Cancer-associated stroke from progressive acinic cell carcinoma.

Cancer-associated stroke is an evolving subgroup of embolic strokes of undetermined source. A man in his mid-20s with progressive follicular variant acinic cell carcinoma of the parotid was admitted because of new onset left-sided weakness. Neuroimaging confirmed a right middle cerebral artery infarction. After extensive diagnostics, stroke aetiology was deemed from cancer-induced hypercoagulability. Questions which arose regarding his management included (1) What was the best antithrombotic for secondary stroke prevention? (2) What was his risk for intracranial or tumorous bleeding once antithrombotics had been started? (3) How many days post-stroke could the antithrombotic be initiated? and (4) When could he be cleared for palliative chemotherapy and whole brain irradiation? The approach to address the abovementioned questions in the management of a rare cancer complicated by stroke is presented. Although treatments are guided by known pathomechanisms, additional studies are needed to further support current treatment strategies for this subgroup of patients.

Expansion and Subsequent Rupture of Carotid Pseudoaneurysm After Tandem Carotid and Middle Cerebral Artery Occlusion Treated With Mechanical Thrombectomy and Carotid Stenting.

BACKGROUND AND IMPORTANCE: Extracranial carotid artery pseudoaneurysm is a rare entity with potential etiologies including infection, blunt trauma, postsurgical atherosclerotic disease, and invasive neoplasia. Although the natural history of carotid pseudoaneurysm is difficult to determine because of its rarity, complications such as stroke, rupture, and local mass effect may occur at staggering rates. CLINICAL PRESENTATION: In this case, a middle-aged man presented with a tandem carotid, middle cerebral artery occlusion that was treated with a carotid stent and mechanical thrombectomy. He returned 3 weeks later with a ruptured carotid pseudoaneurysm that was then treated with a covered stent. He made a full recovery and was neurologically intact on follow-up. CONCLUSION: This case illustrates a rare potential complication of carotid occlusion and stenting with possible catastrophic consequences. The goal of this report was to educate other clinicians in remaining vigilant in awareness of this complication and provide a framework for potential treatment if and when it occurs.

Machine learning prediction of malignant middle cerebral artery infarction after mechanical thrombectomy for anterior circulation large vessel occlusion.

OBJECTIVE: Prediction of malignant middle cerebral artery infarction (MMI) could identify patients for early intervention. We trained and internally validated a ML model that predicts MMI following mechanical thrombectomy (MT) for ACLVO. METHODS: All patients who underwent MT for ACLVO between 2015 - 2021 at a single institution were reviewed. Data was divided into 80% training and 20% test sets. 10 models were evaluated on the training set. The top 3 models underwent hyperparameter tuning using grid search with nested 5-fold CV to optimize the area under the receiver operating curve (AUROC). Tuned models were evaluated on the test set and compared to logistic regression. RESULTS: A total of 381 patients met the inclusion criteria. There were 50 (13.1%) patients who developed MMI. Out of the 10 ML models screened on the training set, the top 3 performing were neural network (median AUROC 0.78, IQR 0.72 - 0.83), support vector machine ([SVM] median AUROC 0.77, IQR 0.72 - 0.83), and random forest (median AUROC 0.75, IQR 0.68 - 0.81). On the test set, random forest (median AUROC 0.78, IQR 0.73 - 0.83) and neural network (median AUROC 0.78, IQR 0.73 - 0.83) were the top performing models, followed by SVM (median AUROC 0.77, IQR 0.70 - 0.83). These scores were significantly better than those for logistic regression (AUROC 0.72, IQR 0.66 - 0.78), individual risk factors, and the Malignant Brain Edema score (p < 0.001 for all). CONCLUSION: ML models predicted MMI with good discriminative ability. They outperformed standard statistical techniques and individual risk factors.

The Effect of RADA16-I and CDNF on Neurogenesis and Neuroprotection in Brain Ischemia-Reperfusion Injury.

Scaffold materials, neurotrophic factors, and seed cells are three elements of neural tissue engineering. As well-known self-assembling peptide-based hydrogels, RADA16-I and modified peptides are attractive matrices for neural tissue engineering. In addition to its neuroprotective effects, cerebral dopamine neurotrophic factor (CDNF) has been reported to promote the proliferation, migration, and differentiation of neural stem cells (NSCs). However, the role of RADA16-I combined with CDNF on NSCs remains unknown. First, the effect of RADA16-I hydrogel and CDNF on the proliferation and differentiation of cultured NSCs was investigated. Next, RADA16-I hydrogel and CDNF were microinjected into the lateral ventricle (LV) of middle cerebral artery occlusion (MCAO) rats to activate endogenous NSCs. CDNF promoted the proliferation of NSCs, while RADA16-I induced the neural differentiation of NSCs in vitro. Importantly, both RADA16-I and CDNF promoted the proliferation, migration, and differentiation of endogenous NSCs by activating the ERK1/2 and STAT3 pathways, and CDNF exerted an obvious neuroprotective effect on brain ischemia-reperfusion injury. These findings provide new information regarding the application of the scaffold material RADA16-I hydrogel and the neurotrophic factor CDNF in neural tissue engineering and suggest that RADA16-I hydrogel and CDNF microinjection may represent a novel therapeutic strategy for the treatment of stroke.

Nilotinib-Associated Atherosclerosis Presenting as Multifocal Intracranial Stenosis and Acute Stroke.

Nilotinib, a BCR-ABL tyrosine kinase inhibitor (TKI), has been associated with vascular events and accelerated arterial stenosis, presumably of atherosclerotic etiology. Studies of nilotinib-associated atherosclerosis are mainly associated with progressive peripheral artery occlusive disease (PAOD), and only a few cases of coronary artery disease (CAD), and cerebrovascular disease (CVD) have been reported. The mechanisms by which nilotinib promotes atherosclerosis are poorly understood but endothelial and perivascular factors, mast cell depletion, and metabolic factors such as promotion of dyslipidemia and impaired glucose metabolism are thought to play a role. We present a case of a patient with chronic myelogenous leukemia (CML) treated with nilotinib who developed intracranial atherosclerosis leading to acute onset of stroke. Our patient had no cardiovascular risk factors prior to treatment with nilotinib and developed accelerated atheromatous cerebrovascular disease with severe left middle cerebral artery (MCA) stenosis. These findings suggest that nilotinib may be associated with the development of intracranial atherosclerotic disease (ICAD) independently of any preexisting vascular risk factors leading to acute stroke. Clinicians should have increased awareness of the association between nilotinib and the development of progressive atheromatous disease and vascular adverse events including PAOD, CAD, and CVD. In certain patients, these events can be severe and life threatening. Thus, screening for vascular risk factors including CVD prior to starting nilotinib and close follow up during treatment is crucial.

Recreational cannabis use causing non-ischaemic cardiomyopathy and cardioembolism in a young adult.

Cannabis is one of the most common illicit drugs and has been implicated with various complications which include stroke, acute myocardial infarction, arrhythmia and limb arteritis. We are reporting a case of a young man, who is a recreational cannabis smoker along with tobacco, who developed exertional progressive breathlessness for the last 4 months, mild cough for 2 months and acute left-sided hemiparesis along with ipsilateral facial palsy for 1 day that was attributed to an acute right middle cerebral artery territory infarct. There was also gangrene in his left forearm as a result of left radial artery thrombosis. Non-ischaemic-dilated cardiomyopathy was found in contrast-enhanced cardiac MRI and he was managed in the line of decompensated heart failure; the right-hand gangrene was later amputated in the subsequent follow-ups. Hence, cannabis can lead to cardiomyopathy and resulting cardioembolism. The mainstay of management remains supportive and avoidance of the offending agent. Social education is the need of the hour.

Casticin protected against neuronal injury and inhibited the TLR4/NF-κB pathway after middle cerebral artery occlusion in rats.

Although stroke is a major human neurological disease, there is a paucity of effective neuroprotectants that can improve its treatment. Casticin is a natural monomer drug with many biological effects such as anti-inflammatory and anti-tumor actions. However, it is not clear whether it has a neuroprotective effect in ischemic stroke. In this study, the neuroprotective effect of casticin in a rat middle cerebral artery occlusion (MCAO) model was investigated. Results showed that casticin reduced the volume of the cerebral infarction, mNSS scores, swimming distance, time to find the submerged platform, and serum concentrations of TNF-α, TGF-ß, IL-6 in MCAO rats. Moreover, casticin also decreased the expression of TLR4, NF-κB p65, and NF-κB p50 proteins and reversed the reduced expression of IκB protein in the brain tissue of MCAO rats. The in vitro study revealed that casticin decreased apoptosis of OGD/R-PC12 cells, reduced the expression of TLR4, NF-κB p65, and NF-κB p50, while increased IκB protein expression. In conclusion, casticin improved the neurological functions of MCAO rats via inhibiting the TLR4/NF-κB pathway and might have the potential to be developed into a neuroprotective agent for stroke patients.

Prevalence and outcome of young stroke patients with middle cerebral artery stenosis.

BACKGROUND: Etiologies of acute ischemic stroke in young adults are heterogeneous. Middle cerebral artery (MCA) stenosis is a common finding in Asians which may be an important cause of stroke in young adults. However, studies of stroke in young Asian populations are rare. Our study was to investigate the prevalence and outcome of young stroke patients with MCA stenosis in Chinese populations. METHODS: Young patients with MCA territory infarction between January 2013 and September 2018 were retrospectively recruited. Subjects were defined as stenosis group (MCA stenosis ≥50%) and no-stenosis group (MCA stenosis<50% or no stenosis) by their MCA stenosis. For patients in stenosis group, they were categorized as uni-MCA stenosis subgroup and multiple stenosis subgroup. Demographic data, risk factors, imaging feature and complications were compared between groups. Prevalence of MCA stenosis and risk factor score (score ≥ 2 or 3) in different age groups were investigated. Modified Rankin Scale (mRS) was used for evaluating functional outcome at discharge (unfavorable outcome: 3-6). Binary logistic regression was performed to determine independent risk factors of unfavorable outcome. RESULTS: Two hundred forty-nine young stroke patients were included in our study and 110 (44.2%) patients were defined as stenosis group. 55 (50%) patients were categorized as uni-MCA stenosis subgroup and 55 (50%) were multiple stenosis subgroup. The most common traditional vascular risk factors included hypertension, hyperlipemia, smoking, hyperhomocysteinemia and alcohol consumption. Prevalence of risk factor score ≥ 2 or 3 increased with age, but not incidence of MCA stenosis. By TOAST classification, the most common etiologies were large-artery atherosclerosis (41.0%) and small vessel disease (33.7%). Compared with no-stenosis group, patients in stenosis group were more likely to have large territorial infarct, develop complications and have unfavorable outcome. No significant difference was found between patients in uni-MCA stenosis and multiple stenosis subgroups except history of stroke/TIA, risk factor score ≥ 3 and silent infarct. By logistic regression, hypertension (OR = 3.561; 95%CI, 1.494 to 8.492; p = 0.004), NIHSS scores at admission (OR = 1.438; 95%CI, 1.276 to 1.620; p = 0,000) and infarct size (p = 0.015) independently predicted unfavorable outcome. CONCLUSIONS: Forty-four point two percent young Chinese adults with MCA territory infarction had MCA stenosis. Prevalence of MCA stenosis did not increase with age. Patients with MCA stenosis had worse clinical outcome, however, only hypertension, NIHSS scores at admission and infarct size were independent predictors.

Systemic thromboembolism including multiple cerebral infarctions with middle cerebral artery occlusion caused by the progression of adenomyosis with benign gynecological tumor: a case report.

BACKGROUND: Adenomyosis, a benign gynecological disease, causes cerebral infarction. Similar to Trousseau's syndrome, it elevates cancer antigen 125 (CA125) and D-dimer levels; causes hypercoagulability; and results in cerebral infarction. However, no case of adenomyosis causing major cerebral artery occlusion and requiring endovascular thrombectomy has yet been reported. We report on a woman with middle cerebral artery occlusion caused by adenomyosis progression with a benign gynecological tumor and recurrent cerebral infarction. She was successfully treated by endovascular thrombectomy and hysterectomy. CASE PRESENTATION: A 48-year-old woman with heavy uterine bleeding was transported by ambulance to our hospital. Upon arrival, she presented with impaired consciousness. Laboratory test results revealed decreased hemoglobin (8.2 g/dL) and elevated D-dimer (79.3 µg/mL) levels. Radiological imaging revealed adenomyosis, a left ovarian tumor, multiple uterine myomas, and old and new bilateral renal infarctions. She experienced repeated episodes of excessive menstruation caused by adenomyosis and was scheduled for hysterectomy in 2 months at another hospital. After hospital admission, uterine bleeding stopped. However, 5 days after initial bleeding, she had another episode of heavy uterine bleeding and developed left hemiparesis and dysarthria 20 min later. Brain magnetic resonance imaging revealed bilateral multiple cerebral infarctions indicating right middle cerebral artery occlusion. Thus, endovascular thrombectomy was performed, and anticoagulant therapy was administered. Laboratory test results after thrombectomy revealed elevated CA125 (3536 U/mL) and CA19-9 (892 U/mL) levels. She was at a risk of recurrent heavy uterine bleeding leading to repeated cerebral infarction because of anticoagulant treatment. Therefore, we performed hysterectomy and ovariectomy 11 days after initial bleeding. Histopathological assessment revealed no malignancy. Although she developed asymptomatic pulmonary thromboembolism 14 days after initial bleeding, D-dimer and tumor marker levels returned to normal soon after gynecological surgery. At 15 months post-surgery, she had not experienced further ischemic events. CONCLUSIONS: Adenomyosis with benign gynecological tumors may be associated with elevated D-dimer and tumor marker levels; excessive menstruation; and anemia. It may cause systemic thromboembolism, including cerebral infarction. To our knowledge, no other study has reported that adenomyosis causes major cerebral artery occlusion requiring endovascular thrombectomy. Hysterectomy may be an effective radical treatment of this condition.

Kellerin from Ferula sinkiangensis exerts neuroprotective effects after focal cerebral ischemia in rats by inhibiting microglia-mediated inflammatory responses.

ETHNOPHARMACOLOGICAL RELEVANCE: Ferula sinkiangensis K. M. Shen is a traditional Chinese medicine that has a variety of pharmacological properties relevant to neurological disorders and inflammations. Kellerin, a novel compound extracted from Ferula sinkiangensis, exerts a strong anti-neuroinflammatory effect by inhibiting microglial activation. Microglial activation plays a vital role in ischemia-induced brain injury. However, the potential therapeutic effect of kellerin on focal cerebral ischemia is still unknown. AIM OF THE STUDY: To explore the effect of kellerin on cerebral ischemia and clarify its possible mechanisms, we applied the middle cerebral artery occlusion (MCAO) model and the LPS-activated microglia model in our study. MATERIALS AND METHODS: Neurological outcome was examined according to a 4-tiered grading system. Brain infarct size was measured using TTC staining. Brain edema was calculated using the wet weight minus dry weight method. Neuron damage and microglial activation were observed by immunofluorescence in MCAO model in rats. In in vitro studies, microglial activation was examined by flow cytometry and the viability of neuronal cells cultured in microglia-conditioned medium was measured using MTT assay. The levels of pro-inflammatory cytokines were measured by qRT-PCR and ELISA. The proteins involved in NF-κB signaling pathway were determined by western blot. Intracellular ROS was examined using DCFH-DA method and NADPH oxidase activity was measured using the NBT assay. RESULTS: We found that kellerin improved neurological outcome, reduced brain infarct size and decreased brain edema in MCAO model in rats. Under the pathologic conditions of focal cerebral ischemia, kellerin alleviated neuron damage and inhibited microglial activation. Moreover, in in vitro studies of LPS-stimulated BV2 cells kellerin protected neuronal cells from being damaged by inhibiting microglial activation. Kellerin also reduced the levels of pro-inflammatory cytokines, suppressed the NF-κB signaling pathway, and decreased ROS generation and NADPH oxidase activity. CONCLUSIONS: Our discoveries reveal that the neuroprotective effects of kellerin may largely depend on its inhibitory effect on microglial activation. This suggests that kellerin could serve as a novel anti-inflammatory agent which may have therapeutic effects in ischemic stroke.

Enhanced Mesenchymal Stromal Cells or Erythropoietin Provide Long-Term Functional Benefit After Neonatal Stroke.

BACKGROUND AND PURPOSE: Perinatal stroke is a common cause of life-long neurobehavioral compromise. Mesenchymal stromal cells (MSCs) and EPO (erythropoietin) have each demonstrated short-term benefit with delayed administration after stroke, and combination therapy may provide the most benefit. The purpose of this study is to determine the long-term histological and functional efficacy of enhanced, intranasal stem cell therapy (MSC preexposed to EPO) compared with standard MSC or multidose systemic EPO. METHODS: Transient middle cerebral artery occlusion or sham surgery was performed in postnatal day (P) 10 Sprague-Dawley rats, who were treated with single-dose intranasal MSC, MSC preexposed to EPO (MSC/EPO), multidose systemic EPO (EPO3; 1000 u/kg per dose×3 every 72 hours), or cell-conditioned media on P13 (day 3 [P13-P19] for EPO), or on P17 (day 7 [P17-P23] for EPO). At 2 months of age, animals underwent novel object recognition, cylinder rearing, and open field testing to assess recognition memory, sensorimotor function, and anxiety in adulthood. RESULTS: MSC, MSC/EPO, and EPO3 improved brain volume when administered at 3 or 7 days after middle cerebral artery occlusion. MSC/EPO also enhanced long-term recognition memory with either day 3 or day 7 treatment, but EPO3 had the most long-term benefit, improving recognition memory and exploratory behavior and reducing anxiety. CONCLUSIONS: These data suggest that single-dose MSC/EPO and multidose systemic EPO improve long-term neurobehavioral outcomes even when administration is delayed, although EPO was the most effective treatment overall. It is possible that EPO represents a final common pathway for improved long-term repair, although the specific mechanisms remain to be determined.

Fungal endocarditis with heart valve replacement and atrial fibrillation posing a treatment challenge: A case report.

RATIONALE: Fungal endocarditis (FE) is a rare disease, in which antifungal treatment is necessary. When FE is complicated with prosthetic heart valve and/or atrial fibrillation, the coadministration of antifungal agents and warfarin is inevitable. We report a case of rheumatic heart disease with atrial fibrillation who developed FE following prosthetic heart valve replacement. The international normalized ratio (INR) increased significantly during the antifungal treatment with fluconazole. A discussion of the antifungal strategy in FE patients with prosthetic heart valves and/or atrial fibrillation and the interaction between antifungal agents and warfarin was performed. PATIENT CONCERNS: A 54-year-old Chinese woman experienced intermittent fevers, aphemia, and weakness in her right extremities. Her temperature was 38.7°C, and there was atrial fibrillation with heart rate 110 times/min. Neurological examination revealed that she had drowsiness, Broca aphasia, right central facial paralysis, and hemiplegia (Medical Research Council scale, upper limb grade 0, lower limb grade II). DIAGNOSES: Multiple infarction on magnetic resonance imaging and the occlusion of left middle cerebral artery suggested the occurrence of cerebral embolism. The presence of Candida parapsilosis in the results of 4 blood cultures and the existence of valve vegetation in the reexamination of echocardiogram supported the diagnosis of FE. INTERVENTIONS: The patient was given antifungal therapy with fluconazol. The INR increased dramatically on the 9th day of antifungal treatment, and subcutaneous bruising occurred at the intravenous infusion site. The antagonist of vitamin K1 was used and warfarin was reduced to a smaller dosage. The antifungal agent was replaced with caspofungin. OUTCOMES: Her speech improved significantly, and the muscle strength of her paralyzed side reached the Medical Research Council scale of grade IV. She continued to receive caspofungin for antifungal treatment with relatively stable INR and waited for heart valve surgery. LESSONS: The choice of antifungal agents is often a big challenge for FE patients, especially when they need warfarin for anticoagulation. It is better to administer a low dose of warfarin while carefully monitoring the INR or choose the antifungal drugs with little or no effect on warfarin.

Acute progressive stroke with middle cerebral artery occlusion caused by idiopathic hypereosinophilic syndrome: a case report.

BACKGROUND: Idiopathic hypereosinophilic syndrome (IHES) is associated with various organ system dysfunctions. Neurologic abnormalities have been previously noted in this syndrome. Cerebral infarction secondary to occlusion of large cerebral artery is rarely reported. Here we described a patient with IHES presented progressive multiple cerebral infarctions caused by bilateral middle cerebral artery occlusion. CASE PRESENTATION: A 55-year-old Chinese woman presented to our hospital with acute onset of right limbs weakness and slurred speech. Laboratory tests showed a significant eosinophilia of 5.29 × 109/L (normal, < 0.5), 49.9% of leukocytes. Brain magnetic resonance imaging (MRI) revealed multiple acute cerebral ischemic lesions. Magnetic resonance angiography (MRA) demonstrated stenosis in horizontal segment of right middle cerebral artery. A pretibial skin biopsy revealed eosinophilic infiltration around the capillaries in deep dermis and adipose tissue. The patient was given oral dual anti platelet agents and intravenous methylprednisolone. However, one week later, the patient presented significant neurological deterioration with right-sided hemiparesis and totally motor aphasia. Brain MRI and computed tomography perfusion (CTP) demonstrated new acute cerebral ischemia in left hemisphere. Digital subtraction angiography (DSA) revealed left middle cerebral artery completely occluded. The patient received a high-dose of intravenous methylprednisolone 500 mg per day and the eosinophil count quickly fell to normal within 2 days. She was transferred to a rehabilitation center and her neurological symptoms improved with modified Ranking Scale from 4 to 2. CONCLUSIONS: IHES is one of the rare causes of acute ischemic stroke with large cerebral artery occlusion. An early high-dose of corticosteroids therapy should be considered in cases of IHES patients. Our case study is benefit to clinical diagnosis and treatment of cerebral infarction with IHES.

Tumor Embolism Through Right-to-Left Shunt Due to Venous Invasion of Esophageal Carcinoma.

A 69-year-old man was admitted to the hospital with right hemiparesis and global aphasia. Perfusion computed tomography imaging revealed ischemic penumbra in the middle cerebral artery territory. Angiography showed left middle cerebral artery occlusion. Mechanical thrombectomy with one pass was performed, and successful recanalization was obtained. Embolic material was retrieved; it contained tumor fragments with atypical keratinizing squamous cell carcinoma. Contrast computed tomography imaging indicated tumor invasion into the superior vena cava, and contrast transcranial Doppler indicated the presence of a right-to-left shunt after the Valsalva maneuver. We diagnosed the patient with acute ischemic stroke of large vessel occlusion due to venous invasion of esophageal carcinoma via a right-to-left shunt. To the best of our knowledge, this is the first case of embolic occlusion resulting from an extracardiac tumor via a right-to-left shunt. Contrast transcranial Doppler potentially detects right-to-left shunts in patients who cannot undergo transesophageal echocardiography.

Enhancing the Therapeutic Potential of CCL2-Overexpressing Mesenchymal Stem Cells in Acute Stroke.

Although intravenous administration of mesenchymal stem cells (MSCs) is effective for experimental stroke, low engraftment and the limited functional capacity of transplanted cells are critical hurdles for clinical applications. C-C motif chemokine ligand 2 (CCL2) is associated with neurological repair after stroke and delivery of various cells into the brain via CCL2/CCR2 (CCL2 receptor) interaction. In this study, after CCL2-overexpressing human umbilical cord-derived MSCs (hUC-MSCs) were intravenously transplanted with mannitol in rats with middle cerebral arterial occlusion, we compared the differences between four different treatment groups: mannitol + CCL2-overexpressing hUC-MSCs (CCL2-MSC), mannitol + naïve hUC-MSCs (M-MSC), mannitol only, and control. At four-weeks post-transplantation, the CCL2-MSC group showed significantly better functional recovery and smaller stroke volume relative to the other groups. Additionally, we observed upregulated levels of CCR2 in acute ischemic brain and the increase of migrated stem cells into these areas in the CCL2-MSC group relative to the M-MSC. Moreover, the CCL2-MSC group displayed increased angiogenesis and endogenous neurogenesis, decreased neuro-inflammation but with increased healing-process inflammatory cells relative to other groups. These findings indicated that CCL2-overexpressing hUC-MSCs showed better functional recovery relative to naïve hUC-MSCs according to the increased migration of these cells into brain areas of higher CCR2 expression, thereby promoting subsequent endogenous brain repair.

Large Vessel Occlusion Secondary to COVID-19 Hypercoagulability in a Young Patient: A Case Report and Literature Review.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) initially most appreciated for its pulmonary symptoms, is now increasingly recognized for causing multi-organ disease and stroke in the setting of a hypercoagulable state. We report a case of 33-year-old African American woman with COVID-19 who developed acute malignant middle cerebral artery infarction due to thromboembolic occlusion of the left terminal internal carotid artery and middle cerebral artery stem. Mechanical thrombectomy was challenging and ultimately unsuccessful resulting in limited reperfusion of <67% of the affected vascular territory, and thrombectomized clot was over 50 mm in length, at least three times the average clot length. The final stroke size was estimated at 224 cubic centimeters. On admission her D-dimer level was 94,589 ng/mL (normal 0-500 ng/ml). Throughout the hospitalization D-dimer decreased but never reached normal values while fibrinogen trended upward. Hypercoagulability panel was remarkable for mildly elevated anticardiolipin IgM of 16.3 MPL/mL (normal: 0-11.0 MPL/mL). With respect to remaining stroke workup, there was no evidence of clinically significant stenosis or dissection in the proximal internal carotid artery or significant cardioembolic source including cardiomyopathy, atrial fibrillation, cardiac thrombus, cardiac tumor, valvular abnormality, aortic arch atheroma, or patent foramen ovale. She developed malignant cytotoxic cerebral edema and succumbed to complications. This case underscores the importance of recognizing hypercoagulability as a cause of severe stroke and poor outcome in young patients with COVID-19 and highlights the need for further studies to define correlation between markers of coagulopathy in patients with COVID-19 infection and outcome post stroke.

Resistance to Antiplatelet Therapy Is Associated With Symptoms of Cerebral Ischemia in Carotid Artery Disease.

BACKGROUND: Platelet inhibitory therapy is prescribed to prevent arterial thromboembolism in patients with atherosclerotic disease. Although taken by millions of people, around 30% are resistant to the treatment they are being prescribed. AIMS: To determine whether symptoms of cerebral ischemia, or pre-operative cerebral emboli, in patients admitted for a carotid endarterectomy were associated with resistance to aspirin or clopidogrel. METHODS: Venous blood from 133 patients immediately before carotid endarterectomy (CEA) was analyzed for resistance to aspirin and clopidogrel by multiplate impedance aggregometry. The number of emboli/hour entering the ipsilateral middle cerebral artery was counted by transcranial Doppler (TCD) on the day before surgery in 33 of these patients. RESULTS: Resistance was found in 21 (26.3%) of 100 patients taking aspirin and 14 (42%) of 33 taking clopidogrel. Mean (sd) residual platelet aggregation was significantly higher at 41.9(32) Au in patients who had suffered recent symptoms of cerebral ischemia compared with 30.8(16) Au in asymptomatic patients (p = 0.012). Residual platelet aggregation also correlated significantly with the number of emboli/hour counted by TCD in the ipsilateral middle cerebral artery (r = 0.45, p = 0.009). CONCLUSION: Antiplatelet resistance was associated with the frequency of cerebral emboli and recent symptoms of cerebral ischemia in patients with carotid disease. Definitive clinical studies are needed to explore whether testing for antiplatelet resistance should be undertaken routinely in patients starting platelet inhibitory therapy for cardiovascular disease.

Transplantation of neural progenitor cells generated from human urine epithelial cell-derived induced pluripotent stem cells improves neurological functions in rats with stroke.

As a potentially unlimited autologous cell source, induced pluripotent stem cells (iPSCs) provide a needed option for the application of iPSC-derived neural progenitor cells (NPCs) for regenerative medicine for the treatment of stroke. To enable the application of iPSC technology, it is essential to develop a practical approach to generate iPSC cells under a non-viral, non-integration, feeder-free condition from the most optimal somatic cell type. In this study, we differentiated NPCs from a urine-derived iPSC line (UC-05) which was generated with optimized episomal vectors in a feeder-free culture system. UC-05 can be induced into NPCs efficiently in monolayer cultures using dual SMAD inhibitions, and have the ability to differentiate further into astrocytes and functional neurons in vitro. We then characterized UC-05-derived NPCs upon transplantation into the striatum of adult male rats subjected to transient middle cerebral artery occlusion (tMCAO) reperfusion. While NPCs were grafted into rats 7 days before the MCAO surgery, cells were found to migrate from the grafted side to the lesion side of the brain via corpus callosum 14 days after tMCAO. UC05-derived NPCs were grafted into the striatum 7 days after tMCAO, grafted cells can survive and differentiate into neurons and astrocytes 35 days after transplantation, and synaptic protein SYNAPSIN 1 could also be detected around the grafted human cells. tMCAO rats with NPC engraftment showed better behavior improvement in both postural reflex test and cylinder test compared to control rats engrafted with the cell medium only. Our data indicate that NPCs differentiated from urine-derived iPSCs could act similarly to endogenous neural progenitors in vitro and in vivo. Urine-derived iPSCs could be a potential candidate for cell transplantation therapy in stroke.

Activity in grafted human iPS cell-derived cortical neurons integrated in stroke-injured rat brain regulates motor behavior.

Stem cell transplantation can improve behavioral recovery after stroke in animal models but whether stem cell-derived neurons become functionally integrated into stroke-injured brain circuitry is poorly understood. Here we show that intracortically grafted human induced pluripotent stem (iPS) cell-derived cortical neurons send widespread axonal projections to both hemispheres of rats with ischemic lesions in the cerebral cortex. Using rabies virus-based transsynaptic tracing, we find that at 6 mo after transplantation, host neurons in the contralateral somatosensory cortex receive monosynaptic inputs from grafted neurons. Immunoelectron microscopy demonstrates myelination of the graft-derived axons in the corpus callosum and that their terminals form excitatory, glutamatergic synapses on host cortical neurons. We show that the stroke-induced asymmetry in a sensorimotor (cylinder) test is reversed by transplantation. Light-induced inhibition of halorhodopsin-expressing, grafted neurons does not recreate the impairment, indicating that its reversal is not due to neuronal activity in the graft. However, we find bilateral decrease of motor performance in the cylinder test after light-induced inhibition of either grafted or endogenous halorhodopsin-expressing cortical neurons, located in the same area, and after inhibition of endogenous halorhodopsin-expressing cortical neurons by exposure of their axons to light on the contralateral side. Our data indicate that activity in the grafted neurons, probably mediated through transcallosal connections to the contralateral hemisphere, is involved in maintaining normal motor function. This is an example of functional integration of efferent projections from grafted neurons into the stroke-affected brain's neural circuitry, which raises the possibility that such repair might be achievable also in humans affected by stroke.