CTA, where available, was processed in real time by both Rapid and Brainomix software. Ground truth on vessel occlusion was ascertained using clinical review of electronic medical records. Occlusion location was coded as intracranial internal carotid artery terminus (ICA-T), middle cerebral artery (MCA) M1 or MCA M2. If more than one occlusion was observed, the most proximal of these was taken as the primary vessel affected. Results: There were 561 suspected stroke patients scanned during the study period across the three sites. Of these, CTA was sent for processing by both Rapid LVO and Brainomix 360 Triage LVO for 359 cases. Cases were excluded if no contrast was detected (n=17), leaving 342 cases (Table 1). Of these, proximal LVO (ICA-T or MCA M1) was confirmed in 14 cases and MCA M2 occlusions were present in 6 cases. Table 2 shows the LVO detection results for all cases from the two software packages. For both devices, sensitivity was higher when considering only proximal occlusions (ICA-T or M1). Performance was similar overall, but there was a trend towards differing sensitivity for more distal occlusions. As a composite measure, area under the curve (AUC) was higher for Brainomix than Rapid (Figure 1) but this difference was not significant. The positive predictive value (PPV) was low for both software packages due to the low incidence of LVO in the patient population. Conclusions: This study demonstrated consistent performance of two AI software devices, Brainomix 360 Triage LVO and Rapid LVO, for detection of LVO on CTA imaging, in prospective, real-world use. The low number of positive cases in the dataset (N=21) is a limitation of the study. There was a trend towards different performance for more distal vessel occlusion locations. Overall, the sensitivity observed in this dataset was in line with reports from previous retrospective studies for both software packages and underlines the importance of prospective evaluation to understand real-world performance.

Background: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) can be misdiagnosed as multiple sclerosis (MS). This study aims to contrast demographic, clinical, neuroimaging, and genetic features of CADASIL patients with vs. without prior MS misdiagnosis. Methods: We conducted a retrospective cohort study to compare genetically or histopathologically confirmed CADASIL patients with and without a prior MS misdiagnosis across Mayo Clinic. Patients were classified into high-, medium-, low-, or unknown-risk by location of NOTCH3 mutation. Disease severity was assessed using NOTCH3 Small-Vessel Disease (N3SVD) scale. Between-group comparisons used independent t-test for age, chi-square or Fisher’s exact test for categorical variables, and Mann–Whitney U test for quantitative variables. Within the misdiagnosed subgroup, neuroimaging changes between MS to CADASIL diagnosis were assessed using Wilcoxon signed-rank test for quantitative data and Stuart–Maxwell test for categorical data. Significance was set at p<0.05 (two-sided). Results: Among 107 patients (mean age 57.5±13.4 yrs) with CADASIL, 12 (11.2%) had a prior MS misdiagnosis (Table 1). Compared to patients without misdiagnosis (n=95), those misdiagnosed were younger, more frequently Asian, more likely to undergo lumbar puncture (83.3% vs 26.3%, p <0.001), and less likely to have had stroke (33.3% vs 65.3%, p =0.031). There were no significant differences in deep white matter hyperintensity scores or lacune counts. However, the misdiagnosed group had a higher median modified Rankin Scale ( p =0.008) and a different distribution of N3SVD stages ( p =0.017), with a higher proportion in stage 3A (33.3% vs 5.3%). There was no significant difference in genetic risk categories (Figure), but 5 of 12 misdiagnosed cases clustered in the medium risk EGFR 13, 13.5, and 14 domains. Among the misdiagnosed, 41.7% received MS-specific treatment during a median of 10.2 months (range 0.4–138.1) before diagnostic correction (Table 2). Over this period, there were no significant changes in DWMH score, lacune count, mRS, or N3SVD stage (all p >0.05). Conclusions: About one in nine CADASIL patients had a prior MS diagnosis. Atypical presentations in younger individuals without a clear stroke history may prompt consideration of MS over CADASIL, leading to diagnostic delays and unnecessary treatments. EGFR domain risk category did not correlate with misdiagnosis.

Introduction: Migraine with aura may be the earliest symptom in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Female patients have a higher incidence of migraine with an increased associated disability. In this study, we systematically evaluate the clinical features and management of migraine in female patients with CADASIL in a multi-center health system. Methods: Clinical data was extracted from the electronic medical records of female patients diagnosed with CADASIL and managed at Mayo Clinic Enterprise. Diagnosis was confirmed by a pathogenic NOTCH3 mutation or granular osmiophilic material on skin biopsy. Results: Forty-three female patients with CADASIL were identified. Twenty-two patients (51.2%) had a diagnosis of migraine with aura and eight patients (18.6%) had a diagnosis of migraine without aura. The most common type of aura was visual (81.8%). Nineteen patients (63.3%) required at least one acute medicine and/or one preventive medicine. Acute therapy helped in 18 cases (94.7%) and preventive therapy helped in 13 cases (68.4%). Six patients (20%) tried at least three forms of acute therapy, and eleven patients (36.7%) tried at least three forms of preventive therapy. The presence of visual aura was associated with higher likelihood of need for acute therapy (OR = 3.0, 95% CI = 1.6 - 5.8, P = 0.015). However, the presence of any type of aura was associated with lower likelihood of need for or resistance to preventive therapy (OR = 0.08, 95% CI = 0.01 - 0.57, P = 0.005). Also, headache onset after age of 45 years was associated with higher likelihood of need for or resistance to preventive therapy (OR = 38.0, 95% CI = 2.7 - 528.0, P <0.001). The most common acute therapy was nonsteroidal anti-inflammatory drugs (NSAIDs) (14, 73.7%). Classes of preventive therapy involved anticonvulsants (15, 78.9%), antidepressants (11, 57.9%), Botox injections (7, 36.8%), beta blockers (6, 31.6%), calcium channel blockers (3, 15.8%), and calcitonin gene-related peptide (CGRP) inhibitors (3, 15.8%). Conclusion: Half of female patients with CADASIL had a diagnosis of migraine with aura. Around two thirds of them tried at least one form of acute therapy, most commonly NSAIDs, or preventive therapy, most commonly anticonvulsants. Resistance to preventive therapy was seen in more than 30% of the cases, highlighting the need for advances in migraine management in CADASIL.