BACKGROUND: The potential association between bivalent COVID-19 vaccination and ischemic stroke remains uncertain, despite several studies conducted thus far.
OBJECTIVE: This study aimed to evaluate the risk of ischemic stroke following bivalent COVID-19 vaccination during the 2022-2023 season.
METHODS: A self-controlled case series study was conducted among members aged 12 years and older who experienced ischemic stroke between September 1, 2022, and March 31, 2023, in a large health care system. Ischemic strokes were identified using International Classification of Diseases, Tenth Revision codes in emergency departments and inpatient settings. Exposures were Pfizer-BioNTech or Moderna bivalent COVID-19 vaccination. Risk intervals were prespecified as 1-21 days and 1-42 days after bivalent vaccination; all non-risk-interval person-time served as the control interval. The incidence of ischemic stroke was compared in the risk interval and control interval using conditional Poisson regression. We conducted overall and subgroup analyses by age, history of SARS-CoV-2 infection, and coadministration of influenza vaccine. When an elevated risk was detected, we performed a chart review of ischemic strokes and analyzed the risk of chart-confirmed ischemic stroke.
RESULTS: With 4933 ischemic stroke events, we found no increased risk within the 21-day risk interval for the 2 vaccines and by subgroups. However, risk of ischemic stroke was elevated within the 42-day risk interval among individuals aged younger than 65 years with coadministration of Pfizer-BioNTech bivalent and influenza vaccines on the same day; the relative incidence (RI) was 2.13 (95% CI 1.01-4.46). Among those who also had a history of SARS-CoV-2 infection, the RI was 3.94 (95% CI 1.10-14.16). After chart review, the RIs were 2.34 (95% CI 0.97-5.65) and 4.27 (95% CI 0.97-18.85), respectively. Among individuals aged younger than 65 years who received Moderna bivalent vaccine and had a history of SARS-CoV-2 infection, the RI was 2.62 (95% CI 1.13-6.03) before chart review and 2.24 (95% CI 0.78-6.47) after chart review. Stratified analyses by sex did not show a significantly increased risk of ischemic stroke after bivalent vaccination.
CONCLUSIONS: While the point estimate for the risk of chart-confirmed ischemic stroke was elevated in a risk interval of 1-42 days among individuals younger than 65 years with coadministration of Pfizer-BioNTech bivalent and influenza vaccines on the same day and among individuals younger than 65 years who received Moderna bivalent vaccine and had a history of SARS-CoV-2 infection, the risk was not statistically significant. The potential association between bivalent vaccination and ischemic stroke in the 1-42-day analysis warrants further investigation among individuals younger than 65 years with influenza vaccine coadministration and prior SARS-CoV-2 infection. Furthermore, the findings on ischemic stroke risk after bivalent COVID-19 vaccination underscore the need to evaluate monovalent COVID-19 vaccine safety during the 2023-2024 season.

Stroke is the most common cause of death and disability in the world, and ischemic etiology plays a major role. Atrial septal aneurysm (ASA) is a localized saccular deformity of the atrial septum, associated with ischemic stroke independently or in association with other atrial septal defects (ASD). There is a higher incidence of stroke in the population with ASD. In these patients, the presence of ASA is an important predictor of recurrent stroke. This is a case of ischemic stroke in a 44-year-old who presented with sudden-onset right-sided body weakness, expressive aphasia, and non-specific confusion for one hour, with an initial National Institutes of Health Stroke Scale (NIHSS) score of 7. CT angiogram revealed occlusion of the M3 branch of the left middle cerebral artery in the left lateral frontal lobe. Code stroke was called, and the patient was given tenecteplase (TNK), after which her right-side weakness and aphasia resolved. Trans-thoracic echo with bubble study showed ASA with positive bubble study. Lone ASA or ASA with concomitant ASD poses a higher risk of recurrent stroke in younger patients, especially those without significant risk factors for strokes. Patients with ASA and concomitant ASD are at high risk for recurrent ischemic stroke and should be kept under surveillance with continued medical therapy. We present a case of ischemic stroke caused by ASA and a review of the current literature and case reports documenting cases with similar presentations.

BACKGROUND: The relative availability of the essential amino acid tryptophan in the brain, as indicated by the tryptophan index, which is the ratio of tryptophan to its competing amino acids (CAAs) in circulation, has been related to major depression. However, it remains unknown whether tryptophan availability is involved in the pathogenesis of ischemic stroke.
OBJECTIVE: We aimed to investigate the relationship between the tryptophan index and the risk of ischemic stroke.
METHODS: We performed a nested case-control study within a community-based cohort in eastern China over the period 2013 to 2018. The analysis included 321 cases of ischemic stroke and 321 controls matched by sex and date of birth. The plasma levels of tryptophan and CAAs, including tyrosine, valine, phenylalanine, leucine, and isoleucine, were measured by ultra-high-performance liquid chromatography-tandem mass spectrometry. Conditional logistic regression analyses were employed to determine incidence rate ratios (IRRs) and their 95% confidence intervals (CIs).
RESULTS: After adjustment for body mass index, current smoking status, educational attainment, physical activity, family history of stroke, hypertension, diabetes, hyperlipidemia, and estimated glomerular filtration rate, an elevated tryptophan index was significantly associated with a reduced risk of ischemic stroke in a dose-response manner (IRR, 0.76; 95% CI, 0.63-0.93, per standard deviation increment). The plasma tryptophan or CAAs were not separately associated with the risk of ischemic stroke.
CONCLUSIONS: The tryptophan index was inversely associated with the risk of ischemic stroke. Our novel observations suggest that the availability of the essential amino acid tryptophan in the brain is involved in the pathogenesis of ischemic stroke.

BACKGROUND: Neuroimaging is the gold-standard diagnostic modality for all patients suspected of stroke. However, the unstructured nature of imaging reports remains a major challenge to extracting useful information from electronic health records systems. Despite the increasing adoption of natural language processing (NLP) for radiology reports, information extraction for many stroke imaging features has not been systematically evaluated.
OBJECTIVE: In this study, we propose an NLP pipeline, which adopts the state-of-the-art ClinicalBERT model with domain-specific pretraining and task-oriented fine-tuning to extract 13 stroke features from head computed tomography imaging notes.
METHODS: We used the model to generate structured data sets with information on the presence or absence of common stroke features for 24,924 patients with strokes. We compared the survival characteristics of patients with and without features of severe stroke (eg, midline shift, perihematomal edema, or mass effect) using the Kaplan-Meier curve and log-rank tests.
RESULTS: Pretrained on 82,073 head computed tomography notes with 13.7 million words and fine-tuned on 200 annotated notes, our HeadCT_BERT model achieved an average area under receiver operating characteristic curve of 0.9831, F1-score of 0.8683, and accuracy of 97%. Among patients with acute ischemic stroke, admissions with any severe stroke feature in initial imaging notes were associated with a lower probability of survival (P<.001).
CONCLUSIONS: Our proposed NLP pipeline achieved high performance and has the potential to improve medical research and patient safety.

Delayed ischemic stroke associated with intractable vasospasm after clipping of unruptured intracranial aneurysms (UIAs) has been rarely reported. We report a patient with delayed ischemic stroke associated with intractable vasospasm following UIA clipping. A middle-aged female underwent surgery for unruptured middle cerebral artery bifurcation aneurysms. The patient tolerated the neurosurgical procedure well. Seven days postoperatively, the headache was unbearable; a postcraniotomy headache persisted and abruptly presented with global aphasia and right-sided hemiplegia after a nap. Emergency digital subtraction angiography showed severe luminal narrowing with segmental vasoconstriction, consistent with severe vasospasm. The patient\'s neurological deficit improved after chemical angioplasty. Neurosurgeons should pay close attention to this treatable/preventive entity after neurological deterioration following UIA clipping, even in patients without subarachnoid hemorrhage.

Spontaneous thrombosis of an unruptured large or giant saccular intracranial aneurysm is a well-known phenomenon and can cause ischemic stroke (IS), which is a rare event. The possible pathogenic mechanisms of IS include distal embolic occlusion secondary to migration of the intra-aneurysmal thrombus, occlusion of the parent artery lumen caused by the retrograde extension of the aneurysmal thrombosis, external compression of the parent artery due to the increased aneurysmal mass effect. Among these, IS due to simultaneous thromboses of the aneurysm and its parent artery is extremely rare, with only a few cases reported in the literature. Herein, we present a case of a 18-year-old woman who suffered an acute IS, attribute to spontaneous complete thrombosis of an unruptured large saccular aneurysm of the right middle cerebral artery with occlusion of the parent artery, and we review the literature simultaneously.

We present a case of ischemic stroke treated by stent retriever angioplasty for restenosis during mechanical thrombectomy. An 85-year-old man was admitted to our hospital because of left hemiplegia and left-sided hemispatial neglect caused by an occlusion at the origin of the right middle cerebral artery. Although mechanical thrombectomy transiently resulted in recanalization of the occluded lesion, restenosis immediately occurred and recurred repeatedly. On an angiogram, the stent retriever appeared poorly dilated at the stenosis and showed a contrast deficit. We concluded that restenosis was due to a secondary thrombus resulting from a ruptured atherosclerotic plaque. The stent retriever was kept deployed for 15 minutes. After the stent was retrieved, restenosis did not occur. Stent retriever angioplasty may be effective for determining the cause of restenosis after mechanical thrombectomy as well as for the treatment of restenosis.

Stroke ranks among the prevalent factors contributing to child mortality. Cryptogenic stroke has been linked with patent foramen ovale (PFO), which has been suggested as a possible route for thrombus, gas bubble, or another particulate that comes through systemic venous circulation to the brain artery. Yet, the most effective approach for managing cryptogenic stroke involving a PFO remains uncertain. This case aims to report a PFO patient with complications of stroke. A 5-year-old girl was admitted to the emergency department at Dr. Zainoel Abidin Hospital, Banda Aceh, Indonesia, after experiencing numbness and weakness on her right side and a sudden onset of slurred speech three days before admission. Laboratory findings only showed leukocytosis, while coagulation tests were normal. Non-contrast brain CT revealed an occurrence of cerebral infarction in the left hemisphere. Transcranial Doppler showed no atherosclerosis in cerebral arteries, and carotid Doppler ultrasound results were reported normal. Transthoracic echocardiography showed a PFO with the right-to-left shunt. The patient was treated with an intravenous infusion of citicoline 250 mg twice daily, oral aspirin 80 mg daily, and oral mecobalamin 250 mg daily and was planned to undergo a PFO closure procedure. However, the patient\'s parents rejected the plan to perform a PFO closure procedure. PFO has the potential to be a contributing factor to cryptogenic stroke among children. PFO closure followed by antiplatelet therapy for a couple of months has been shown to outperform medical therapy alone. However, additional evaluation should be done to cautiously consider the PFO closure procedure in children.

BACKGROUND Brugada syndrome is characterized by specific electrocardiographic changes predisposing individuals to ventricular arrhythmias and sudden cardiac death. Cases of coexisting Brugada syndrome and ischemic stroke are seldom documented, and an underlying pathophysiological link is yet unknown. This article presents a case in which a patient exhibited both Brugada syndrome patterns and an ischemic stroke, prompting a comprehensive literature review to explore the potential association between Brugada syndrome and ischemic stroke. CASE REPORT A 49-year-old man, previously healthy, was admitted to the hospital after being discovered unconscious at his workplace. Physical exam showed low oxygen saturation, fever, and abnormal neurological findings. Head computed tomography revealed a significant posterior circulation ischemic stroke. An electrocardiogram revealed Brugada syndrome type II initially, progressing to type III pattern. Despite efforts, the patient\'s condition rapidly deteriorated, leading to death within 24 hours. As far as we\'re aware, Brugada patterns following a posterior circulation ischemic stroke have only been documented in 1 other instance, in which the patient was also diagnosed with atrial fibrillation. CONCLUSIONS Both our literature review and the presented case indicate that Brugada patterns may coexist with and even be associated with ischemic stroke. More extensive research is required to shed light on this potential association. The question of whether Brugada syndrome is a precursor to or a result of ischemic stroke remains unanswered. We propose that patients with ischemic stroke should undergo an evaluation for electrocardiographic signs indicative of Brugada syndrome, particularly if no clear causes, like cardioembolism, are evident.

Stylocarotid artery syndrome (SAS) is a rare variant of Eagle\'s syndrome that may lead to transient ischemic attack or stroke. The underlying pathophysiological mechanism involves compression of the internal carotid artery by an elongated styloid process (ESP), potentially resulting in vascular occlusion or dissection. An ESP exceeding 2.5 cm is deemed elongated, with a length of 3.0 cm considered clinically significant. Although the prevalence of ESP ranges from 4.0% to 7.3%, symptomatic cases are rare; symptoms are present in only approximately 4.0% of individuals with an ESP. Unlike the typical symptoms of Eagle\'s syndrome, SAS may not cause pharyngeal discomfort, the sensation of a foreign body in the throat, dysphagia, or facial pain. This absence of characteristic symptoms as well as the development of central nervous system symptoms often leads patients to seek care from neurologists instead of otolaryngologists, increasing the likelihood of misdiagnosis or underdiagnosis. We herein report a unique case of ischemic stroke caused by SAS and present a literature review on cases of SAS-associated ischemic stroke published in the past decade. The reporting of this study conforms to the CARE guidelines.